Semantic Analytics and Ontologies - Data Governance: Creating Value from Information Assets - page 103

The chart in Figure 5.1 is created by focusing on three blank nodes of
_:hs1, _:p1, and _:d1, which denote “admission,” “admitted subject,” and
“person in-charge,” respectively. It is constructed with two RDF triples
from the relations of these three nodes: “datatype,” “admission,” and
“date of admission and discharge” of each of the three blank nodes, and
seven RDF triples formed by the names of “admitted subject,” “person in-
charge,” and so on. Furthermore, in this chart, there are uniquely defined
properties that have the “prefix” of two basic properties mentioned earlier:
“rdfs:type” and “ex” properties.
OWL (Web Ontology Language)
Although RDFS provides the basis for building ontology in an RDF
framework, in order to perform a series of operations (such as the deduc-
tion of ontology), an enhanced framework is required, such as that which
ensures the possibility of calculations related to such operations. For these
purposes, OWL is used as a framework for defining the constraint condi-
tions, such as a more specific method to construct classes and properties,
the number of units, or the comparability among classes and instances.
OWL can be divided into three languages—OWL Lite, OWL DL, and
OWL Full—in accordance with the computability of the classes and
properties structured by these frameworks. OWL DL consists of expres-
siveness; in other words, it has the same level of expressiveness as the
description logic SHOIN(D) with respect to the definability of classes
and properties. This implies that the compatibility of a series of man-
agements of classes and properties defined on the basis of OWL DL and
the limit of complexity are assured. * In contrast, even though OWL Full
consists of higher levels of expressiveness as compared to OWL DL, com-
patibility is not assured. On the other hand, OWL Lite is considered to be
simpler and more legible than OWL DL, and it consists of the same level
of expressiveness as the description logic SHIF(D) that has less complex-
ity than SHOIN(D).
The vocabulary of OWL is given by defining axioms based on the follow-
ing basic class descriptions: “owl:Class,” “owl:Thing,” and “owl:Nothing”
* Complexity here refers to the complexity in inferring inclusive relations among constructed classes.
In this topic, we will not discuss the deinition of Compatibility, Complexity, or Description Logic.
(Horrocks et al., 2003) and (Horrocks et al., 2007).