|Submitted by:||MariaPoveda, MariCarmenDeFigueroa|
|Also Known As:|
|Intent:|| The goal of this pattern is to represent objects that can be simple or aggregated (that is, several objects gathered in another object acting as a whole).
The main difference between the aggregation relation and other mereological relationships (such as part-of or componency) is that the aggregated object and its aggregated members should belong to the same concept. For example, a turbine is part of an engine, whereas an aggregated provider is formed by providers.
|Solution description:|| The class "ObjectByCardinality" has been created to classify simple and aggregated objects into its subclasses "SimpleObject" and "AggregatedObject", respectively. These subclasses are disjoint among them.
The aggregation relationship between objects means that objects can be composed by other objects. This relationship is represented by the transtive property "hasAggregatedMember" and its inverse "isAggregatedMemberOf". These properties have as subproperties the non transitive properties "hasDirectAggregatedMember" and its inverse "isDirectAggregatedMemberOf", respectively. By means of this structure of properties, we provide a mechanism (a) to represent transitive aggregation relationships (that is, if A has B as aggregated member and B has C as aggregated member then A has C as aggregated member) and (b) to link each aggregated member just to the next level (that is, A has B as direct aggregated member).
Finally, the class "AggregatedObject" has been defined as equivalent to those things that have some values for the property "hasAggregatedMember". This modelling allows the automatic classification of aggregated objects in this class when a reasoner is applied.
|Reusable OWL Building Block:||http://delicias.dia.fi.upm.es/ontologies/SimpleOrAggregated.owl (96)|
|Consequences:|| This Content OP allows designers to represent both simple individuals of a given concept (that is, an individual that is made up of itself) and aggregated individuals of a given concept (that is, an individual that is made up of several individuals of the same concept).
In summary, this pattern allows to represent both simple objects and aggregated objects and their members. In addition, this pattern can be used to detect the following contradictory situation by means of applying a reasoner: 'to instantiate the relationship "hasAggregatedMember" for an Object that belongs to "SimpleObject"'. This situation represents a consistency error and it is detected when a resoner is applied due to the following modelling decisions included in the pattern: (a) "AggregatedObject" class represents the "hasAggregatedMember" domain and (b) "AggregatedObject" is disjoint with "SimpleObject".
|Scenarios:||A service provider can be simple or be an aggregate of a set of service providers. A context source can be simple or be an aggregate of a set of context sources. A computing or storage resource can be simple or be an aggregate of a set of computing or storage resources.|
|Examples (OWL files):|
The SimpleOrAggregated Content OP locally defines the following ontology elements:
Un objeto resultante de la agregaciÃ³n de dos o mÃ¡s objetos.
Cualquier objeto fÃsico, social o mental o sustancia.
Un objeto simple, es decir, un objeto que no tiene objetos agregados.
|Submission to event|