On Mon, Dec 13, 2010 at 5:27 PM, John Graybeal <jbgraybeal at mindspring.com>wrote:
> A minor clarification as to how MMI is doing things:
>
> Benno, all,
>
> On Dec 13, 2010, at 07:25, Benno Blumenthal wrote:
>
> We have tried to get standard URIs for CF concepts, but the effort bogged
>> down.
>>
>
> As for standard names, MMI established a set of URIs at
>
> http://marinemetadata.org/cf
>
> but has not been keeping up to date.
>
>
> Thanks for the mention. This is our older URL, sorry; we are now
> maintaining CF standard names in our ontology repository, using resolvable
> URLs. [1]
>
> There was a period when MMI was not keeping up to date with CF changes, but
> in the recent past we have been continuously updating the SKOS ontology for
> the parameter names at the site Carlos mentioned [1] (We will forward the
> misleading /cf URL above, or fix it to make clear in some other way the
> current status; thanks for calling that out.)
>
Glad you have a new system that can need up-to-date. Let me point out two
things, very important to me at least.
1) you changed the namespace of the standard names, so your new document is
not a direct replacement of the old, you would need to provide a mapping to
make the new replace the old.
2) you changed the ontology. SKOS is good and fine, but it makes it
impossible to connect to CF -- that is external to what you are providing.
Your old ontology, because it was a complete representation of what was in
the XML file, gave a handle to map from a XML representation of a netcdf
file to the semantic representation of standard names. You cannot get that
by a redirect to your SKOS representation.
To be more concrete, in my system, I have cfatt:standard_name which is
string_valued, and is one of many attributes a variable in a netcdf file can
have.
If a variable has that string valued attribute, it can be connected to the
SKOS term corresponding to the standard name. Since SKOS is deprecating
that property, (or at least was last time I looked), I use my own property
iriterm:isDescribedBy So my variable has
var iriterm:isDescribedBy cfsn:air_temperature.
and
var cfatt:standard_name "air_temperature".
when the crosswalking is done.
The crosswalk uses the standard_name property of the old Standard_Name
objects to connect the objects to the cfatt property of the netcdf variable.
SKOS is important for interrelating concepts, but we need to relate to the
CF structure as well. Please do not throw away this key piece of the
problem in an effort to "standardize".
Benno
>
> As with Roy's handling, we provide URLs both for the current version at the
> reference URL, and for individual releases of the vocabulary.
>
> John
>
> [1] http://mmisw.org/ont/cf/parameter
>
>
>
> I have written a XSL transform at
>
> http://iridl.ldeo.columbia.edu/ontologies/xslt/.cfsn2rdf.xsl
>
> that can be applied to
>
>
> http://cf-pcmdi.llnl.gov/documents/cf-standard-names/standard-name-table/16/cf-standard-name-table.xml
>
> to generate an up-to-date version, e.g.
>
> xsltproc http://iridl.ldeo.columbia.edu/ontologies/xslt/.cfsn2rdf.xsl
> http://cf-pcmdi.llnl.gov/documents/cf-standard-names/standard-name-table/16/cf-standard-name-table.xml
>
> On the other hand, Roy has created opaque URIs for standard names at
>
> http://vocab.ndg.nerc.ac.uk/list/P07/9 contains all the Standard Names
>> that have ever been published, including names that have been aliased
>>
>> http://vocab.ndg.nerc.ac.uk/list/P071/9 contains the Standard Names that
>> are currently valid (i.e. those that have not been deprecated through
>> aliasing)
>>
>> http://vocab.ndg.nerc.ac.uk/list/P072/9 contains the Standard Names that
>> have been deprecated through aliasing
>>
>> The mapping between deprecates and their replacement aliases my be
>> obtained through the following API call
>>
>>
>> http://vocab.ndg.nerc.ac.uk/axis2/services/vocab/getMap?subjectList=http://vocab.ndg.nerc.ac.uk/list/P072/current&predicate=255&objectList=http://vocab.ndg.nerc.ac.uk/list/P071/current&inference=false
>>
>
>
> he changes them with each version, so it is both more definitive and harder
> to use. It is also pure SKOS, so one needs to add structure to actually
> connect it with a CF-described dataset. I plan to write out a map between
> the two, so that I can use his relationships between CF standard_names, but
> I do not have it yet.
>
> Additional information and ontologies describing the CF structure both as
> attributes and conceptually are available at
> http://iridl.ldeo.columbia.edu/ontologies/, including the connections
> between the standard_name ontologies and the CF structure.
>
>
>
> Benno
>
>
> On Mon, Dec 13, 2010 at 9:22 AM, Dominic Lowe <dominic.lowe at stfc.ac.uk>
> wrote:
> > Hello all,
> >
> > What's the current CF recommended scheme for referencing a standard name
> on
> > the web? (either by URL or URN).
> >
> > I know about the vocab server and the xml/html online versions and could
> > choose to use URLs to point to items in any of these but is there a
> > definitive pattern that should be used? (or at least a best practice
> that
> > should be encouraged?).
> >
> > Much appreciated,
> >
> > Dominic
> > --
> > Scanned by iCritical.
> > _______________________________________________
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> > CF-metadata at cgd.ucar.edu
> > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
> >
>
>
>
> --
> 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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>
>
>
>
> John Graybeal <mailto:jgraybeal at ucsd.edu <jgraybeal at ucsd.edu>>
> phone: 858-534-2162
> System Development Manager
> Ocean Observatories Initiative Cyberinfrastructure Project:
> http://ci.oceanobservatories.org
> 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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