Comments for MetaSD Model Library http://models.metasd.com A system dynamics model archive Tue, 01 May 2012 18:17:17 +0000 hourly 1 http://wordpress.org/?v=3.1.2 Comment on Bathtub Statistics sandbox by Bathtub Statistics « MetaSD http://models.metasd.com/bathtub-statistics-sandbox/comment-page-1/#comment-16034 Bathtub Statistics « MetaSD Tue, 01 May 2012 18:17:17 +0000 http://models.metasd.com/?p=434#comment-16034 [...] Update: The model is in my library. Tweet This Post Post to Delicious Post to Facebook Post to Google Buzz Send Gmail Post to LinkedIn Stumble This Post Post to Technorati [...] [...] Update: The model is in my library. Tweet This Post Post to Delicious Post to Facebook Post to Google Buzz Send Gmail Post to LinkedIn Stumble This Post Post to Technorati [...]

]]> Comment on A System Zoo by Karan Khosla http://models.metasd.com/a-system-zoo/comment-page-1/#comment-14694 Karan Khosla Mon, 02 Apr 2012 07:14:49 +0000 http://models.metasd.com/?p=267#comment-14694 I'm working my way through Systems Zoo 1 this week - this is such a good overview of classic system physics, every SD student should have access to this! I’m working my way through Systems Zoo 1 this week – this is such a good overview of classic system physics, every SD student should have access to this!

]]> Comment on Lotka-Volterra predator-prey system by Sangdon Lee http://models.metasd.com/lotka-volterra/comment-page-1/#comment-13532 Sangdon Lee Wed, 07 Mar 2012 15:52:28 +0000 http://models.metasd.com/?p=309#comment-13532 The various solutions of prey-predator model will show oscillatory nature of the population of the two species in a state of "dynamic equilibrium" even though there are very very few preys. If stochastic nature (e.g., random noise) is incorporated into the prey-predator model, prey (or predatory) might be extingushied and thus no dynamic equilibrium solution. Leif Gustafsson, "Poisson simulation-a method for generating stochastic variations in continuous system simulation," Simulation, 74: 5, 264-274, 2000. The various solutions of prey-predator model will show oscillatory nature of the population of the two species in a state of “dynamic equilibrium” even though there are very very few preys.

If stochastic nature (e.g., random noise) is incorporated into the prey-predator model, prey (or predatory) might be extingushied and thus no dynamic equilibrium solution.

Leif Gustafsson, “Poisson simulation-a method for generating stochastic variations in continuous system simulation,” Simulation, 74: 5, 264-274, 2000.

]]> Comment on Lotka-Volterra predator-prey system by Tom http://models.metasd.com/lotka-volterra/comment-page-1/#comment-13206 Tom Sun, 26 Feb 2012 16:39:24 +0000 http://models.metasd.com/?p=309#comment-13206 See my other comment - if you're still having trouble I can post the vmf or mdl version. See my other comment – if you’re still having trouble I can post the vmf or mdl version.

]]> Comment on Vensim Model Documentation Tool by Tom http://models.metasd.com/vensim-model-documentation-tool/comment-page-1/#comment-13205 Tom Sun, 26 Feb 2012 16:38:22 +0000 http://models.metasd.com/?p=217#comment-13205 You should be able to click on any variable using the equation tool and see/edit the equation, as you would in any normal .vmf or .mdl format model. These .vpm published models do not use any security features to lock up the code. You should be able to click on any variable using the equation tool and see/edit the equation, as you would in any normal .vmf or .mdl format model. These .vpm published models do not use any security features to lock up the code.

]]> Comment on Vensim Model Documentation Tool by Dr R Ghosh http://models.metasd.com/vensim-model-documentation-tool/comment-page-1/#comment-13201 Dr R Ghosh Sun, 26 Feb 2012 12:34:16 +0000 http://models.metasd.com/?p=217#comment-13201 I am using free vensim ple software. How do I see the Vensim equation of a published model (with the software) in the software? I am using free vensim ple software. How do I see the Vensim equation of a published model (with the software) in the software?

]]> Comment on Lotka-Volterra predator-prey system by Dr R Ghosh http://models.metasd.com/lotka-volterra/comment-page-1/#comment-13199 Dr R Ghosh Sun, 26 Feb 2012 11:48:14 +0000 http://models.metasd.com/?p=309#comment-13199 Can you please mail the Vensim equations of predator-prey system above. Thanks Can you please mail the Vensim equations of predator-prey system above.
Thanks

]]> Comment on WORLD3-03 by J Yelland http://models.metasd.com/world3-03/comment-page-1/#comment-12542 J Yelland Tue, 07 Feb 2012 13:50:12 +0000 http://models.metasd.com/?p=127#comment-12542 Thank you for putting the model onto your page - the original book has it but print is so small and I needed a version that I could use within a dissertation and like the other comment the new book does not have it in. I agree that the model is simplified and does not take into account a number of factors, but like all models it is indicative rather than utterly accurate. I agree that the warning and the call for radical change still stands today. Thank you for putting the model onto your page – the original book has it but print is so small and I needed a version that I could use within a dissertation and like the other comment the new book does not have it in.

I agree that the model is simplified and does not take into account a number of factors, but like all models it is indicative rather than utterly accurate. I agree that the warning and the call for radical change still stands today.

]]> Comment on Vensim Model Documentation Tool by Help! http://models.metasd.com/vensim-model-documentation-tool/comment-page-1/#comment-9691 Help! Sun, 04 Dec 2011 10:12:01 +0000 http://models.metasd.com/?p=217#comment-9691 We are looking for someone to make a Vensim model and I was wondering if you're up for the job and how much it would cost. You may contact me via the email address here. Thank you! We are looking for someone to make a Vensim model and I was wondering if you’re up for the job and how much it would cost. You may contact me via the email address here. Thank you!

]]> Comment on Social network valuation with logistic models by Et tu, Groupon? « MetaSD http://models.metasd.com/facebook-valuation-with-a-logistic-model/comment-page-1/#comment-9118 Et tu, Groupon? « MetaSD Mon, 21 Nov 2011 18:46:26 +0000 http://models.metasd.com/?p=411#comment-9118 [...] usual, the models are in my library. http://blog.metasd.com/2011/11/time-to-short-some-social-network-stocks/ Tweet This Post Post [...] [...] usual, the models are in my library. http://blog.metasd.com/2011/11/time-to-short-some-social-network-stocks/ Tweet This Post Post [...]

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