Building Trustworthy Semantic Webs Lecture 11 Ontology Engineering Dr Bhavani Thuraisingham September 25 2006 01 15 19 04 25 11 2 Objective of the Unit 0 This unit will provide an overview of the software engineering aspects of ontologies The field is called Ontology Engineering 01 15 19 04 25 11 3 Outline of the Unit 0 Summary of semantic web technologies discussed so far 0 Applications discussed so far 0 Ontology Engineering 0 Directions 01 15 19 04 25 11 4 Semantic web technologies discussed so far 0 XML XML Schema 0 RDF RDF Schema 0 Ontology OWL 0 Logic Rules Inference 0 Some discussion of security issues for each technology Policy specification Securing documents 01 15 19 04 25 11 5 Types of Application 0 Horizontal Information Products at Elsevier Integration 0 Data integration at Audi Integration 0 Skill finding at Swiss Life Search 0 Think Tank Portal at EnterSearch Knowledge man agent 0 E Learning Knowledge management 0 Web Services Web services for any of the other applications discussed 0 Multimedia Collection at Scotland Yard Searching 0 Online Procurement at Daimler Chrysler E Business 0 Device Interoperability at Nokia Interoperability 01 15 19 04 25 11 6 Revisiting Ontology 0 Common definitions for any entity person or thing 0 Several ontologies have been defined and available for use 0 Defining common ontology for an entity is a challenge 0 Mappings have to be developed for multiple ontologies 0 Specific languages have been developed for ontologies RDF OWL DAML OIL etc 01 15 19 04 25 11 7 What is Ontology Engineering 0 Tools and Techniques to Create Ontologies Specify Ontologies Maintain Ontologies Query Ontologies Evolve Ontologies Reuse Ontologies Incorporate features such as security data quality integrity 01 15 19 04 25 11 8 Manual Constructiob of Ontologues 0 Determine Scope 0 Consider Reuse 0 Enumerate Terms 0 Define Taxonomy 0 Define Properties 0 Define facets 0 Define Instances 0 Check for Anomalies 01 15 19 04 25 11 9 Reuseing Exitsing Ontologies 0 The goal is not to reinvent the wheel 0 Several ontologies have been developed for different domains 0 Codieid Bodies of Expert Knowledge 0 Integrated Vocabularies 0 Upper Level Ontologies 0 Topic Hierarchies 0 Linguistic Resources 0 Ontology Libraries 01 15 19 04 25 11 10 Semi Automatics Methods for Ontology Generation 0 Much of the research is focusing on developing ontologies 0 0 0 0 using tools from multiple heterogeneous data sources Essentially extracting concepts and expanding on concepts from the data sources Uses combination of data integration metadata extraction and machine learning techniques E g Clustering of concepts Classification of concepts etc Text Book describes Semantic Web Knowledge Management Architecture 01 15 19 04 25 11 11 What is Knowledge Management 0 Knowledge management or KM is the process through which organizations generate value from their intellectual property and knowledge based assets 0 KM involves the creation dissemination and utilization of knowledge 0 Ontologies are a form of Knowledge 0 Reference http www commerce database com knowledge management htm source google 01 15 19 04 25 11 12 Directions 0 Need tools for developing semantic web technologies XML documents RDF documents Ontologies etc 0 How to integrate the multiple ontologjes and tools 0 Role of Agents agents are processes that reasons with semantic web technologies 0 Semantic web services data mining knowledge management integrated
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