1. Introduction to Resource Description Framework (RDF)
MV 4920
10/14/2018
Major Brent P. Christie USMC

2. Outline Need for RDF What is RDF? Uses of RDF? RDF Model RDF in XML
Application of RDF  GINF
Major Brent P. Christie USMC
10/14/2018

3. Need for RDF RDF and Metadata Scenario 1: The library
Lookup system search properties include author, title, subject etc.
Scenario 2: The video store
Lookup system search properties include directors, actors, etc.
The common thread:
“Metadata”: information about information
Major Brent P. Christie USMC
10/14/2018

4. Need for RDF What about the Web?
One big library, need call number to get things without a search
Has hardly any metadata, HTML
Yahoo
Has metadata based lookup facility, uses human generated subject categories and site labels
Library example to illustrate need for metadata
Major Brent P. Christie USMC
10/14/2018

5. Search results using Yahoo!
Found 0 Categories and 0 sites for “Raising birds as pets”
Science > Biology > Zoology > Animals, Insects, and Pets > Birds > Magazines
Game Bird and Conservationists' Gazette - provides information on raising and breeding game birds such as pheasants, quail, partridges, geese, and more. Also offers classroom guides and free pictures for teachers.
Major Brent P. Christie USMC
10/14/2018

6. Search Results using Excite
Top 10 of about 466,620 found in Web Sites for: Raising birds as pets
Totally Unique Birds Pets and Supplies Handfed baby parrots-lovingly home raised, specializing in Cockatoos, Macaws, Amazons and Congos. We take pride in raising top quality pets that are Vet. checked and close banded. All our weaned   [more from this site]
Winged Wisdom Pet Bird Magazine - Raising Good Pets - From Breeding to... A successful breeder shares her basic concepts and experiences in breeding and raising good baby birds.   [more from this site]
Parrot Nursery Management The tremendous increase in the number of birds kept as pets has blossomed into increased demands for dometic, handfed babies and accelerating interest in raising birds for both fun and potential pr...   [more from this site]
Major Brent P. Christie USMC
10/14/2018

7. What is RDF?
It is a foundation for describing and interchanging metadata. Its objective is to support the interoperability of metadata
RDF allows descriptions of Web resources [Any object with a Uniform Resource Identifier (URI) as its address] to be made available in machine understandable form.
Resource Description Framework (RDF) Model and Syntax Specification W3C Recommendation 22 February 1999
Resource Description Framework (RDF) Schema Specification 1.0 W3C Candidate Recommendation 27 March 2000
Major Brent P. Christie USMC
10/14/2018

8. Uses of RDF
Resource Discovery – to provide better search engine capabilities
Cataloging – for describing the content and content relationships
Intelligent software agents – to facilitate knowledge sharing exchange
Content rating – in describing collections of pages that represent a single logical “document”
Major Brent P. Christie USMC
10/14/2018

9. Uses of RDF Describing intellectual property rights
Privacy preferences – expression of a user as well as the privacy polices of a Web site
“Web of Trust” – RDF with digital signatures will be key to building the “Web of Trust” for electronic commerce, collaboration, and other applications.
Major Brent P. Christie USMC
10/14/2018

10. RDF Model
Key: RDF is a model for representing named properties and property values
RDF data models — are ER diagrams
The basic data model consists of three object types:
Resources – URI + optional anchor ID
Properties – specific aspect, characteristic, attribute, or 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 statement
Major Brent P. Christie USMC
10/14/2018

11. RDF Model The RDF model for these sentences is:
The individual referred to by employee id is named Ora Lassila and has the address The resource was created by this individual.
The RDF model for these sentences is:
Major Brent P. Christie USMC
10/14/2018

12. RDF Model Subject – source of relationship Predicate – labeled arc
Always a resource
Predicate – labeled arc
Object – relationship’s destination
Resource or literal
Subject and Predicates are first-class objects
Which means they can be used as subjects or objects of other statements
Major Brent P. Christie USMC
10/14/2018

13. RDF Model
Major Brent P. Christie USMC
10/14/2018

14. RDF Model Containers Bag – An unordered list of resources or literals.
property has multiple values
no significance to the order
duplicate values are permitted
Sequence – An ordered list of resources or literals.
the order of the values is significant
Alternative – A list of resources or literals that represent alternatives for the (single) value of a property.
Application can choose any one of the items in the list as appropriate.
Major Brent P. Christie USMC
10/14/2018

15. Major Brent P. Christie USMC
10/14/2018

16. RDF and XML RDF is an implementation of XML Why not just use XML?
XML falls apart on the scalability design goal.
There are two problems:
Order of elements important – unnatural in metadata, also expensive in practace
Representation of XML documents in memory – trees difficult to manage when large
XML unequalled as an exchange format on the Web, but it doesn’t provide a metadata framework
Major Brent P. Christie USMC
10/14/2018

17. RDF and XML Basic Serialization Syntax
[1] RDF ::= ['<rdf:RDF>'] description* ['</rdf:RDF>']
[2] description ::= '<rdf:Description' idAboutAttr? '>' propertyElt* '</rdf:Description>‘
[3] idAboutAttr ::= idAttr | aboutAttr
[4] aboutAttr ::= 'about="' URI-reference '"'
[5] idAttr ::= 'ID="' IDsymbol '"'
[6] propertyElt ::= '<' propName '>' value '</' propName '>' | '<' propName resourceAttr '/>'
[7] propName ::= Qname
[8] value ::= description | string
[9] resourceAttr ::= 'resource="' URI-reference '"'
[10] Qname ::= [ NSprefix ':' ] name [11] URI-reference ::= string, interpreted per [URI]
[12] IDsymbol ::= (any legal XML name symbol)
[13] name ::= (any legal XML name symbol)
[14] NSprefix ::= (any legal XML namespace prefix)
[15] string ::= (any XML text, with "<", ">", and "&" escaped)
Major Brent P. Christie USMC
10/14/2018

18. RDF and XML What does RDF look like in XML? Figure 3, Slide 11
<rdf:RDF>
<rdf:Description about="
<s:Creator rdf:resource="
</rdf:Description>
<rdf:Description about="
<v:Name>Ora Lassila</v:Name>
</rdf:RDF> OR
<s:Creator rdf:resource="
v:Name="Ora Lassila"
/>
Major Brent P. Christie USMC
10/14/2018

19. Application of RDF: GINF
Generic Interoperability Framework (GINF)
Developed to facilitate integration of heterogeneous components
One of the main principles it employs is the generic representation of protocols, languages, data and interface descriptions.
Current implementation based on RDF
Major Brent P. Christie USMC
10/14/2018

20. Application of RDF: GINF
The implementation of GINF provides semantic-oriented middleware for application development and integration
GINF middleware allows creating open and highly extensible client/server applications. It is available for download.
Current status: highly experimental, i.e. vaporware, interfaces are subject to evolution, i.e. larva stage
Major Brent P. Christie USMC
10/14/2018

21. Major Brent P. Christie USMC
QUESTIONS?
10/14/2018
Major Brent P. Christie USMC