rdf (resource description framework). 2 table of contents introduction basic rdf –basic rdf...

RDF(Resource Description Framework)

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Table of Contents

Introduction Basic RDF

– Basic RDF Model– Basic Syntax

Containers Statements about Statements examples

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Introduction

Conception– Foundation for processing metadata.– Provides interoperability between Applications

that exchange machine-understandable information on the Web.

– A Model for representing RDF metadata.– A Syntax for encoding and Transporting this

metadata in a manner. ( using of XML Syntax)– Have a Class System much like OOP.

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Introduction

using– Resource discovery.– Digital library.– Intelligent software agents.– Privacy Policies.– Etc..

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Basic RDF Model No1

A Model for representing named properties and property values

A Syntax-neutral way of representing RDF expressions

Consists of Object types– Resource– Properties– Statements

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Basic RDF Model No2

Resources– ALL things being described by RDF expressions are cal

led resources

Properties– A Property is a specific aspect, characteristic, attribute o

r relation used to describe a resource

Statements– A specific resource together with a named property plus

the value of that property for that resource is an RDF statment

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Basic RDF Model No3

Subject(Resource) http://www.w3c.org/Home/Lassila

Predicate(Propery) Creator

Object(literal) “Ora Lassila”

sentence

Ora Lassila the creator of the resource http://www.w3c.org/Home/Lassila

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Basic RDF Model (Simple node and arc diagram)

http://www.w3c.org/Home/Lassila Ora LassilaCreator

The graph consists of two nodes connected by a single arc. One node (represented as an oval) contains the URI text http://www.w3.org/Home/Lassila and the other (represented as a rectangle) contains the text "Ora Lassila". The arc connecting these nodes bears the label Creator.

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Basic RDF Model (Property with structured Value)

http://www.w3c.org/Home/Lassila

Lassila@w3.org

Creator

Ora Lassila

Name Email

sentence

The individual whose name is Ora Lassila, email <lassila@w3.org>, is the creator of http://www.w3.org/Home/Lassila.

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Basic RDF Model (Structured value with identifier)

http://www.w3c.org/Home/Lassila

Lassila@w3.org

Creator

Ora Lassila

http://www.w3.org/staffId/85740

Name Email

sentence

The individual referred to by employee id 85740 is named Ora Lassila and has the email address lassila@w3.org. The resource http://www.w3.org/Home/Lassila was created by this individual.

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Basic RDF Syntax No1

RDF data model provides an abstract, conceptual framework for defining and using metadata

Concrete syntax is also needed for the purpose of creating and exchanging this metadata

Syntax descriptions in this document use the Extended Backus-Naur Form notation of [XML] to describe the essential RDF Syntax elements

Define two XML Syntax for encoding an RDF data model instance

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Basic RDF Syntax No2

Serialization Syntax Express– The RDF XML syntax has been designed to accomoda

te this easily by grouping multiple statements for the same resource into a Description element

Abbreviated Syntax Express– Describle to use a more compact XML form

– Three forms of abbreviation are defined for the basic serialization syntax

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Serialization Syntax Express

sentenceOra Lassila is the creator of the resourcehttp://www.w3c.org/Home/Lassila

<?XML version=“1.0 ?><rdf:RDF xmlns:rdf = “http://www.w3c.org/1999/02/22-rdf-syntax-ns#”xmlns:s = “http://description.org/schema/ “ >

<rdf:Description about=“http://www.w3c.org/Home/Lassila><s:Creator>Ora Lassila </s:Creator>

</rdf:Description></rdf:RDF>

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Abbreviated Syntax Express

The first is usable for properties that are not repeated within a Description and where the values of those properties are literals

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Abbreviated Syntax Express

<rdf:RDF> <rdf:Description about="http://www.w3.org">

<s:Publisher>World Wide Web Consortium</s:Publisher> <s:Title>W3C Home Page</s:Title>

<s:Date>1998-10-03T02:27</s:Date> </rdf:Description>

</rdf:RDF>

<rdf:RDF> <rdf:Description

about="http://www.w3.org" s:Publisher="World Wide Web Consortium" s:Title="W3C Home Page" s:Date="1998-10-03T02:27"/>

</rdf:RDF>

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Abbreviated Syntax Express

The second RDF abbreviation form works on nested Description elements

SentenceThe individual referred to by employee id 85740 is named Ora Lassila an

d has the email address lassila@w3.org. The resource http://www.w3.

org/Home/Lassila was created by this individual.

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Abbreviated Syntax Express

<rdf:RDF> <rdf:Description about="http://www.w3.org/Home/Lassila">

<s:Creator rdf:resource="http://www.w3.org/staffId/85740"/> </rdf:Description>

<rdf:Description about="http://www.w3.org/staffId/85740"> <v:Name>Ora Lassila</v:Name>

<v:Email>lassila@w3.org</v:Email> </rdf:Description>

</rdf:RDF>

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Abbreviated Syntax Express

<rdf:RDF> <rdf:Description about="http://www.w3.org/Home/Lassila"> <s:Creator>

<rdf:Description about="http://www.w3.org/staffId/85740"> <v:Name>Ora Lassila</v:Name>

<v:Email>lassila@w3.org</v:Email> </rdf:Description>

</s:Creator> </rdf:Description> </rdf:RDF>

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Abbreviated Syntax Express

<rdf:RDF> <rdf:Description about="http://www.w3.org/Home/Lassila">

<s:Creator rdf:resource="http://www.w3.org/staffId/85740" v:Name="Ora Lassila" v:Email="lassila@w3.org" />

</rdf:Description> </rdf:RDF>

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Abbreviated Syntax Express

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:s="http://description.org/schema/"> <rdf:Description about="http://www.w3.org/Home/Lassila"> <s:Creator>

<rdf:Description about="http://www.w3.org/staffId/85740"> <rdf:type resource="http://description.org/schema/Person"/>

<v:Name>Ora Lassila</v:Name> <v:Email>lassila@w3.org</v:Email> </rdf:Description>

</s:Creator> </rdf:Description> </rdf:RDF>

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Abbreviated Syntax Express

<rdf:RDF> <rdf:Description about="http://www.w3.org/Home/Lassila"> <s:Creator> <s:Person about="http://www.w3.org/staffId/85740">

<v:Name>Ora Lassila</v:Name> <v:Email>lassila@w3.org</v:Email>

</s:Person> </s:Creator> </rdf:Description> </rdf:RDF>

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Reference

W3C RDF– http://www.w3c.org/rdf– Resource Description Framework

(RDF) Model and Syntax Specification