What The Problem?

• Consider a typical web page

• Mark-up consists of: rendering information

• Semantic content is accessible to humans but not (easily) to computers…

• Machine requires Natural Language understanding

Our Goal

• Accessing the deep web by various web technologies

e.g. XML Schema, RDF, OWL

• Represent the data in a machine accessible way

• Enriching ontologies using this data

The Semantic Web

The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in co-operation.

[Tim Berners-Lee , 2001]

Accessing semantic deep web

Two main approaches-•Ontology plug-in search•Deep web service annotation

Both approaches require a semantic deep web crawler or bot.

Ontology plug-in search

ReferentFormSearch engine replies

refers toevokes

Concept

“Jaguar“

Ontology plug-in search

Two processes-•Harvesting concepts or deep web form attribute.

•Iteratively link this concepts to build enriched ontology.

This ontology provides- - domain specific terms. - useful relationship and further related information.

Deep web service annotation

How to represent data in a machine accessible way?

• Semantic data signature represented in computational graph -XML -RDF -RDF Schema -OWL (Web ontology language)

The Semantic Web Layers

Standard

Standard

Standard

XML

•User definable and domain specific markupcourse

teachertitle students

name http

=<course date=“...”> <title>...</title> <teacher>...</teacher> <name>...</name> <http>...</http> <students>...</students></course>

File Format Tree Structure

•Why not use XML to represent ontologies?XML makes no commitment on: Domain specific ontological vocabulary Conceptual meaning

RDF(Resource Description Framework)

•A mechanism for annotating data and resources

•RDF is a graphical formalism

-for representing metadata about Web resource

-for describing the semantics of information in a machine- accessible way

Person

subClassOfsubClassOf

type

domain range

type

RDF(S): RDF Schema

• Defines vocabulary for RDF•Organizes this basic vocabulary terms and the relations between those terms

-Class, subClassOf, type-Property, subPropertyOf-domain, range

Has Supervisor

OWL :Web Ontology Language

•Ontologies standardize and formalize the meaning of words through concepts

•It helps softbots by serving knowledge about synonyms, antonyms, semantic relationship between concept.

Conclusion

Ontology helps to find the concepts. Semi-automatic ontology generation from the deep web, quality of ontology measurement(reliability) is challenging. It requires natural language processing.

Reference•Y. Sure and R. Studer. Vision for Semantically-Enabled Knowledge Technologies. Online at: KTweb -- Connecting Knowledge Technologies Communities, 2003.•Search on the semantic web IEEE Computer october 2005.•www.w3.org/TR/owl-features/•. M. Dean and G. Schreiber, OWL Web Ontology Language Reference, Feb. 2004; http://www.w3.org/ TR/2004/REC-owl-ref-20040210/. •T. Berners-Lee, J. Hendler, and O. Lassila, “The Semantic Web,” Scientific American, May 2001