filtering & selecting semantic web services with interactive composition techniques by evren...

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Filtering & Selecting Semantic Web Services with Interactive Composition Techniques By Evren Sirin, Bijan Parsia, and James Hendler Presenting By : Mirza Tania Nasreen Mohammad Hasan

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Filtering & Selecting Semantic Web Services with Interactive Composition Techniques

By

Evren Sirin, Bijan Parsia, and James Hendler

Presenting By : Mirza Tania Nasreen Mohammad Hasan

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Outline of the Presentation

Main Idea of the Paper Works done by Authors Relevant Terms Comparisonal Work Flow Technology Used Implementation details Conclusion

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Main Idea of the Paper

Composition of Web Services

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Why Composition ???

Goal: applications will be able to communicate each other very flexibly to achieve some combined and new functionality from existing ones.

Present Condition: failed to achieve this goal

the expected ability to compose web services has not been achieved yet

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Works Done by the Authors

Developed goal-oriented interactive composition approach

Implemented In a Prototype system

Help the users to dynamically compose web services from internet with filtering capabilities

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Web Service

Web Service is a software system designed to support interoperable Machine to Machine interaction over a network. [W3C]

A web service is a collection of protocols and standards used for exchanging data between applications or systems. [Wikipedia]

No Semantics in WSDL

Current State of SOA

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Drawback with Example

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Semantic Web Service

World Wide Web

Semantic Web

a services whose properties, capabilities, interfaces, and effects are encoded in an unambiguous, machine-understandable form.

Web Service

Semantic Web Service

Web Service + Semantics = Semantic Web Service

[ HOW & WEHERE ]

[ WHAT & WHY ]

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Why Semantics ????

(Discovery) Neither WSDL nor UDDI allows for software to determine what a Web service offers to the client. A Semantic Web service describes its properties and capabilities so that software can automatically determine its purpose.

(Invocation) A Semantic Web service provides a descriptive list of what an agent needs to be able to do to execute and fulfill the service. This includes what the inputs and outputs of the service are.

(Monitoring) services can interoperate with each other seamlessly and can combine results for a valid solution.

Dynamic Composition

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Why Semantics? An Example

Semantic Annotation is the main concept behind Dynamic Composition

DictionaryTranslator

word translated word word meaning

French to English Dictionary

French word translated English word meaning

How & Where

WSDL

How & Where

WSDL

string string string string

WS 1 WS 2

+What & Why

+What & Why

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How Semantics ????

UDDI

Dynamic Composition

WSDL

SOAP

Standards for Service Directory

Standards for Description

Standards for Messaging Protocols

First System to directly combine the OWL-S semantic service descriptions with actual invocations of the WSDL descriptions.

WSDL + OWL-S = Semantic Web Service Description

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Major Focuses of the Paper

Filtering and Selecting Semantic Web Services with

Interactive Composition Techniques

Filtering Selecting Interactive Composition

Techniques

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Filtering

When a service goes into the composition, this service’s information about input, output, preconditions, and effects (IOPE) serves to automatically filter the services whose outputs are incompatible with the current selection.

Filter is designed to examine each input or output request for certain qualifying criteria and then process or forward it accordingly.

Filtering helps to determine the service that best fits user’s/clients personal preferences.

Filtering for their tool done by using matchmaking algorithms

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Selecting

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Interactive Composition

A successful, executable composition correctly combines a set of compatible components to achieve the composition’s overall goal.

At each step, their system adds a new service to the composition and filters further possibilities based on the current context and user decisions.

Gradually generates the composition with a forward or backward chaining of services.

Filtering + Selecting = Interacting Compositing Techniques

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Step-by-step Composition

Fixing a GOAL

Select 1st web Service

Filtering

Filtering

Select 2nd web Service

Compose 2 web services

RESULT

Auto. Filtering

List of Services

Selecting

Auto. Filtering

List of Services

Selecting

Monitoring

Selection

Manual Composition Dynamic CompositionPartial Automation of Composition

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Creating Semantic Service Description – OWL-S OWL : Enables greater access only to content

OWL-S ( formerly DAML-S): Enables greater access to the Web Services

OWL-S partitions a Web Service’s description into three components :

1. Service Profile

- IOPE parameters

- service parameter

2. Process Model

-Atomic Process

-Composite Process

3. Grounding

-Mapping from OWL-S to WSDL

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Translation from WSDL to OWL-S WSDL Operation ≡ OWL-S Atomic Process WSDL message parts ≡ OWL-S Process’s Parameters

Difficulties with Type Conversion :

Message parts are described by XML Schema data types OWL itself permits only a subset (constrained range) of

XML Schema data types (integers / strings). OWL references data types by URI No canonical way in XML Schema to determine a URI for

a complex data type

Preferred Solution : Parameter types of OWL-S services be OWL classes

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Translation from WSDL to OWL-S cont’d…

Author’s Solution: Treated the WSDL-supplied types as descriptions of the service

parameters i.e. the serialization of the values the process actually uses. Extended the OWL-S grounding to include marshaling and

unmarshaling functions using XSLT Unmarshalling function : XML Schema type to an RDF graph

serialized in the RDF/XML exchange syntax That graph encodes the relevant assertions about the individual,

which becomes the actual input to the service

Difficulties: It’s difficult to write XSLT that can handle all the legal

serializations of a given RDF graph.

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Implementation

The Prototype System

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Implementation 4 Types of IOPE Matching:

Exact: If advertisement A and request R are equivalent concepts

PlugIn: If request R is a subconcept of advertisement A

Subsume: If request R is a superconcept of advertisement A

Fail: No match.

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Matching IOPE

Only IO was used for matching Specifications of PE are still an open OWL-S issue Exact and Plug-In matches between the parameters of

ServiceProfiles yields useful results

Returns an ordered list

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Matching Service Parameters

To get rid of long list of available choice Service names themselves might not contain

enough information Means of introducing more user constraint Applies the result of this new query to the

previous result set

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Matching Service Parameters

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Generating and Executing Composed Services

Generation : Each Composition ≡ OWL-S CompositeProcess It can also be advertised, discovered, and composed

with other services Generates exactly such a CompositeProcess

description Creates the corresponding ServiceProfile

Execution : Invoking each individual services and passing the

data Client program serves as the central control authority

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Improvement and further automation

Strong need for a suitable set of service descriptions of sufficient and compatible detail to support

Converting the IO type descriptions from XML Schema data types to OWL classes

Removing human interaction from the loop by integrating a planner

Introduce machine learning – better and preferred suggestions

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Conclusion

Semantic Web

Semantic Web Service

Maturity Hill

Web Service

Full Automation

Partial Automation of Composition

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References

Filtering and Selecting Semantic Web Services with Interactive Composition Techniques. IEEE Intelligent Sytems. 19(4): 42-49 (2004).

Semantic Web Services. IEEE Intelligent Systems, Volume: 16 Issue: 2, March-April 2001, Pages: 46 -53

Semantic Web Service Architecture — EvolvingWeb Service Standards toward the Semantic Web. American Association for Artificial Intelligence (www.aaai.org).

Bringing Together Semantic Web and Web Services. Proceedings 1st International Semantic Web Conference (ISWC 02), 2002.

http://www.w3.org/Submission/OWL-S/

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Thank You ...