RDF- Crack (RDFa, triples,FOAF) ( part 2 )

July 1, 2008

RDF is a way of presenting knowledge, relationship or a thing in the format of triples. For everything in the web will be represented as a triples format. As we know about grammer we read it in our child hood, like every basic sentence is represented as format of triples. That means subject, predicate & objects.

FOAF:

FOAF is the vocabulary to represent RDF the objects & relationship between them. FOAF is a way of describing a person / company. FOAF is Friend of A friend using RDF to represent its data. It will describe a person in the following way.

nandakumar -> is -> http://www.desiji.com/ndotnanda

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:foaf="http://xmlns.com/foaf/0.1/">
 <foaf:Person>
   <foaf:name>Nandakumar</foaf:name>
   <foaf:mbox rdf:resource="http://www.desiji.com/ndotnanda"/>
 </foaf:Person>
</rdf:RDF>

N3 Notation & triples:
A syntax to represent RDF.
@prefix pref <http://www.example.org/vacobulary #>.
<#nandakumar><pref:working><#ndot>

RDFa:
RDFa is way to integrate RDF into XHTML pages. It reduces the lot of work & difficulties for
normal people those who want to represent their blog / personal data into semantic web. RDFa helps
them to represent their information to semantic web with XTHML. we can take an small example about
how we can represent a data with RDFa,

Here we are going to explain a FOAF integration into XHTML page.

Triples:
Nandakumar knows Preethi

RDFa:

<body xmlns:foaf="http://xmlns.com/foaf/0.1">
<span about="#Nandakumar" property="foaf:name">
Nandakumar Somasundaram
</span>
</body>
Triple : Nandakumar -> Name -> Nandakumar Somasundaram

RDFa : example 2
<body xmlns:foaf="http://xmlns.com/foaf/0.1">
<span about="#Nandakumar" property="foaf:name">
Nandakumar Somasundaram
</span>
<span about="#Preethi" property="foaf:name">
Preethi
</span>
<span about="#Nandakumar" rel="foaf:knows" resource="#Preethi">
Nandakumar is classmate of preethi
</span
</body>

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RDF – Crack ( part I )

June 29, 2008

Resource Description Framework – is the w3c standard, language to describe information in (semantic) web.Is it a new language / structure that we have to read? Absolutely not. It’s an XML /N3 format of representing the data.

RDF is about describing relationship between web resources ex. URLs. It will be represented as triples format.

Basic Structure:

http://www.desiji.com/ndotnanda has a profile whose value is Nandakumar Somasundaram

It is in triples format.

  • the subject is the URL http://www.desiji.com/ndotnanda
  • the predicate is the word “profile”
  • the object is the phrase “Nandakumar Somasundaram”

Normally RDF data is represented as triples Triples are a sequence of (subject, predicate, object) terms. N-Triples is a line-based, plain text format for encoding an RDF graph.

There are few ways to define RDF data.

  1. RDF/XML ( for machine reading ) rdf/xml
  2. RDF/Notation3(N3) ( for human reading ) MIME type : text/rdf+n3
  3. Turtle is a subset of N3 to represent the RDF data

RDF/XML representation: RDF defines a specific XML markup language, referred to as RDF/XML, for use in representing RDF information, and for exchanging it between machines.

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
         xmlns:dc="http://purl.org/dc/elements/1.1/">
  <rdf:Description rdf:about="http://www.w3.org/2001/08/rdf-test/">
    <dc:creator>Jan Grant</dc:creator>
    <dc:creator>Dave Beckett</dc:creator>
    <dc:publisher>
      <rdf:Description>
        <dc:title>World Wide Web Consortium</dc:title>
        <dc:source rdf:resource="http://www.w3.org/"/>
      </rdf:Description>
    </dc:publisher>
  </rdf:Description>
</rdf:RDF>

RDF example

N3 (Notation 3)

Notation 3 is a way of presenting semantic data in human understandable format. N3 representation of above RDF graph.

<http://www.example.org/index.html> <http://purl.org/dc/elements/1.1/creator> <http://www.example.org/staffid/85740> .

<http://www.example.org/index.html> <http://www.example.org/terms/creation-date> "August 16, 1999" .

<http://www.example.org/index.html> <http://purl.org/dc/elements/1.1/language> "en" .

N3 Subsets

N3 subsetsMore Information:

RDF Schema – http://www.w3.org/TR/rdf-schema/

RDF Syntax – http://www.w3.org/TR/REC-rdf-syntax/#basicconcepts

RDF – http://vanirsystems.com/danielsblog/2008/04/23/rdf-simpler-if-you-look-at-it-in-a-different-way/

http://infolab.stanford.edu/~melnik/rdf/syntax.html

http://www.w3.org/TR/rdf-syntax-grammar/#section-Syntax

Upcoming “RDF- Crack” versions will have lot of examples, details.

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Buzzwords of semantic web

June 26, 2008

Since 2000, people are talking much about semantic web, web 2, web 3 .. what are the buzzwords behind the semantic web ?

semantic web – a meaning of web by the web itself. Making the web understandable by machines.

RDF -  Resource Description Framework – W3C Standards to descripe anything in semantic web – it is an XML - RDF is a directed, labeled graph data format for representing information in the Web

FOAF - Friend Of A Friend – W3C standards to describe people & networks, the links between them and the things they create and do

SIOC - Semantically interconnected Online Communities -  a Semantic Web ontology for representing rich data from the Social Web in RDF

OWL - Web Ontology Language (Ontology – representation of a set of concepts within a domain and the relationships between them) – it is a family of ontologies to describe semantic web – OWL ontologies are most commonly serialized using RDF/XML syntax

SPARQL - SPARQL Protocol and RDF Query Language , is an RDF query language

Linked Open Data – is a community lead effort to create openly accessible, and interlinked, RDF Data on the Web

APML - allows users to share their own personal Attention Profile

Attention Profile – A profile that have build with a combination of your Semantic data

Open ID - open decentralized ID system that provides single access to the web

OAuth - OAuth is a simple way to publish and interact with protected data. It’s also a safer and more secure way for people to give you access.

Single Sign ON (SS0) -  a secured authentication for over the web.

Data Portability – a mixing of open standars inclucing RDF,OPML,Micro formats,APML,OpenID ..

Microformats - Designed for humans first and machines second, microformats are a set of simple, open data formats built upon existing and widely adopted standards

NLP – Natural Language Processing -  handling human languages

Some Buzz Applications :

know3 – http://www.know3.com

Twine – http://www.twine.com

powerset – http://www.powerset.com

Yahoo Search Monkey

DBpedia

freebase

radarnetworks

trueknowledge.com

talis platform

opencalais

Data Portability.org

zemanta.com

Add more applications & buzzwords & comments to make this a library for beginners .. thanks for reading this..

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