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Full-Text Articles in Computer Engineering
Calibration Of Complex System Dynamics Models: A Practioner's Report, Rod Walker, Wayne Wakeland
Calibration Of Complex System Dynamics Models: A Practioner's Report, Rod Walker, Wayne Wakeland
Systems Science Faculty Publications and Presentations
This paper is not a typical academic paper that is solidly grounded in the literature. Instead, this paper reports practitioner’s experiences in rebuilding and calibrating a very large system dynamics model. A prior version of this model had been in use for over 10 years in an ongoing executive training simulation. That model had never worked correctly in several key areas, requiring the outputs to be manually adjusted by very experienced facilitators during the course of the simulation. The present project rebuilt the system dynamics model, redesigned the parts that weren’t working, and calibrated the resulting model to match the …
A System Dynamics Model Of Pharmaceutical Opioids: Medical Use, Diversion, And Nonmedical Use, Teresa Schmidt, Wayne Wakeland, J. David Haddox
A System Dynamics Model Of Pharmaceutical Opioids: Medical Use, Diversion, And Nonmedical Use, Teresa Schmidt, Wayne Wakeland, J. David Haddox
Systems Science Faculty Publications and Presentations
A dramatic rise in the nonmedical of pharmaceutical opioids has presented the United States with a substantial public health problem. Nonmedical use of prescription pain relievers has become increasingly prevalent in the US over the last two decades, and diversion of medicines obtained by prescription is assumed to be a major source of supply for nonmedical opioid use. Policymakers striving to protect population health by ameliorating the adverse outcomes of nonmedical use of opioid analgesics could benefit from a systems-level model which reflects the complexity of the system and incorporates the full range of available data. To address this need, …
Comparing Discrete Simulation And System Dynamics: Modeling An Anti-Insurgency Influence Operation, Wayne Wakeland, Una E. Medina
Comparing Discrete Simulation And System Dynamics: Modeling An Anti-Insurgency Influence Operation, Wayne Wakeland, Una E. Medina
Systems Science Faculty Publications and Presentations
This paper contrasts the tradeoffs of modeling the same dynamic problem at a micro scale and at a macro scale of analysis: discrete system simulation (DS) versus continuous system simulation or system dynamics (SD). Both are employed to model the influence of entertainment education on terrorist system decay, with implications for field application. Each method optimizes different design, scope/scale, data availability/accuracy, parameter settings, and system sensitivities. Whether the research served by the computer model is applied or theoretical, DS tends to be useful for understand low-level individual unit/step influences on system change over time, whereas SD tends to shine when …
System Dynamics Implementation Of An Extended Brander And Taylor-Like Easter Island Model, Takuro Uehara, Yoko Nagase, Wayne Wakeland
System Dynamics Implementation Of An Extended Brander And Taylor-Like Easter Island Model, Takuro Uehara, Yoko Nagase, Wayne Wakeland
Systems Science Faculty Publications and Presentations
We provide a system dynamics implementation of a dynamic ecological economics model. Dynamic economic models are often constrained to use functions, such as the Cobb-Douglas function, chosen “conveniently” to allow for analytic solutions. The C-D function, however, suffers from its fixed elasticity that does not allow for the substitutability between man-made capital and natural capital to change, which is vital for economic sustainability. Using system dynamics removes this constraint and enables more realistic ecological economics models containing functions not amenable to analytic solution. The base model is the natural resource and population growth model developed by Brander and Taylor (1998) …
The Case For Thoroughly Testing Complex System Dynamic Models, Wayne Wakeland, Megan Hoarfrost
The Case For Thoroughly Testing Complex System Dynamic Models, Wayne Wakeland, Megan Hoarfrost
Systems Science Faculty Publications and Presentations
In order to determine whether model testing is as useful as suggested by modeling experts, the full battery of model tests recommended by Forrester, Senge, Sterman, and others was applied retrospectively to a complex previously-published system dynamics model. The time required to carry out each type of test was captured, and the benefits that resulted from applying each test was determined subjectively. The resulting benefit to cost ratios are reported. These ratios suggest that rather than focusing primarily on sensitivity testing, modelers should consider other types of model tests such as extreme condition tests and family member tests. The study …