Resource Description Framework - PowerPoint PPT Presentation

1 / 26
About This Presentation
Title:

Resource Description Framework

Description:

RDF in words ... From Wikipedia. March 20, 2006. 15. An RDF document ... date 1999-07-01 written in the format text/html and in the language en (English) ... – PowerPoint PPT presentation

Number of Views:49
Avg rating:3.0/5.0
Slides: 27
Provided by: eldon2
Category:

less

Transcript and Presenter's Notes

Title: Resource Description Framework


1
Resource Description Framework
Presentation by Ray James For Semantic Web UT
Austin, Spring 2006
  • Out of chaos, order

2
RDF overview
  • What RDF is
  • What RDF can do
  • How to use RDF
  • Current RDF applications
  • RDFs future
  • Summary Sources

3
RDF basics
  • Metadata is constructed information
  • Metadata is developed by people for a purpose or
    function
  • Metadata can be a surrogate

From Karen Coyle
4
What RDF is
  • Key Definitions
  • Resource Description Framework An XML expression
    used to make simple assertions about
    relationships between things.
  • RDF Schema A language used to describe the
    relationship between classes of things, or
    relationships between concepts in a particular
    domain.

5
In other words
  • RDF defines a convention essential for the
    Semantic Web
  • RDF is machine and human readable but primarily
    for the machine
  • RDF is an infrastructure that enables the
    encoding, exchange, and reuse of structured
    metadata.

Eric Miller
6
What RDF is
  • History dates just over a decade
  • Creation process began in 1990s outgrowth of
    PICS
  • First RDF working draft October 1997
  • Semantic Web Activity first RDF Interest Group
    meeting, February 2001
  • Collaborative design process

7
What RDF is
  • Breaking down RDF
  • Anything can be a resource Web page, PDA,
    document, etc. (identified with URI)
  • Description means how a resource is related to
    any other resource or object
  • Framework means ontological construct

Source www.w3.org
8
Describing RDF
RDF promotes semantic interoperability XML
promotes syntactic interoperability.
Diagram from Dr. Miles Efron lecture notes.
9
Describing RDF
  • RDF is all about the triples
  • Resource, Property, Value
  • Or
  • Subject, Predicate, Object

10
RDF triples graphically
11
More on RDF triples
  • An Object can become Subject of new triple
  • Nesting of properties without limit
  • Triples concept maintained in RDF Schema
  • RDFS creates vocabularies
  • RDFS triples are classes, class properties and
    (atomic) values

12
RDF graphically
From Explorers Guide to the Semantic Web
13
RDF in words
  • There is a person who is named William Sparks who
    has a telephone number 435-555-6789 and who has
    an address which is composed of an address
    (number and street) and a city and a state and
    who has an e-mail account which was opened on
    Aug. 1, 2001 and uses the address
    wsparks_at_malto.com.

Subject Predicate Object Nested-subject Object
14
Reification
  • Reification describes the act of making a data
    model for a previously abstract concept.
  • Reification allows a computer to process an
    abstraction as if it were any other data

From Wikipedia
15
An RDF document
lt?xml version"1.0"?gt ltrdfRDF
xmlnsrdf"http//www.w3.org/1999/02/22-rdf-syntax
-ns" xmlnsdc"http//dublincore.org/2003/03/24/d
ces"gt ltrdfDescription rdfabout"http//www.ukol
n.ac.uk/metadata/resources/dc/datamodel/WD-dc-rdf/
"gt ltdctitlegt Guidance on expressing the Dublin
Core within the Resource Description Framework
(RDF) lt/dctitlegtltdccreatorgt Eric Miller
lt/dccreatorgtltdcsubjectgt Dublin Core Resource
Description Framework RDF eXtensible Markup
Language XML lt/dcsubjectgtltdcpublishergt Dublin
Core Metadata Initiative lt/dcpublishergtltdccontri
butorgt Dublin Core Data Model Working Group
lt/dccontributorgtltdcdategt 1999-07-01
lt/dcdategtltdcformatgt text/html
lt/dcformatgtltdclanguagegt en lt/dclanguagegtlt/rdfD
escriptiongt lt/rdfRDFgt
Adapted from http//www.ukoln.ac.uk/metadata/resou
rces/dc/datamodel/WD-dc-rdf
Subject Predicate Object
16
In words
  • There is a document declared in Dublin Core
    Schema found at the Dublin Core namespace ( RDF
    etc)
  • http//www.ukoln.ac.uk/metadata/resources/dc/datam
    odel/WD-dc-rdf/
  • which has the title Guidance on expressing the
    Dublin Core within the Resource Description
    Framework (RDF) created by Eric Miller whose
    subject keywords are Dublin Core Resource
    Description Framework RDF eXtensible Markup
    Language XML published by Dublin Core Metadata
    Initiative contributed by Dublin Core Data Model
    Working Group on the date 1999-07-01 written in
    the format text/html and in the language en
    (English).

Subject Predicate Object
17
How RDF works
  • All essential information is at
  • http//www.w3.org/RDF
  • Find RDF validator at the website
  • http//www.w3.org/RDF/Validator/

18
RDF applications
19
RDF document
  • lt!-- /Creative Commons License --gt
  • lt!-- ltrdfRDF xmlns"http//web.resource.org/cc/
    " xmlnsdc"http//purl.org/dc/elements/1.1/
    " xmlnsrdf"http//www.w3.org/1999/02/22-rd
    f-syntax-ns"gt ltWork rdfabout""gt
    ltdctitlegtMetadata Data with a
    Purposelt/dctitlegt ltdcdategt2004lt/dcdategt
    ltdcdescriptiongtA general discussion of
    document/resource metadata and some related
    uses.lt/dcdescriptiongt ltdccreatorgtltAgentgt
    ltdctitlegtKaren Coylelt/dctitlegt
    lt/Agentgtlt/dccreatorgt ltdcrightsgtltAgentgt
    ltdctitlegtKaren Coylelt/dctitlegt
    lt/Agentgtlt/dcrightsgt ltdctype
    rdfresource"http//purl.org/dc/dcmitype/Text"
    /gt ltdcsource rdfresource"http//www.kcoyle
    .net/meta_purpose.html"/gt ltlicense
    rdfresource"http//creativecommons.org/licenses/
    by-nc-nd/2.0/" /gt lt/Workgt ltLicense
    rdfabout"http//creativecommons.org/licenses/by-
    nc-nd/2.0/"gt ltpermits rdfresource"http//we
    b.resource.org/cc/Reproduction" /gt ltpermits
    rdfresource"http//web.resource.org/cc/Distribut
    ion" /gt ltrequires rdfresource"http//web.re
    source.org/cc/Notice" /gt ltrequires
    rdfresource"http//web.resource.org/cc/Attributi
    on" /gt ltprohibits rdfresource"http//web.re
    source.org/cc/CommercialUse" /gt lt/Licensegt
    lt/rdfRDFgt

20
RDF applications
  • Mozilla describes e-mail, news
  • RSS describes blogs
  • Annotea describes Web pages
  • Dublin Core describes meta data
  • Webscripter defines and fuses

21
RDF(S) creation applications
22
More on Altova site
23
RDFs Future
  • Growing acceptance by Web site producers and
    users of metadata
  • Programs like SemanticWorks are positive signs
    that standard is healthy
  • Acceptance means use use means continuing
    acceptance
  • Continued support (likely) from W3C

24
RDF Summary
  • RDF
  • is about relationships.
  • brings interoperability.
  • is all about triples.
  • can be found at http//www.w3.org/RDF

25
Sources
  • http//www.w3.org/RDF
  • http//www.altova.com
  • http//www.mozilla.org/rdf/doc/
  • http//www-db.research.bell-labs.com/user/pfps/pub
    lications/oil-ieee.pdf
  • OIL An Ontology Infrastructure (Fensel and
    others)
  • www.dlib.org/dlib/may98/miller/05miller.html
  • An Introduction to the Resource Development
    Framework (Miller)
  • Explorers Guide to the Semantic Web (Passin)
  • http//www.kcoyle.net/jal2_Metadata.html
  • Understanding Metadata and Its Purpose
    (Coyle)

26
Questions?
Write a Comment
User Comments (0)
About PowerShow.com