Ventana software support forum

On Mon, 29 Apr 1996 11:36:53 -0600, gbackus@boulder.earthnet.net <gbackus@boulder.earthnet.net> wrote: > >An important issue Joel Rahn brought up but I think went over the heads of many >is the stochastic aspect. A discrete system representation invariably has >discrete delays (the old DYNAMO boxcar...

On Mon, 29 Apr 1996 14:21:57 +-1000, John Wolfenden <jwolfend@metz.une.edu.au> wrote: >Would it be more correct to say that the nature of the difference >equations as implemented in SD is that they enable us to model a dynamic >system via a series of static steps? A better phrasing, one that tries t...

On 29 Apr 96 11:03:35 EDT, Jack Homer <70312.2217@compuserve.com> wrote: > >But this is also a system with feedback loops, the most important of which is >the influence of current drilling data on the reliability of subsequent prospect >estimates. So one ends up with a discrete-element model with fe...

On Mon, 29 Apr 1996 13:15:34 GMT, Nath <MSORNSY@cleaver.wbs.warwick.ac.uk> wrote: >Any suggestions? You could do worse than take a look at Dennis Meadows Commodity Cycle book and adapt/extend the results there (for example, to semi-conductors or, perhaps closer to the spirit of the book, memory chip...

On Sun, 28 Apr 1996 18:55:42 -0700, jimhines@interserv.com <jimhines@interserv.com> wrote: >for me: What determines the choice of SD vs. Discrete Event is the >character of the understanding desired.... So ... suggestions? Yes, the results of discrete event simulations are sometimes given as the mea...

On Mon, 29 Apr 1996 19:36:13 +0000, Shaun Tang <STANG@fcit-m1.fcit.monash.edu.au> wrote: >a. Continuous-time system that can only be simulated by an analogue computer; >or b. Discrete-time system to be simulated by digital computers. While I understand the difference between analogue and digital com...

On Sun, 28 Apr 1996 20:03:33 -0700, jimhines@interserv.com <jimhines@interserv.com> wrote: >Joel: two questions >1) What is "fixed-time-advance" approach? It is the discrete time step approach beloved of econometricians and time series mavens. Their observable variables are generally aggre...

On Fri, 26 Apr 1996 10:53:19 +-1000, John Wolfenden <jwolfend@metz.une.edu.au> wrote: >My impression of the system dynamics approach is that it uses systems of = >*difference* equations to *approximate* continuous or differential = >equations of the form dX/dt =3D f(X,p). Unfortunately, and at the r...

On Fri, 26 Apr 1996 01:15:11 -0400, CrbnBlu@aol.com <CrbnBlu@aol.com> wrote: > >As I perceive the question of determining between discrete and continous >model development there are 4 factors that come into play. > I agree that these are important factors. I would kike to suggest some alternative im...

On Thu, 25 Apr 1996 10:59:13 +0000, Jim Hines <jimhines@interserv.com> wrote: > >The plus for system dynamics modelers is that we can more easily >represent the fact that things are continually changing and >influencing eachother. I think this probably helps with the >representation of feedback. > M...