Oh well, here I go again...
I disagree that this list is complete or mutually exclusive. There are only
a few basic physical quantities that can be tracked. they are:
mass,
length,
time,
electrical charge,
temperature.
Charge doesn't appear on your list. A rigorous physicist may even argue
that time and length are redundant ( 1 nanosec = 30 cm, more or less) and
that temperature is just an energy per particle, angles are just numbers
(measured in radians, of course). This would drop us down to mass, length
and charge. The physicist would then add 'exotic' measures like charm and
strangeness for completeness.
The quantities listed (above)will provide us with the building blocks to
specify the dimension of any physical quantity.
area = length^2 ( hence the list is not mutually exclusive)
volume = length^3
energy = mass *length^2/(time^2)
electrical potential = energy / charge
specific heat capacity = energy/(mass * temperature)
speed = length/time
weight = force = mass * length / time^2
pressure = force / area = mass / (length^2 * time^2)
etc ...
Any commonly encountered physical quantity can be reduced to the list of
five basic quantities in the first list. I would agree that adding angle,
amount (capital), and quantity (count) are also useful as we move beyond
the physicist's set of units. I will accept the 'text', 'identifier' and
'code' types as they have been proven useful.
I would like to generalized the unit type 'rate' has been replaced by the
exponents to which the 'fundamental' units have been raised.
I find the coordinate type problematic. This is a rather different concept
(component of vector vs. scalar) than dimensional analysis. It is clearly
important to take this into account at a low level, but the choice of
coordinate values depends upon coordinate system. This is more like a
'collection' than a dimensional type.
We must also specify a measure and a unit for any physical quantity. This
idea is tied to the difference between 'time' and 'date'. Both are measures
of time, but they use different units. By sticking with 'time' fewer types
are needed. We do need to be able to convert between various 'units'
(seconds, hours, days) of the same 'quantity' (time).
In short, I feel that XML should be used to specify measured quantities in
terms of a number and a unit. The 'unit' should be tied to a underlying
'dimensional group'. Measurements with the same 'dimensional group' may be
added ( 10 seconds + 100 days is ok since both are time, 5 USD + 10 FF is ok
since both are money, 10 pounds + 10 Kg is wrong since force is not mass, 5
apples + 5 oranges would be ok since both are 'counts'). Computers can be
programmed to multiply units & manage dictionaries of standard units ( so
that you see force in 'Newtons' rather than Kg m /s^2.) Based on locale and
other aspects of the context, you could even change the display of a
quantity to suit the user.
This is indeed a great place for an XML 'microstandard'.
Bob Folkerts
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Monday, May 01, 2000 11:58 AM
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED];
[EMAIL PROTECTED]
Subject: RE: "Tower of Babel" or Bizcodes, UDEF (standard tag IDs)
David, XML/EDI list,
The 17 property words of DoD 8320.1-M-1 were carefully selected over the
course of many years within DoD's data administration function. This list of
17 words appears to enable semantics conflict resolution in the simplest
manner. By forcing any data element concept (see ISO/IEC 11179 Part 1 for a
definition) to a common starting point (one of 17 properties) it appears to
be a viable way of aligning data element concepts that are semantically
equal but have been assigned different names.
It has been my experience within industry and shared by those within the DoD
data administration function that the 17 property words are intuitive,
mutually exclusive, and seemingly exhaustive. The committee I chaired within
the CALS Industry Steering Group was tasked with defining a means for
integrating the data within the enterprise. The UDEF was the result.
The 17 UDEF property words (class words within DoD 8320.1-M-1) are as
follows:
* Amount - A monetary value.
* Angle - The rotational measurement between two lines and/or planes
diverging from a common point and/or line.
* Area - The two dimensional measurement of a surface expressed in
unit squares.
* Code - A combination of one or more numbers, letters, or special
characters substituted for a specific meaning.
* Coordinate - One of a set of values which identifies the location of
a point.
* Date - The notation of a specific period of time.
* Dimension - A one dimensional measured linear distance.
* Identifier - A combination of one or more numbers, letters, or
special characters which designates a specific object and/or entity, but has
no readily definable meaning.
* Mass - The measure of inertia of a body.
* Name - A designation of an object and/or entity expressed in a word
or phrase.
* Quantity - A nonmonetary numeric value.
* Rate - A quantitative expression that represents the numeric
relationship between two measurable units.
* Temperature - The measure of heat in an object.
* Text - An unformatted character string generally in the form of
words.
* Time - A notation of a specified chronological point within a
period.
* Volume - A measurement of space occupied by a three dimensional
figure.
* Weight - The force with which an object is attracted toward the
earth and/or other celestial body by gravitation.
Based on experience, it appears that any data element concept property can
be mapped into one of these 17 property words. For example, velocity is a
type of "rate" and part number is a type of "identifier"
Ron Schuldt
> ----------
> From: David RR Webber[SMTP:[EMAIL PROTECTED]]
> Sent: Monday, May 01, 2000 9:53 AM
> To: INTERNET:[EMAIL PROTECTED]
> Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED];
> [EMAIL PROTECTED]
> Subject: RE: "Tower of Babel" or Bizcodes, UDEF (standard tag IDs)
>
> Message text written by INTERNET:[EMAIL PROTECTED]
> >
> The UDEF naming convention conforms to the requirements of ISO/IEC 11179
> and
> uses the same 17 property words (class words) as those specified by DoD
> 8320.1-M-1. Each data element within DoD's data dictionary (based on DoD's
> Enterprise-wide Data Model) uses one of the 17 property words. Each data
> element within MIL-STD-2549, Configuration Management Data Interface was
> named based on the UDEF naming convention. See Appendix C to MIL-STD-2549
> at
> http://www.acq.osd.mil/io/se/cm&dm/cm&dm_pubs.htm
> <<<<<<<<<<<<<
>
> Ron,
>
> Perhaps it would clarify if you could pen some lines on the purpose behind
> the
> idea of having 17 property words - and how this is applicable more
> generally?
>
> Obviously in a global context you can translate the 17 words into local
> usage.
>
> As we wrestle with the issues of BPR and Core Components within ebXML,
> I'm seeing the top down can often get very confusing for the lay person -
> or
> someone who just understands the business domain - but not the
> technobabble!
>
> I'm always trying to distill out what will work at the bottom up - so that
> the two
> world can co-exist without tripping each other up. The Army seems to
> avoid
> words at all cost afterall - its that A317-B12 you are needing, etc!
>
> At the end of the day some Army Quartermaster has to understand how his
> warehouse is organized, and where that actual physical part really is!
>
> DW.
>
>
==========================================
XML/EDI Group members-only discussion list
Homepage = http://www.xmledi.org
Brought to you by: Online Technologies Corporation
Home of BizServe - www.bizserve.com
TO UNSUBSCRIBE: Send email to <[EMAIL PROTECTED]>
Leave the subject blank, and
In the body of the message, enter ONLY: unsubscribe
Questions/requests should be sent to: [EMAIL PROTECTED]
To join the XML/EDI Group complete the form located at:
http://www.geocities.com/WallStreet/Floor/5815/mail1.htm
==========================================
XML/EDI Group members-only discussion list
Homepage = http://www.xmledi.org
Brought to you by: Online Technologies Corporation
Home of BizServe - www.bizserve.com
TO UNSUBSCRIBE: Send email to <[EMAIL PROTECTED]>
Leave the subject blank, and
In the body of the message, enter ONLY: unsubscribe
Questions/requests should be sent to: [EMAIL PROTECTED]
To join the XML/EDI Group complete the form located at:
http://www.geocities.com/WallStreet/Floor/5815/mail1.htm
