[Crm-sig] Object containership shortcuts?

Robert Sanderson RSanderson at getty.edu
Thu Jul 11 00:40:49 EEST 2019


Yes, completely agree with the problems posed!

My preference would a shortcut that was parallel to P8 – your “Pxxx is located on or within”. It has P8 as precedent, it shortcuts around an entity that exists only through the existence of the object and it works in RDF as well as in other implementations of the higher level logic.

I would be concerned about a Period+Thing class to replace P8. For that specific scenario it seems comprehensible, but it opens up a lot more confusion (as per the STV discussion) as to the nature of the entity that I think can be avoided.

Rob

From: Martin Doerr <martin at ics.forth.gr>
Date: Tuesday, July 9, 2019 at 12:19 PM
To: Robert Sanderson <RSanderson at getty.edu>, "crm-sig at ics.forth.gr" <crm-sig at ics.forth.gr>
Subject: Re: [Crm-sig] Object containership shortcuts?

Dear Robert,

That is one idea. The question is actually, if it is only containers that carry things around. My computer has a hard disk in it, but also the "bears feature" is nothing else than indirectly referring to the object as a place.

Another question is, why we do have "P8 took place on or within", which "...describes the location of an instance of E4 Period with respect to an E19 Physical Object.  P8 took place on or within (witnessed) is a shortcut of the more fully developed path from ‘E4 Period’ through ‘P7 took place at’, ‘E53 Place’, ‘P156i is occupied by’, to ‘E18 Physical Thing’"

...and not another "Pxxx is located on or within" . One could either introduce that or give up both in favor of the IsA. We had however in CRMSci concerns if all physical things qualify to define a spatial reference frame, if they are too plastic. On the other side, their extent is always a spatial confinement, even without being able to mark relative positions within them, e.g., an Amoeba having swallowed some algae.

 Following CRMgeo, instances of Place do only exist as long as their reference object exists. It cannot be otherwise. Only spacetime points are absolute in the universe, because they exist only for their instant of time, and do not cause problems of spatial reference systems moving in different directions.

Indeed, the question of being "on" is an interesting one. It should be interpreted as being adjacent to the surface. Imagine a young bock in the hunter's rucksack, limbs protruding: Is it in, or on, or in and on?

In order to avoid such ambiguities, I would rather stick to a notion of adjacency, in case of things. If we use IsA, then "bears feature' becomes superfluous, but we need to check the implications of topological relations with other places, such as  places within such places.

If you just declare containers and gravity-bound storage features to be IsA place, you avoid the more general questions.

Best,

Martin

On 7/9/2019 7:49 PM, Robert Sanderson wrote:

Thank you Martin.

Having the same instance be both the physical thing and the place that the physical thing is the reference for is interesting. It certainly cuts out the mostly unnecessary entities.

Given that Place and Human-Made Object only intersect at E1, there doesn’t seem to be any significant confusion by having a new class that’s a sub class of both E22 and E53. It could be called a Container.

There’s some weirdness about partitioning of the physical, and how that relates to the positional, but so far nothing that produces inconsistency that wouldn’t also be inconsistent with the fully expressed path. For example, a desk with drawers is a Container, that has parts which are Containers. The place-ness of the desk and drawers are not necessarily also partitioned in the same way, which is fine – we might consider only the top of the desk as the place that it defines, which would be distinct from the drawers.  Equally, if we took the drawer out of the desk and put it on top, we would not have part of the place being contained within itself.

It means that the place is destroyed along with the object … but that’s not bad either. Without the reference system of the object, the place no longer has any meaning.  It does get a little strange with former_or_current_location – the former location is a thing that has been destroyed – but that’s indeed what has happened.

Could we have another RDFS join class - E22_E53_Container ?

Rob


From: Crm-sig <crm-sig-bounces at ics.forth.gr><mailto:crm-sig-bounces at ics.forth.gr> on behalf of Martin Doerr <martin at ics.forth.gr><mailto:martin at ics.forth.gr>
Date: Tuesday, June 25, 2019 at 1:49 PM
To: "crm-sig at ics.forth.gr"<mailto:crm-sig at ics.forth.gr> <crm-sig at ics.forth.gr><mailto:crm-sig at ics.forth.gr>
Subject: Re: [Crm-sig] Object containership shortcuts?

On 6/24/2019 10:59 PM, Robert Sanderson wrote:

Dear all,

Has anyone used P54 has current permanent location in practice in an information system, where the containing Place is defined only with respect to some other physical object?

Some use cases for this pattern:

·         A set of letters in a folder, or a set of paintbrushes in a box

·         A set of coins in a display case

·         Books on a bookshelf

This seems like a very easy use case for a shortcut between Physical Objects to avoid creating Places that exist only to be the P54 of some other object.  The containing object is typically 1:1 with its container-space, as even if there are drawers in a desk, you could model the drawer as a part of the desk, which had its own space. Thus the cutlery in one drawer, the cooking utensils in a different drawer, despite being part of the same kitchen cupboard unit.

The most simple solution is Physical Object IsA Place, with the respective semantics, of being itself the reference system.

The temporal aspects of P53, P55 are given by the Presence class, which requires E18 IsA STV, otherwise the paths get very long...

We will try in our team a logical definition of these things.

Thoughts?

Best,

Martin

Similarly, P53 and P55 could also benefit from such a shortcut for their different temporal aspects.

Thoughts?

Rob




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--

------------------------------------

 Dr. Martin Doerr



 Honorary Head of the

 Center for Cultural Informatics



 Information Systems Laboratory

 Institute of Computer Science

 Foundation for Research and Technology - Hellas (FORTH)



 N.Plastira 100, Vassilika Vouton,

 GR70013 Heraklion,Crete,Greece



 Vox:+30(2810)391625

 Email: martin at ics.forth.gr<mailto:martin at ics.forth.gr>

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