web semantics 1

8/3/2019 Web Semantics 1

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WEB SEMANTICHOW TO IMPROVE THE WEB TODAY


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SEMANTICS?


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Semantics vs Syntax


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Internet

hey Yo!


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Web

Icancheeseburger.com


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The problem?


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The problemInternet is meant to talk to each otherbut They dont reallyunderstand

what they mean

Who is a pretty

boy

Bank robber

floyd is a pretty

boymale parrot

Poly want a

crackerI wanna be a

sailor[1937]


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Scenario Buying A Car

UserYou live in London and want to buy a car locally. You can afford upto 500. The car must bered.

Honest EuroJoes Used Car Web Site

Joeuses:

Brixton

400

maroon

Old banger

Ford Escort

Result

Car not found even though structured information is provided.

A human would know that this was a valid match, because it

understands the meanings and relationships.

The Semantic Web aims to solve this problem.


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Web Of things


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RDF

Resource description framework.

Represents any conceptsrelationship

between things.

Its an index ofresources and ability to

glue them together.


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RDF and triples

Format knowledge into

subject,predicate and object.

Subject:things that ur describing

Predicate:Attributes of the things

that ur describing.

Object:things that ur referring to

with the predicate.


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Knowledge Network represented

in thisRDF

s. A RDF tripple can formed from anysemanticallly meaningfulstatement.here aresomeeg.

Depending on the format choosen rdf can live inside an xml or

xhtml file.


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Semantics Apps

Freebase

PowerSet

Twine Hakia

Talis

True

knowledge

Adaptiveblue


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Technologies that make up the Semantic Web

To represent theSemantic Web, you'll use thefollowing technologies:

A global namingscheme (URIs)

A standard syntax for describing data (RDF)

A standard means of describing the properties ofthat data (RDFSchema)

A standard means of describingrelationshipsbetween data items (ontologies defined with theOWL Web Ontology Language)


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Challenges

Vastness: The World Wide Web contains at least 24

billion pages as of this writing (June13, 2010).

Vagueness: These are imprecise concepts like

"young" or "tall".

Uncertainty: These are precise concepts with

uncertain values.Forexample, a patient might

present a set ofsymptoms which correspond to a

number of different distinct diagnoseseach with a

different .

Deceit: This is when the producer of the information

is intentionally misleading the consumer of the

information


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Questions?


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web semantics 1

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