Ventana software support forum

There has been some discussion of how to model the classroom demonstration in which people in a group all move to a point equidistant from two others. While not exactly the same, the type of model called for is similar to models of crowds moving through different spaces. A particularly interesting a...

Bob Hill asks about resources to provide "how to" approaches for model construction, and the example is agricultural extension issues in the Carribean. Andy Fords text Modeling the Environment: An Introduction to System Dynamics Modeling of Environmental Systems (Island Press, 1999; ISBN 1...

In addition to the memorials for Dana planned for Hanover, NH, Boston, and Washington, here is information on the San Francisco event, from Mathis Wackernagel of Redefining Progress. John Sterman ******************* Dear Friends: A number of groups have come together to celebrate Dana in the San Fra...

Content-Type: text/plain; charset="us-ascii" Niall Palfreyman, in his interesting discussion of SD and CAS modeling approaches, suggests that "SD typically describes the behaviour of a system in terms of 5-20 components...." This is simply not the case. There is a huge range in t...

Folks, There are now more definite plans for memorial services for Dana. Gatherings will take place in Hanover NH, Washington DC, and other locations around the world on April 22 (Earth Day). Here is some information on the Washington gathering, from Betsy Taylor of the Balaton Group. John Sterman D...

This conference may be of interest to system dynamics practitioners, academics, and teachers. John Sterman >Date: Wed, 07 Mar 2001 22:02:23 -0500 >From: "James R. Wilson" <jwilson@eos.ncsu.edu> >Organization: North Carolina State University >To: informs-cs <ics.email2@umich.edu> >Subject: ...

From Carnegie Mellon University (via John Sterman): Can you please assist us in our search for a Post Doc Fellow by posting the following ad: Environmental Social Science. A post-doctoral fellow position is available immediately in the Center for Integrated Assessment of the Human Dimensions of Glob...

To the system dynamics community: Dana Meadows passed away yesterday after complications from meningitis. I append here an obituary written by Alan AtKisson, a long-time member of the Balaton Group. As of this morning (Wednesday 21 Feb) plans for a memorial service have not yet been announced. I kno...

As many of you know by now, Herbert Simon passed away on Friday 9 February at age 84, after a brief illness. Herb contributed to so many different fields of science and social science it is daunting even to catalogue them. These include economics (for which he won the Nobel Memorial Prize in 1978), ...

Call for Nominations for the Jay W. Forrester Award Nominations are invited for the 2001 Jay W. Forrester Award. The Jay Wright Forrester Award is presented as often as once annually for the best contribution to the field of system dynamics published in the preceding five years. Papers, articles, bo...

>I am interested in reviewing any models that refer to the regulation of >blood-sugar in normal and diabetic conditions. Erik Mosekilde and Jeppe Sturis of the Technical University of Denmark, along with colleagues from the Univ. of Chicago medical school, developed a series of models and supporting...

Geoff Coyle points out the useful formula relating the order of an Erlang delay to the mean and variance of the delay process: Order = (Mean Delay)^2/Variance As intuition suggests, the smaller the variance relative to the mean delay, the tighter the distribution of the outflow around its mean, and ...

The discussion about ways to represent delay distributions other than the Erlang family (and its limiting distribution, the pipeline delay given by output(t) = input(t - DelayTime)) has been helpful. Personally, I look forward to using the arbitrary delay shape capability Bob Eberlein has created fo...

Achara Changsiri wonders whether SD mdoels can address the transient behavior of a system and asks about SD models of recycling. System dynamics models are designed as behavioral, dynamic, disequilibrium models - the main value is their ability to capture the nonequilibrium (transient) behavior of a...

Achara Changsiri wonders whether SD mdoels can address the transient behavior of a system and asks about SD models of recycling. System dynamics models are designed as behavioral, dynamic, disequilibrium models - the main value is their ability to capture the nonequilibrium (transient) behavior of a...

Massachusetts Institute of Technology Sloan School of Management FACULTY POSITION The MIT Sloan School of Management invites applications for a tenure-track faculty position in system dynamics, to begin Fall, 2001. Candidates must have a doctoral degree completed or near completion, have demonstrate...

The paper describing Rogelio Olivas service delivery model, discussed several weeks ago in this list, has been revised and updated. The latest version of the paper is available for download, along with the simulation model and historical data, on http://www.people.hbs.edu oliva esearch/service/esq.h...

Regarding models of call centers, Rogelio Oliva, in his PhD thesis, developed a model of a large UK banks back office retail and small business lending operation, which was similar to a call center. Through observation, interviews, collection of archival and statistical data, and participation in th...

X-UIDL: 10319-938505322 Status: O X-Status: The problem of modeling the recruitment, aging, mortality, and migration of a shrimp population described by Richard Dudley is an example of the general formulation issue of an aging chain. This formulation is treated in detail in chapter 12 of Business Dy...

******************** Folks, Here is an opportunity to organize sessions on simulation applications at the next INFORMS conference. Since the theme is applications, system dynamics is quite appropriate. John Sterman From: John Sterman <jsterman@MIT.EDU> >CALL FOR SPONSORED SESSIONS > >This is an open...

John Hayward asks about the causal structure of the classic epidemic model (the so-called SIR (Susceptible-Infectious-Recovered) model, in particular about the feedback structure of the model. This class of model, applied to both epidemiology and innovation diffusion, is treated extensively in chapt...

Ivan Taylor wonders if my new system dynamics text, Business Dynamics, is too advanced for beginners. I hope not. Certainly one of my goals was to provide a resource that would help people who want to learn to build effective models of difficult situations. To that end the book does go into depth on...

Call for Nominations for the Jay W. Forrester Award Nominations are invited for the 2000 Jay W. Forrester Award. The Jay Wright Forrester Award is presented as often as once annually for the best contribution to the field of system dynamics published in the preceding five years. Papers, articles, bo...

This postdoc opportunity may be of interest to the SD community. >POSTDOCTORAL TRAINING FELLOWSHIPS >in the COGNITIVE SCIENCE PROGRAM >INDIANA UNIVERSITY in >MODELING OF COGNITIVE PROCESSES > >The Psychology Department and Cognitive Science Program at Indiana >University anticipate one or more Postd...

Content-Type: text/plain; charset="us-ascii" Re models of culture: Nelson Repenning and I have a paper, just published, that presents a feedback theory and case studies illustrating how certain erroneous attributions about the causes of low performance in an organization can become self-co...