Integrating semantic web knowledge and Service Oriented Architectures

Jesús Soto-CarriónElisa GarcíaSalvador Sánchez-Alonso

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Introduction

• Although the use of Semantic Web frameworks should be transparent and decoupled…

• …integration and interoperability between ontologies and applications are effort and time consuming

• New architectural models (SOA-ESB) can help us to reach transparent integration and decoupling

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SOA / ESBs

• Service Oriented Architectures allow software components to "plug in" to a middleware

• An Enterprise Service Bus (ESB) acts as the necessary interoperability scenario

JBI (Java Business Integration) standard:

-Normalized Message Router

- Binding component

- Service Engine

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The problem

• Ont-Space – Java-based software framework providing the

services of a semantic learning object repository used in several projects

– Strong dependencies among other problems…

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Semantic Web frameworks in SOA?

• Knowledge bases with a sound logic model, and many mature ontologies available would enhance interoperability between components plugged in to an ESB

• Benefits:– Rich semantic knowledge – Inference operations

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The hard work has already been done!

• OpenCyc– hundreds of thousands of terms– millions of assertions relating the terms – domain: all of human consensus reality

• Many other mature ontologies

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What is this presentation about?

• A service engine prototype that enables ontology query and reasoning capabilities through an ESB

A general ontology reasoning connector would provide a normalized interface to semantic facilities

GORCON

GORSE

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Semantic Web frameworks

1. Schema API: function set to build and manipulate classes, relationships...

2. Individual API

3. Inference API: allows additional facts to be inferred from existing konwledge

4. Query API

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State of the art

• Middleware vendors did not make Semantic Web connectors available yet so…

• …We must build our own components using a particular semantic web framework.

• Disadvantages:– Hidden development tasks– Strong dependencies Application logic – Semantic framework– Coupled applications

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Benefits of a general semantic connector

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General Ontology Service Engine

• The GORSE prototype implements sample functionalities

• Deployable on JBI conformant ESBs

• Developed using ideas taken from OpenESB SQL eng.

GORSE setup

• Users must set up GORSE with a short set of parameters

gorse-settings.xml

<connection>

<database-url value='jdbc:mysql://localhost:3306/model'/>

<knowledge-base value='ontomaps'/>

</connection>

• Other ontology serialized representations can be specified – E.g. an OWL file

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An example of use

GORSE

Example

• Test query:

author:diego-Velazquez ? dc:creator[Oil-onCanvas]

• GIS coordinator translates it to SPARQL:

PREFIX ontoK: http://www.samples.org/OntoKnowledgeBase.owl

SELECT ?resource ?coordinates WHERE{

?picture rdf:type ontoK:Oil-OnCanvas

?picture dc:creator ontoK:DiegoVelazquez

?track ontoK:uri ?resource

?track ontoK:coords ?coords

}

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Example

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Conclusions

• SOA provides new scenarios for interoperability of heterogeneous services

• Our prototype was aimed at showing that any application connected to an ESB can take advantage of the benefits provided by Semantic Web technologies– Even legacy systems!

• Future: add more functionalities to GORSE

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Closing time

• Thank you for your attention!

• Contact us:

– Development issues: jesus.soto@upsam.net– General issues: salvador.sanchez@uah.es – Information Engineering research unit:

http://www.ieru.org