Using DAML+OIL to Enrich RDF Schema for the Information Integration

10-Sep-0210-Sep-02 Page Page 11Gadjah Mada University - Yogyakarta - IndonesiaGadjah Mada University - Yogyakarta - Indonesia

Gadjah MadaUniversity

10-Sep-0210-Sep-02 Page 1Page 1Gadjah Mada University - Yogyakarta - IndonesiaGadjah Mada University - Yogyakarta - Indonesia

Using DAML+OIL to Enrich RDF Schema for the Information Integration

Ahmad AshariIIWAS 2002 Bandung - Indonesia

Sept 10th-12th 2002

Faculty of Mathematics and Natural Sciences


Gadjah MadaUniversityOutline

• Information Integration• Resource Description Framework (RDF)• DAML+OIL• RDF Schema vs DAML+OIL• Conclusion and Future work


Gadjah MadaUniversityInformation Integration

There are three type of information integration task:• Technical Integration already done with TCP/IP, HTTP, FTP, etc.• Syntactic Integration also already done with HTML• Semantic Integration Semantic Web in the future


Gadjah MadaUniversityIntegration Problem

Too much unintegrated data:– from a variety of incompatible sources– no standard naming convention– each with a custom browsing and querying mechanism (no common interface)– and poor interaction with other data sources


Gadjah MadaUniversityData Sources

• Flat Files• URLs• Proprietary Databases• Public Databases• Spreadsheets• Emails• Etc.





Gadjah MadaUniversityResource Description Framework

Resource Description Framework (RDF):• (Syntactical) basis of the “semantic web”• Similar to semi-structured data: graphs (RDF ~ OEM)• Three basic object types:

– resources: all things being described; named by URIs– properties: attributes to describe a resource– statements: subject + predicate + object;

are all resources (object can also be a literal)• Example:

– “the creator of this home page is Ahmad Ashari”• subject: http://www.ifs.tuwien.ac.at/~ashari/• predicate: http://www.purl.org/dc/.../creator• object: “Ahmad Ashari”


Gadjah MadaUniversity

• Representation– Model as graph:

– Serialized in XML syntax (“RDF/XML”):<?xml version="1.0"?><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#” xmlns:dc="http://www.purl.org/dc/elements/1.0/">

<rdf:Description about="http://www.ifs.tuwien.ac.at/~ashari/"><dc:creator>Ahmad Ashari</dc:creator>

</rdf:Description></rdf:RDF>

RDF Model and Syntax

http://www.ifs.tuwien.ac.at/~ashari/ Ahmad Asharidc:creator


Gadjah MadaUniversityRDF Schema

• RDF = simple data model• RDF Schema allows definition of vocabularies for RDF data• Simple frame system / ontology language:

– classes, subclasses, properties, sub-properties, domain, range• Extension of RDF in RDF


Gadjah MadaUniversityXML Name Space

XML Name Space (XMLNS) are use for abbreviated a Universal Resource Identifier (URI) for example:

– xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#“for rdf, which point to RDF Model and Syntax Specification URI

– xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#“for rdfs, which point to RDF Schema Specification URI





Gadjah MadaUniversityDAML

• DAML or DARPA Agent Markup Language is a language created by DARPA as an ontology and inference language based upon RDF

• DAML takes RDF Schema a step further, by giving us more in depth properties and classes

• DAML allows one to be even more expressive than with RDF Schema, and brings us back on track with our Semantic Web discussion by providing some simple terms for creating inferences


Gadjah MadaUniversityDAML Language

• 2001-03: DAML+OIL (March 2001) • 2000-12: DAML+OIL (December 2000) • 2000-10: DAML-ONT • 2000-08: DAML 0.5


Gadjah MadaUniversityDAML+OIL

• Bringing together DAML’s ontology language and OIL– OIL stand for Ontology Inference Layer or Ontology Interchange Language– Ontology is a formal, explicit specification of a shared conceptualization

• Keeps OIL’s mapping to Description Logic. – OIL support for Frame Based and Description Logic

• Use XML syntax and extension of RDF• Support for concrete types (from XML Schema)





Gadjah MadaUniversityRDF Schema vs DAML+OIL

Class definition for enumeration<daml:Class rdf:ID="Height">

<daml:oneOf rdf:parseType="daml:collection">

<Height rdf:ID="short"/>

<Height rdf:ID="medium"/>

<Height rdf:ID="tall"/>

</daml:oneOf>

</daml:Class>


Gadjah MadaUniversityClass definition for a property

<daml:Class rdf:ID="TallThing">

<daml:sameClassAs>

<daml:Restriction>

<daml:onProperty rdf:resource="#hasHeight"/>

<daml:hasValue rdf:resource="#tall"/>

</daml:Restriction>

</daml:sameClassAs>

</daml:Class>


Gadjah MadaUniversityDatatype Property

<daml:DatatypeProperty rdf:ID="age">

<rdf:type rdf:resource="&daml;#UniqueProperty"/>

<rdfs:range rdf:resource= "&xmlschema;#nonNegativeInteger"/>

</daml:DatatypeProperty>


Gadjah MadaUniversityObject Property

<daml:ObjectProperty rdf:ID="hasParent">

<rdfs:domain rdf:resource="#Animal"/>

<rdfs:range rdf:resource="#Animal"/>

</daml:ObjectProperty>

<daml:ObjectProperty rdf:ID="hasFather">

<rdfs:subPropertyOf rdf:resource="#hasParent"/>

<rdfs:range rdf:resource="#Male"/>



Gadjah MadaUniversityInstances

<continent rdf:ID="Asia"/>

<rdf:Description rdf:ID="Asia">

<rdf:type>

<rdfs:Class rdf:about="#continent"/>

</rdf:type>

</rdf:Description>

<rdf:Description rdf:ID="India">

<is_part_of rdf:resource="#Asia"/>

</rdf:Description>


Gadjah MadaUniversityUnique Property

<daml:UniqueProperty rdf:ID="hasMother"> <rdfs:subPropertyOf rdf:resource="#hasParent"/>

<rdfs:range rdf:resource="#Female"/>

</daml:UniqueProperty>

Cardinality=1


Gadjah MadaUniversityInverse and Transitivity

<daml:ObjectProperty rdf:ID="hasChild">

<daml:inverseOf rdf:resource="#hasParent"/>


<daml:TransitiveProperty rdf:ID="hasAncestor"/>

<daml:TransitiveProperty rdf:ID="descendant"/>


Gadjah MadaUniversityBroadening Classes

<daml:Class rdf:ID="Male"> <rdfs:subClassOf rdf:resource="#Animal"/></daml:Class>

<daml:Class rdf:ID="Female"> <rdfs:subClassOf rdf:resource="#Animal"/> <daml:disjointWith rdf:resource="#Male"/></daml:Class>

<daml:Class rdf:ID="Woman"> <rdfs:subClassOf rdf:resource="#Person"/> <rdfs:subClassOf rdf:resource="#Female"/></daml:Class>


Gadjah MadaUniversitySub-class

<daml:Class rdf:ID="Person">

<rdfs:subClassOf rdf:resource="#Animal"/>

<rdfs:subClassOf>

<daml:Restriction>

<daml:onProperty rdf:resource="#hasParent"/>

<daml:toClass rdf:resource="#Person"/>

</daml:Restriction>

</rdfs:subClassOf>

Person : (and Animal (all (restrict hasParent Person))


Gadjah MadaUniversitySub-class (2)

<rdfs:subClassOf>

<daml:Restriction daml:cardinality="1">

<daml:onProperty rdf:resource="#hasFather"/>

</daml:Restriction>

</rdfs:subClassOf>

<rdfs:subClassOf>

<daml:Restriction>

<daml:onProperty rdf:resource="#shoesize"/>

<daml:minCardinality>1</daml:minCardinality>

</daml:Restriction>

</rdfs:subClassOf> (atmost 1 father) (atleast 1 shoesize))


Gadjah MadaUniversitySub-clas (3)

<daml:Class rdf:about="#Person">

<rdfs:subClassOf>

<daml:Restriction daml:maxCardinalityQ="1">

<daml:onProperty rdf:resource="#hasOccupation"/>

<daml:hasClassQ rdf:resource="#FullTimeOccupation"/>

</daml:Restriction>

</rdfs:subClassOf>

</daml:Class>


Gadjah MadaUniversityComplement Class

<daml:Class rdf:ID="Car">

<rdfs:subClassOf>

<daml:Class>

<daml:complementOf rdf:resource="#Person"/>

</daml:Class>

</rdfs:subClassOf>

</daml:Class>


Gadjah MadaUniversityDisjoint Class

<daml:Class rdf:about="#Person">

<daml:disjointUnionOf rdf:parseType="daml:collection">

<daml:Class rdf:about="#Man"/>

<daml:Class rdf:about="#Woman"/>

</daml:disjointUnionOf>

</daml:Class>


Gadjah MadaUniversityEquivalent Class

<daml:Class rdf:ID="HumanBeing">

<daml:sameClassAs rdf:resource="#Person"/>

</daml:Class>


Gadjah MadaUniversityIntersection Class

<daml:Class rdf:ID="TallMan">

<daml:intersectionOf rdf:parseType="daml:collection">

<daml:Class rdf:about="#TallThing"/>

<daml:Class rdf:about="#Man"/>

</daml:intersectionOf>

</daml:Class>


Gadjah MadaUniversityComparison Summary

Feature RDFS DAML+OIL

Syntax XML RDF

Basic Datatypes only one use XSDL type

Enumeration of Property Values No Yes

Bounded Lists No Yes

Transitive Properties No Yes

Negation No Yes

Disjunctive / Disjoint No Yes

Intersection No Yes


Gadjah MadaUniversityInference vs Information Integration

• The principle of “inference” is being able to derive new data from data that we already know

• Querying is a form of inference (being able to infer some search results from a mass of data, for example)

• Inference is one of the driving principles of Information Integration


Gadjah MadaUniversityRDF Schema Model

rdf := 'http://www.w3.org/...rdf-syntax-ns#'.rdfs := 'http://www.w3.org/.../PR-rdf-schema-...#'.type := rdf:type.subPropertyOf := rdfs:subPropertyOf.subClassOf := rdfs:subClassOf.FORALL Mdl @rdfschema(Mdl) {

transitive(subPropertyOf).transitive(subClassOf).FORALL O,P,V O[P->V] <- O[P->V]@Mdl.FORALL O,P,V O[P->V] <- EXISTS S (S[subPropertyOf->P] AND O[S->V]).FORALL O,P,V O[P->V] <- transitive(P) AND EXISTS W (O[P->W] AND W[P->V]).FORALL O,T O[type->T] <- EXISTS S (S[subClassOf->T] AND O[type->S]).

}


Gadjah MadaUniversityDAML+OIL

daml := 'http://www.daml.org/.../daml+oil#'.animals := 'http://www.example.org/animals#'.@animals:ontology {

animals:Animal[rdf:type -> daml:Class].animals:Herbivore[rdf:type -> daml:Class; rdfs:subClassOf -> animals:Animal].animals:Carnivore[rdf:type -> daml:Class; rdfs:subClassOf -> animals:Animal;

daml:disjointWith -> animals:Herbivore].animals:Omnivore[rdf:type -> daml:Class; rdfs:subClassOf -> animals:Herbivore;

rdfs:subClassOf -> animals:Carnivore].}FORALL Ont @check(Ont) {

FORALL C unsatisfiable(C) <-C[daml:subClassOf -> daml:Nothing]@daml_oil(Ont).

}


Gadjah MadaUniversityConclusion and Future Work

• DAML+OIL system can enrich RDF and RDFS, which is with this ontology based language we can eliminate the limitation of RDF Schema in describing the meaning of each information sources.

• In the previous work we already used RDF and RDF Schema for the Information Integration in tourism domain. DAML+OIL introduces many constructs and richer than RDF and RDFS, therefore in the future our works will use DAML+OIL for the Information Integration in the same or other domain.

Documents

Using DAML+OIL to Enrich RDF Schema for the Information Integration