Re: Compositions Types:Static and Dynamic

Daniela and Xuan,

For semantic web, I would give a somewhat different definition about 
"dynamic" vs "static" than conventional  definition.  "Dynamic" means 
composition and invocation is programed by program-programmer.  "Static" 
means it is programed by human programmer.  The more dynamic it is, the 
more a human programmer needs to make his/her program closer to a 
program-programmer.  "Dynamic" composition/invocation in conventional 
technology like Java, CORBA, ActiveX, or Web Services are very limited.  
The goal of semantic web is to create an order-of-magnitude more 
flexible program-programmer.  Semantic annotation is to assist them to 
write programs  to use a particular service just as API specification 
and programmer's guide to assist human programmer.

Even though, we are still far away from creating program-programmer 
close to human programmer.  The research in semantic web has 
dramatically improved the capability of program-programmers.  To do 
this, it requires a paradigm shift from conventional object-oriented 
model to semantic-oriented model.  It requires a different kind of 
programming language, a different kind of data store, a different kind 
of API, and most of all, a different kind of API specification.


William Wu
Semansoft Corporation

Shi, Xuan wrote:
> Daniela,
>
> Thanks very much for your kind advice and discuss. To my opinion, dynamic
> composition may be a part of the service discovery and matchmaking process.
> Semantic information is useful in such situation. Dynamic invocation,
> however, may have to deal with programming issue.
>
> So when we know the composite process of a service chain, how can you
> dynamically invoke each of the services described in your composition
> document? Given the example that you know the WSDL URLs and IOPEs for both
> Microsoft's TerraService and ESRI's address geocoding services, you know you
> have to first use the "address" information to invoke geocoding service to
> retrieve lat/lon values, which will then be used to invoke TerraService's
> function to retrieve the image you want. How can you invoke the service
> through composition? 
>
> I know even it's a difficulty and complex process to create/deploy a static
> java Web service, but did not try dynamic invocation in java. However, I do
> know how to dynamic invoke a WS in .NET in the proposed OSRR approach which
> is much much better and convenient than the traditional WSDL-based dynamic
> invocation-a difficulty for such task.
>
> Best wishes,
>
> Xuan
>
>
> -----Original Message-----
> From: Daniela CLARO
> To: public-sws-ig@w3.org
> Sent: 4/26/06 4:11 AM
> Subject: RE: Compositions Types:Static and Dynamic
>
>
> Hi Xuan, 
>   
>
>   
>> One more question is about the relationship between dynamic 
>> service composition and dynamic service invocation. If the 
>> purpose of dynamic service composition is for dynamic service 
>> invocation, given the example of retrieving an aerial photo 
>> from Microsoft's Terraservice, how such dynamic composition 
>> will enable the dynamic invocation? 
>>     
> For me, one think is dynamic composition, i.e. when your goal is to
> construct a stair(ws1) and for this you need to supply the
> concrete(ws2). However the ws2 (supply concrete) you do not know yet.
> Thus the dynamic composition is responsible to put the ws2 in your
> composition to achieve the goal 'create a stair'. On the other hand,
> dynamic invocation, we can have already done dynamic composition, and at
> the moment you will execute these services w1 and w2, the w2 is offline.
> Thus you should find another service, with the same functionalities to
> replace the ws2. 
>
> Thus we can have dynamic compositions and dynamic invocations or both!
> This is my point of view :o)! And most of the papers in planning, as I
> could observe, treats dynamic invocation. Actually I do not know if they
> treat dynamic composition also, do they? 
>
>
>   
>> In this case, the known 
>> WSDL documents can be identified, thus you know the IOPEs for 
>> this task. 
>>     
> Yes... 
>   
>> I never tried the dynamic invocation in Java, but in .NET, I 
>> know it's a difficulty to build dynamic invocation in the 
>> traditional WSDL approach.
>>     
> I think dynamic invocation as people are doing, as I have read in some
> papers is using planning and semantic web, because how you will find
> other services, with the same functionalities (and probably others
> non-functional criteria as QoS) without semantics, it will be more
> difficult. Thus many approaches are using planning with semantics. The
> paper Template-based Composition of Semantic Web Services E. Sirin, B.
> Parsia, J. Hendler used a planner based on Java, the Jshop. 
>
> I created a planning algorithm using a rule-based engine, called JESS.
> It not efficient as a planner with relaxed restrictions as a HTN, but we
> should start by something! JESS is completely integrated with Java.
> JSHOP I do not know, but the authors can say something about it! I
> created a dynamic composition and not a dynamic invocation. In my
> invocation I consider that everything works fine!
>
> Hope that helps,
> Daniela
>
>
>

Received on Thursday, 27 April 2006 13:29:06 UTC