[esip-semanticweb] help with marking up WMS/WCS Capability docs?

Thu Jul 16 16:53:59 EDT 2009

So it would seem that the proper way to encode an RDF triple where the
object is an URI (as opposed to a datatype) in an XML context is to use
xlink with the role pointing to the predicate URI.   A datatype object would
be done as simple XML (i.e. XMLelement with content) with the XMLelement
name the same as the predicate URI.

Or did I miss something?

Benno

On Thu, Jul 16, 2009 at 4:40 PM, John Graybeal <graybeal at mbari.org> wrote:

> To the best of my knowledge, the use of role and arcrole[2] within xlink[1]
> to specify the purpose of the locator (href) attribute is limited only to
> requiring URIs. So you can create a vocabulary that describes any set of
> roles that you want.
>
> John
>
> [1] xlink semantics: http://www.w3.org/TR/xlink/#att-method
> [2] Role, Arcrole, and Title: http://www.w3.org/TR/xlink/#link-semantics
>
>
> On Jul 16, 2009, at 1:15 PM, Benno Blumenthal wrote:
>
>  Hello Chris,
>>
>> I have not chimed in yet because I have not had a chance to review the
>> options for metadata in WMS, and I wanted to say something precise.
>>  Essentially if you just want controlled vocabulary, XML and RDF are quite
>> similar (i.e. if Brian's machine tag implies a particular controlled
>> vocabulary for the value, then you have represented the information
>> isomorphically to using RDF objects for the concepts, and you can
>> crosswalk).  If you want to relate two objects, the xlink is XML's version
>> of what is native in RDF, but I think xlink is very limited as to the
>> meanings of the connections, whereas RDF lets the connection's meaning be
>> specified explicitly according to a convention.
>>
>>  But meanwhile, could you explain your example more fully -- I don't
>> understand what
>>
>> dataset=OMI_A_G
>>
>> means (you called it a relationship).
>>
>> Benno
>>
>> On Thu, Jul 16, 2009 at 3:55 PM, Christopher Lynnes <
>> Chris.Lynnes at nasa.gov> wrote:
>> On Jul 15, 2009, at 6:52 PM, John Graybeal wrote:
>>
>> I am not deep in any one of these details, but I am a little familiar
>> with all the possibilities you mention. So consider the following as
>> notions to be verified:
>>
>> 1) RDFa won't fit gracefully into the OGC schema as written, because
>> it is using a different set of elements (that is, it is tuned to the
>> HTML elements). "To date, because XHTML is extensible while HTML is
>> not, RDFa has only been specified for XHTML 1.1." [1]  The way it
>> works is to add attributes, which must be in an RDFa-compatible XHTML
>> schema if the document is to validate.
>>
>> 2) I wholeheartedly endorse the intent to use controlled vocabularies
>> in a way that is compatible with the semantic web. All that should be
>> necessary to do this is to find a suitable place where a URI can be
>> placed.  Then you can create controlled vocabularies whose terms
>> correspond to URIs. There is extensive guidance on this topic at the
>> MMI site [2].  I do not know of any reason these approaches would be
>> incompatible with the ESIP ontologies.
>>
>> 3) The way OOSTethys [1] chose to add more specific descriptions/
>> references to SensorML/O&M was through the use of xlink, which is
>> supported in the OGC schema. Examples are on the OOSTethys site. As
>> far as I know, this is the most used OGC practice to meet this need to
>> date. (Because I don't know of any other particular recommendation.)
>> Note that if a standard allows a name to be specified as a URI (which
>> most of the SWE standards do, yes?), that is another place where the
>> sensor web.
>>
>>
>> Can you point me to any specific examples (i.e., URLs to files)?
>>
>> I'm having some difficulty seeing how a *relationship*, like
>> 'dataset=OMI_A_G' can be expressed with the xlink or URI...
>>
>> Thx,
>>
>>
>>
>> On Jul 15, 2009, at 12:53 PM, Christopher Lynnes wrote:
>>
>> Greetings!
>>
>> Over in the Air Quality Cluster, we are experimenting with using
>> some kind of structured markup / tagging of OGC WMS and WCS
>> capabilities documents (inside <Keyword> elements) to allow us to do
>> structured searches on the documents.  An example might be, "give me
>> the layers where Dataset = 'OMI_AI_G'". Seehttp://
>> wiki.esipfed.org/index.php/WMS_GetCapabilities#WMS_GetCapabilities_Layer_Description
>>
>> Thing is, we figure if we are going to try to implement this kind of
>> markup with a quasi-controlled vocabulary, we should do it in such a
>> way that it is compatible with or even leverages the semantic web.
>> We have pondered a machine tags approach, e.g.,
>> <Keyword>esip:dataset=OMI_AI_G</Keyword>.  (A link to an initial
>> attempt of a WMS that includes the current keyword encoding:
>> http://webapps.datafed.net/AIRNOW.ogc?service=wms&request=getCapabilities&version=1.1.1
>> )
>> .
>>
>> Alternatively, we have heard RDFa mentioned for microformats, though
>> mostly in the context of XHTML.  Can this be applied to OGC's XML
>> and if so, how?
>>
>> Can the ESIP Semantic Web cluster provide a recommendation or
>> suggestion in how to move forward that would be:
>> (a) flexible and extensible,
>> (b) compatible with the evolving ESIP datatype and services ontology
>> and
>> (c) lightweight and easy to use?
>> --
>> Christopher Lynnes             NASA/GSFC, Code 610.2
>> 301-614-5185
>>
>> _______________________________________________
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>> esip-semanticweb at rtpnet.org
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>>
>>
>> John
>>
>> --------------
>> John Graybeal   <mailto:graybeal at mbari.org>  -- 831-775-1956
>> Monterey Bay Aquarium Research Institute
>> Marine Metadata Interoperability Project: http://marinemetadata.org
>>
>>
>> --
>> Christopher Lynnes             NASA/GSFC, Code 610.2         301-614-5185
>>
>> _______________________________________________
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>> esip-semanticweb at rtpnet.org
>> http://lists.deltaforce.net/mailman/listinfo/esip-semanticweb
>>
>>
>>
>> --
>> Dr. M. Benno Blumenthal          benno at iri.columbia.edu
>> International Research Institute for climate and society
>> The Earth Institute at Columbia University
>> Lamont Campus, Palisades NY 10964-8000   (845) 680-4450
>> _______________________________________________
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>> http://lists.deltaforce.net/mailman/listinfo/esip-semanticweb
>>
>
>
> John
>
> --------------
> John Graybeal   <mailto:graybeal at mbari.org>  -- 831-775-1956
> Monterey Bay Aquarium Research Institute
> Marine Metadata Interoperability Project: http://marinemetadata.org
>
>

-- 
Dr. M. Benno Blumenthal          benno at iri.columbia.edu
International Research Institute for climate and society
The Earth Institute at Columbia University
Lamont Campus, Palisades NY 10964-8000   (845) 680-4450
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