- From: Ugo Corda <UCorda@SeeBeyond.com>
- Date: Sun, 1 Feb 2004 18:54:28 -0800
- 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