Re: RE: [owl-s] communication between web services

Hello,

Once a service, provided by some provider is described using DAML-S/OWL-S, the service requestor must be capable of understanding this description. Inside the service model (process model) of the provided service, each input and output (and precondition/effect if defined) will be associated with a class type, defined in some ontology. You may define your own, but ultimately you would reference some preexisting one. An ontology allows for the description of class types and their relationships, to each other (eg subclass, equivelent, union of.. etc). A service requestor must know the class types of the inputs and outputs it requires. It would submit this as a request to a matchmaking engine. Such an engine can perform inference to find services that contain inputs and outputs, that match these ontology class types - contained inside the submitted request. The key all of all this is the class relationships associated with each input and output of the provided service. This is h
ow "web service A could understand that name1 is the name of the sender, name2 is the name of the receiver and address his address"

Hope that is of some use,
Luke





----- Original Message -----
From: jean-michel nougayrede <nougay_j@epita.fr>
Date: Saturday, September 11, 2004 0:09 am
Subject: RE: [owl-s] communication between web services

> 
> Hi, thanks for your answer.
> 
> I agree that process model describe what the web service needs to 
> executecorrectly.
> But in my case, let's imagine that the web service B has the function
> sendpackage (name1, name2, address). The process model describes 
> that the
> function sendpackage need the three arguments name1, name2 and 
> address. But
> how the web service A could understand that name1 is the name of 
> the sender,
> name2 is the name of the receiver and address his address?
> 
> What I don?t understand is that in the white paper owl-s, it is 
> explainedhow the web service must be described but not how an 
> extern web service can
> understand this description and use it. Am I wrong?
> 
> Jean-Michel
> 
> 
> 
> > -----Message d'origine-----
> > De : Massimo Paolucci [paolucci@cs.cmu.edu]
> > Envoyé : jeudi 9 septembre 2004 16:43
> > À : jean-michel nougayrede; public-sws-ig@w3.org
> > Objet : Re: [owl-s] communication between web services
> > 
> > jean-michel nougayrede wrote:
> > 
> > >Hi,
> > >I'm working on web services that can communicate between each 
> others> without
> > >knowing the other ones.
> > >
> > >For example there is a web service A which sells a product P 
> and then
> > >connect to another web service B in order to ship the product 
> P. But the
> > web
> > >service A doesn't know the web service B which can do the 
> shipping. The
> > web
> > >service A searches on the web in order to find one, and when it 
> finds> one,
> > >it uses it. But the problem is that the web service A doesn't 
> know what
> > are
> > >the functions to be called and with which arguments and in 
> which order.
> > >
> > >When I read the white paper DAML-S it seems that it is possible to
> > >automatize the execution of web services but I don't understand the
> > process.
> > >How can the web service A understand what function it has to 
> call and
> > which
> > >are the arguments on the web service B?
> > >
> > >
> > In a nutshell, in OWL-S (or DAML-S that preceded it) the 
> execution of
> > the Web service is controlled by a Process Model that describes what
> > information service B needs to execute correctly.  In turn 
> processes in
> > the Process Model map into WSDL operations that can become remote
> > function calls.
> > There are a bunch of papers that describe how this can be done,  
> you can
> > find them at http://www.daml.org/services/owl-s/ or on the Web 
> pages of
> > the OWL-S coalition members, as well as in the proceedings of
> > conferences such as the Semantic Web Conferences, World Wide Web
> > Conference or the conference on Web services (ICWS).
> > 
> > >Must web services share the same language (in our case all the web
> > services
> > >for the shipping have the same function and argument)?
> > >
> > >
> > OWL-S assumes that they share the same ontology, that is a set 
> of terms
> > and relations between them, and that they share a proof theory 
> to make
> > same derivations given the same knowledge.  In practice,  if 
> service A
> > sends to B a purchase order, than B should understand that it is an
> > order to purchase exactly the things that A wants to buy.  
> Finally, the
> > ontology should be written in OWL or one of its derivatives, 
> such as
> > SWRL (although with some sweet talk, and a few beers, I may be 
> convinced> that is more general than that.)
> > 
> > >Thanks a lot for your help.
> > >
> > >
> > I hope that helped.
> > 
> > --- Massimo
> > 
> 
> 
> 
>

Received on Friday, 10 September 2004 15:59:59 UTC