Delivery Context Ontology

1.1.1 Disjoint Classes

The ontology contains a large number of disjoint classes. OWL-DL requires explicit definition of each disjoint relationship between classes. The number of such definitions becomes unmanageably large in ontololgies with a large number of classes.

Fortunately, there is an alternative mechanism for ensuring that classes are considered disjoint, without requiring the use of explicit statements. The mechanism relies on each class including a property that has a unique value. In this ontology, the property used is called deliveryContextEntityName. Each class derived from DeliveryContextEntity includes this property. Each class has a unique value for this property. The mechanism is referenced in the OWL Guide[OWL] in the discussion on disjoint classes. An illustration of the technique appears in [OWL-Test] in the section on Positive Entailment Test.

1.2.1 Conformance Information

1.3.1 Reading the Property Tables

Each class in the ontology is associated with a set of properties. These properties are defined in tables in the appropriate section of the specification. Each row in a table defines a single property in terms of a number of fields. The fields used in these tables are described as follows:

Name

This field contains the formal name of the property within the class.

Type

This field contains the type of the property. Datatype properties have types that are not themselves classes. Examples include xsd:int, xsd:boolean, xsd:string and xsd:float. Object properties have types that are classes. Usually these classes are themselves defined in the ontology.

Description

This field contains a description of the property.

Restriction(s)

This field contains restrictions about the property, including:

• Cardinality of the property. The number of occurences of the property within the class is shown as an expression. If there is no expression it means that the property can have any number of instances, including 0. For example, the expression ≥ 0 and ≤ 1 indicates that a property is optional and if defined can only occur one time i.e. can only have one value. It's cardinality is 0 or 1. Similarly, the expression =1 indicates that a property always occurs exactly once.

• Values that apply across every instance of a class. Some property values are fixed for every instance of a class. Where this is the case, the value is prefixed by the phrase Class Value(s):. For example, every instance of the class Meters, which represents a physical length in meters, has a unitName property with the value "meter". Some properties can hold values from a specific, predefined set. Where this is the case is prefixed by the phrase Values of:. For example, the Orientation class, which represents the orientation of features such as displays or cameras, has an orientationValue property which can take only the values 0, 90, 180 or 270.

• If the property is functional i.e. its cardinality can only be zero or one (≥ 0 and ≤ 1). In other words if a functional property has more than one value an OWL reasoner will treat those values as the same instance. Where this is the case, the value is prefixed by the phrase Functional

Subproperty(ies)

This field defines the subproperties of a property.

1.3.2 Reading the Example Tables

Examples are given for specific classes in the specification. The associated tables contain one or more example classes, complete with values for each of their properties. The fields used in these tables are described as follows:

Example Instance

This field contains the identification of the instance that provides the example.

Property Name

This field contains the formal name of the property whose value is shown as part of the example.

Type

This field contains the type of the property in the example. Datatype properties have types that are not themselves classes. Examples include xsd:int, xsd:boolean, xsd:string and xsd:float. Object properties have types that are classes. Usually these classes are themselves defined in the ontology.

Value(s)

This field contains the value(s) of the property. Where a property has a cardinality of >1, multiple values may be shown in the example.

3.1.1 Geographical Coordinate Reference System

This class represents a geographical coordinate system

3.1.2 Geographical Coordinates

This class represents geographical coordinates that allow to locate precisely a point on the Earth surface

3.1.3 Location

This class represents all the location information about something

3.1.4 Location Method

It represents an specific mechanism used to calculate the location of a thing

3.1.5 Location Provider

Represents an entity capable of providing location information

3.1.6 Location Provider Feature

This class represents location provider features

3.1.7 Location Provider Support

This class represents location provider support

3.1.8 Place

This class represents all the information about the current location associated with the current Delivery Context

3.1.9 Point

This class represents a point on the Earth surface

3.2.1 Bearer Type

This class represents bearer types

3.2.2 Mobile Network

A mobile network that supports several network bearers

3.2.3 Network Bearer

This class represents a network bearer in a delivery context.

3.2.4 Network Environment

This class represents the network environment present in a delivery context

3.2.5 Newtwork Mode

A mode of operation of a network which includes a network type and operation frequency bands

3.2.6 Network Support

This class represents the network in a delivery context

3.2.7 Network Type

This class represents different network types

4.10.1 Pointing Input Type

This class represents the means available on a device for pointing input.

4.10.2 Tactile Input Type

This class represents the means available on a device for tactile input.