Search found 24 matches

by jforestr@MIT.EDU (Jay W. Forrest
Thu Jun 05, 1997 7:58 pm
Forum: SD Mailing List Archive
Topic: Differential equations
Replies: 25
Views: 39574

Differential equations

>From "William Steinhurst" <wsteinhu@psd.state.vt.us> >Difficult and confusing, certainly. Unrealistic, often. But weak? >Could you clarify? JWF reply: They do not deal usefully with nonlinearity or high order systems, and especially not both together. Jay W. Forrester Professor of Managem...
by jforestr@MIT.EDU (Jay W. Forrest
Sat May 31, 1997 10:00 pm
Forum: SD Mailing List Archive
Topic: Differential equations
Replies: 25
Views: 39574

Differential equations

In (SD0901), Jaideep Mukherjee asked that I comment on experience with system dynamics in K-12 education, apparently in regard to their not having had a background in ordinary differential equations. Elsewhere* I have written: ------------------------------------------------------- 15. Differential ...
by jforestr@MIT.EDU (Jay W. Forrest
Thu May 22, 1997 9:32 am
Forum: SD Mailing List Archive
Topic: Modelling of tax system
Replies: 3
Views: 3731

Modelling of tax system

On the nature of system dynamics and modeling, perhaps the following will be useful to you. ----------------------------- You can get a system dynamics bibliography that has over 3000 entries: To order the system dynamics bibliography, specify IBM type PC, or Macintosh Send $35 in US$ drawn on a US ...
by jforestr@MIT.EDU (Jay W. Forrest
Thu May 08, 1997 9:56 am
Forum: SD Mailing List Archive
Topic: HISTORY Source of the "Beer Game"
Replies: 0
Views: 1627

HISTORY Source of the "Beer Game"

>>>>>Date: Tue, 6 May 1997 10:42:45 +0200 >>>>>To: nlux@MIT.EDU >>>>>From: jmachuca@cica.es (Jose Antonio Dominguez Machuca) >>>>>Subject: About the Beer Game >>>>> >>>>>Dear Nan: >>>>> >>>>> I hope everything is going well with you. Do you know who was the >>>>>creator of the Beer Game? was it Jay?...
by jforestr@MIT.EDU (Jay W. Forrest
Wed Apr 16, 1997 12:54 pm
Forum: SD Mailing List Archive
Topic: sensitivity analysis: anyone heard about it?
Replies: 14
Views: 7226

sensitivity analysis: anyone heard about it?

The Vensim software includes facilities for doing automatic variation of all parameters and ranking the results on a specified criteria. Jay W. Forrester Professor of Management, Emeritus and Senior Lecturer, Sloan School Massachusetts Institute of Technology Room E60-389 Cambridge, MA 02139 tel: 61...
by jforestr@MIT.EDU (Jay W. Forrest
Tue Apr 15, 1997 4:57 pm
Forum: SD Mailing List Archive
Topic: Principles of Psychohistory
Replies: 2
Views: 3050

Principles of Psychohistory

Perhaps a diversion and a bit of history will be of interest to the system dynamics and K-12 discussion groups, even if it does nothing to promote the frontier of system dynamics. I received the following email from Chris Trost, Ctrost@aol.com, referring to his two system dynamics subjects at MIT: >...
by jforestr@MIT.EDU (Jay W. Forrest
Sat Apr 12, 1997 6:10 pm
Forum: SD Mailing List Archive
Topic: Skill levels in system dynamics
Replies: 0
Views: 1463

Skill levels in system dynamics

REPLY to: Differential equations (SD0910) From:Bill Harris >Some on this list seem to >have argued in favor of SD being practiced only after serious study in a >university program (at the graduate level?) with the opportunity for the >prospective SD person to receive feedback on their modeling effor...
by jforestr@MIT.EDU (Jay W. Forrest
Sat Apr 12, 1997 6:09 pm
Forum: SD Mailing List Archive
Topic: Road Maps and electronic courses
Replies: 6
Views: 3842

Road Maps and electronic courses

Reply to: Differential equations (SD0918) >Have the creators of Road Maps considered offering an electronic course. The suggestion of an electronic course based on present and future "Road Maps" is an interesting idea. Being able to do so would depend on financial support, which would need...
by jforestr@MIT.EDU (Jay W. Forrest
Wed Apr 09, 1997 8:52 pm
Forum: SD Mailing List Archive
Topic: Is there a "theory of system dynamics."
Replies: 2
Views: 2411

Is there a "theory of system dynamics."

Recent communications from Mukherjee (SD0788), Rodrigues (SD0784, SD0789, SD0792), and from others have raised the question of a theory of system dynamics. I see system dynamics as a profession similar to engineering or medicine. System dynamics is devoted to designing policies to create systems wit...
by jforestr@MIT.EDU (Jay W. Forrest
Wed Mar 26, 1997 9:14 pm
Forum: SD Mailing List Archive
Topic: Systems Thinking outside classroom
Replies: 0
Views: 1761

Systems Thinking outside classroom

The following message from the K-12 discussion group may be of interest to the system dynamics list. Jay W. Forrester jforestr@MIT.EDU ------- Forwarded Message Date: Wed, 26 Mar 1997 10:40:17 -0800 From: dfisher@pps.k12.or.us (Diana M. Fisher) Subject: Re: Systems THinking outside classroom To Mr. ...
by jforestr@MIT.EDU (Jay W. Forrest
Wed Mar 26, 1997 10:34 am
Forum: SD Mailing List Archive
Topic: Chemical Lab Management
Replies: 1
Views: 1907

Chemical Lab Management

Perhaps the following will help: -------------------------------------------- You can get a system dynamics bibliography that has over 3000 entries: Order System dynamics bibliography, specify IBM type PC, or Macintosh Send $35 in US$ drawn on a US bank to: System Dynamics Society University at Alba...
by jforestr@MIT.EDU (Jay W. Forrest
Wed Feb 12, 1997 11:32 am
Forum: SD Mailing List Archive
Topic: ON IRRIGATED LANDS MODELS
Replies: 3
Views: 38932

ON IRRIGATED LANDS MODELS

Perhaps you will find useful information here: ----------------------------- You can get a system dynamics bibliography that has over 3000 entries: Order System dynamics bibliography, specify IBM type PC, or Macintosh Send $35 in US$ drawn on a US bank to: System Dynamics Society University at Alban...
by jforestr@MIT.EDU (Jay W. Forrest
Sun Oct 27, 1996 10:53 pm
Forum: SD Mailing List Archive
Topic: Regarding my request for identification
Replies: 0
Views: 1398

Regarding my request for identification

It appears that my previous message asking for more identification on the discussion group messages was not clear. I had only hoped we could have a few lines more than just a name at the bottom of each message. Some people have sent me full biographies, and others made suggestions for a web page wit...
by jforestr@MIT.EDU (Jay W. Forrest
Sat Apr 27, 1996 1:46 pm
Forum: SD Mailing List Archive
Topic: Reading List
Replies: 1
Views: 1800

Reading List

Here is some resource information sent by Jay Forrester (jforestr@MIT.EDU) You can get a system dynamics bibliography that has over 3000 entries: Order System dynamics bibliography, specify IBM type PC, or Macintosh Send $35 in US$ drawn on a US bank to: System Dynamics Society 49 Bedford Road Linco...
by jforestr@MIT.EDU (Jay W. Forrest
Tue Apr 23, 1996 3:26 pm
Forum: SD Mailing List Archive
Topic: Feedback -forward? / fermentation
Replies: 1
Views: 1954

Feedback -forward? / fermentation

The following information may be of use to you: Jay W. Forrester jforestr@MIT.EDU ------------------------You can get a system dynamics bibliography that has over 3000 entries: Order System dynamics bibliography, specify IBM type PC, or Macintosh Send $35 in US$ drawn on a US bank to: System Dynamic...
by jforestr@MIT.EDU (Jay W. Forrest
Sat Apr 13, 1996 11:16 am
Forum: SD Mailing List Archive
Topic: SyM Bowl 96
Replies: 3
Views: 2812

SyM Bowl 96

Perhaps the following information will be useful to you. ------------------ You can get a system dynamics bibliography that has over 3000 entries: Order System dynamics bibliography, specify IBM type PC, or Macintosh Send $35 in US$ drawn on a US bank to: System Dynamics Society 49 Bedford Road Linc...
by jforestr@MIT.EDU (Jay W. Forrest
Sun Apr 07, 1996 9:13 pm
Forum: SD Mailing List Archive
Topic: can you help me?
Replies: 3
Views: 2888

can you help me?

The following may be of use to you: Jay W. Forrester jforestr@MIT.EDU ------------------------- You can get a system dynamics bibliography that has over 3000 entries: Order System dynamics bibliography, specify IBM type PC, or Macintosh Send $35 in US$ drawn on a US bank to: System Dynamics Society ...
by jforestr@MIT.EDU (Jay W. Forrest
Wed Mar 29, 1995 5:00 pm
Forum: SD Mailing List Archive
Topic: Models of developing countries
Replies: 0
Views: 2162

Models of developing countries

Modeling of issues in developing countries has been done for many years
by Gerald Barney:

GERALD O. BARNEY
INSTITUTE OF 21ST CENTURY STUDIES
1611 NORTH KENT ST., SUITE 610
ARLINGTON VA 22209-2111

tel: 703-841-0048
fax: 703-525-1744
email: millennium@igc.apc.org
by jforestr@MIT.EDU (Jay W. Forrest
Fri Mar 24, 1995 8:51 pm
Forum: SD Mailing List Archive
Topic: Future of system dynamics and the SD Review
Replies: 0
Views: 2160

Future of system dynamics and the SD Review

I very much agree with the March 24 communication from George Richardson: Re: SDR Reformatting, Comment#3. The future of system dynamics rests on high quality work that serves a useful, practical purpose. Dangers lie in proliferation of models that are trivial, and in modeling that addresses only ac...
by jforestr@MIT.EDU (Jay W. Forrest
Thu Mar 23, 1995 10:45 pm
Forum: SD Mailing List Archive
Topic: Acceptance of system dynamics models
Replies: 2
Views: 3515

Acceptance of system dynamics models

In his March 20 communication, Wolpert observes, " During the past five years 25% of my time has been spent in Phase II: trying to introduce the model and its implications. I am finding terrific resistance in Phase II. My first hand awareness of this resistance has made it clear that Phase II r...
by jforestr@MIT.EDU (Jay W. Forrest
Sat Feb 04, 1995 7:16 pm
Forum: SD Mailing List Archive
Topic: Order of discrete equations
Replies: 0
Views: 2225

Order of discrete equations

Comment on Feb. 4 email by George Richardson <GR383@ALBNYVMS.BITNET> George comments "It has always seemed puzzling to me that the conditions for mathematical chaos in continuous systems are more restrictive than in discrete representations (at least three stocks, for example, instead of just o...
by jforestr@MIT.EDU (Jay W. Forrest
Wed Jan 11, 1995 8:31 pm
Forum: SD Mailing List Archive
Topic: System dynamics bibliography
Replies: 0
Views: 2104

System dynamics bibliography

Jim Neale <jneale@ac.dal.ca> asked me how to obtain the system dynamics bibliography. Perhaps others will be interested: Order System dynamics bibliography, specify IBM type PC, or Macintosh Send $35 in US$ drawn on a US bank to: System Dynamics Society 49 Bedford Road Lincoln, MA 01773 USA Tel: 617...
by jforestr@MIT.EDU (Jay W. Forrest
Tue Jan 10, 1995 9:42 pm
Forum: SD Mailing List Archive
Topic: Glitz; Addiction Models
Replies: 0
Views: 2306

Glitz; Addiction Models

Glitz on Jan 10 asked about references on models of illegal drug use. The following are from the System Dynamics Bibliography, which can be obtained on computer disk. Levin, Gilbert, Gary B. Hirsch, and Edward B. Roberts. (1975). The Persistent Poppy: A Computer Aided Search for Heroin Policy. Cambr...
by jforestr@MIT.EDU (Jay W. Forrest
Mon Jan 02, 1995 9:10 pm
Forum: SD Mailing List Archive
Topic: Soft variables
Replies: 0
Views: 7071

Soft variables

On Dec. 18, Stephen Robbins asked for references on soft variables. There may not be a full specific discussion of the subject, but various insights have been discussed in some of my writing. I will give the references. However, there is no sharp distinction between hard and soft variables. Take an ...