- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Tue, 8 Mar 2005 10:30:38 -0500
- To: Danny Ayers <danny.ayers@gmail.com>, "IC Dept.- MIT-Maqbool Al Maimani" <maqbool@oas.com.om>
- Cc: Abir Qasem <abir.qasem@gmail.com>, semantic-web@w3.org, public-owl-dev@w3.org
- Message-Id: <p06200725be53740bad92@[10.4.131.226]>
At 11:48 +0100 3/8/05, Danny Ayers wrote: >A little side question: > >On Mon, 7 Mar 2005 08:12:53 +0400, IC Dept.- MIT-Maqbool Al Maimani > >> In our work Lehigh we use HTN planning to compose Semantic Web services. To >> avoid redundancy in service composition we use Local Closed World reasoning >> (LCW). > >I've not looked very closely at HTN, but I was wondering how far its >semantics can be expressed/applied in an OWL DL system. Presumably the >descriptive constructs used can be expressed reasonably cleanly in >OWL, but are there any algorithms that can be rearranged to work with >DL reasoning? > >My main reason for asking is that I'm hoping to put together a >planner-like system for goal-oriented project management. Ok, that's >rather a grandiose way of putting it - all I'm after is a simple >system that will accept to-do lists, help you decompose them into >discrete tasks & subgoals and then tell you which task you should >probably do next. I'm still at the stage of putting together the basic >infrastructure, but had anticipated using an OWL DL reasoner (or even >just RDFS) for fact-expansion alongside an auxiliary rule engine >(maybe Prolog-based, maybe Rete-based, as a last resort hard-coded) to >do prioritisation. But the more I can get under the DL umbrella the >happier I'll be. Suggestions appreciated. > >Cheers, >Danny. > I'm just running out the door and saw this - let me suggest you check out the work of Evren Sirin, my student, who is doing his PhD on the combination of HTN planners and Sem Web services. He, Bijan Parsia, and I are giving a tutorial on this topic at WWW - if you go to http://www.mindswap.org/papers and look for the papers by Sirin and also the ones with Kuter and with Wu (both of whom are Dana Nau's students) you'll find a number of papers on different aspects of the combination of HTN planners and OWL The paper http://www.mindswap.org/papers/SHOP-JWS.pdf is probably the best oe to start with - abstract is: Automated composition ofWeb Services can be achieved by using AI planning techniques. Hierarchical Task Network (HTN) planning is especially well-suited for this task. In this paper, we describe how HTN planning system SHOP2 can be used with OWL-S Web Service descriptions. We provide a sound and complete algorithm to translate OWL-S service descriptions to a SHOP2 domain.We prove the correctness of the algorithm by showing the correspondence to the situation calculus semantics of OWL-S. We implemented a system that plans over sets of OWL-S descriptions using SHOP2 and then executes the resulting plans over the Web. The system is also capable of executing information-providing Web Services during the planning process. We discuss the challenges and difficulties of using planning in the information-rich and human-oriented context of Web Services. -- Professor James Hendler Director, Semantic Web and Agent Technologies Maryland Information and Network Dynamics Lab. 301-405-2696 8400 Baltimore Ave, Suite 200 301-314-9734 (Fax) College Park, MD 20742 http://www.cs.umd.edu/users/hendler
Received on Tuesday, 8 March 2005 15:31:46 UTC