System Dynamics in Water/Wastewater Mgmt
Posted: Mon Apr 14, 1997 7:05 pm
At 09:04 AM 3/8/97 +0100, Roberto Vacca Wrote:
>Dear Jaideep: I think there are serios fallacies hidden n the paucity of
>data acceptance. At ISIS, Rome, Italy we use SD, but never alone. After
>major drives to get data & assess their quality, we use lgistic
>substitution models [based on Volterra 3-parameter logistc equtions] and,
>where appropriate i.e. in regional o urban models, also econometric
>Input-Output models. We produced models of Rome city &are workig now on
>land use-transportation-energy-emissions-dispersion-environment on
>contract to European Commission in Brussels.
>Concerning data & xplanations, Galileo wrote:"whatever our senses and
>experience indicate, has to be put above any discourse - even if the
>latter
>sounds well founded. Look up in literture papers by C.Marchetti &
>N.Naikichenovich.
>Best. Roberto Vacca
>MC4634@mclink.it
Dear Roberto
Thanks for your reply. Your points are well-taken - ideally we would like
to have the best statistically valid parameters in SD models, but that is
not always possible. I view SD as a (VERY) extended way of back-of-the
envelope calculations - which are necessary because we have to deal with a
big and complex reality all the time, and so we cant always wait for the
best estimates. I really wonder if in social systems there can ever be any
fixed parameters - much of neoclassical economics and quantitative modeling
acts as if you can have E=mc^2 type equations to cleanly describe human
behavior. I doubt it, so we take a middle of the road (muddling-through
approach) between the verbal-emotional-intuitive and the
mathematical-analytical-objective.
Thanks for your valuable comments,
Regards
Jaideep
jm62004@Jetson.UH.EDU
****************************************
Jaideep Mukherjee, Ph. D.
Research Associate
Department of Industrial Engineering
University of Houston
4800 Calhoun Road
Houston, TX 77204-4812
Phone: 713 743 4181; Fax: 713 743 4190
****************************************
>Dear Jaideep: I think there are serios fallacies hidden n the paucity of
>data acceptance. At ISIS, Rome, Italy we use SD, but never alone. After
>major drives to get data & assess their quality, we use lgistic
>substitution models [based on Volterra 3-parameter logistc equtions] and,
>where appropriate i.e. in regional o urban models, also econometric
>Input-Output models. We produced models of Rome city &are workig now on
>land use-transportation-energy-emissions-dispersion-environment on
>contract to European Commission in Brussels.
>Concerning data & xplanations, Galileo wrote:"whatever our senses and
>experience indicate, has to be put above any discourse - even if the
>latter
>sounds well founded. Look up in literture papers by C.Marchetti &
>N.Naikichenovich.
>Best. Roberto Vacca
>MC4634@mclink.it
Dear Roberto
Thanks for your reply. Your points are well-taken - ideally we would like
to have the best statistically valid parameters in SD models, but that is
not always possible. I view SD as a (VERY) extended way of back-of-the
envelope calculations - which are necessary because we have to deal with a
big and complex reality all the time, and so we cant always wait for the
best estimates. I really wonder if in social systems there can ever be any
fixed parameters - much of neoclassical economics and quantitative modeling
acts as if you can have E=mc^2 type equations to cleanly describe human
behavior. I doubt it, so we take a middle of the road (muddling-through
approach) between the verbal-emotional-intuitive and the
mathematical-analytical-objective.
Thanks for your valuable comments,
Regards
Jaideep
jm62004@Jetson.UH.EDU
****************************************
Jaideep Mukherjee, Ph. D.
Research Associate
Department of Industrial Engineering
University of Houston
4800 Calhoun Road
Houston, TX 77204-4812
Phone: 713 743 4181; Fax: 713 743 4190
****************************************