Extending UML to Support Ontology Engineering Kenneth Baclawski and Mieczylaw K. Kokar Northeastern University Paul A. Kogut, William S. Holmes III and Michael L. Aronson Lockheed Martin Management and Data Systems Lewis Hart -- GRC International Jeffrey Smith -- Mercury Computer Jerzy Letkowski -- Western New England College
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Extending UML to Support Ontology Engineering Kenneth Baclawski and Mieczylaw K. Kokar Northeastern University Paul A. Kogut, William S. Holmes III and.
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Extending UML to Support Ontology Engineering
Kenneth Baclawski and Mieczylaw K. Kokar
Northeastern University
Paul A. Kogut, William S. Holmes III
and Michael L. Aronson
Lockheed Martin Management and Data Systems
Lewis Hart -- GRC International
Jeffrey Smith -- Mercury Computer
Jerzy Letkowski -- Western New England College
Knowledge Representation (KR)
Data representation language for knowledge-based systems
Usually based on logic or networks (directed graphs)
Usually do not rigidly separate meta levelsEnables reasoning and semantic
interoperability of agents at run-timeAssumes an open rather than closed world.
Example of a KR
PersonCompanyVehicle
BerizonRover
GeorgeFord 243
Toyota 853type
type typetype
type
isOwnedowns
Dog
Ontology
Formal, declarative semantic modelData (instances) conforming to an ontology
are called annotations.An ontology may include:
Vocabulary terms Taxonomies Relations Constraints, rules and assertions
Example Ontology
Class ObjectProperty
DogCompany
Vehicle
Restriction
isOwned
OwnedByAtMostOne
1
type
typetype
type
type
maxCardinality
onPropertysubClassOf
Berizon
type
Ford 243
Toyota 853
type
type subClassOf
Persontype
UML as an ontology language
UML class diagrams can define ontologies.Constraints such as cardinality constraints can
be mapped to UML constructs or to OCL.Statecharts and Activity Diagrams are useful
for service and process related ontologies.See “UML for Ontology Development” to appear in
Knowledge Engineering Review
Example Ontology in UML
Company Vehicle
0..1
owns
0..1
Person Dog
0..1
owns
0..1
Advantages of UML for ontology
Leverages UML tools and experience in ontology development.
Provides profiles, packages and other modularity mechanisms currently lacking in knowledge-based systems.
Supports an established mechanism for specifying the behavior associated with knowledge representations.
Limitations of UML
Does not (yet) have a formal semantics.Not Web enabled.Does not support properties (associations)
as first-class model elements.
RDF and DAML
The Resource Description Framework (RDF) and DARPA Agent Markup Language (DAML) have been proposed as the basis for the “Semantic Web.”
DAML supports semantic interoperability between Web pages, databases, programs and sensors by autonomous agents at run-time.