Transcript Semantic Web And Its Applications

Semantic Web
BY: Josh Rachner and Julio Pena
What is the Semantic Web?
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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?
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Make data machine-readable
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Describe and infer about content
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Provide ways to share and link data
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Supply better search results
Evolution of the Web
Current Classifying Methods
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Meta tags
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XHTML/XML tags
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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
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
Better for specialized organizations and
internal within companies
It's an idea that people have not come to
terms with
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Privacy and censorship of data
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Redundancy of information
Components of Semantic Web
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eXtensible Markup Language (XML)
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Resource Description Framework (RDF)
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Uses N-triples (e.g. enzyme IS a protein)
Ontologies
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<item>Enzyme</item>
Hierarchies of concepts
Rules for inference
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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)
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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
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There are three sublanguages of OWL:
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OWL Lite – classification hierarchy w/ simple
constraints
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OWL DL – more expressive but is also limited
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OWL Full – allows maximum expressiveness
Phosphatase Ontology
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Defined in terms of p-domain composition
Tyrosine phosphatase → Protein phosphatase
→ Phosphatase
Example:
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1 immunoglobin p-domain
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2 protein tyrosine phospatase p-domains
Why OWL Description Logic
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Description of classes and subclasses
Restriction to unary predicates and binary
predicates - contains
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Distinction between relationships of classes
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Full boolean operators
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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