[GO-ESSP] Re: [NERC-DataGrid] Units and NERC DataGrid

[Kieron Taylor]

>> > I also feel that what we need is more along the lines of a
>> > semantic web resource rather than a downloadable executable
>> > approach: in other words a units ontology that provides a
>> > units vocabulary plus the knowledge about which units may be
>> > interconverted and how.  Such an ontology could be
>> > interlinked with parameter vocabularies indicating the subset
>> > of units that may sensibly be associated with particular parameters.
> 
> I think we are very keen to take this route. I believe that many of the 
> tricky problems of units (user preferences, dimensionless, preservation 
> of context) can be done more effectively with RDF. Kieron Taylor 
> (Southampton) has been exploring this in chemistry

Although such a thing should be possible with XML, RDF provides 
formality for the relationships that aids machine processing. By 
limiting yourself to RDF triples, you make a more navigable data 
structure. Complicated inferencing is beyond the scope of RDF, but can 
be supplemented with things like the Web Ontology Language - OWL.

The set back is that RDF is still a bit new (comparitively), and 
existing tools are rather clunky and undeveloped. It is also even more 
verbose than xml.

>> >
>> > Before embarking on building such an ontology for NERC
>> > DataGrid, I am circulating this e-mail far and wide
>> > (apologies for  multiple postings) to obtain answers to two
>> > simple questions.
>> >
>> > What do you think of this approach?
>> >
>> > More importantly:
>> >
>> > Does anybody know of anybody who is building/has built such
>> > an ontlogy and can save me a job?
> 
> 
> I think if Kieron can say what he has done it could help (Kieron, make 
> sure it doesn't preempt your thesis content).

I have been developing an RDF schema for chemical data with an eye to 
capturing all the peripheral information that databases typically 
discard. While on the job, I encountered the issue of storing units and 
have since attempted to describe units in pure rdf. This includes the 
issues of conversion, even though I have no intention of pursuing that 
particular aspect. I have my own rough and ready solution, but still 
need to apply it in anger. I am in the process of writing this up and 
could circulate a draft copy to interested parties, but as Peter points 
out, this will become part of my thesis. I should have my report 
finished in a few weeks, and I will discuss it with my supervisor.

Regards

Kieron Taylor