Pat,
Makes sense to me.
May we include an attribute on role signfying effect-iveness? Role
effectiveness will partially depend on actor (if you have ever seen Peter
Sellers play Hamlet).
Jack
On Feb 1, 2012, at 7:32 PM, Pat Hayes wrote: (01)
> Very good question, Matthew. Let me try out an idea on you. Your P101 is
>actually a role played by a pump, rather than a pump itself. Think of it as
>being like Hamlet, as played by Lawrence Olivier (P101 as played by S3556).
>You can change actors, and Hamlet is still Hamlet - same role - and while
>Olivier is playing the role, he *is* Hamlet, at least in a sense. But this
>second "is" cannot be identity, since you can kick the actor, but you can't
>kick a role.
>
> Both a pump and a pump-role are spatiotemporal entities, but they have
>different identity conditions. The identity of a pump, like any other physical
>object, is determined by the disposition of pieces of material stuff (metal,
>plastic, rubber), but the identity of the role is determined by its
>interfaces to the rest of the system (being connected to this pipe in this
>place and operated by this controller, etc..)
>
> You can identify a pump-phase (temporal slice) with a pump-role-phase, but
>you must not identify the actual individuals, so its safer to actually have a
>relation of 'functioning as' of the like to attach a role-playing thing to its
>role. Or, you can treat the role as a time-dependent property of the physical
>thing, but you will probably need a CL-style ability to have properties of
>properties if you go that (elegant) route.
>
> Make sense?
>
> Pat
>
>
>
> On Jan 29, 2012, at 3:48 AM, Matthew West wrote:
>
>> Dear Colleagues,
>>
>> Last Thursday I complained that most ontologies do not give adequate
>> treatment to what I call system components, and if ontology is going to gain
>> traction within the systems world, it needs to get a better understanding of
>> this central idea in systems engineering.
>>
>> I illustrated the issue by telling the (simplified) life story of a system
>> component: the pump, P101, at the bottom of a distillation column. Here is
>> its story.
>>
>> The designer creates a drawing of the distillation column including at the
>> bottom of the column a pump to pump away the column bottoms. He labels it
>> P101, decides that one pump will be sufficient, and gives the specification
>> for the pump in terms of Net Positive Suction Head, differential head, flow
>> rate, materials of construction, and many other things.
>>
>> The construction engineer picks up the drawing and specification and notices
>> he has to install a pump as P101. Fortunately, he has a pump in stock from a
>> previous project, that has been in stores unused for 5 years which exactly
>> meets the specification. On it is stamped Serial No S3556.
>>
>> The designer and the Operator comes to see the pump be installed, and once
>> the connections are made, he gives the pump a friendly kick and says to the
>> construction engineer "It's good to see P101 realized at last". The
>> construction engineer says in return "Yes, and it's good to get S3556 off my
>> hands at last." He turns to the operator and says "Why don't we change your
>> drawings to show S3556 instead of P101?" The operator says "No, don't do
>> that, it's a replaceable part, and one day another pump will be put there,
>> and I don't want to have to change all the drawings and other documentation
>> that refers to P101 each time it is replaced, as far as I am concerned it's
>> the same pump whatever is installed there."
>>
>> Some time later the pump breaks down and needs to be taken back to the
>> workshop. The maintenance engineer says to the operator "Hi, can I take
>> S3556 installed as P101 back to the workshop?" The operator replies "Sure,
>> but what am I supposed to do without my P101? If it does not exist I cannot
>> operate my distillation column." The maintenance engineer responds, "I
>> understand. We have another pump S4567, that meets the same specification as
>> P101. We'll replace S3556 with it and you will only be without P101 for a
>> few hours. I don't understand how you can continue to call it P101 though
>> when all the parts have changed at once." The operator replies "I don't care
>> about that. What I care about is what is connected in my system to pump the
>> liquid from the bottom of the column. As long as it does that, it is P101 to
>> me."
>>
>> Later the distillation column is demolished. The operator says, "A sad end,
>> I was very fond of P101, but it is no more." The demolition engineer says,
>> "Yes indeed. Fortunately, we can take S4567 and use it on another plant."
>>
>> It's probably worth summarising the key characteristics of a system
>> component:
>> - It comes into existence the first time it is installed.
>> - It is identical to the equipment items installed, whilst they are
>> installed (but not before or after).
>> - It can survive complete replacement of all its parts at once.
>> - It can survive periods of non-existence.
>> - It ceases to exist when the system it is a component of ceases to exist.
>>
>> This is clearly rather different from the life of ordinary physical objects.
>> However, relatively few ontologies recognise that such things exist. Many
>> try to fob system components off as being classes, or abstract individuals,
>> though these clearly do not have the required characteristics.
>>
>> Ontologists need to step up to the mark here and provide proper recognition
>> for system components.
>>
>> Regards
>>
>> Matthew West
>> Information Junction
>> Tel: +44 1489 880185
>> Mobile: +44 750 3385279
>> Skype: dr.matthew.west
>> matthew.west@xxxxxxxxxxxxxxxxxxxxxxxxx
>> http://www.informationjunction.co.uk/
>> http://www.matthew-west.org.uk/
>>
>> This email originates from Information Junction Ltd. Registered in England
>> and Wales No. 6632177.
>> Registered office: 2 Brookside, Meadow Way, Letchworth Garden City,
>> Hertfordshire, SG6 3JE.
>>
>>
>>
>>
>>
>> _________________________________________________________________
>> Msg Archives: http://ontolog.cim3.net/forum/ontology-summit/
>> Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontology-summit/
>> Unsubscribe: mailto:ontology-summit-leave@xxxxxxxxxxxxxxxx
>> Community Files: http://ontolog.cim3.net/file/work/OntologySummit2012/
>> Community Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012
>> Community Portal: http://ontolog.cim3.net/wiki/
>>
>
> ------------------------------------------------------------
> IHMC (850)434 8903 or (650)494 3973
> 40 South Alcaniz St. (850)202 4416 office
> Pensacola (850)202 4440 fax
> FL 32502 (850)291 0667 mobile
> phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
>
>
>
>
>
>
> _________________________________________________________________
> Msg Archives: http://ontolog.cim3.net/forum/ontology-summit/
> Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontology-summit/
> Unsubscribe: mailto:ontology-summit-leave@xxxxxxxxxxxxxxxx
> Community Files: http://ontolog.cim3.net/file/work/OntologySummit2012/
> Community Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012
> Community Portal: http://ontolog.cim3.net/wiki/ (02)
_________________________________________________________________
Msg Archives: http://ontolog.cim3.net/forum/ontology-summit/
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontology-summit/
Unsubscribe: mailto:ontology-summit-leave@xxxxxxxxxxxxxxxx
Community Files: http://ontolog.cim3.net/file/work/OntologySummit2012/
Community Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012
Community Portal: http://ontolog.cim3.net/wiki/ (03)
|