[kepler-users] System Dynamics Actor?

[Louis Macovsky]

I have used system dynamics programs like STELLA for physiological, 
pharmacological, and ecotoxicological models/simulations.  The 
pharmacological models in particular are quite robust.  Applications with 
stock and flow diagrams simplify communication with those unfamiliar with 
the mathematics.

http://www.systemdynamics.org/conferences/2007/proceed/papers/HELAL482.pdf 
is a recent conference paper that I would like to pass on to you.  If you 
have the time, I would like your reaction to the concept of CT and Discrete 
hybrid modeling and if this paper's methodology is relavant to your methods 
or approach to programming for Kepler.  Again I am not a programmer.

Thanks for the discussion,
Louis


----- Original Message ----- 
From: "Matthew Jones" <jones at nceas.ucsb.edu>
To: "Edward A. Lee" <eal at eecs.berkeley.edu>
Cc: "Timothy McPhillips" <tmcphillips at mac.com>; "PtolemyMailingList" 
<ptolemy-hackers at bennett.EECS.Berkeley.EDU>; "[User List] KEPLER-USER" 
<kepler-users at ecoinformatics.org>
Sent: Thursday, January 31, 2008 10:59 PM
Subject: Re: [kepler-users] System Dynamics Actor?


>I think ecologists would use that sort of thing a lot.  They like stella 
>for its simplicity as a model prototyping tool, even when they end up 
>implementing the models for their final runs in a different system. I've 
>even seen Stella used as a front end in the Spatial Modeling Environment 
>(SME) for building stock-flow models that are then run through a 
>code-generator to produce executables that are run on high-end parallel 
>supercomputers (see [1]).  We don't have the resources right now to tackle 
>this project, but I think it would indeed be valuable.
>
> Matt
>
> [1] http://www.uvm.edu/giee/SME3/
>
> Edward A. Lee wrote:
>> It does sound like it would be an interesting project to build
>> some Stocks and Flows actors, a-la Stella... The underlying ODE
>> solver of the CT or Continuous domains would be leveraged...
>>
>> Anyone interested in doing that?
>>
>> Edward
>>
>> At 02:06 PM 1/31/2008, Timothy McPhillips wrote:
>>> Hi Louis,
>>>
>>> As Edward mentioned, the continuous time domain can be used to model 
>>> dynamic systems of the sort I think you are talking about.  However, 
>>> these models aren't quite as easy to build or understand as STELLA 
>>> models, say.  A few years ago I spent a few days trying to emulate 
>>> STELLA's capabilities (i.e, modeling dynamic systems in terms of  stocks 
>>> and flows) in Kepler, but the results weren't as clean as  STELLA models 
>>> for a number of reasons, most especially because the  stocks and flows 
>>> were not distinct actors.  I, too, would like to see  such support in 
>>> Kepler, along with capabilities for easily running  these models 
>>> multiple times in a parameter sweep or search,  summarizing the results 
>>> of multiple runs of the model, etc.
>>>
>>> Cheers,
>>>
>>> Tim
>>>
>>> On Jan 31, 2008, at 11:50 AM, Louis Macovsky wrote:
>>>
>>>> Hi,
>>>>
>>>> Is there any work being done to add a system dynamics Actor?
>>>>
>>>> I have raised this question about 1.5 yrs ago but I am still hoping  to 
>>>> hear
>>>> that it is someone's project using for example BerkeleyMadonna
>>>> http://www.berkeleymadonna.com/ and maybe the more suitable  JMadonna 
>>>> which
>>>> is in development.  I point out JMadonna because I "assume" that its
>>>> development would be accessible to Ptolemy and Keppler developers.
>>>>
>>>> There is an open source SD application that is a relatively new 
>>>> addition to
>>>> NetLogo.  Could it be a candidate around which an Actor could be 
>>>> developed?
>>>>
>>>> In addition to BerkeleyMadonna, I use STELLA http:// 
>>>> www.iseesystems.com/ and
>>>> Vensim http://www.vensim.com/ .  I have not used Simile
>>>> http://simulistics.com/ but for a commercial SD package it may be a
>>>> candidate to work around.  There are other SD programs but I have  not 
>>>> used
>>>> them.
>>>>
>>>> I am not a programmer, so I do not have the answers and perhaps I  am 
>>>> not
>>>> even posing the right question(s).
>>>>
>>>> Thanks,
>>>> Louis
>>>>
>>>>
>>>> _______________________________________________
>>>> Kepler-users mailing list
>>>> Kepler-users at ecoinformatics.org
>>>> http://mercury.nceas.ucsb.edu/ecoinformatics/mailman/listinfo/ 
>>>> kepler-users
>>>
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>>>
>>
>> ------------ 
>> Edward A. Lee
>> Chair of EECS and Robert S. Pepper Distinguished Professor
>> 231 Cory Hall, UC Berkeley, Berkeley, CA 94720-1770
>> phone: 510-642-0253, fax: 510-642-2845
>> eal at eecs.Berkeley.EDU, 
>> http://www.eecs.berkeley.edu/Faculty/Homepages/lee.html 
>> _______________________________________________
>> Kepler-users mailing list
>> Kepler-users at ecoinformatics.org
>> http://mercury.nceas.ucsb.edu/ecoinformatics/mailman/listinfo/kepler-users
>
> -- 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Matthew B. Jones
> Director of Informatics Research and Development
> National Center for Ecological Analysis and Synthesis (NCEAS)
> UC Santa Barbara
> jones at nceas.ucsb.edu                       Ph: 1-907-523-1960
> http://www.nceas.ucsb.edu/ecoinfo
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
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