Semantic Annotation for Process Models: - Department of Computer ...

20 CHAPTER 2. PROBLEM SETTING
2.3.2 RML and OWL
Two modeling languages – RML and OWL – related to ontology modeling in this
thesis, are introduced in this sub-section. RML (Referent Model Language) [168] [169]
is a concept modeling language representing structural perspective [76]. OWL (Web
Ontology Language) is a language for defining and instantiating Web ontologies for
creating Semantic Web applications [195].
RML
RML is concentrated on describing the static structure of a model. It is targeted towards
applications in areas of information management and heterogeneous organization
of data. The formal basis of RML is the set theory. The phenomena in RML are modeled
as collections (set) or atoms (an individual phenomenon). A set is represented
by a list of elements, or by stating property that all elements must have to qualify
as a member of the set. Four different types of concepts – individual concepts, class
concepts, relation concepts and quantitive concepts, are identified in RML. From the
four types, the modeling constructs of RML are derived: class concepts, individual
concepts, attributes, binary relationships, cardinality of a relationship, hierarchical abstraction
of classification (instance of), aggregation(part of), generalization (is-a), and
association (member of). Refined semantics can also be specified in RML: generalization
is specified into disjoint generalization (e.g. A person is either a man or a woman.)
and overlapping generalization (e.g. A person may both be an artist and an athlete.);
relation concepts are distinguished into individual relation concepts, class relation concepts,
order concepts and operation concepts; binary relation concepts are depicted as
many-to-many, many-to-one or one-to-one mappings; "any" (∀) and "some" (∃) value
restrictions are specified as the coverage of a relation concept; properties can be elaborated
into reflexivity, symmetry, transitivity and connexity. Part of notations of RML
are displayed in Figure 2.3. Detailed specifications of RML are provided in [169].
Figure 2.3: Graphical Notations of RML (limited to the constructs used in this thesis)