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RE: Web Services Architecture Document

From: Stephane Fellah <fellah@pcigeomatics.com>
Date: Fri, 30 Jan 2004 16:35:25 -0500
Message-ID: <8ED21571324EB145933ACCD22B86AC36470267@bach.ncr.pcigeomatics.com>
To: "Ugo Corda" <UCorda@SeeBeyond.com>, "Katia Sycara" <katia@cs.cmu.edu>, <www-ws-arch@w3.org>

Ugo,

I have been actively involved in different OpenGIS web services testbeds
(http://www.opengis.org/initiatives/?iid=79). The goal is to enable the
integration of different information communities using geospatial
information and services (map, feature, coverage, processing
services...).

One of the most obvious need for a web service ontology is to enable
web-agent to perform automatic (read intelligent) web service discovery
and choregraphy of services. 
Let's suppose you want to perform a complex task such as create a 3D map
on a specific area. Your 3D Map agent will need to find the map from
some Web Map Server (WMS) and the DEM from a Web Coverage Service (WCS)
and use a Web Terrain Service (WTS) to create a 3D view from the data
retrieved from the WMS and WCS. 
To be able to automate this task, there are two approaches. The first
one is a syntaxic one. You define XML schema to describe each service
and data information. The problem with this approach ? It does not
scale. You have to write code to parse each schema and make semantic
mapping  between the terms of different XML schema. With the floraison
of XML schema standards that exist out there, you can be sure that
integration of different systems is impossible. 
The second approach is a semantic approach , which deal with
heterogeity. You describe the services and data with metadata using a
common metamodel (read RDF/OWL). Using inferencing and rules and common
upper ontologies, you can automate the search of services based on the
agent criteria and perform semantic translation of parameters between
the services. WSDL is far to be sufficient to be able to automate
service chaining. In my scenario, you need to find geospatial
information within a specific location. The information generated by the
service will need to be provided in compatible formats for the WTS. 

To enable the semantic web, all the backend services and information
needs to be viewed by agent as RDF graphs. Using semantic protocol, the
web becomes a huge semantic bus and expert system. Instead of relying on
specific protocols and syntax, the agents are communicating using
semantic information. 

Best regards
 
Stephane Fellah
Senior Software Engineer
 
PCI Geomatics
490, Boulevard St Joseph
Hull, Quebec
Canada J8Y 3Y7
Tel: 1 819 770 0022 Ext. 223
Fax 1 819 770 0098
Visit our web site:  www.pcigeomatics.com
 


-----Original Message-----
From: Ugo Corda [mailto:UCorda@SeeBeyond.com] 
Sent: Friday, January 30, 2004 2:47 PM
To: Katia Sycara; Stephane Fellah; www-ws-arch@w3.org
Subject: RE: Web Services Architecture Document


Katia,
I am trying to think of examples of how your idea of spec compliance
verification could be applied.

Are you saying, for example, that if the WSDL 2.0 spec were to be
rewritten using OWL, then I could run a compliance verifier against the
WSA ontology and find out that WSDL 2.0 lacks intermediaries support?
This seems rather far fetched to me.

Ugo

> -----Original Message-----
> From: Katia Sycara [mailto:katia@cs.cmu.edu]
> Sent: Friday, January 30, 2004 11:34 AM
> To: Ugo Corda; 'Stephane Fellah'; www-ws-arch@w3.org
> Cc: katia@cs.cmu.edu
> Subject: RE: Web Services Architecture Document
> 
> 
> Ugo, for one, as Stephen suggests the OWL formalization can
> be used as an upper ontology for the work of groups such as 
> the OWL-S coalition or the Semantic Web Services Language 
> committee (SWSL) and Semantic Web Services Architecture 
> committee (SWSA). The upper OWL ontology could be further 
> specialized by these groups, constraints could be added etc. 
> In a long term view, one could imagine that if a new spec for 
> example were to be expressed in such an ontology, then 
> inferences about compliance of the new spec with the 
> architecture could be inferred.  Cheers, Katia
> 
> -----Original Message-----
> From: Ugo Corda [mailto:UCorda@SeeBeyond.com]
> Sent: Friday, January 30, 2004 11:34 AM
> To: Katia Sycara; Stephane Fellah; www-ws-arch@w3.org
> Subject: RE: Web Services Architecture Document
> 
> What I have not been able to figure out so far is the "then
> what?" part. In other words, what is the goal for the OWL 
> formalization of WSA (besides being a showcase of semantic 
> technologies)? Is there a plan to do anything with that 
> formalization? What kind of results would you like to achieve 
> once you apply a reasoning engine to that information?
> 
> Ugo
> 
> > -----Original Message-----
> > From: www-ws-arch-request@w3.org [mailto:www-ws-arch-request@w3.org]

> > On Behalf Of Katia Sycara
> > Sent: Friday, January 30, 2004 7:52 AM
> > To: 'Stephane Fellah'; www-ws-arch@w3.org
> > Cc: katia@cs.cmu.edu
> > Subject: RE: Web Services Architecture Document
> > 
> > 
> > 
> > Staphane,
> >  We are working on an OWL formalization of the concepts and 
> > relationships in the Web Services Architecture. It will be published

> > along with the final Working Group product by end of next week.
> >  As for OWL-S it is not a Working Group of the W3C, though 
> > some of us would like it to become one.
> >   Cheers, Katia
> > 
> > -----Original Message-----
> > From: www-ws-arch-request@w3.org [mailto:www-ws-arch-request@w3.org]

> > On Behalf Of Stephane Fellah
> > Sent: Thursday, January 29, 2004 5:27 PM
> > To: www-ws-arch@w3.org
> > Subject: Re: Web Services Architecture Document
> > 
> > 
> > Hi,
> > 
> > I have a couple of questions related to the scope of your working 
> > group. Is there any chance to see an OWL formalization of the 
> > different concepts and relationships exposed in the WS Architecture 
> > Document ? What would be the next step for W3C : define again new 
> > XML schemas (syntaxic
> > approach) or using semantic web technologies (OWL). I clearly
> > favor the last option because the syntaxic approach is too 
> > brittle to scale on the web. The OWL-S effort seems to 
> > address the same problem, but uses different terms. Is there 
> > any harmonization effort between the working groups ? 
> > 
> > Thanks in advance.
> >  
> > Best regards
> >  
> > Stephane Fellah
> > Senior Software Engineer
> >  
> > PCI Geomatics
> > 490, Boulevard St Joseph
> > Hull, Quebec
> > Canada J8Y 3Y7
> > Tel: 1 819 770 0022 Ext. 223
> > Fax 1 819 770 0098
> > Visit our web site:  www.pcigeomatics.com
> >  
> > 
> > 
> > 
> 
> 
Received on Friday, 30 January 2004 16:36:54 GMT

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