Semantic Web Services

As part of my ongoing research in these technologies, web services should be annotated through
ontology constructions to create web services. Cardoso has a good article "On the Move to Semantic Web Services" at http://www.waset.org/pwaset/v8/v8-3.pdf . For example, we could compile an ontology to Java classes that generate atomic semantic web services and compose a complex semantic web service.

This implies a two-stage Semantic web service creation:

(1) Extract ontologies to Java APIs
(2) Create semantic web services from Java APIs


In Cardoso's article, he shows how to use WSDL-S to map between WSDL descriptions and ontological concepts. He uses WSDL4J at http://sourceforge.net/projects/wsdl4j/ for WSDL-S document management. Furthermore, the article discusses the use of OWL-S as a web service language for OWL.

In order to compose the web service, logic rules derived from the ontologies can be used to check existence, extract instance, compare values and check constraints. Kalyanpur et al. has a good article on "Automatic Mapping of OWL Ontologies into Java" at http://www.mindswap.org/~aditkal/SEKE04.pdf as well as one by Drumm on "Integrating eGovernment Services uisng Semantic Web Technologies" at http://dip.semanticweb.org/documents/DRUMM-Integrating-eGovernment-Services-using-Semantic-Web-Technologies.pdf. I like the high level architecture of the prototype with (1) presentation layer, (2) Semantic Web Service Layer, (3) Service Abstraction Layer, and (4) Legacy systems. This enables interfacing with backend services that run on different platforms and operate with different technologies.

Another good article for understanding annotation issues is by Patil et. al. on the Meteor-S Web Service Annotation Framework at http://lsdis.cs.uga.edu/lib/download/POSV-WWW2004.pdf . They discuss issues in matching XML schemas to ontologies. I believe it is important to understand the issues with algorithm development and implementation to match and annotate WSDL files for relevant ontologies. What is nice about Meteor-S is that it is an Eclipse plug-in that permits the creation of semantic web services from java source code or already existing services.

Of course, Jena is a semantic web platform for Java. It uses RDF, OWL, SPARQL and has a rule based engine as well as being open source, http://jena.sourceforge.net/. An article with code examples for Jena is at http://www.devx.com/semantic/Article/34968 . Here the author shows how Jean's inference processing works with OWL reasoners and ontology model. There are other reasoning services that one can use such as Pellet at http://clarkparsia.com/pellet.

This is an initial step to develop ontological models for spatial-time series modeling that can be then used across multiple knowledge domains in the form of semantic web services.