Introduction to the Semantic Web Vision and Technologies

1 © Copyright IBM Corporation 2006

AP/AmericasMarch 5-8, 2006 Orlando, Florida

Introduction to the

Semantic Web Vision and TechnologiesCody Burleson

EMT-070

2 © Copyright IBM Corporation 2006AP/AmericasMarch 5-8, 2006 Orlando, Florida

Software and Information Architects

Session ObjectivesAfter completing this session, you should be able to:

Understand and articulate the semantic web vision

Know the basic framework and core technologies

Be aware of some available tools Understand how mature the technology is

and how you might (or might not) use it today

Get involved for further learning, contribution, or just plain geek fun

3© Copyright IBMCorporation 2006


The semantic web is…

A vision for the future web (a ‘web of meaning’ - semantics) Not a separate web but an extension of the current one Better enabling computers and people to work in cooperation Machine reasoning will be ubiquitous and powerful

An emerging set of standards, markup languages, and related processing tools

A rolling snowball Interest and momentum is building fast - heads up!

Currently under the direction of Tim Berners-Lee (a.k.a. “father of the Web”) http://www.w3.org/2001/sw/

The Semantic Web Activity



“Semantics” is…

A $2 billion per year market and projected to grow to over $50 billion by the year 2010. Leading analysts have estimated that 35-65% of our System Integration costs are due to Semantic issues. – source: SemTech 2006, http://www.semantic-conference.com/

Time

Integration Requirements(people, data, process)

20152015201020102005200520042004

O(n) components => O(n2) integrations

IT Project Resources (Budgets, Time)

Market Opportunity for better Integration Solutions

Business Componentization + Service Oriented Architecture -> Increased Integration Requirements



The semantic web stack

Unicode URI

XML + NS + xmlschema

RDF + rdfschema

Ontology vocabulary

Logic

Proof

Trust

Dig

ital S

ign

atu

re

Self-desc. doc

Data

Data

Rules



Resource Description Framework (RDF) The Resource Description Framework (RDF) is a standard for

describing resources (anything we can identify). Describes resources in terms of nodes and arcs

http://...//CodyBurleson

Cody Burleson

vcard:FN

SUBJECTA resource (node in URI)

PREDICATEHas a property that points (arcs) to…

OBJECTA literal value or anotherresource



Resource Description Framework (RDF)

Source: Semantic Searchhttp://www2003.org/cdrom/papers/refereed/p779/ess.html



Resource Description Framework (RDF)

This article has the title “Intro to the Semantic Web Vision and Technologies", and was written by someone whose name is “Cody Burleson".

It leverages and combines two vocabularies…

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc=http://purl.org/dc/elements/1.1/xmlns:foaf="http://xmlns.com/0.1/foaf/" ><rdf:Description rdf:about="">

<dc:creator rdf:parseType="Resource"> <foaf:name>Cody Burleson</foaf:name>

</dc:creator><dc:title>Intro to the Semantic Web Vision and Technologies</dc:title>

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

Dublin Core Metadata Initiative (DC)http://dublincore.org/

Friend of a Friend (foaf)http://www.foaf-project.org/



Notable points

Distributed Extensibility Different sites may contribute data about a particular resource We can all extend the cumulative knowledge on the Semantic Web about

any resource in a distributed fashion

• A version of RSS, the famous syndication (content feeds) format is a sub-set of RDF

• IBM case-in-point:• The new RSS Consumer being developed for WebSphere Web Content

Management (WCM) leverages the extensibility of RDF to add special elements into the standard RSS.

• This allows for integration with other Content Management Systems like Interwoven and Vignette.



Ontology

A formal way to organize knowledge and terms. Typically represented as graphical relationships or networks, as opposed to

taxonomies which are usually represented hierarchically. Defines a domain of knowledge

The objects that exist in that domain The properties those objects can have The relationships those objects and their properties can have to other objects and

properties (in the same domain or across domains)

What are the differences between a vocabulary, a taxonomy, a thesaurus, an ontology, and a meta-model? See: http://www.metamodel.com/article.php?story=20030115211223271

“An ontology is an explicit specification of a conceptualization.” - T. R. Gruber

(…whatever…)



This is an ontology

Source: TopQuadrant



OWL Web Ontology Language

Designed for use by applications that need to process the content of information instead of just presenting information to humans.

Has three increasingly-expressive sublanguages: OWL Lite, OWL DL, and OWL Full.

OWL adds more vocabulary for describing properties and classes on top of RDF. Example: Disjointness

Man and Woman are Disjoint Classes. Joan is an instance of Woman => Joan is not an instance of Man.

Cardinality Person has exactly one value for the property hasBirthMother

Equality Bill Clinton is sameAs William Jefferson Clinton

Symmetry Frank is a friend of Deborah => Deborah is a friend of Frank.

Yep…the acronym should be ‘WOL’, but

the creators thought

‘OWL’ was much cooler.



Tools



Jena

An open source Semantic Web Framework for Java Developed by HP Labs Semantic Web Program Provides a programmatic environment for RDF, RDFS and OWL,

including a rule-based inference engine Includes:

A RDF API Reading and writing RDF in RDF/XML, N3 and N-Triples An OWL ontology API In-memory and persistent storage (works with DB2) RDQL – a query language for RDF

A Semantic Web Framework for Javahttp://jena.sourceforge.net/



Protégé Screenshot 2 – Protégé-OWL

Ontology Editing and Knowledge Managementhttp://protege.stanford.edu/



TopQuadrant’s TopBraid:An Eclipse Tool

Source: TopQuadrant



TopBraid:UML-like Visualization

Source: TopQuadrant



Haystack - Screenshot

HaystackA semantic web browser http://haystack.csail.mit.edu/overview.html



Other Tools and Technologies

IBM Integrated Ontology Development Toolkit http://www.alphaworks.ibm.com/tech/semanticstk?

open&S_TACT=104AHW61&S_CMP=GR Based on Eclipse EMF Implements the ODM specification(OMG)

SPARQL - The W3C RDF Data Access Working Group (DAWG) http://www.w3.org/2001/sw/DataAccess/ RDF Query Language and protocol (for issuing SPARQL queries) SPARQL is already implemented in many RDF stores (including ARQ, the

query component of Jena) IBM reps to the DAWG

Lee Feigenbaum Elias Torres

Rule Interchange Format http://www.w3.org/2005/rules/Overview.html IBM reps

Leora Morgenstern Christopher Welty (co-chair)



How mature is the technology and how might you use it?



A simple test case

Can we build some sort of semantic web application using RDF/OWL for our data model?

Technologies used: Protégé for ontology

development Protégé and Protégé-OWL

API for engine JavaServer Faces WebSphere Application

Server Rational Software Architect

Test Case Ontology…

(…after conversion to Java Objects)



Test Case Screen 1



Test Case Screen 2



Test Case Screen 3



Test Case Screen 4

Resource information (the data) shows in left pane.

All related resources attached for multi-faceted browsing



Some Lessons Learned

No “right” way to model an ontology. Depends upon the end-use cases you have in mind Depends on whether you intend to reason (engine) and auto-classify Depends on personal preferences 1-2 weeks of playing with Protégé and learning about OWL Rebuilt ontology up to 3 times before starting to code

Wanted a dynamic model so that you can change ontology only without recoding application Ended up generating Java objects from ontology using Protégé OWL’s Java code generation

feature (lazy, I guess) Totally dynamic model is still doable (perhaps I should have used Jena OWL API?) Need more

time.

Ontology + auto generate Java model + Java Server Faces + Rational = Drag and drop development and very little code!

Discovered IBM Research projects after-the-fact Wish I would have used our stuff; some of it is very cool

Total time = 2 months learning and experimenting (off-time) Now “I get it”…and want to start over.



Ready for prime time?

Data modeling YES Ontology-based approach to data modeling is highly beneficial

Horizontal integration (breaking down "silos") YES, sort of… The tools are there, but they aren’t baked in to many enterprise products Concepts may be “too new” for customer comfort Opportunity for IBM to take a stronger leadership role.

Machine-driven interpretation (i.e. inference, rules engines, etc.) NO Not mature, slow, or based on rapidly evolving standards A big pill to swallow at first; learn the basics before getting into inference, rules, and

reasoning.

CONCLUSION: “Semantic Web” as a concept may not be ready for prime time, but it is ready for

our attention Many semantic web technologies are mature and immediately beneficial Learning curve is rather steep (or I’m slow) – get started!



Get involved, learn, contribute, and have some fun…



@ IBM

Semantics on AlphaWorks http://www.alphaworks.ibm.com/topics/semantics Flash Demos: http://www.alphaworks.ibm.com/demo/flash/wssem

Semantic Tools for Web Services http://w3.alphaworks.ibm.com/techs/alphabrief.jsp?tech=wssem A set of Eclipse plug-ins for semantic matching and composition of Web services. (This is an ETTK

technology.) Semantic Layer Research Platform

On IBM Internal Open Source Bazaar http://w3.opensource.ibm.com/projects/slrp/ A platform for building Semantic applications that use RDF, LSID and other Semantic Web

technologies. The platform includes several components such as an RDF server with collections, acls, replication and transactions, client and web development kits including an Eclipse suite of plugins for RDF consumption. This project also contains several prototypes such as Life Sciences Workbench and Unified Activity Management.

Semantic Super Computing On IBM Internal Open Source Bazaar http://w3.opensource.ibm.com/projects/ssc/ The Semantic Super Computing project performs research on large amount of data or large amount of

computation. The aim is to explore innovative way to deal with the scalability issues and user interface problems of such projects.

Watson Research Semantics Wiki http://semanticswiki.watson.ibm.com/FrontPage

Blue Pages Search entire profile for “Semantic Web” 39 results as of 1/31/2006



Others…

HP Labs Semantic Web Research http://www.hpl.hp.com/semweb/ Research group aiming to enable semantic web

benefits for HP customers and partners. Provides most popular semantic web API:

Jena 2 - a Java framework for writing Semantic Web applications

TopQuadrant http://www.topquadrant.com/ Established in 2001 as a premier semantic web

solutions firm.



More…

Sandsoft - “The Ontology Company” http://www.sandsoft.com/ An IBM partner

Semantical.org – “Promote and advancing the state of the art in the establishment of the commercial Semantic Web” http://semantical.org/ Recent launch: open source semantic web-based search engine

Nepomuk – “$20 million EU-backed project that aims to create a next-generation computing approach known as the ‘Social Semantic Desktop’. http://nepomuk.semanticdesktop.org/xwiki/bin/Main1/



A few reference resources Google “Semantic Web” – you’ll be reading for hours. The Semantic Web. Scientific American May 2001.

http://www.sciam.com/article.cfm?articleID=00048144-10D2-1C70-84A9809EC588EF21 SWAD-Europe

http://www.w3.org/2001/sw/Europe/ The SWAD-Europe project ran from May 2002 to October 2004, and aimed to support W3C's

Semantic Web initiative in Europe, providing targeted research, demonstrations and outreach to ensure Semantic Web technologies move into the mainstream of networked computing.

Semantic Web Best Practices Discussion List http://lists.w3.org/Archives/Public/public-swbp-wg/

Ontologies Come of Age. By Deborah L. McGuinness. In “The Semantic Web: Why, What and How” MIT Press

Semantic Web Technologies Take Middleware to Next Level – Gartner Report 20 August 2002

The Semantic Web: Trying to Link the World – Gartner Report 30 August 2001 The Integrated Enterprise From 2003 to 2012 - Gartner Report dated 12/3/02 by J.

Fenn, Y. Natis, J. Sinur, A. Linden Integration’s Dirty Little Secret: It’s a matter of Semantics- by Jeff Pollack Modulant

Software http://www.modulant.com/PDFs/dirty_little_secret.pdf Semantic Information Architecture: Solving the Enterprise Data Problem. Executive

White paper by Zvi Schreiber. Unicorn 2003. http://www.dmreview.com/whitepaper/WID532.pdf


Session Summary

Now that you have completed this session, you should be able to: Understand and articulate the semantic

web vision Know the basic framework and core

technologies Be aware of some of available tools Understand how mature the technology is

and how you might (or might not) use it today

Get involved for further learning, contribution, or just plain geek fun


Extra Slides

Misc. stuff.



Imagine…

A web that computers (not just humans) can understand. Intelligent search, augmented search, automated search Better enterprise application integration

Integration at the data layer rather than the API layer – reduced programming Universal data exchange Automatic and ad hoc configuration Better service discovery “Serendipitous interoperability” (interoperability under unchoreographed conditions) Semantics can bring us closer to the vision of SOA

Example: WebSphere Process Server looks up best service based on the semantic descriptions rather than calling service directly.

Semantics can give us better On Demand Workplaces Better ways to integrate the “thousand tribes” intranet into one comprehensive, yet personalized web portal

Improved Systems and Software Engineering Model Driven Architectures (using ontology approach to models) One example: http://www.w3.org/2001/sw/BestPractices/SE/ODA/ See also:

Ontology-based Web Services for Business Integration http://www.alphaworks.ibm.com/tech/owsbi

Comprehensive desktop application integration An army of intelligent agents working on your behalf



Technology Trends

Semantic Modeling Languages gaining Standards’ Acceptance

Time

Integration/ModelingLanguage Adoption Cycle

HTML

RDF

OWL

XML

20032003199719971996199619911991

Foundations for SemanticsFoundations for Semantics

19941994

Semantics

Syntax

Presentation

DTDs

XML Schema

RDF Schema

19991999



Trends

Web standards: from presentation to semantics

Modeling Language

Degree of Semantic Specification

RDF RDF SchemaSchema

XML XML SchemaSchema

DTDsDTDsHTMLHTML XMLXML

SemanticsSyntaxPresentation

RDFRDF OWLOWL



Trends

Semantics enable next generation integration solutions

“By 2005, lightweight ontologies will be part of 75% of application integration projects (0.7 probability)” – Gartner Report August 2002

“Through 2012, Semantic Web technologies will offer the infrastructure for the much-improved, unified semantics that are needed to support dynamic application integration at the enterprise level”. - Gartner Report Dec 2002

Time

Semantic Technologies

20152015201020102005200520042004

Ontologies for Data & Content Management

Semantic Web Services for Dynamic Application

Integration

Introduction to the Semantic Web Vision and Technologies

Documents

Transcript of Introduction to the Semantic Web Vision and Technologies