David Leal wrote: (01)
> This is good progress. (02)
Thanks, but real progress would be if we had captured chapter and verse
from various reference documents and put this someplace. (03)
> You say:
>> But what is important is that there are 4 distinct concepts:
>> - particular quantity = a physical instance to be quantified
>> - kind of quantity = a category of comparable particular quantities
>> - magnitude of quantity = an abstract quantification of particular
>quantities
>> - quantity value = the expression of a magnitude as a number and a
> measurement unit (where the number is the ratio of the magnitude to the unit)
>
> Probably we need to look at two "kinds of quantity":
> - categories such as that which includes Ed Barkmeyer's height, width of the
> Thames at London Bridge, the diameter of the earth's orbit;
> - categories such as that which includes ultimate tensile strength, yield
> strength in tension, yield strength in compression (all are stresses). (04)
If I understand you right, yes. There is a set of categories that are
'kinds of quantity', such that all instances of any 'kind of quantity'
category are comparable and no pair of instances from two different
kinds of quantity are comparable. There are other categories that must
be subclasses of the 'kinds of quantity' (each of which is a subclass of
the general category 'quantity'), which is your second bullet. (As I
mentioned in the email to Martin, these might be "roles" instead of
subclasses. I don't know.) (05)
I notice that Pat Hayes uses 'dimension' for 'kind of quantity'. I
think the VIM also uses the term 'dimension', but I can't recall what
meaning VIM assigns to it. (06)
-Ed (07)
--
Edward J. Barkmeyer Email: edbark@xxxxxxxx
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528
Gaithersburg, MD 20899-8263 FAX: +1 301-975-4694 (08)
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority." (09)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/uom-ontology-std/
Subscribe: mailto:uom-ontology-std-join@xxxxxxxxxxxxxxxx
Config/Unsubscribe: http://ontolog.cim3.net/mailman/listinfo/uom-ontology-std/
Shared Files: http://ontolog.cim3.net/file/work/UoM/
Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?UoM_Ontology_Standard (010)
|