Dear All,
May be we should relax the definition of E54 to either representing the
approximation of a true quantity of a thing or phenomenon provided by a
measurement, with all reservations to which degree the measurement
measures what it is supposed to do, or a derived quantity computed
indirectly from observation data comparable to reality, or a quantity
produced by simulation of reality-like situations.
If we take for instance measuring the weight or length of an object, we
know that it changes continuously, regardless whether within negligible
margins or not. The indeterminacy/precision intervals given are those of
the measurement and not those of the property itself. In that sense, we
may abandon that the Dimension is the true quantity of the thing, but
rather true measured.
In case of physical constants, such as the proton diameter (see recent
literature), which is not property of a particular but may quite well
be, we may talk about medium values from multiple measurements.
We can continue to include counting letters in a text, once this is
based on comparing physical copies. A monetary amount is still a more
tricky thing theoretically. It could be turned into paper money, but in
case of bitcoins etc., it may never be. As a measure to compare social
obligations, it pertains to a reality.
In case the value is a complex structure, the "unit" can describe the
structure and elementary units of subfields.
A dataset may be composed of Dimensions, or be a Dimension as a whole.
I am in favor of taking a digital image or the results of a gene
activation measurement array as a Dimension.
Comments?
Best,
martin
E54 Dimension
Subclass of:E1 <#_E1_CRM_Entity> CRM Entity
Scope note:This class comprises quantifiable properties that can be
measured by some calibrated means and can be approximated by values,
i.e. points or regions in a mathematical or conceptual space, such as
natural or real numbers, RGB values etc.
An instance of E54 Dimension represents the true quantity, independent
from its numerical approximation, e.g. in inches or in cm. The
properties of the class E54 Dimension allow for expressing the numerical
approximation of the values of an instance of E54 Dimension. If the true
values belong to a non-discrete space, such as spatial distances, it is
recommended to record them as approximations by intervals or regions of
indeterminacy enclosing the assumed true values. For instance, a length
of 5 cm may be recorded as 4.5-5.5 cm, according to the precision of the
respective observation. Note, that interoperability of values described
in different units depends critically on the representation as value
regions.
Numerical approximations in archaic instances of E58 Measurement Unit
used in historical records should be preserved. Equivalents
corresponding to current knowledge should be recorded as additional
instances of E54 Dimension as appropriate.
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Research Director | Fax:+30(2810)391638 |
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Information Systems Laboratory |
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