semantic web technology

Semantic Web Technology

STANLEY WANG SOLUTION ARCHITECT, TECH LEAD @SWANG68 http://www.linkedin.com/in/stanley-wang-a2b143b

What is Semantic Web?

• The current Web activities are mostly focus on Machine-to-Human;

• Machine-to-Machine activities are not particularly well

• supported by software tools.

“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.“ [Berners-Lee, 2001]

Evolution of Web Technology

Web (since 1992) • HTTP • HTML/CSS/JavaScript

Semantic Web •Reasoning •Logic, Rules •Trust

Social Web (since 2003) • Folksonomies/Tagging • Reputation, sharing • Groups, relationships

Data Web (since 2006) • URI de-reference • CBD • RDF serializations

From Web of Document to Web of Linked Data

Many Web sites containing unstructured,

textual content

Few large Web sites are specialized on

specific content types

Many Web sites containing & semantically syndicating

arbitrarily structured content

Pictures Video

Encyclopedic articles + +

Web 1.0 Web 2.0 Web 3.0

Semantic Web Stack

• Machine Processable, Global Web Standards:

• Assigning Unambiguous Names (URI)

• Expressing data, including metadata (RDF, RDFS)

• Modelling Ontologies (OWL)

• Query and Retrieve (SPARQL)

Key Functions of Semantic Web Technology

• Ontology Modeling Agreement with a common vocabulary, conceptual models and

domain Knowledge; Schema + Knowledge base Agreement is what enables interoperability Formal description - Machine processability is what leads to

automation

• Semantic Annotation Metadata Extraction: Associating meaning with data, or labeling

data so it is more meaningful to the system and people.

Can be manual, semi-automatic (automatic with human verification),

automatic

• Reasoning Computation semantics enabled search, integration, answering complex queries,

connections and analyses (paths, sub graphs), pattern finding,

mining, hypothesis validation, discovery, visualization

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Semantic Technology Market Forecasting Semantic solution, services & software markets will

grow rapidly, topping $60B by 2020

Semantic Web: Annotations

Semantic

AnnotationsOntologies Logical Support

Languages ToolsApplications /

Services

Web content

UsersCreatorsWWW

and

Beyond

Semantic

Web

Semantic Web

content

UsersSemantic

Web and

Beyond

Creators

applications

agents

Semantic annotations are

specific sort of metadata,

which provides information

about particular domain

objects, values of their

properties and relationships, in

a machine-processable, formal

and standardized way.

Semantic Web: Ontologies

Semantic



Services

Web content

UsersCreatorsWWW

and

Beyond

Semantic

Web

Semantic Web

content

UsersSemantic

Web and

Beyond

Creators

applications

agents

Ontologies make metadata

interoperable and ready for

efficient sharing and reuse. It

provides shared and common

understanding of a domain, that

can be used both by people and

machines. Ontologies are used as

a form of agreement-based

knowledge representation about

the world or some part of it and

generally describe: domain

individuals, classes, attributes,

relations and events.

Semantic Web: Rules

Semantic



Services

Web content

UsersCreatorsWWW

and

Beyond

Semantic

Web

Semantic Web

content

UsersSemantic

Web and

Beyond

Creators

applications

agents

Logical support in form of rules is needed to infer

implicit content, metadata and ontologies from

the explicit ones. Rules are considered to be a

major issue in the further development of the

semantic web. On one hand, they can be used in

ontology languages, in conjunction with or as an

alternative to description logics. And on the other

hand, they will act as a means to draw

inferences, to configure systems, to express

constraints, to specify policies, to react to

events/changes, to transform data, to specify

behavior of agents, etc.

Semantic Web: Languages

Semantic



Services

Web content

UsersCreatorsWWW

and

Beyond

Semantic

Web

Semantic Web

content

UsersSemantic

Web and

Beyond

Creators

applications

agents

Languages are needed for machine-processable

formal descriptions of: metadata (annotations) like e.g.

RDF; ontologies like e.g. OWL.; rules like e.g.

RuleML. The challenge is to provide a framework for

specifying the syntax (e.g. XML) and semantics of all

of these languages in a uniform and coherent way.

The strategy is to translate the various languages into

a common 'base' language (e.g. CL or Lbase)

providing them with a single coherent model theory.

Semantic Web: Tools

Semantic



Services

Web content

UsersCreatorsWWW

and

Beyond

Semantic

Web

Semantic Web

content

UsersSemantic

Web and

Beyond

Creators

applications

agents

User-friendly tools are needed for

metadata manual creation (annotating

content) or automated generation, for

ontology engineering and validation, for

knowledge acquisition (rules), for

languages parsing and processing, etc.

Semantic Web: Applications and Services

Semantic



Services

Web content

UsersCreatorsWWW

and

Beyond

Semantic

Web

Semantic Web

content

UsersSemantic

Web and

Beyond

Creators

applications

agents

Utilization of Semantic Web

metadata, ontologies, rules,

languages and tools enables to

provide scalable Web applications

and Web services for consumers and

enterprises" making the web 'smarter'

for people and machines.

The Idea of Web Linked Data • Think of the semantic web as building on the ideas behind Linked Data; • Linked Data is nor a specification, but a set of best practices for providing

a data infrastructure that makes it easier to share data across the web; • Use semantic web technologies such as RDFS, OWL, and SPARQL to build

applications around that data;

Four Principles of Linked Data:

1. Use URIs as names for things;

2. Use HTTP URIs so that people can look up those names;

3. When looking up a URI, provide useful information with the standards

such as RDF, RFFS, OWL, SPARQL;

4. Include links to other URIs to discover more information;

Foundation for Future Enterprise Systems

• Semantic technology as a software technology allows the meaning of information to be known and processed at execution time. For a semantic technology there must be a knowledge model of some part of the world that is used by one or more applications at execution time.

Semantic Technologies represent meanings separately from data, content, or program code, using the open standards

for the semantic web such as RDF and OWL W3C standards.

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Drivers for the Semantic Web Technology

• Business models develop rapidly these days, so

infrastructure that supports change is needed;

• Organizations are increasingly forming and disbanding

collaborations;

• Data is growing so quickly that it is no longer possible for

individuals to identify patterns in their heads;

• Increasing recognition of the benefits of collective

intelligence;

It is, essentially, the Web of Data.

“Semantic Web Technologies” is a collection of standard technologies to realize a Web of Data

Semantics Web Technology in Nut Shell • “Semantics” provides a universal framework to describe and

link different data so that it can be better understood and searched holistically, allowing both people and computers to see and discover relationships in the data;