SUO: Re: Lifecycle Integration Schema
o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
LIS. Discussion Note 12
o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
Focusing on this Fleur de LIS --
you knew it was coming eventually --
now you can breathe a sigh of relief --
LIS: | possible_individual
|
| A <possible_individual> is a <thing>
| that exists in space and time.
|
| This includes:
|
| - things where any of the space time dimensions are
| vanishingly small,
|
| - those that are either all space for any time,
| or all time and any space,
|
| - the entirety of all space time,
|
| - things that actually exist, or have existed,
|
| - things that are fictional or conjectured and
| possibly exist in the past, present or future,
|
| - temporal parts (states) of other individuals,
|
| - things that have a specific position, but zero extent in
| one or more dimensions, such as points, lines, and surfaces.
|
| In this context existence is based upon being imaginable within
| some consistent logic, including actual, hypothetical, planned,
| expected, or required individuals.
|
| EXAMPLE. The pump with serial number ABC123,
| Battersea Power Station, Sir Joseph Whitworth,
| Shakespeare, and the starship "Enterprise" can be
| represented by instances of <possible_individual>.
|
| EXPRESS specification:
|
| ENTITY possible_individual
|
| SUBTYPE OF (thing);
|
| END_ENTITY;
|
| http://www.tc184-sc4.org/wg3ndocs/wg3n1328/lifecycle_integration_schema/lexical/possible_individual.html
JA: I am trying to figure out:
JA: (1) what you mean by the term "possible_individual" ...
MW: http://www.matthew-west.org.uk/Documents/Spatio-temporal-Paradigm.pdf
JA: (2) whether that meaning can be formalized
in terms of an axiomatic theory ...
JA: (3) what sorts of things come under the
heading of a "possible_individual".
JA: By what sort of decision process can I judge whether the
Starship Enterprise is "imaginable within some consistent
logic, including actual, hypothetical, planned, expected,
or required individuals"?
JA: In other words:
JA: What is the operational definition of
"imaginable within some consistent logic".
MW: By logically consistent we meant that the existance
of objects did not present a logical inconsistency.
JA: I recognize this as the "mark of mathematical existence" (MOME).
But most folks would draw, if they could figure out how, a very
hard line between this brand of mathematical existence and, well,
the existential kind, if you know what I mean. In other words,
there are models of theories that have very little attachment
to physical or spacetime realities, and so we still have to
decide which of the logical models are analogical models
of any given objective domain in realworld experience.
MW: OK.
MW: Imaginable means that they could exist in this or some possible world.
JA: Imaginable means "able to be an object of images".
MW: When I use a term, it means what I intend it to.
Sigh, if only we could computers
to act on our intentions,
instead of our code.
The question here is what it will demand to fully formalize
the provisional hints of formulation that you have provided.
The condition of your working document is very like all the
others that we're likely to see here in its fledgling state.
The fact is that we just don't yet have the engines that it
would take to get any of them off the ground, for all their
fancied puffing up, the fluff of feathers, the gloss of wax.
JA: I am aware of many realworld applications that would
actually require us to address all of these problems
and more in our formally implemented theories, if we
can think of computationally effective ways to do it
all well, and so these tangents present live options.
Still, it's really a bit much to lay on one person's
plate, at one particular sitting, at one day's feast.
MW: Example requirements we have are plans (including alternative
scenarios) and incident investigation -- looking at alternative
histories of how we might have got here after, e.g., an accident.
This sounds real enough for anybody.
JA: Could you tell us what a typical application is like
and what your ontology does for you in such a setting?
MW: A typical application would be the bringing together of
engineering design data for an offshore oil-rig (think
pantechnicans in paper form) from multiple systems,
integrate and consolidate that data for handover
to the operator of the rig for putting into the
various operations and maintenance systems.
MW: The ontology gives us a common language that can be used to describe
the design so that the various data can be brought together into a
consolidated data set, so we can check consistency and completeness
of the data set. Being a standard data model (and reference data)
means that we will in time be able to compare performance and
reliability of equipment across Shell.
MW: The next step in developing the ontology would be to add details
like design rules and regulations so that at least some design
checks can be automated.
This is more like what what I need to know.
I will try to keep these gemmy bits in mind
as I drill deeper into the ontological strata.
JA: Could you pick out a few terms or concepts that you think
are especially important and tell us how defining them the
way you do is critical to success in practical applications?
MW: It doesn't matter which one you look at, the highest priority
is for clarity and lack of ambiguity in meaning. The ontology
is intended to be used by a broad range of people who will not
necessarily meet each other, even when one creates the data
another uses.
Okay.
MW: One reason for choosing a 4D paradigm is that the
principles are simple and can be rigorously applied.
I've never understood that whole 3d/4d controversy.
For me the number of columns in a relational table
is the ostensible dimensionality that I start with.
JA: I think that the more concrete detail we can bring out to fill in
the spaces currently swept out by the abstractions of <thing> and
<abstract_object> and <possible_individual> and so on, the better
we will come to comprehend what is really desirable and feasible
in the present setting.
MW: If we return to possible_individual and what can be axiomatised
about it, then 4D objects are subject to classical (4D) mereology.
I would assume that topology would also apply.
I think that we're a long way from anything that I could recognize
as an axiomatic formulation of the intended relations among things,
abstract_objects, and possible_individuals, but at least I seem to
be getting much better soundings than I've heard heretofore.
Jon Awbrey
o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o