SUO: RE: CAD "data models", "FOL type stuff" and translators
Dear Mike,
>
>
> Phil Jackson said:
MW: It was me actually not Phil, not that it matters.
>
> > The focus of TC184/SC4 is technical data exchange and
> integration. This can
> > be from property data to CAD data to product catalogues.
> >
> > There is quite a lot that has gone on in the area (I think)
> you are talking
> > about. ISO 10303-50 (mathematical representation) and
> ISO10303-45 (material
> > properties) come to mind.
> >
> > Of course the basis is data models, rather than FOL type
> stuff, but as I am
> > increasingly realising the gap between the two is narrower
> than most people
> > think. It is just that very few try to cross it.
>
> This is a good observation, and I am one of those few. I
> recently attended a
> mini-conference on product data exchange where most of the
> emphasis was on CAD
> data. I have been struggling a long time to figure out what
> exactly the
> difference is between "data models" and "FOL type stuff", and
> to understand the
> extent to which the AI/FOL techniques have anything to offer
> that is of value
> in that arena. I have not made a lot of progress, I'm afraid...
MW: Well as far as I can make out, FOL is like a C++, where data models are
like a 4GL. So data models enable you to do some things well and quickly,
but can't do everything you can do with FOL. In particular data models are
good for facts, not so good for rules (you have to pretend they are facts
too).
On the other hand data models have a good translation into databases,
whereas FOL is weaker at this, which is one of the main reasons why it is
not as widely used.
>
> The cost of translation to large manufacturing companies like Boeing,
> RollsRoyce, Ford etc is EENNOORRMMOOUUSS!! Standards are
> tricky business,
> literally. Vendors are happy to provide translators *into*
> standard formats,
> but much less so, *from* them into their own format -- it
> just does not pay!
> There is a crying need for a standard in this area, but it
> would entail
> changing the whole marketplace. Vendors currently compete on
> features of their
> language. With a standard, they would have to compete on the
> basis of how easy
> to use the GUI/Environment was,and the speed of compilers, etc.
MW: Well for geometry and related product data ISO10303 is a standard that
is increasingly being applied. Boeing and RR are amongst those active in
developing and deploying it. I'm working on what might become the next
generation.
>
> By the way, this issues arises over and over in many
> domains - another is
> Geographical Information Systems. It would seem that an
> SUO could provide
> considerable value, if someone could figure out how to do it.
MW: There is an ISO group (TC32 I think) that are working on this, also
using data models.
>
> There are various companies whose main/sole business is to
> provide translation
> services between different CAD tools. Some translate between
> native formats,
> point to point. Others attempt to build neutral formats, in
> hopes of addressing
> the number of translators being O(n-squared) vs O(n). This
> would seem an
> obvious place for a 'upper' geometry ontology (UGO), from
> which a standard CAD
> format could be specified.
MW: ISO 10303-42, -50 have just about got that covered.
> What is interesting, is that
> no-one in this area
> seems to know or care about 'ontologies'. I have an
> impression that the
> neutral formats in this area, in some cases, are not so much
> carefully thought
> out rationalized models of the domain, but rather more like
> 'representational
> dumpsters' which have one of everything.
MW: Thats because we call ontologies data models. Some are better than
others.
> Nore are they explicit
> representations -- instead, they may be implicit in whatever
> internal data
> structures are used by the translators. Having one of
> everythign is important,
> if one is to ensure lossless translation *into* the neutral
> format. Of course,
> there will always be loss in translation from more expressive to less
> expressive formats. At any rate, is not clear to me that a
> good Upper Geometry
> Ontology would be of immediate value to people in that
> community. On the other
> hand, it also might!
MW: I think this is more a case of one of the things we can bring is an
ontology (data model) of geometry.
>
> This is probably slightly off the topic of SUO, but if there
> are any folk who
> have this as a core interest, and would like to have a
> discussion, please let
> me know who you are. I will collect names and respond back in
> time. I suggest
> that you email ME only, not the SUO group, there is already
> far too much
> volume...
>
> Mike Uschold
>
Regards
Matthew
============================================
Matthew West
Operations & Asset Management
Shell Services International
H3229, Shell Centre, London, SE1 7NA, UK.
Tel: +44 207 934 4490 Fax: 7929
Mobile: +44 7796 336538
E-mail: Matthew.R.West@is.shell.com
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