Re: How to handle processes that must occur

Drew,

Thank you for the response. I think an example would be appropriate.

We are looking to use OWL-S to model military process, namely tactical 
behaviors. We are not using OWL-S for a web service, per se. We chose to 
use OWL-S since many of the concepts that we needed to capture for our work 
have already been addressed in OWL-S in one way or another. We are using 
Protege with the OWL plug-in to build our ontology. We are expecting it to 
be a mechanism to electronically capture the knowledge necessary for 
performing tactical behaviors so that this information can be used by an 
autonomous vehicle to perform those behaviors without human intervention 
(as much as possible). This effort is being funded by the Army.

To give you an example corresponding to my earlier question, let's say that 
we have a service called "Prepare for Road March" that a Platoon agent 
performs when the condition "Quartering Party is Clear of Start Point" is 
met. This is the 7th step in a list of steps that all must be performed 
when executing this tactical behavior. For the sake of argument, let's say 
that all of the steps are in serial and there is no branching (which 
actually is not true, but it will make our example a bit simpler). After 
step 6 has completed, I want the system to check to see if the "Quartering 
Party is Clear of the Start Point". If it is, then the Platoon agent should 
"Prepare for Road March." If it is not, the system should "wait" and 
continuously check to see if that condition is true. It should not try to 
perform any of the other actions in the list until the "Prepare for Road 
March" action is performed.

Hopefully this makes my earlier question a bit clearer (which I re-included 
below). Thanks again for your help.

Craig

  > [Craig Schlenoff]
 >
 > I have a process in my OWL-S representation that must occur. However, it 
has
 > a condition associated with it. Somehow I want to tell the system to wait
 > until the condition is true so that the process will occur. The process is
 > in a sequence list, and I am afraid that an implementation of the OWL-S
 > specification will skip to the next step in the sequence if the 
condition is
 > not met at that point in the execution, which is not what I want to occur.
 >
 > One way to do this is to create a composite process that contains a
 > repeat-until ControlConstruct which states that the systems should 
perform a
 > "wait" activity until the condition is met and then it can perform the
 > desired process. This seems clumsy. Is there a better way to do it?

Request for clarification: What is the condition and what resources must 
the agent (process executor) expend in order to verify that the condition 
is true? -- -- Drew McDermott Yale Computer Science Department


-------------------------------------------------------------------------------
Craig Schlenoff
Mechanical Engineer
Intelligent Systems Division
National Institute of Standards and Technology (NIST)
100 Bureau Drive, Stop 8230
Gaithersburg, MD 20899
Phone: 301-975-3456
Fax: 301-990-9688
Email: craig.schlenoff@nist.gov

Received on Monday, 19 April 2004 17:22:27 UTC