Semantic Web BY: Josh Rachner and Julio Pena
What is the Semantic Web? • The semantic web is a part of the world wide web that allows data to be better represented by its actual meaning and content and provides access to collections of information that are in machine-readable formats “Most of the Web's content today is designed for humans to read, not for computer programs to manipulate meaningfully. ” Berners-Lee, T, Hendler, J & Lassila, O ‘The semantic web’, Scientific American, May 2001
Why use Semantic Web? Make data machine-readable Describe and infer about content Provide ways to share and link data Supply better search results
Evolution of the Web
Current Classifying Methods Meta tags XHTML/XML tags Actual Web content What's the problem here?
Example <item>Club</item> VS <item rdf: about="http: //dbpedia. org/page/Club">Club</item>
Link to Club Object
Critics of Semantic Web Better for specialized organizations and internal within companies It's an idea that people have not come to terms with Privacy and censorship of data Redundancy of information
Components of Semantic Web e. Xtensible Markup Language (XML) – Resource Description Framework (RDF) – Uses N-triples (e. g. enzyme IS a protein) Ontologies – <item>Enzyme</item> Hierarchies of concepts Rules for inference – If A = B, and B = C, then A = C
Using OWL to Model Biological Knowledge Robert Stevens, Mikel Aranguen, Katy Wolstencroft, Ulrike Sattler, Nick Drummond, Matthew Horridge, Alan Rector
Web Ontology Language (OWL) • OWL is a representative language; its main use is to make it easier for web content to be read by machines rather than just humans • There are three sublanguages of OWL: – OWL Lite – classification hierarchy w/ simple constraints – OWL DL – more expressive but is also limited – OWL Full – allows maximum expressiveness
Phosphatase Ontology Defined in terms of p-domain composition Tyrosine phosphatase → Protein phosphatase → Phosphatase Example: 1 immunoglobin p-domain 2 protein tyrosine phospatase p-domains
Why OWL Description Logic Description of classes and subclasses Restriction to unary predicates and binary predicates - contains Distinction between relationships of classes Full boolean operators Open world
Overview • Semantic web is a possible solution for relating data and finding more meaning to information • It is a new concept but could really change the world wide web and how information is shared • Many organizations and companies currently use semantic web for research and commercial purposes
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