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SWOG - Semantic Web Ontology Generator Masters Defense of Dackral Scott Phillips Committee Members: Juan E. Gilbert, Ph. D. T. Dean Hendrix, Ph. D. N. Hari Narayanan, Ph. D. Masters Defense of Dackral Scott Phillips Committee Members: Juan E. Gilbert, Ph. D. T. Dean Hendrix, Ph. D. N. Hari Narayanan, Ph. D. Slide 2 ABSTRACT The semantic Web offers many benefits for Web users, ranging from smarter search engines, to devices that can interact with each other. In order to provide the semantic Web with the artificial intelligence backbone it needs to facilitate the abovementioned tasks, as well as many other unmentioned abilities, ontologies, or computer-readable definitions of terms must be created. Because of this, this presentation describes SWOG (Semantic Web Ontology Generator), a software system that has been specifically designed to facilitate this task. It provides tools whereby authors can easily create ontologies by offering syntax help, shortcuts, and highlighting. Using SWOG, ontology authors will be able to gain an understanding behind the syntax used in the semantic Web, and semantic Web agents will be able to make inferences from the ontologies produced by the system. Slide 3 Discussion Outline 1) Brief History of the World Wide Web 2) Discussion of the Semantic Web 3) Semantic Web Languages 1) XML 2) Resource Description Framework (RDF) 3) RDF Schema (RDFS) 4) Darpa Agent Markup Language + Ontology Information Language (DAML+OIL) 5) Dublin Core Slide 4 Discussion Outline 4) Semantic Web Examples 5) SWOG Overview 1) SWOG Application Desktop 2) SWOG Ontology Editor 3) SWOG Help Browser 6) Demonstration 7) Future Work Slide 5 WWW History Started in 1990 by Tim Berners-Lee at the European Center for Nuclear Physics Research (CERN). Data transfer hard due to multiple protocols Berners-Lee created HTTP & HTML CERN releases protocols into public domain. [1] Slide 6 WWW History National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign (NCSA) creates Mosaic. Netscape & Microsoft Internet Explorer. May 1993 50 Websites [1] Today Google indexes 2,073,418,204 [2] Slide 7 Semantic Web Vision of Berners-Lee & World Wide Web Consortium (W3C) Extension of the current Web Metadata for machine processing Provides AI backbone Slide 8 Semantic Web Languages XML (eXtensible Markup Language) Basis language for web agent use RDF (Resource Description Framework) A model for metadata syntax Slide 9 Semantic Web Languages RDFS (RDF Schema) Ontology vocabulary definitions DAML+OIL (Darpa Agent Markup Language + Ontology Information Language) Formal semantics and reasoning primitives Slide 10 XML ADVANTAGES Allows for user developed markup e.g. Offers some ontology support through DTDs (Document Type Definitions) Parsers are already widely available [3] Slide 11 XML DISADVANTAGES Multiple DTDs abound and are generally not compatible with each other. While DTDs can act as dictionaries, defining terms, they cannot make inferences about other DTDs. Slide 12 RDF OVERVIEW Statements are comprised of 3 elements Resources as URLs Properties describing resources Statements composed of subject (resource) predicate (property) and object (value) [4] XML Definitions given in [5] Slide 13 RDF EXAMPLE STATEMENT http://www.auburn.edu/~phillds/ has Dack Phillips for an author. Dack Phillips Slide 14 RDF ADVANTAGE Provides a basic syntax for metadata on the web, since XML is not capable of this Slide 15 RDF DISADVANTAGE Does not allow for user defined syntax (e. g. hasAuthor technically does not exist under strict RDF) Slide 16 RDFS OVERVIEW Allows developers to define a vocabulary for ontologies Describes what object types RDF statements can reference [6] XML Definitions outlined in [7] Slide 17"> RDFS EXAMPLE STATEMENT hasAuthor definition Has Author Indicates the author of a particular resource. Slide 18 RDFS ADVANTAGES Allows Ontology authors to create custom defined classes and properties. Provides some semantic inferences to be made through primitives, e. g. subClassOf, subPropertyOf [6] Slide 19 RDFS DISADVANTAGE Does not give a wide range of inferences necessary for full knowledge description, e.g. no negation or equivalence [6] Slide 20 DAML+OIL OVERVIEW Provides the inference primitives that RDFS lacks, e. g. equivalence, and negation Adds mathematical and set based logic to ontologies XML Definitions given in [8] Slide 21 DAML+OIL EXAMPLES Animals have 2 parents, one female and one male. A graduate student must have a bachelors degree. Human and person are equivalent synonyms. Slide 22 Dublin Core Provides a way to give metadata about an ontology Series of primitives that gives information such as the title, date, language, publisher, and format about an ontology Not an actual Language Currently can be used in HTML 4.0 per RFC 2731 [9] Slide 23 Dublin Core XML Definitions of Dublin Core primitives can be found in [10] Slide 24 Semantic Web Languages Slide 25 Semantic Web Examples Keyword Searching: Jaguar Slide 26 Semantic Web Examples Smart Devices [11] Slide 27 Semantic Web Timeline Slide 28 SWOG Overview 3,714 LOC Written in Java Swing (JDK 1.3.1) Lightweight - Less than 500 KB Slide 29 SWOG Features Extensive Help System Text Editor Look and Feel Source Code Skeletons Syntax Highlighting Slide 30 SWOG Application Desktop Slide 31 SWOG Ontology Editor Slide 32 SWOG Help Browser Slide 33 SWOG Demonstration Slide 34 Future Work Add more editor features: Find/Replace, User Preferences, etc. Add Open from URL Functionality Add Automatic Indentation System Add access to SWOG from the Web Slide 35 References [1]J. Deep, and P. Holfelder, Developing CGI Applications with Perl. New York: Wiley Computer Publishing, 1996, pp.2-4. [2]Google. http://www.google.com. [3]Markup Languages and Ontologies. http://www.semanticweb.org/knowmarkup.html. [4]O. Lassila, and R. Swick, Resource Description Framework (RDF) Model and Syntax Specification, February 1999, http://www.w3.org/TR/REC-rdf-syntax/. Slide 36 References [5]RDF. http://www.w3.org/1999/02/ 22-rdf-syntax-ns#. [6]S. Decker, et. al., The Semantic Web: The Roles of XML and RDF, IEEE Internet Computing, p. 5, September-October 2000. [7]RDFS. http://www.w3.org/2001/01/rdf-schema#. [8]DAML+OIL. http://www.daml.org/2001/03/daml+oil#. Slide 37 References [9]J. Kunze, Encoding Dublic Core Metadata in HTML, December 1999, http://www.ietf.org/rfc/rfc2731.txt. [10]Dublin Core Element Set. http://dublincore.org/2001/08/14/dces#. Slide 38 Questions