06.12.04 updated 27.12.06 CmpE 583 Fall 2008 Ontology Integration- 1

CmpE 583- Web Semantics: Theory and Practice

ONTOLOGY INTEGRATION

Atilla ELÇİ

Computer Engineering Department

Eastern Mediterranean University

06.12.04Rev. 16 Dec 2008 CmpE 583 Fall 2008 Ontology Integration- 2

Introduction

SW data come associated with its ontology Combining data from different sources requires

integration of their corresponding ontologies Integration of ontologies necessitates finding out

terms that are “same”, “like”, and “different” in the ontologies to be integrated.

Formation of the resultant ontology using a graphical, OWL, and other languages is required.

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Agenda

Taxonomy Ontology Integrating ontologies.

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Overview of Taxonomies [Smith et

al]

The study of the general principles of scientific classification: SYSTEMATICS OF CLASSIFICATION; especially: orderly classification of plants and animals according to their presumed natural relationships [Merriam-Webster OnLine: http://www.m-w.com/]

For a detailed account: submit “taxonomy” at MW Rosetta Edition at A. Elçi’s home page.

“The classification of information entities in the form of a hierarchy, according to the presumed relationships of the real-world entities that they represent”

Class structure: A simple taxonomy: Ref. Figure 7.1

Generalization vs. specialization: Ref. Figure 7.2 Tabular vs. tree forms: Ref. Table 7.1 and Figure 7.4.

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Use of Taxonomies

Examples: Table 7.2: The Dewey Decimal System: A

Taxonomy Table 7.3: The Dewey Decimal System: 500

Natural Sciences and Mathematics.

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Ontology Spectrum

The following concepts all attempt to address issues in representing, classifying, and disambiguating semantic content (meaning): taxonomies, thesauri, conceptual models, and logical theories.

Figure 7.5: The ontology spectrum: Weak to strong semantics.

Taxonomy: part-of, subclass-of relationship Thesaurus: equivalence, homographic, hierarchical,

and associative relationships (Table 7.4). Logical theory: A set of axioms, inference rules, and

theorems. In a logical theory, one can express the semantics of a model to the highest degree possible.

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Ontology Spectrum (continued)

Ontology: “An ontology defines the common words and concepts (meanings) used to describe and represent an area of knowledge, and so standardizes the meanings”.

An ontology includes the following: Classes (general things) in the many domains of interest Instances (particular things) Relationships among those things Properties (and property values) of those things Functions of and processes involving those things Constraints on and rules involving those things.

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Ontology Integration (in passing)

Data/Ontology Integration Systems [Baojie-a]: Mostly DB integration cases.

Bibliography on Ontology integration [Baojie-b].

Appears more like a wizardry at this time.

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Ontology Integration: Methods Probabilistic ontology mapping with explicit info:

Sushama Prasad et al., "A Tool For Mapping Between Two Ontologies Using Explicit Information", InProceedings, AAMAS 2002 Workshop on Ontologies and Agent Systems, July 2002.

Context brokerage: Harry Chen et al., "Semantic Web in in the Context Broker Architecture",

InProceedings, Proceedings of PerCom 2004, March 2004. Smart environment:

Harry Chen et al., "Intelligent Agents Meet the Semantic Web in Smart Spaces", Article, IEEE Internet Computing, November 2004.

Ontology ranking: Li Ding et al., "Swoogle: A Search and Metadata Engine for the Semantic Web"

, InProceedings, Proceedings of the Thirteenth ACM Conference on Information and Knowledge Management , November 2004.

Graphical methods: tba.

Summary of Combining and Relating Ontologies: Article by M. Klein [Klein].

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Where to Get More Information? [Smith et al] Chapter 7 - Undstanding Taxonomies. In

The Semantic Web: A Guide to the Future of XML, Web Services, and Knowledge Management, 1st edition, by Kevin T. Smith, Michael C. Daconta, Leo J. Obrst. John Wiley & Sons, 2003. ISBN:0471432571. Available as e-book at ACM Professional Development Center.

[Baojie-a] Data/Ontology Integration Systems [Baojie-b] Bibliography on Ontology integration [Klein] M. Klein, “Combining and Relating Ontologies: an

Analysis of Problems and Solutions”, In Proc. The 17th Int’l Joint Conf. On Artificial Intelligence (IJCAI-01), Workshop on Ontologies and Information Sharing, Vol. 47, pp:53-62, Seattle, WA, USA, August 2001.