From: Hart, Lewis ([email protected])
Date: 01/24/01
The mapping which I have posted is primarily for UML to DAML. This mappings
is many to one, that is there are several UML situations which are mapped
into the single DAML Property. Typical of a many to one mapping, the inverse
mapping looses some information. For a given DAML property, it is not
apparent from the DAML alone what UML elements resulted in that property.
Clearly, the reverse mapping is free to pick any one of the UML
representations that are semantically equivalent. The I believe this
prevents the unbounded situation, though the UML representation will not be
identical.
Consider the "child" and "mother" roles of the "Parent" association found at
link [1], and shown crudely below. Starting from one UML binary association
with two roles:
child mother
[Person] -------- Parent> -------------[Woman]
it is mapped/transformed into three DAML properties(ignoring cardinality,
domain and range):
<Property id="child"/>
<Property id="mother">
<subPropertyOf resource = "Parent"/>
</Property>
<Property id="Parent"/>
The inverse transformation could result in three associations without roles
and a generalization between stereotyped classes:
[ ] -----------mother> ---------- [ ]
[person] ---------- Parent> ---------- [Woman]
[ ] --------- <child ------------ [ ]
[<<Property>>] [<<Property>>]
[ mother ] ---- generalization > ---- [ Parent ]
I do not see how this results in an unbounded situation, since both of these
UML representations result in identical DAML when transformed.
Furthermore, I think it is unreasonable for UML<->DAML transformations to be
totally reversible. That is, if UML1 is transformed into DAML1 and then back
to UML2, then UML1 will be not identical to UML2. What I believe should be
true is that if the transform is applied again to UML2 to produce DAML2,
then DAML1 and DAML2 should be identical. This defines semantic equivalence
for UML models with respect to DAML.
Regards - Lewis
[1]
http://grcinet.grci.com/maria/www/codipsite/UML/UML_Properties.htm#_example
-----Original Message-----
From: Ken Baclawski [mailto:[email protected]]
Sent: Tuesday, January 23, 2001 11:29 PM
To: Hart, Lewis
Cc: [email protected]
Subject: re: revised UML profile for DAML
Producing a consistent mapping is certainly a good idea.
However, the "minor changes" are not nearly as innocuous as they may seem.
As I pointed out in my last posting, mapping association ends into
separate properties would (in general) result in an unbounded
transformation (or more precisely, the transformation and the reverse
transformation would together be unbounded).
Even if one is willing to accept unboundedness, it is still questionable
whether association ends should be mapped individually to properties.
This results in a proliferation of properties that the designer probably
did not intend, and it would violate the following part of the statement
of purpose <ubot.lockheedmartin.com/ubot/details/uml_to_daml.html>:
"The assumption is that the UML class diagrams were created specifically
for the purpose of designing DAML ontologies. This mapping does not
attempt to map all elements on a class diagram to DAML."
-- Ken Baclawski
On Wed, 10 Jan 2001, Hart, Lewis wrote:
> Comments about UML mappings to DAML Properties
>
> The current mapping, discussed in detail on the Lockheed Martin UBOT site
> [Link 1], uses several features of UML (i.e. attributes, associations,
> stereotyped classes and dependencies) to represent DAML properties.
> However, these features are largely considered independently or as various
> optional approaches. I would like to propose a new mapping that
reconciles
> these various approaches into a consistent mapping of UML elements into
DAML
> properties. The new mapping largely just consolidates and restates the
> current mapping, however it does introduce some minor changes:
>
> - Associations and roles (association ends) would map into separate
> properties.
> - Dependencies would use name rather that stereotype to identify
> mapped properties.
>
> A full discussion of this new mapping can be found at [Link 2].
>
> - Lewis
>
> [1] http://ubot.lockheedmartin.com/ubot/details/uml_to_daml.html
> [2] http://grcinet.grci.com/maria/www/codipsite/UML/UML_Properties.htm
>
> ___________________________________________
> Lewis L Hart
> GRC International [email protected]
> 1900 Gallows Rd. Voice (703)506-5938
> Vienna, Va 22182 Fax (703)556-4261
>
>
>
>
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