Re: Planning under Description Logic ?--an obstacle towards WSAC

After getting more information from [1][2][3][4] about applying HTN planning to 
WSAC,
I'm wondering its applicability based on the following reasons(Due to my 
knowledge limitation, there must be something wrong, pls point it out):
1) SHOP2 approach seems to use a partially ordered set of tasks to describe the 
user's requirements. I don't think it's a feasible way comparing with
goal formula.
Actually, the underlying intention of the abstract tasks are their outputs and 
effects, which are goal formulas. However, these goal formulas may be
achieved by
different abstract tasks. 
2) The HTN planning domain includes a set of operators (that is,
atomic service)
and a set of methods (that is, composite service). I don't know whether the 
process model of OWL-S intents to be shared among agents. But from the 
viewpoint of security, I thow doubt on the agents' willing to expose
their process
model, which may reflect their business logic. 
3) In [3], it extends HTN planning algorithm to handle incomplete-information 
planning problem. While some information can be provided by web services, some 
must be provided by the user himself since we can't require the user
to provide all
the needed information to accomplish the plan. The question is, how to
distinguish
what information should be provided by other web services and what should be 
provided by the user? As discussed in the mailing list before, since we can't 
control other services, the information gathered during planning may
be different
when executing. As mention at the end of the paper, I agree that
inserting queries
to the plan (leading conditional plans) is more proper.

[1] SHOP2: An HTN Planning System;
http://www.cs.cmu.edu/afs/cs/project/jair/pub/volume20/nau03a.pdf
[2] Automatic Web Services Composition Using SHOP2;
http://www.mindswap.org/papers/ICAPS03-SHOP2.pdf
[3] http://www.mindswap.org/papers/ISWC04-Enquirer.pdf
[4] http://www.mindswap.org/papers/SWS-ISWC04.pdf

-- 
Best regards!
			
Manshan Lin 
Email: lmshill@hotmail.com;lms-hill@21cn.com;lmshill@gmail.com
Affiliation: School of Computer Science and Engineering, the South
China University of Technology
Phone: (+86)13711287277
2004-12-06

Received on Monday, 6 December 2004 10:28:34 UTC