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RE: Web Services Architecture Document

From: Ugo Corda <UCorda@SeeBeyond.com>
Date: Sun, 1 Feb 2004 18:54:28 -0800
Message-ID: <EDDE2977F3D216428E903370E3EBDDC9032B8A3A@MAIL01.stc.com>
To: "Francis McCabe" <frankmccabe@mac.com>
Cc: "Katia Sycara" <katia@cs.cmu.edu>, "Stephane Fellah" <fellah@pcigeomatics.com>, <www-ws-arch@w3.org>

Frank,
My point was that, if the ontology does not tell me where to find the
URI (which I think it doesn't, am I right?), then it is of little
practical significance. Given a Web service, there might be all kind of
URIs associated with it (the port address, the URL of the associated
WSDL file, the URI of a related resource - see WS-Resource, etc.). If I
don't know which one is the one that the architecture is referring to,
how can I decide whether the Web service complies with the architecture?

Ugo

> -----Original Message-----
> From: Francis McCabe [mailto:frankmccabe@mac.com] 
> Sent: Saturday, January 31, 2004 6:20 PM
> To: Ugo Corda
> Cc: Katia Sycara; Stephane Fellah; www-ws-arch@w3.org
> Subject: Re: Web Services Architecture Document
> 
> 
> Ugo:
>   Services do have URIs; that is clear. However, the URI of a service 
> may not be dereferenceable. The URI of a service is entirely 
> different 
> to any URI that might be used to access its functionality, 
> description, 
> etc.
> The primary purpose of a service URI has to be so that you can make 
> inferences and declarations of the form: XXX used service 
> xxxx at time 
> TTTT.
> Frank
> 
> On Jan 30, 2004, at 5:27 PM, Ugo Corda wrote:
> 
> >
> > Katia,
> > This is a very simple example, but I already have a problem 
> with its 
> > practical usefulness. How would I verify that the service 
> has a URI? 
> > Since we have not defined exactly what a service's URI is 
> (is it the 
> > port address? Is it some document describing the service? 
> etc.), then 
> > the compliance criterion derived from that reasoning does 
> not buy us 
> > much.
> >
> > I suspect the same problem would surface with most other logical 
> > conclusions we could derive from the WSA ontology. (That's why the 
> > concept of WSA-compliance has a much more fuzzy meaning 
> than the usual 
> > concept of standard compliance - this, by the way, is not 
> the fault of 
> > WSA, it just comes from its special nature of being an architecture 
> > document instead of, for instance, the definition of a specific 
> > vocabulary).
> >
> > What I am challenging is the practical benefit of using the 
> semantic 
> > machinery in the context of the WSA ontology, not the 
> abstract concept 
> > itself.
> >
> > Ugo
> >
> >> -----Original Message-----
> >> From: Katia Sycara [mailto:katia@cs.cmu.edu]
> >> Sent: Friday, January 30, 2004 1:55 PM
> >> To: Ugo Corda; 'Stephane Fellah'; www-ws-arch@w3.org
> >> Subject: RE: Web Services Architecture Document
> >>
> >>
> >> Ugo,
> >>  If you define an X as a Web service then, since a Web 
> service is a 
> >> service and since a service is a resource, then this X has 
> to have a 
> >> URI (this is a very simple example, but if this X does not have a 
> >> URI, then it is not compliant with what the wsa document 
> calls a Web 
> >> service).
> >>   --Katia
> >>
> >>
> >> -----Original Message-----
> >> From: Ugo Corda [mailto:UCorda@SeeBeyond.com]
> >> Sent: Friday, January 30, 2004 4:44 PM
> >> To: Stephane Fellah; Katia Sycara; www-ws-arch@w3.org
> >> Subject: RE: Web Services Architecture Document
> >>
> >> Stephane,
> >> I understand the idea of "automating the search of 
> services based on 
> >> the agent criteria and perform semantic translation of parameters 
> >> between the services" (the UDDI TC has being discussing 
> exactly this 
> >> kind of issues recently). I just don't see how all that 
> would relate 
> >> to the WSA ontology and leverage it.
> >>
> >> Ugo
> >>
> >>> -----Original Message-----
> >>> From: Stephane Fellah [mailto:fellah@pcigeomatics.com]
> >>> Sent: Friday, January 30, 2004 1:35 PM
> >>> To: Ugo Corda; Katia Sycara; www-ws-arch@w3.org
> >>> Subject: RE: Web Services Architecture Document
> >>>
> >>>
> >>> 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 Sunday, 1 February 2004 21:55:02 UTC

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