Search found 6 matches
- Mon Feb 02, 2004 9:57 am
- Forum: SD Mailing List Archive
- Topic: Using Statistics in Dynamics Models
- Replies: 28
- Views: 33926
Using Statistics in Dynamics Models
Joel Rahn wrote: >All of these examples completely ignore the time dimension in the sense >that observations are lumped together as if they happened at the same time >or, in the case of those like pharmaco-kinetic studies, as if they >happened over the same time interval. This strikes a chord with m...
- Mon Apr 08, 2002 11:15 am
- Forum: SD Mailing List Archive
- Topic: Representing constraints
- Replies: 30
- Views: 54098
Representing constraints
As with others replying to this query I have felt the need to check that I have understood it. Thanks Niall for that clarification, I feel on safer ground that I have not spoken at random. No, you are not alone in thinking that "acausal (ie, instantaneous and mutual) interaction might be a usef...
- Wed Apr 03, 2002 2:01 pm
- Forum: SD Mailing List Archive
- Topic: Representing constraints
- Replies: 30
- Views: 54098
Representing constraints
Niall Palfreyman asks if there is any way for SD software to represent mutual dependancies, for example where you dont wish to specify which variables are dependant or independant in advance. He focusses on the ideal gas equation PV = NkT, where P,V and T are variables and N,k are constants. In SD t...
- Sat Apr 28, 2001 10:47 pm
- Forum: SD Mailing List Archive
- Topic: SD and Markov processes
- Replies: 7
- Views: 25892
SD and Markov processes
Hail SDers! I wonder if anybody has done any work representing Markov processes (dynamic statistical processes where the current value depends partly on the previous value) using system dynamics? One would think that this kind of closed recursive loop would be ideal for SD, but in fact I find it fai...
- Sat Apr 08, 2000 12:32 pm
- Forum: SD Mailing List Archive
- Topic: Ethical considerations of quantifying soft variables
- Replies: 0
- Views: 5518
Ethical considerations of quantifying soft variables
[ Hosts note. One of Jay Forresters favorite quotes was from the mayor of a city who, when commenting about Urban Dynamics said - I dont care if its right or wrong the answer is unacceptable. This is an interesting area but also one which falls on the edge of this discussion forum. I am not inclined...
- Sat Apr 01, 2000 11:33 am
- Forum: SD Mailing List Archive
- Topic: Building your own models
- Replies: 18
- Views: 68124
Building your own models
Jaideeps struggle with the uncertainty principle is a great analogy for these philosophically murky Unstructured Systems (if we can continue to use that very helpful term). The popular literature on physics these days (e.g. almost anything by Paul Davies in a good bookshop) is so accessible that you...