Ontology Formalism Transformation

Petr AUBRECHT & Monika ŽÁKOVÁ

CTU in Prague

Department of Cybernetics

{aubrech,zakovm1}@labe.felk.cvut.cz

CIPHER Project

ApolloCH

ontology editor

development of ontologies/annotations

RAT-O

annotation & outline editor

use of ontologies

DNAT – conceptual graph editor

use of ontologies

Story Fountain – story repository

use of ontologies

SumatraTT – data processing system

processing and visualisation of ontologies

Ontology Sharing

ontology = shared knowledge

many ready ontologies (e.g. daml.org)

upper ontologies (SUMO, IEEE standard)

cultural heritage ontologies (CRM)

others

Where is the problem?

Multiple Formalisms

There exists multiple formalisms appropriate for different purposes.

frame-based, usually based on Lisp

Ontolingua, OCML (ApolloCH)

description logic, web-oriented

RDF, RDFS, DAML+OIL, OWL

others

Transformations are currently done by simple I/O modules for editors.

Transf. Problems Example

RDFS (DAML, OWL, description logic)

->

OCML (frames)

sub-property – hierarchy of properties

instance of instance – there can be instance of another instance

restrictions used to specify default property values – structural part is expressed in procedural form

Generalised Ontology Formalism

only one type of objects: concept

six arrows:

instanceOf (-o)

decrease of abstractness of the concept. It corresponds to the is-a relation in frames

subclassOf (->)

specialisation relation between a more general and a more specific concepts

has-domain (-<|)

“domain of a property,” this property is a property of the target class or its subclass

has-range (-[])

“range of a property”

propertyOf (-<)

“an assignment of a value to an instance of a property domain”

has-value (->)

“a particular value of a property”

GOF (2)

sample

model of a frame-based formalism

Gates

GOF

OWL

Apollo

SQL

Prolog

Bookmarks

Filesystem

...

Java

Gate ontology

Uninformed Transformation

GOF

OWL

Apollo

<owl:Ontology>

<owl:Class>

<SubclassOf>...

</owl:Class>

<owl:ObjectProperty>

SQL

<KnowledgeBase>

<class>

<subclasses>...

<slots>

<slot...

</slots>

<class>

mapping to g.o.

Informed Transformation

GOF

OWL

Apollo

<owl:Ontology>

<owl:Class>

<SubclassOf>...

</owl:Class>

<owl:ObjectProperty>

<KnowledgeBase>

<class>

<subclasses>...

<slots>

<slot...

</slots>

<class>

Known Translation

+ covers wide range of possible situations (not restricted to currently known formalisms)

+ allows to change types – class, property, instance

+ un/informed transformation

– mapping (rule based) to gate ontology (uninformed tr.) is NP, although very fast

Pros and Cons

SumatraTT

SumatraTT is a general tranformation framework (presented last year) with graphical interface

gates are implemented as STT modules

automatic code generator from GOF gates to STT modules

uninformed transformation is done by simple connection between gates

informed transformation is a specialised module

SumatraTT Screenshot

Visualisation

necessary for ontology investigation

required interactivity

search

1D – a list of terms, indented

user cannot find a concept

2D – more space to get overview

common on computers

3D – the most natural for humans

difficult motion within the space (inappropriate hardware)

Visualisation 1D

Visualisation 2D

Visualisation 3D

Visualisation – GraphViz

Visualisation – HyperGraph

Visualisation (3)

Further Work

finish mapping engine from set of rules valid for a gate

transformation from diff to gate ontology (in gate terms)

visualisation

Questions?

2004-08-29T10:39:05