Dear Geoffrey, (01)
I think that this is well worth discussing with the metrology experts. (02)
Two meanings of "quantity"?
---------------------------
The reference
http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=111-11-01
has the following note to the definition of (physical) quantity: (03)
NOTE 1 – The term quantity may refer to a quantity in a general sense
(examples: length, time, mass, temperature, electrical resistance,
amount-of-substance concentration) or to a particular quantity (examples:
length of a given rod, electrical resistance of a given specimen of wire,
amount-of-substance concentration of ethanol C2H5OH in a given sample of wine). (04)
This note, which is not present in the VIM, may be crucial. Does it mean
that there are two meanings of quantity:
- quantity in a general sense: The following are different objects of type
"quantity in a general sense" - length, time (duration), mass.
- particular quantity: The following are different objects of type
"particular quantity" (and of type length) - the metre, the astronomical
unit, the width of the Thames at London Bridge. (05)
If this is the case, then the term "quantity" is used in either sense
according to context. We have: (06)
NOTE 2 – Quantities that can be placed in order of magnitude relative to one
another are called quantities of the same kind. (07)
In this note "quantity" means "particular quantity". The metre, the
astronomical unit and the width of the Thames at London Bridge are
"particular quantities" that can be placed in order of magnitude. (08)
NOTE 3 – Quantities of the same kind may be grouped together into categories
of quantities, for example:
- work, heat, energy
- thickness, circumference, wavelength (09)
In this note "quantity" means "quantity in a general sense". Work, heat and
energy are "quantities in a general sense" that can be grouped together. (010)
Clarification
-------------
It would be good to confirmation that this is the intent of the VIM and the
International Electrotechnical Vocabulary. (011)
It would also be good to have confirmation that the terms "quantity in a
general sense" and "particular quantity" are correct. If they are, perhaps
they should be added to the vocabulary. (012)
Best regards,
David (013)
p.s. The use of one term for objects at two different meta-levels is
familiar to those working with ISO 10303. In ISO 10303-41, the entity type
*product* is defined as follows: "A *product* represents a product or a type
of product." (This is not a tautology - the entity type *product* is defined
using the defined term "product".) (014)
Ontologically this is not very nice, and as ISO 10303 evolves towards being
an ontology, it will be good to separate out the two uses. (015)
At 15:35 14/07/2009 +0100, you wrote:
>David Leal says
>
>>>>>>
><Aside>
>Evan uses the term "quantity value" which is defined within the VIM. I have
>read the definition many times: "number and reference together expressing
>magnitude of a quantity". I think that this phrase should be read as follows:
>
> number_and_reference_together - expressing_magnitude_of - a_quantity
>
>but it could be read as:
>
> number_and_reference_together - expressing - magnitude_of_a_quantity
>
>Hence is the thing identified by (or "expressed by") 2.54 cm a "quantity" or
>a "magnitude_of_a_quantity"? Somebody must know, or is there a deliberate
>ambiguity. :)
></Aside> >>>>>>>>>>>
>
>
>[GW] Nobody seems to have picked this comment up. I am concerned that
there is a misunderstanding here. My understanding of the VIM definition of
_quantity_value_ is based on the following:
>
>_Quantity_ is defined by 1.1 of VIM (JCGM 200:2008 = ISO/IEC Guide 99:2007)
http://www.bipm.org/en/publications/guides/vim.html
>
>See also definition of (physical) quantity in Electropedia
(http://www.electropedia.org ) section 111.11.01
>Electropedia is an online searchable database version of the International
Electrotechnical Vocabulary, IEC 60050
>
>Definition 1.19 of VIM (JCGM 200:2008 = ISO/IEC Guide 99:2007) defines
_quantity _value_ (or _value_of_quantity or _value_) and I am certain in my
own mind that the term means "magnitude_of_a_quantity" not "quantity"
>
>In David's example the quantity is a length and the magnitude is 2.54 cm ie
expressed as a number and reference (unit).
>
>I can seek clarification of this interpretation from JCGM/WG 2 if this is a
contentious issue
>
>Regards
>
>Geoffrey Williams
>Programme Manager,
>Business Process Improvement Standards
>Standards Operations
>
>_____________________________
>
>
>BSI, 389 Chiswick High Road, London, W4 4AL, UK
>Tel: +44 (0)20 8996 7411
>Fax: +44(0)20 8996 7249
>email: geoff.williams@xxxxxxxxxxxx
>Web: www.bsigroup.com
>
>
>P Please consider the environment before printing this email
>
>-----Original Message-----
>From: uom-ontology-std-bounces@xxxxxxxxxxxxxxxx
[mailto:uom-ontology-std-bounces@xxxxxxxxxxxxxxxx] On Behalf Of David Leal
>Sent: 10 July 2009 22:20
>To: uom-ontology-std
>Subject: Re: [uom-ontology-std] UoM ontology standard - a proposed program
ofwork
>
>Dear All,
>
>I strongly support Ed's proposed approach, and especially his reference to
>the VIM:
>
>> We should extract the UoM parts of these ontologies into a
>>repository and look at them side-by-side. (The basic VIM concept set is
>>only a dozen concepts or so. It should not be necessary to include all
>>the infrastructure on which the UoM part is built -- the idea here is to
>>identify the UoM concepts that are captured.)
>
>The need to produce a set of UoM concepts that is both a formal ontology and
>related to the VIM concepts is important. It give us a chance of creating
>"the ontology for units of measure" rather than "yet another ontology for
>units of measure". The work also has a possibility of adding clarity to the
VIM.
>
><Aside>
>Evan uses the term "quantity value" which is defined within the VIM. I have
>read the definition many times: "number and reference together expressing
>magnitude of a quantity". I think that this phrase should be read as follows:
>
> number_and_reference_together - expressing_magnitude_of - a_quantity
>
>but it could be read as:
>
> number_and_reference_together - expressing - magnitude_of_a_quantity
>
>Hence is the thing identified by (or "expressed by") 2.54 cm a "quantity" or
>a "magnitude_of_a_quantity"? Somebody must know, or is there a deliberate
>ambiguity. :)
></Aside>
>
>I would like to volunteer for a role in the ontology formulation as
>suggested in Ed's proposal. It would fit well with my the work within the
>CEN ELSSI Workshop, which is creating an ontology derived from ISO material
>test data standards for the formal definition of material test procedures
>and for the formal representation material test data.
>
>Best regards,
>David
>
>At 15:15 10/07/2009 -0400, you wrote:
>>With respect to language selection for UoM, Ed wrote:
>>
>>> (2) Language selection
>>> Since we are going to propose a standard ontology, it should be
>>> documented in one or more standard languages.
>>> Technically, we have at this time only 3 good choices: CLIF, RDF,
>>> and OWL. But it should be noted that "OWL" is an umbrella for several
>>> languages, one of which (OWL/Full) might be considered the best choice
>>> for an appropriate RDF dialect. We need to make choices among these for
>>> the normative ontologies.
>>> These languages have very different expressive powers. I suggest
>>> that we choose one axiomatic form and one (extended) DL form, and do all
>>> the formal ontology work in exactly those languages.
>>> We also need a non-normative graphical representation, to enable
>>> rapid comprehension. The ODM Profile for OWL (using UML tools) suggests
>>> itself, but I usually use a more vanilla UML form for presentation of
>>> basic concepts. And something adequate that is supported by
>>> web-available tooling (like Protegé) is a good alternative.
>>> I suggest that we choose a useful graphical form supported by
>>> available tools and use it, exclusively, for presentation and discussion
>>> in the group. Further, I suggest that we will include non-normative
>>> diagrams in this language in the proposed standard, as an aid to reader
>>> comprehension.
>>I would second the idea of developing the ontology model simultaneously in
>>an expressive language like IKL and an extended version of OWL DL. One form
>>of the latter might actually mostly define an extension to OWL per [1].
>>The goal
>>would be to insure support in OWL DL reasoners for the UoM model that we
>>develop,
>>where that support would include dimensional analysis, conversion, and
>>appropriate
>>interpretation of the results (essentially identity correspondence of
>>quantities with
>>equivalent quantity values, e.g., 2.54 Centimeters and 1 Inch).
>>Whatever we do for
>>OWL, it is important that each model make sense on its own, and that
>>each makes
>>appropriate use of the language (or the language+extension) in which it
>>is expressed.
>>
>>-Evan
>>
>>[1] http://www.webont.org/owled/2008/papers/owled2008eu_submission_34.pdf
>>
>>_________________________________________________________________
>>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
>>
>>
>>
>
>============================================================
>David Leal
>CAESAR Systems Limited
>registered office: 29 Somertrees Avenue, Lee, London SE12 0BS
>registered in England no. 2422371
>tel: +44 (0)20 8857 1095
>mob: +44 (0)77 0702 6926
>e-mail: david.leal@xxxxxxxxxxxxxxxxxxx
>web site: http://www.caesarsystems.co.uk
>============================================================
>
>
>
>_________________________________________________________________
>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
>
>====================================================================
>
>Visit the BSI website at www.bsigroup.com
>
>This email may contain confidential information and/or copyright
>material. This email is intended for the use of the addressee only.
>Any unauthorised use may be unlawful. If you receive this email
>by mistake, please advise the sender immediately by using the
>reply facility in your email software.
>
>Thank you for your cooperation.
>
>________________________________________________________________________
>This e-mail has been scanned for all known viruses.
>
>_________________________________________________________________
>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
>
>
> (016)
============================================================
David Leal
CAESAR Systems Limited
registered office: 29 Somertrees Avenue, Lee, London SE12 0BS
registered in England no. 2422371
tel: +44 (0)20 8857 1095
mob: +44 (0)77 0702 6926
e-mail: david.leal@xxxxxxxxxxxxxxxxxxx
web site: http://www.caesarsystems.co.uk
============================================================ (017)
_________________________________________________________________
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 (018)
|