Download Semantic Web And Its Applications

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

eXtensible 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