Hi Lou, Wikipedia defines System Dynamics as:
System dynamics is one approach to modeling the dynamics of complex systems such as population, ecological and economic systems, which usually interact strongly with each other. Systems Dynamics was founded in the early 1960s by Jay W. Forrester of the MIT Sloan School of Management with the establishment of the MIT System Dynamics Group. At that time, he began applying what he had learned about systems during his work in electrical engineering to everyday kinds of systems. What makes using System Dynamics different from other approaches to studying complex systems is the use of feedback loops. Stocks and flows are the basic building blocks of a System Dynamics model. They help describe how a system is connected by feedback loops which create the nonlinearity found so frequently in modern day problems. Computer software is used to simulate a system dynamics model of the situation being studied. Running "what if" simulations to test certain policies on such a model can greatly aid in understanding how the system changes over time. (http://en.wikipedia.org/wiki/System_Dynamics) I'm not sure what SD software looks like and how it differs from Ptolemy. The wiki page has some links to some software, a quick glance did not bring up a screen shot. Is there a particular package I should look at? There are several ways to encourage development in an area: 1) Provide financial support the Ptolemy project via the California Micro grant system. This requires finding a student, or covering Edward's time or my time. Details are at http://ptolemy/sponsoring_main.htm 2) Do the work yourself, follow the Ptolemy style guide and contribute the software. See http://ptolemy/ptolemyII/ptIIfaq.htm#Contributions 3) This sounds like it might work well in Kepler, where the CT domain gets reskinned as an SD model. Kepler is doing lots of usability work and has nifty icons. Kepler is targeted more towards scientists whereas Ptolemy is targeted towards researchers interested in models of computation. It sounds like your stakeholders would prefer Kepler over Ptolemy. _Christopher -------- Hi, I use System Dynamics (SD) models to engage stakeholders (those of little background or interest in the necessary math but are the policy-makers, hold the purse strings, and hold the biases as the system experts). I believe SD is probably the most intuitive modeling platform to build CT models but there are many constraints that Kepler/Ptolemy could rectify. I am asking my question under the notion that stakeholders will have trouble "seeing" their system with the Ptolemy mapping/icon modeling layer. Models are probably useless in the practical world if stakeholders cannot "buy into" the model. To many stakeholders, modeling is intellectual voodoo and there is a lack of trust (e.g. you can prove anything to the layperson with the wrong statistics model) that must be overcome and SD is a tool that enables this. What would it take to encourage Ptolemy developers to build a SD-like layer of system modeling (using icons of stock and flows and also keep the converters and look-up tables or graphs) interfaced with the more mathematically versatile modeling of ptolemy. For example the SD stock is the integration thus a link to an integrator actor (?). A package of SD-specific actors? Thanks, Lou ----- Original Message ----- From: "Haiyang Zheng" <[EMAIL PROTECTED]> To: "Christopher Brooks" <[EMAIL PROTECTED]>; "Louis Macovsky, Dynamic BioSystems" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; <ptolemy-hackers@bennett.eecs.berkeley.edu> Sent: Monday, May 01, 2006 8:56 AM Subject: Re: Berkeley Madonna and System Dynamics > Hi, Lou, > > Sorry for the late reply. I was out of town. As for your > question, there is no connection between BM and ptolemy. > > -Haiyang > > > ----- Original Message ----- > From: "Christopher Brooks" <[EMAIL PROTECTED]> > To: "Louis Macovsky, Dynamic BioSystems" > <[EMAIL PROTECTED]> > Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > Sent: Friday, April 28, 2006 11:04 AM > Subject: Re: Berkeley Madonna and System Dynamics > > > > Hi Lou, > > > > There is no Berkeley Madonna interface that I know of. > > > > I've cc'd Haiyang Zheng here, he is our local CT expert, > > he might know. > > > > Haiyang, if you respond, can you cc > > [EMAIL PROTECTED] > > > > > > _Christopher > > > > -------- > > > > Thanks for the reply to the GIS querry. > > > > Another one: > > I use system dynamics platforms of CT modeling. Its > > mapping or systems > > concept drawing layer is great for educating and > > involving stakeholders in > > the modeling process. > > > > In that Oster's Berkeley Madonna (BM) was born at UCB, > > I would like to know > > if anyone has linked system dynamics platforms such as > > BM or any of the > > other system dynamics packages to Ptolemy or Kepler. > > > > Thanks again, > > Lou > > > > > > > > > ------------------------------------------------------------------------- - - > > - > > Posted to the ptolemy-hackers mailing list. Please > > send administrative > > mail for this list to: > > [EMAIL PROTECTED] > > -------- > > > > -------- ---------------------------------------------------------------------------- Posted to the ptolemy-hackers mailing list. Please send administrative mail for this list to: [EMAIL PROTECTED]
