>
> From my understanding, ISO only tries to cover its costs by charging for
> the
> standards documents. (And standards documents are never runaway
> bestsellers). I
> believe that if you're trying to develop an ontology consistent with the
> technical use, it is a must read. You may find copies in local technical
> or
> reference libraries.
>
> I have a no copying allowed, watermarked pdf, but it seems I could copy
> and
> paste this excerpt:
> +++++++snip++++++++ (01)
But what comes below is exactly paragraph 1.2 in VIM 2008 (= JCGM 200:2008
(E/F)). (02)
Ingvar J (03)
> 3.2
> kind of quantity
> aspect common to mutually comparable quantities
>
> NOTES
>
> 1 — The division of the concept ‘quantity’ into several kinds is to some
> extent
> arbitrary.
> EXAMPLES
> a) The quantities diameter, circumference, and wavelength are generally
> considered to be quantities of the same kind, namely, of the kind of
> quantity
> called length.
> b) The quantities heat, kinetic energy, and potential energy, are
> generally
> considered to be quantities of the same kind, namely, of the kind of
> quantity
> called energy.
>
> 2 — Quantities of the same kind within a given system of quantities have
> the
> same quantity dimension. However, quantities of the same dimension are not
> necessarily of the same kind.
>
> EXAMPLE
> The quantities moment of force and energy are, by convention, not regarded
> as
> being of the same kind, although they have the same dimension. Similarly
> for
> heat capacity and entropy, as well as for number of entities, relative
> permeability, and mass fraction.
>
> 3 — In English, the terms for quantities in the left half of the table in
> 1.1,
> Note 1, are often used for the corresponding 'kinds of quantity'. In
> French, the
> term “nature” is only used in expressions such as “grandeurs de même
> nature” (in
> English, “quantities of the same kind”).
>
> ++++++++snip++++++++
>
> I interpret the statement:
> "The division of the concept ‘quantity’ into several kinds is to some
> extent
> arbitrary."
> and the phrase "generally considered" to mean it's up to individual user
> communities to fully develop the notion of "kind" as relating to
> quantities.
>
> Note that "moment of force" (or torque) when multiplied by angle (radians)
> becomes energy.
>
> R/jbc
>
> John Graybeal wrote:
>> First I'd like to thank Patrick and Gunther for their great recent
>> posts that have cleared up a lot of my own confusion about those
>> existing documents, and even suggested a way forward.
>>
>> It sounds like the 'kind' that Joe refers to is analogous to the
>> 'family' that Patrick refers to, I hope to see more about that
>> alignment.
>>
>> And I am just about convinced to purchase ISO 80000-1. Unfortunately,
>> like ITU's Metric objects and attributes spec [1], which was
>> recommended to me yesterday, its minor cost will guarantee only a
>> subset of the population will read it; most will rely on the expertise
>> of others to read and interpret the contents. (And that split will
>> grow larger as the 'free information' model/mentality increasingly
>> takes over.) Further, if we did read it and said "That's the right
>> way to do it!", would we be able to legally model the ontology on it?
>> Without passing judgment on those concerns, it does seem that non-free
>> information will always suffer 'in the marketplace of ideas'.
>>
>> More to the point, if there is some way to legally and appropriately
>> summarize the key points of each of these for this discussion, it may
>> benefit the discussion considerably. At a minimum, understanding
>> whether the material there conflicts with the expressions here will be
>> helpful.
>>
>> John
>>
>>
>> [1] http://www.itu.int/rec/T-REC-X.739/en
>>
>>
>> On Jul 21, 2009, at 7:58 AM, Joe Collins wrote:
>>
>>> "Quantity dimension" has a very precise meaning in SI, as does
>>> "quantity",
>>> "derived quantity" and other terms. There are many examples of
>>> dimensionless
>>> derived quantities (with a quantity dimension of one), and of
>>> products of those
>>> dimensionless derived quantities with other non-dimensionless derived
>>> quantities. You may find the SI nomenclature arcane, but it is very
>>> precise.
>>>
>>> The SI indicates a property of derived quantities, "kind", which is
>>> to be used
>>> for distinguishing between derived quantities having the same quantity
>>> dimension. Its meaning is not fully developed in the SI, rather it
>>> is left to
>>> others, such as yourself, to do so. To be consistent with SI
>>> nomenclature, I
>>> urge you to use the concept of "kind".
>>>
>>> If you are interested in units and their meanings, I strongly
>>> recommend
>>> purchasing and reading INTERNATIONAL STANDARD ISO/DIS 80000-1,
>>> "Quantities and
>>> units" if you haven't already. It is the first, and most complete
>>> source I have
>>> read for international metrology standards. I suggest this because
>>> it seems it
>>> would clear up much of the lack of knowledge and misconceptions
>>> often exchanged
>>> about quantities, units, physical dimensions.
>>> It does cost money, but I urge you to overcome, as I did, the
>>> cheapness
>>> instilled by "free" information elsewhere.
>>>
>>> Regards,
>>> Joe C.
>>>
>>> Patrick Cassidy wrote:
>>>> I would like to pursue the issue of the unit of measure of an
>>>> angle, since
>>>> it also relates to other "ratio'-like quantities that may be used as
>>>> measures. The gist of this note is that I would not like the
>>>> 'dimension' of
>>>> an angle to be considered as null, or 1, or dimensionless, but as
>>>> something
>>>> that means 'angular measure'. For an ontology that is intended to
>>>> represent
>>>> meanings, I am very leery of oversimplifications that work fine in
>>>> restricted contexts but may prove confusing in missed contexts.
>>>>
>>>> The last note from Ingvar Johansson had this portion of a discussion:
>>>>
>>>> [John Sowa] > > I also like that analysis. But it has to be
>>>> extended to
>>>> angles,
>>>>>> since we have to support multiple functions that map angles to
>>>>>> numbers: degree and radian.
>>>> [IJ] > I agree, and in a sense so do also the metrologists that (as
>>>> I said
>>>> in
>>>>> an earlier mail) I criticize. In my opinion, one should say that
>>>>> radian is
>>>>> a unit of the derived dimension length/length, but the SI system
>>>>> and VIM
>>>>> says that it is a dimensionless unit or a unit of dimension-one.
>>>>> However, everyone agrees that angles can be measured by (or mapped
>>>>> on)
>>>> scales
>>>>> whose magnitudes are 'x degree' or 'x radian'.
>>>>>
>>>>> I think, by the way, that it is misleading to say that "angles are
>>>>> mapped to numbers"; angles are mapped to magnitudes of a scale.
>>>>>
>>>> Although an angle in radians can be expressed as a ratio of linear
>>>> measures, the linear measures themselves do not measure arbitrary
>>>> straight
>>>> lines, but are quite specific regions of some imaginary circle. I
>>>> think it
>>>> is a misleading oversimplification, when taking ratios of things
>>>> that are
>>>> not themselves pure numbers, to ignore the meanings of the measures
>>>> that are
>>>> being divided. A similar issue has arisen in the past about how to
>>>> express
>>>> things like "weight percent" which, if one ignores the objects that
>>>> are
>>>> represented by the numerator and denominator, can appear to be a
>>>> dimensionless number (grams/grams). Such ratios have an actual
>>>> conceptual
>>>> "dimension" though the SI and VIM committees may have found it
>>>> possible to
>>>> ignore the meanings in the case of radians, knowing that the
>>>> dimensions will
>>>> likely be interpreted properly in applications. One way to
>>>> recognize the
>>>> problem is to note that if one wants to represent a weight ratio,
>>>> it is
>>>> possible to use micrograms per gram or grams per gram, and the
>>>> "dimensions"
>>>> will appear to cancel out in either case, leaving a "dimensionless"
>>>> number,
>>>> though the resulting numbers differ greatly depending on what units
>>>> are
>>>> chosen for the numerator.
>>>> I would suggest that we promiscuously include all quantifiable
>>>> "units"
>>>> that carry meaning in any application, and not take as
>>>> "dimensionless" any
>>>> measures that are in fact distinguishable in their intended
>>>> meaning. A
>>>> weight ratio does *not* have the same dimension as an angle, though
>>>> one can
>>>> oversimplify either to some dimensionless number.
>>>>
>>>> In this view, a 'radian' is a unit of measure, as is a 'degree-of-
>>>> angle',
>>>> and if the dimension is represented separately from the unit of
>>>> measure, the
>>>> dimension in either case would be 'angular measure'. The dimension
>>>> of a
>>>> weight ratio is the ordered pair of objects or types of objects whose
>>>> weights are being divided (weight ratios might better be treated in a
>>>> different way, but if they were treated as measures with a unit,
>>>> that would
>>>> be my preference for the unit).
>>>>
>>>> It may be possible to consider certain ratios as the 'base unit'
>>>> as in
>>>> the case of a radian, where the subtended arc length and radius are
>>>> the
>>>> defining measures being divided. In the case of weight ratio,
>>>> grams-of-X/grams-of-Y might be the base unit for each X/Y pair.
>>>> Measures
>>>> that are related to other ratio measures by some constant number,
>>>> such as
>>>> angle degrees or micrograms/gram, would then be related to the base
>>>> unit as
>>>> "prefix"-unit is to other base units, where "prefix" may be micro,
>>>> kilo,
>>>> etc. or a special non-SI prefix.
>>>>
>>>> Pat
>>>>
>>>> Patrick Cassidy
>>>> MICRA, Inc.
>>>> 908-561-3416
>>>> cell: 908-565-4053
>>>> cassidy@xxxxxxxxx
>>>>
>>>>
>>>>
>>>>
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>>>>
>>>>
>>>>
>>> --
>>> _______________________________
>>> Joseph B. Collins, Ph.D.
>>> Code 5583, Adv. Info. Tech.
>>> Naval Research Laboratory
>>> Washington, DC 20375
>>> (202) 404-7041
>>> (202) 767-1122 (fax)
>>> B34, R221C
>>> _______________________________
>>>
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>>>
>>
>>
>> John
>>
>> --------------
>> John Graybeal <mailto:graybeal@xxxxxxxxx> -- 831-775-1956
>> Monterey Bay Aquarium Research Institute
>> Marine Metadata Interoperability Project: http://marinemetadata.org
>>
>>
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>>
>>
>
> --
> _______________________________
> Joseph B. Collins, Ph.D.
> Code 5583, Adv. Info. Tech.
> Naval Research Laboratory
> Washington, DC 20375
> (202) 404-7041
> (202) 767-1122 (fax)
> B34, R221C
> _______________________________
>
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> (04)
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