Bringing RDF to Digital Contents Towards the Semantic Web

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Bringing RDF to Digital ContentsTowards the
Semantic Web

• Ching-Long Yeh
• Department of Computer Science and Engineering
• Tatung University
• chingyeh_at_cse.ttu.edu.tw (msn)
• http//www.cse.ttu.edu.tw/chingyeh

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Web Technology Overview

• WWW (human-to-machine interactions)
• Infrastructure
• HTML, HTTP, URI, browsers
• Services
• Search engine and directory navigation
• WWW XML (human-to-machine and
  machine-to-machine interactions)
• Web Services (UDDI, WSDL, SOAP)
• SOA (Registry, provider, requester)
• Automatic service processing
• ebXML
• SOA for business automation
• discovery, implementation, run-time phases
• Business process message service
• Semantic Web
• Meaning processing automation
• WWW metadata layer (OWLRDF)
• Services automation (WWWOWL-S/RDF)
• Semantic Grid

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Semantic Web

• The Semantic Web is a vision

the idea of having data on the web defined and
linked in a way that it can be used by machines
not just for display purposes, but for
automation, integration and reuse of data across
various applications
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Semantic Web

• The Semantic Web a Web with a meaning.

"If HTML and the Web made all the online
documents look like one huge book, RDF, schema,
and inference languages will make all the data in
the world look like one huge database Tim
Berners-Lee, Weaving the Web, 1999
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Introduction from W3C SW Activity

• The Semantic Web is a web of data.
• The Semantic Web is about two things.
• Common formats for interchange of data,
• On the original Web we only had interchange of
  documents.
• Language for recording how the data relates to
  real world objects
• That allows a person, or a machine, to start off
  in one database, and then move through an
  unending set of databases which are connected not
  by wires but by being about the same thing.

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The Semantic Web Architecture
Trust
Sig./ Ency.
Proof
Tim Berners-Lee Axioms, Architecture and
Aspirations W3C all-working group plenary
Meeting 28 February 2001
Logic (FOL)
Rules (SWRL)
(http//www.w3.org/2001/Talks/0228-tbl/slide5-0.ht
ml)
Ontology (OWL)
RDF Schema
I. Horrocks, et al. Semantic web architecture
Stack or two towers? In F. Fages and S. Soliman,
(eds.), Principles and Practice of Semantic Web
Reasoning (PPSWR 2005), number 3703 in LNCS,
pages 37-41. SV, 2005. http//www.cs.man.ac.uk/h
orrocks/Publications/download/2005/HPPH05.pdf
RDF MS
XML Schema
XML
Namespaces
URI
Unicode
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RDF and Schema Languages
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RDF MS

• RDF (Resource Description Framework)
• RDF consists of two parts
• RDF Model (a set of triples)
• RDF Syntax (different XML serialization syntaxes)
• RDF Schema for definition of Vocabularies (simple
  Ontologies) for RDF (and in RDF)

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RDF Data Model

• Resources
• A resource is a thing you talk about (can
  reference)
• Resources have URIs
• Properties
• slots, define relationships to other resources or
  atomic values
• Statements
• Resource has Property with Value
• (Values can be resources or atomic XML data)
• Similar to Frame Systems

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A Simple Example

• Statement
• Ora Lassila is the creator of the resource
  http//www.w3.org/Home/Lassila
• Structure
• Resource (subject) http//www.w3.org/Home/Las
  sila
• Property (predicate) http//www.schema.org/
  Creator
• Value (object) "Ora Lassila
• Directed graph

sCreator
http//www.w3.org/Home/Lassila
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Another Example

• To add properties to Creator, point through an
  intermediate Resource.

http//www.w3.org/Home/Lassila
sCreator
Person//fi/654645635
Email
Name
Ora Lassila
lassila_at_w3.org
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Example Bag

• The students incourse 6.001 are Amy, Tim,John,
  Mary,and Sue

RdfBag
rdftype
/Students/Amy
students
rdf_1
rdf_2
/Students/Tim
bagid1
rdf_3
/Students/John
rdf_4
/Students/Mary
rdf_5
/Students/Sue
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Example Alternative

• The source code for X11 may be found at
  ftp.x.org, ftp.cs.purdue.edu, or ftp.eu.net

http//x.org/package/X11
rdfAlt
rdftype
source
altid
rdf_1
ftp.x.org
rdf_2
ftp.cs.purdue.edu
rdf_3
ftp.eu.net
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lt?xml version"1.0"?gt ltrdfRDF xmlnsrdf"http//w
ww.w3.org/1999/02/22-rdf-syntax-ns"
xmlnscontact"http//www.w3.org/2000/10/swap/pim/
contact"gt ltcontactPerson rdfabout"http//ww
w.w3.org/People/EM/contactme"gt
ltcontactfullNamegtEric Millerlt/contactfullNamegt
ltcontactmailbox rdfresource"mailtoem_at_w3.org
"/gt ltcontactpersonalTitlegtDr.lt/contactperson
alTitlegt lt/contactPersongt lt/rdfRDFgt
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OWLW3C Web Ontology Language

• OWL provides three increasingly expressive
  sublanguages OWL Lite, OWL DL, and OWL Full.

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OWLW3C Web Ontology Language
OWL Lite language constructs
RDF Schema Features Class rdfProperty
rdfssubClassOf rdfssubPropertyOf rdfsdomain
rdfsrange Individual
(In)Equality equivalentClass equivalentProperty
sameAs differentFrom allDifferent
Property Characteristics inverseOf
TransitiveProperty SymmetricProperty
FunctionalProperty InverseFunctionalProperty
Property Type Restrictions allValuesFrom
someValuesFrom
Restricted Cardinality minCardinality (only 0
or 1) maxCardinality (only 0 or 1) cardinality
(only 0 or 1)
Header Information ontology imports
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Semantic Web System Architectures
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Typical System Architecture
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Layered Architecture
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SesameA generic Architecture for Storing and
Querying RDF and RDF Schema
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Adding RDF Metadata to PW
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RDF/OWL Representation of WordNet

• WordNet Fellbaum, 1998 is a heavily-used
  lexical resource in natural-language processing
  and information retrieval.
• More recently, it has also been adopted in
  Semantic Web research community.
• It is used mainly for annotation and retrieval in
  different domains such as cultural heritage
  Hollink et al., 2003, product catalogs Guarino
  et al., 1999 and photo metadata Brickley,
  2002.
• It is also used to ground other vocabularies such
  as the FOAF schema Brickley and Miller, 2005,
  as background knowledge in ontology alignment
  tools and other applications (see
  http//esw.w3.org/mt/esw/archives/cat_applications
  _and_demos.html for a list).
• Currently there exist several conversions of
  WordNet to RDF(S) or OWL.

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Class Hierarchy of the WordNet Schema

• Synset
• AdjectiveSynset
• AdjectiveSatelliteSynset
• AdverbSynset
• NounSynset
• VerbSynset
• WordSense
• AdjectiveWordSense
• AdjectiveSatelliteWordSense
• AdverbWordSense
• NounWordSense
• VerbWordSense
• Word
• Collocation

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Combining the Metadata of Digital Content with
WordNet
The metadata database
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Combining the Metadata of Digital Content with
WordNet
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Combining the Metadata of Digital Content with
WordNet
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Combining the Metadata of Digital Content with
WordNet
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Combining the Metadata of Digital Content with
WordNet
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Combining the Metadata of Digital Content with
WordNet
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Use of RDF Metadata (1)

• Integrating existing programs into the Semantic
  Web
• Newer versions of Picture Write
• Newer versions of PMLS

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Use of RDF Metadata (2)

• Effective management of digital contents
• Defining standard vocabularies (ontology)
• Classifications of digital content
• Conceptual search and semantic navigation
• Web services

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Use of RDF Metadata (3)

• Making digital contents more beneficial
• Pictures bundled with RDF metadata can be further
  processed by clients.
• We sell digital content not only for presentation
  but also for meaning processing.
• We sell not only physical files of pictures but
  also their metadata.
• New business model (?)

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Use of RDF Metadata (4)

• Automatic generation of pictures sequence to
  extend the scope of pictures from word level to
  phrase or even sentence level
• Natural language processing technology is
  employed to enhance the current word-level
  matching method.
• The RDF metadata can be seen as the knowledge
  base to support advanced processing using the
  natural language processing technique.

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Thank You