[rules-users] Planning Under Uncertainty

[Geoffrey De Smet]

drools-planner + drools-chance = planning under uncertainty

I am looking forward to the first alpha release of drools-chance,
so I can experiment with "planning under uncertainty" examples,
such as "investment portfolio optimization" etc.

If you want to do it today, you got 2 options as I see it:
1) Use drools-chance in your score DRL (and contribute to and fix 
drools-chance)
   https://github.com/droolsjbpm/drools-chance
2) Write the uncertainty calculations yourself in your score DRL

Both ways require you to fully understand the math behind "uncertainty 
calculations",
which in your case are "probability calculations" I think.
Here's just the beginning of the begin (Bayes' Rule etc):
   http://www.khanacademy.org/video/probability--part-6
   http://www.khanacademy.org/video/probability--part-7
   http://www.khanacademy.org/video/probability--part-8

 From a drools-planner perspective, there is no uncertainty:
The score DRL's need to produce a Score for a solution which is 
comparable the Score of another solution of the same problem.
Even if the Score instance contains probability parts (which is 
allowed), Planner doesn't care:
you still need to define which of the 2 Score instances is better (by 
compareTo), something which is domain specific
(and might even depend on input data like how much risk you're willing 
to take).

-- 
With kind regards,
Geoffrey De Smet



Op 24-09-11 00:55, Chris Spencer schreef:
> On Fri, Sep 23, 2011 at 6:39 PM, Davide Sottara<dsotty at gmail.com>  wrote:
>> I'm adding support native for uncertainty to drools: the code is in a
>> sub-project repository called "drools-chance". I'll probably commit an
>> update next week, supporting the declaration of beans with distributions as
>> fields.
> That's great to hear. I'm glad I'm not the only one interested in this
> functionality.
>
>> Full support in the rules, instead, will take some more time. I would like
>> to understand better what you mean by "uncertain planning": are you
>> considering actions with uncertain preconditions / effects or both? or are
>> you referring to randomized search algorithms?
>> Of course, you can always manage uncertainty explicitly, using additional
>> facts and calculating the probabilities, but I would not recommend that
>> unless you need a working prototype very quickly.
> I'm mainly interested in planning with uncertain effects, similar to
> what I've found in most probabilistic graphplan implementations (e.g.
> http://www.cs.cmu.edu/~avrim/pgp.html).
>
>> Best,
>> Davide
>>
>> p.s.
>> The paper you found is old and obsolete, definitely not worthy looking at (
>> shame on the main author ;) )
> Heh, I'm glad you're still involved with the community after all these
> years. Thanks for not dropping the research. I've seen a lot of
> interesting graduate research just die as soon as the project/thesis
> is over.
>
> Regards,
> Chris
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