Seminaron

Semantic Web

Presented to –Mr. Shreyaskar GaurAssistant ProfessorDepartment of Computer Science & TechnologyJPIET

Presented by-Pallavi SrivastavaB.Tech(C.S.E)Semester-6Roll no.- 0928210035

W3C

Semantic web

Semantic web themes

Technology map

Applications

Advantages and disadvantages

Future scope

Imaginative aspect

Contents

International consortium directed by Tim Berners-LeeMission: “Lead the Web to its full potential”Hosts: MIT, ERCIM, Keio UniversityDefines Web Standards HTML, CSS, XML, Security Web Accessibility Initiative (WAI) Web Services (SOAP, WSDL, etc.) Semantic Web

Method Technical specifications developed with Working

Groups and extensive public review Advanced Development to chart long term

architectural directions

W3C track record: building infrastructure to address

technical and social needs of the Web

W3C

Need of semantic web

Semantic web“The Semantic Web is a major research initiative of the World Wide

Web Consortium (W3C) to create a metadata-rich Web of resources that can describe themselves not only by how they should bedisplayed (HTML) or syntactically (XML), but also by the meaning of themetadata.”

From W3C Semantic Web Activity Page

“The Semantic Web is an extension of the current web in whichinformation is given well-defined meaning, better enabling computersand people to work in cooperation.”

Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web, Scientific American,

May 2001

Data Integration at Web Scale Web of data

framework for integrating multiple sources to draw new conclusions

architecture for describing all kinds of things (items, collections, services, processes, etc.)

Increase the utility of information by connecting it to its definitions and its context effective management and reuse of

data at various scales (personal, group, enterprise, community, web

Semantic Web

Today, the W3C positions the Semantic Web into a number of areas:

• Linked Data

• Vocabularies

• Query

• Inference

• Vertical Applications

Semantic web themes

Semantic web themes

Linked data Data on the Web should be available in a standard format. Relationships among data should be made available, too, to

create a Web of Data . Collection of interrelated datasets on the Web.

Vocabulary- Concepts and relationships (also referred to as “terms”) used to

describe and represent an area of concern. Used to-

Classify the terms that can be used in a particular application. Characterize possible relationships. Define possible constraints on using those terms.

The role are to help data integration. E.g. a:author same as f:auteur

Query Programmatic mechanisms to retrieve all the data.

Semantic web themesInference * Automatic procedures can generate new

relationships.* Used for data integration on the Web,

by- * discovering new relationships* automatically analyzing the content

of the data * managing knowledge on the Web .

Vertical applications Used to explore how Semantic Web

technologies can help improve operations, efficiencies, and provide better user experiences.

The two most prominent areas for Semantic Web adoption are Health Care/Life Sciences e-Government sectors

Data Integration in Semantic web

1. Map the various data onto an abstract data representation

make the data independent of its internal representation

2. Merge the resulting representations3. Start making queries on the whole!

queries that could not have been done on the individual data sets

Technology map

RDF(Resource Description Framework) is the first and the fundamental technology of semantic web.It describes Resources through a series of Statements. RDF has following important concepts• Resource : The resources being described by RDF are anything that can

be named via a URI. • Property : A property is also a resource that has a name, for instance

Author or Title.• Statement : A statement consists of the combination of a Resource, a

Property, and an associated value. Each statement is a Property and Value that is about a Resource. An RDF Triple (s,p,o) is such that: “s”, “p” are URI-s, ie, resources on the Web; “o” is a URI or a literal “s”, “p”, and “o” stand for “subject”, “property”, and “objectResources can use any URI, e.g.: http://www.example.org/file.xml#element(home) http://www.example.org/file2.xml#xpath1(//q[@a=b])

URI-s can also denote non Web entities: http://www.ivan-herman.net/me is me not my home page, not my publication list, but me

RDF

RDF & RDFS

Another significant part of RDF is it’s Schema language. RDF Schema allows for greater specification of semantics for information models.RDFS defines resources and classes:

everything in RDF is a “resource” “classes” are also resources, but… …they are also a collection of possible

resources (i.e., “individuals”) “fiction”, “novel”

Relationships are defined among classes and resources:

“typing”: an individual belongs to a specific class

“«The Glass Palace» is a novel” to be more precise:

“«http://.../000651409X» is a novel” “sub classing”: all instances of one are

also the instances of the other (“every novel is a fiction”)

RDFS formalizes these notions in RDF

<rdf:Description rdf:about="http://…/isbn/2020386682"> <f:titre xml:lang="fr">Le palais des mirroirs</f:titre> <f:original rdf:resource="http://…/isbn/000651409X"/></rdf:Description>

RDF example

Intersection

Garden st.

Traffic accide

nt

Central ave

Sydney Eveleig

h

In location

Has road

Has road

In Suburb

In Suburb

In city

OWL

Declarative knowledge representation language for the Semantic Web with formally defined meaning for creating ontologies.

It is a ‘Monotonic’ language. Collection of basic “pieces of

knowledge.” Statements that are made in an

ontology are called axioms in OWL. The ontology asserts that its

axioms are true. OWL denotes: • objects as individuals, • categories as classes, and • relations as properties.

SPARQL query language and the accompanying semantics and protocols makes possible to send queries and receive results .

SPARQL queries are similar in syntax to SQL based on the RDF triple models provide patterns against such relationships

in which some resource references are variables.

A SPARQL engine would return the resources that match these patterns for all triples.

Under current development are a SPARQL Update language SPARQL HTTP bindings discovery mechanism for describing the

capabilities of a SPARQL endpoint.

SPARQL

PREFIX ns: <http://road.com/> SELECT ?name WHERE { ?road ns:inSuburb “Eveleigh” . ?road ns:hasName ?name . }

The results would be: Name “Garden St” “Central Ave”

GRDDL* GRDDL is a mechanism for Gleaning Resource Descriptions from Dialects of

Languages.* introduces markup based on existing standards for:

* declaring that an XML document includes data compatible with the RDF* linking to algorithms (typically represented in XSLT), * extracting this data from the document.

POWDER ( Protocol for Web Description Resources ) Supports

the provision of description resources way to apply them to groups of online resources the authentication of those descriptions .

There are two versions of POWDER: one simple version expressed in XML. the other that harnesses the Semantic Web languages (POWDER-S).

SKOS An area of work developing specifications and standards to support the use of

knowledge organization systems (KOS) such as thesauri, classification schemes, subject heading lists and taxonomies within the framework of the Semantic Web

GRDDL & POWDER

Family of specifications which focuses on exchange rather than a single one-fits-all rule language but even rule exchange alone is a complex and daunting area.

Rule systems fall into three categories; first-order logic-programming action rules

Family of languages, called dialects. Core idea : Different rule systems will provide

syntactic mappings from their native languages to RIF dialects and back.

Mappings are required to be preserve their original semantics

Rule Interchange Format

Tools

CategoriesThe following Semantic Web

tools have been recently released:

AceWiki (Version 0.5.3, 19 January 2012)

LDIF (Version 0.4, 16 January 2012)

AllegroGraph (Version 4.4.0.1, 12 January 2012)

Semantic MediaWiki (Version 1.7.0.1, 9 January 2012)

Bigdata (Version 1.1.0, 20 December 2011)

Triple Stores

Inference engines

Converters

Search engines

Middleware CMS

Semantic Web

browsers

Development environments

Semantic Wikis

Applications

Search Engines

Search Engines

Applications

Social semantic web

Applications

Applications

Searches

Agents

Knowledge management

Integration

Virtual community

Machine dialogues across the domains

Online advertising

Multimedia collection

Information Filtering

Serendipity(Unexpected benefits)

Advantages

The fact that the actual WWW is not compatible with the semantic web is a huge problem.(The www uses HTML while the semantic web uses RDF).

If a company decide to write its site in RDF, it won’t be readable by conventional web browsers.

The semantic web is fairly unknown and only few people actually know how to write a web page in RDF.

Disadvantages

Current news

Based in Los Angeles, Cognition Technologies has developed innovative Semantic Natural Language Processing (NLP) technology .

A leading biopharmaceutical company has chosen Semantelli’s CoProtect software to manage its online and social media reputation.

Semantic advertising web service ADmantX has announced a partnership with adBrite, “the largest independent ad exchange, to offer brand safety, greater ad engagement and page-level, cookie-less targeting to advertisers and publishers.

CitizenNet is using semantic analysis and natural language processing to provide customers with automatic social media promotion

Future Aspect

The semantic web is driving the evolution of current web by enabling users to find ,share & combine information more easily.

The US government has propelled the adoption of semantic web in governmental agencies.

More than 2,70,000 data sets are available for public viewing with the help of Data Gov project.

At present , semantic web witnesses funding inflow for product development.

In future, the investments are likely to be made in projects where focus is on enhancing the existing ecosystems on internet especially in : Social computing Search engines enhancements Advertising Analytical tools

Semantic innovations relevant to thriving ecosystems such as Facebook & twitter stand better chance of attracting funds from venture capalists & other funding agencies.

Clarabridge,which delivers highly customized enterprise processing solutions had acquired $4.33 million for marketing & sales expansion.

Imaginative Aspect

Semantic web is about an individual. Searches: With semantic search engines we can

receive right information/content at the right time from anywhere.

Once the Semantic Web exists, it can provide the ability to tag all content on the Web, describe what each piece of information is about and give semantic meaning to the content item.

Thus, search engines become more effective than they are now, and users can find the precise information they are hunting.

E-commerce : “We believe this is what you are looking”

Online ad: “Personalized ad display based on user preferences, community and other characteristics”.

References:

www.w3.org>W3C www.readwriteweb.com Semantic

Web - Wikipedia, the free encyclopedia en.wikipedia.org/wiki/Semantic Web

Tutorial ppt W3C http://www.w3.org/2001/sw/grddl-wg/

Queries…

Mr. Shreyaskar

Gaur

My classmates