Operations Research, Systems Engineering and Industrial Engineering Commons^™

Teen Driver System Modeling: A Tool For Policy Analysis, Celestin Missikpode, Corrine Peek-Asa, Daniel V. Mcgehee, James Torner, Wayne Wakeland, Robert Wallace

Systems Science Faculty Publications and Presentations

Background: Motor vehicle crashes remain the leading cause of teen deaths in spite of preventive efforts. Prevention strategies could be advanced through new analytic approaches that allow us to better conceptualize the complex processes underlying teen crash risk. This may help policymakers design appropriate interventions and evaluate their impacts.

Methods: System Dynamics methodology was used as a new way of representing factors involved in the underlying process of teen crash risk. Systems dynamics modeling is relatively new to public health analytics and is a promising tool to examine relative influence of multiple interacting factors in predicting a health …

Reflections On Teaching System Dynamics Modeling To Secondary School Students For Over 20 Years, Diana Fisher

Systems Science Faculty Publications and Presentations

This paper contains the description of a successful system dynamics (SD) modeling approach used for almost a quarter-century in secondary schools, both in algebra classes and in a year-long SD modeling course. Secondary school students have demonstrated an ability to build original models from the news, write technical papers explaining their models, and present a newfound understanding of dynamic feedback behavior to an audience. The educational learning theory and instructional methods used for both the algebra and modeling courses are detailed, with examples. Successful student SD modeling experiences suggest the SD approach can expand the sophistication of topics that secondary …

Prediction -- The Quintessential Policy Model Validation Test, Wayne Wakeland

Systems Science Faculty Publications and Presentations

It is essential to objectively test how well policy models predict real world behavior. The method used to support this assertion involves the review of three SD policy models emphasizing the degree to which the model was able to fit the historical outcome data and how well model-predicted outcomes matched real world outcomes as they unfolded. Findings indicate that while historical model agreement is a favorable indication of model validity, the act of making predictions without knowing the actual data, and comparing these predictions to actual data, can reveal model weaknesses that might be overlooked when all of the available …

Modeling The Impact Of Simulated Educational Interventions On The Use And Abuse Of Pharmaceutical Opioids In The United States: A Report On Initial Efforts, Wayne Wakeland, Alexandra E. Nielsen, Teresa D. Schmidt, Dennis Mccarty, Lynn Webster, John Fitzgerald, J. David Haddox

Systems Science Faculty Publications and Presentations

Three educational interventions were simulated in a system dynamics model of the medical use, trafficking, and nonmedical use of pharmaceutical opioids. The study relied on secondary data obtained in the literature for the period of 1995 to 2008 as well as expert panel recommendations regarding model parameters and structure. The behavior of the resulting systems-level model was tested for fit against reference behavior data. After the base model was tested, logic to represent three educational interventions was added and the impact of each intervention on simulated overdose deaths was evaluated over a 7-year evaluation period, 2008 to 2015. Principal findings …

Using Agent Based Simulation And Game Theory Analysis To Study Information Sharing In Organizations – The Infoscape, Richard Donald Jolly, Wayne W. Wakeland

Systems Science Faculty Publications and Presentations

Information sharing in organizations, especially the impact of sharing freely versus not sharing, was studied using game theory and agent based simulation. A game theoretic analysis was performed, and Netlogo simulations were carried out wherein some agents hoarded information while others shared information. As expected, sharing was found to greatly increase the overall amount of information within the organization. Unexpectedly, agents who share acquire more information than hoarders. This is due to the synergy that develops between groups of agents who are sharing with each other. The density of the agents is important-as the density increases, the probability increases that …

Emergence Of Networks In Distance-Constrained Trade, Kumar Venkat, Wayne W. Wakeland

Systems Science Faculty Publications and Presentations

Long-distance trade has been rapidly increasing in recent years. As traders from around the world exchange goods, they form networks with traders as nodes and transactions as links. We use an agent-based model of a simple artificial economy to examine the emergence of trade networks when the distance between traders matters. Distance can become an issue if fuel for transportation becomes expensive or if greenhouse gas emissions from transportation become a major concern. We model the distance constraint as a transaction cost proportional to the amount of goods traded and the distance that those goods must be transported. We find …

Using Reconstructability Analysis For Input Variable Reduction: A Business Example, Stephen Shervais, Martin Zwick

Systems Science Faculty Publications and Presentations

We demonstrate the use of reconstructability analysis (RA) on the UCI Australian Credit dataset to reduce the number of input variables for two different analysis tools. Using 14 variables, an artificial neural net (NN) is able to predict whether or not credit was granted, with a 79.1% success rate. RA preprocessing allows us to reduce the number of independent variables from 14 to two different sets of three, which have success rates of 77.2% and 76.9% respectively. The difference between these rates and that of the 14-variable NN is not statistically significant. The three-variable rulesets given by RA achieve success …

A System Dynamics Model Of The Pacific Coast Rockfish Fishery, Wayne Wakeland, Olgay Cangur, Guillermo Rueda, Astrid Scholz

Systems Science Faculty Publications and Presentations

This paper presents a model of the dynamic behavior of the yellowtail rockfish of the Pacific Coast of the United States. The purpose of the model is to generate endogenously the historical data for fish population, fishing vessels, regulatory parameters, and fish harvest. The model was subjected to a variety of tests to determine its sensitivity to changes in key parameters and initial values, including extreme conditions. Model results indicate that acceptable biological catch and fleet capacity must be adjusted quickly in response to changing conditions, in order to improve fishery sustainability. Additional analysis reinforces the policy of setting the …

Global Optimization Studies On The 1-D Phase Problem, Martin Zwick, Byrne Elliot Lovell, Jim Marsh

Systems Science Faculty Publications and Presentations

The Genetic Algorithm (GA) and Simulated Annealing (SA), two techniques for global optimization, were applied to a reduced (simplified) form of the phase problem (RPP) in computational crystallography. Results were compared with those of "enhanced pair flipping" (EPF), a more elaborate problem-specific algorithm incorporating local and global searches. Not surprisingly, EPF did better than the GA or SA approaches, but the existence of GA and SA techniques more advanced than those used in this study suggest that these techniques still hold promise for phase problem applications. The RPP is, furthermore, an excellent test problem for such global optimization methods.

Variance And Uncertainty Measures Of Population Diversity Dynamics, Mark A. Bedau, Martin Zwick, Alan Bahm

Systems Science Faculty Publications and Presentations

We define variance and uncertainty measures of population diversity. Both measures have precise decompositions that we can exploit in analysis of evolutionary dynamics. We discuss how these measures are related and how they can be observed in artificial and natural evolving systems.

Improving Crystallographic Macromolecular Images: The Real-Space Approach, A. D. Podjarny, T. N. Bhat, Martin Zwick

Systems Science Faculty Publications and Presentations

Macromolecular crystallographicy is a unique tool for imaging the structures of proteins and nucleic acids. Images are obtained from the Fourier transform of the diffraction pattern of the crystal by use of X-ray, neutron, and / or electron scattering. When X-ray and neutron scattering are used only diffraction amplitudes are experimentally measured, and phases have to be obtained. Multiple isomorphous replacement (MIR) has been the technique of choice for solving this phase problem in the determination of most macromolecular structures. Unfortunately, the method is extremely time consuming, especially when compared with the solution techniques available for small molecules; moreover, structure …