|To:||"[ontolog-forum] " <ontolog-forum@xxxxxxxxxxxxxxxx>|
|From:||"Richard H. McCullough" <rhm@xxxxxxxxxxxxx>|
|Date:||Sat, 6 Sep 2008 07:39:39 -0700|
I have one remaining question -- what does your
concept hierarchy look like?
In my tabula rasa hierarchy, parts are characteristics
of the entity that they are a part of. So you might
have something like this
But when the car is disassembled, it would look like this
Thus my concept hierarchy - my point of view - changes
with time, as the parts are assembled or disassembled.
In your case, I would think the designers, manufacturers,
sales personnel, etc. would have different hierarchies.
Ayn Rand do speak od mKR done;
mKE do enhance od Real Intelligence done;
knowledge := man do identify od existent done;
knowledge haspart proposition list;
----- Original Message -----
From: "Sean Barker" <sean.barker@xxxxxxxxxxxxx>
Sent: Saturday, September 06, 2008 3:44 AM
Subject: [ontolog-forum] Fw: Thing and Class
> In engineering practice (at least as described through ISO
> 10303), a part is either an inseparable component or an assembly. An
> assembly consists of sub-assemblies (which are assemblies) and
> components. The definition of assembly is recursive.
> A product is a part. In ISO 10303, a part is a subtype of a
> product, and this is quite distinct from a product concept. Thus, a
> product concept might be "Range Rover", a four-wheel drive vehicle,
> which is delivered as physically as a part RR1-801/1, or RR1-801/2, or
> RR1-803/1, or RR1-805/1, or RR2-810/1, etc, where in RRx-yyy/z, the RRx
> is the generic part number, the yyy is the manufacturing assembly suffix
> and the /z is the version number. In theory, all parts with the number
> RR1-801/1 are completely interchangeable, and should be interchangeable
> with parts R1-801/2 (which differs from R1-801/1 in matters not
> affecting form, fit or function), however will have some form, fit or
> function difference from RR1-803/1.
> The occurrences of the Range Rover concept will also be stamped
> with a serial number. A typical maintenance manual will inform you of
> changes made in the product standard in terms of the serial numbers that
> the change effects - e.g. from 1-100,000 it has a 2.3 litre engine, and
> from 100,001 onwards the vehicle has a 2.5 litre engine. In practice,
> minor changes which internally generate new part numbers will not be
> exposed at the level of the maintence manual.
> Of course, the real situation is rather more complicated, but in
> matters of detail, rather than of substance (in the context of this
> The point being, that a change approval creates a commitment to
> create a new part (car, wheel, bolt, etc) which is either a revision of
> an existing part (form, fit, function interchangeable) or a new part. In
> the case of an assembly, this may be because it incorporates a new part,
> or a new combination of existing parts. Conversely, creating a new
> component part has no effect on end product unless it is embodied in the
> chain of assemblies which contributes to an actual part (end product),
> which in turn requires that a new version of these assemblies is
> The issue "is a representation of" versus "is-a" versus
> "is-an-instance-of" is a question of how we ground these relationships
> and how we ground the concept of part. I ground the concept "part" as a
> "form, fit, and function equivalence relation", such that two part
> designs (which specify the part) are equivalent if the physical part
> they specify is form, fit and function interchangeable. This means that
> the physical parts are an instance of the class "part", and that a
> design is a specification for the part. That is, the meaning of the
> concept "part" is grounded in the results of using individual parts.
> Consequently, a design office designs many parts, some of which are
> instantiated by the manufacturing department as physical parts. In the
> design office, parts instantiate the design process outputs, and are
> treated as separate individuals, while in the manufacturing world, a
> part is a class for producing physical parts.
> I hope this answers the question.
> Sean Barker
> Bristol, UK
> -----Original Message-----
> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
> [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Richard H.
> Sent: 05 September 2008 11:24
> To: [ontolog-forum]
> Subject: Re: [ontolog-forum] Thing and Class
> Sean & Dan
> It is hard for me to understand what this discussion is about.
> When I see things like
> part is described by design
> part is instance of design
> I wonder if you are missing the whole concept of
> part is part of design
> i.e., the part-whole relation.
> In Sean's last email, time dependence is mentioned, and I wonder -- are
> you now talking about a part-whole relation which is time-varying?
> Dick McCullough
> Ayn Rand do speak od mKR done;
> mKE do enhance od Real Intelligence done; knowledge := man do identify
> od existent done; knowledge haspart proposition list; http://mKRmKE.org/
> ----- Original Message -----
> From: "Sean Barker" <sean.barker@xxxxxxxxxxxxx>
> To: <ontolog-forum@xxxxxxxxxxxxxxxx>
> Sent: Friday, September 05, 2008 12:25 AM
> Subject: [ontolog-forum] Fw: Fw: Thing and Class
>> While I would agree that, say, the CAD model for a part
>> describes the shape of a part, the issue is not one of design but of
>> configuration management. In particular, the criterion for being a
>> A123 is that it is fit, form and function identical to the "typical
>> part" A123. The design is an "ontological commitment" that some class
>> thing exists (will exist). To reject this is to reject the concept of
>> "is-a" and of labelling things with the concepts they instantiate.
>> Conversely, penguins do not stop being penguins just because some has
>> sequenced their DNA (written down their design).
>> The fact that engineering systems are concerned with coming-to-be and
>> ceasing-to-be suggests that
>> engineering ontologies must use a temporal logic. In fact, many
>> are based on effectivities and change notices. The first explicitly
>> identifies what components
>> make up a product at a particular time or at a point in the product
>> while th second
>> controls when the definitions are changed.
>> Sean Barker
>> BAE SYSTEMS - Advanced Technology CentreBristol, UK
>> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
>> [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Dan
>> Sent: 01 September 2008 19:46
>> To: [ontolog-forum]
>> Subject: Re: [ontolog-forum] Fw: Thing and Class
>> *** WARNING ***
>> This mail has originated outside your organization, either from an
>> external partner or the Global Internet.
>> Keep this in mind if you answer this message.
>> No magic here, just typical abstract and concrete objects.
>> Sean Barker wrote:
>>> 2) The product of a design office is designs, instances of the
>>> mathom "design". In the DO, any class/type structure applied to a set
>>> of designs is a generalization of the set of design instances -
>>> designs are
>> > not classes for anything.
>> A "design" is surely an object in the world of information.
>> It describes something, which you portray below as concrete.
>>> The product of a manufacturing organization is parts, each of
>> > which is an instance of a design.
>> Wrong. Each "part" may be based on the "design", but their
>> relation is described/describes, not instance/class.
>> Dan Corwin
> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
> Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
> Shared Files: http://ontolog.cim3.net/file/
> Community Wiki: http://ontolog.cim3.net/wiki/
> To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx
_________________________________________________________________ Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/ Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx Shared Files: http://ontolog.cim3.net/file/ Community Wiki: http://ontolog.cim3.net/wiki/ To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx (01)
|<Prev in Thread]||Current Thread||[Next in Thread>|
|Previous by Date:||[ontolog-forum] Fw: Thing and Class, Sean Barker|
|Next by Date:||Re: [ontolog-forum] Thing and Class, John F. Sowa|
|Previous by Thread:||[ontolog-forum] Fw: Thing and Class, Sean Barker|
|Next by Thread:||Re: [ontolog-forum] Fw: Thing and Class, Patrick Cassidy|
|Indexes:||[Date] [Thread] [Top] [All Lists]|