Common Logical Data Model: Basis for Global ITS Innovation
Figure 6: ODM Representation of Vehicle Location
with the peculiarities of human language.
While the BSM uses the term “elevation,”
the CAM uses the term “altitude.” Both
terms are intended to mean the same thing.
As a result, Figure 6 indicates that, within the
context of CAM, the “altitude” class is
equivalent to the “elevation” class. This
ensures that any automated process can
equate the two terms properly. This same
sort of mechanism can be used to identify
equivalent terms in different languages.
The left side of this diagram indicates that
the “vehicle” class (term) is a “subclass of” (a
type of) the “object” class and therefore
inherits (can exhibit) all of the properties
associated with the “object” class.
For the purpose of this discussion, there is
one property of interest: “hasPosition.” The
diagram indicates that the “hasPosition”
property is represented by the “location”
class and that an object only has one position.
One type of “location” is a “geolocation” (i.e.,
a point near the Earth’s surface) which has
three
properties:
“hasLatitude,”
“hasLongitude” and “hasElevation” (with
one instance of each).
Finally, the diagram also shows that the
“hasElevation”
association
has
an
association class by the same name. In fact,
every association is associated with this type
of class; the others are not shown to keep
the diagram simple.
Up to this point, the notation is very similar
to a traditional UML class diagram. However,
ODM also defines some useful stereotypes
for dealing with ontologies that have to deal
By defining these association classes, the
ontology can also create relationships
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