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Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering
Parameter Estimation For Patient Enrollment In Clinical Trials, Junyan Liu
Parameter Estimation For Patient Enrollment In Clinical Trials, Junyan Liu
Undergraduate Honors Theses
In this paper, we study the Poisson-gamma model for recruitment time in clinical trials. We proved several properties of this model that match our intuitions from a reliability perspective, did simulations on this model, and used different optimization methods to estimate the parameters. Although the behaviors of the optimization methods were unfavorable and unstable, we identified certain conditions and provided potential explanations for this phenomenon and further insights into the Poisson-gamma model.
Optimizing Combat Capabilities By Modeling Combat As A Complex Adaptive System, Steven Mains
Optimizing Combat Capabilities By Modeling Combat As A Complex Adaptive System, Steven Mains
Dissertations, Theses, and Masters Projects
Procuring combat systems in the Department of Defense is a balancing act where many variables, only some under control of the department, shift simultaneously. Technology changes non-linearly, providing new opportunities and new challenges to the existing and potential force. Money available changes year over year to fit into the overall US Government budget. Numbers of employees change through political demands rather than by cost-effectiveness considerations. The intent is to provide the best mix of equipment to field the best force against an expected enemy while maintaining adequate capability against the unexpected. Confounding this desire is the inability of current simulations …
Lookahead Scheduling In A Real-Time Context: Models, Algorithms, And Analysis, Benjamin J. Coleman
Lookahead Scheduling In A Real-Time Context: Models, Algorithms, And Analysis, Benjamin J. Coleman
Dissertations, Theses, and Masters Projects
Our research considers job scheduling, a special type of resource assignment problem. For example, at a cross-docking facility trucks must be assigned to doors where they will be unloaded. The cargo on each truck has various destinations within the facility, and the unloading time for a truck is dependent on the distance from the assigned door to these destinations. The goal is to assign the trucks to doors while minimizing the amount of time to unload all trucks.;We study scheduling algorithms for problems like the cross-docking example that are different from traditional algorithms in two ways. First, we utilize real-time, …
Low Damage Processing And Process Characterization, Xianmin Tang
Low Damage Processing And Process Characterization, Xianmin Tang
Dissertations, Theses, and Masters Projects
Two novel plasma sources (one neutral source and one pulsed inductively coupled plasma source) and ashing process characterization were investigated. The primary goal was to characterize these source properties and develop corresponding applications. The study includes process damage assessment with these two sources and another continuous wave (13.56MHz) plasma source. A global average simulation of the pulsed discharges was also included.;The transient plasma density and electron temperature from the double probe analysis were compared with single Langmuir probe results with sheath displacement corrections in pulsed discharges (200Hz--10kHz). The equivalent resistance method can be used effectively to analyze these double probe …
Fourier Analysis Of Frequency Domain Discrete Event Simulation Experiments, Mousumi Mitra Hazra
Fourier Analysis Of Frequency Domain Discrete Event Simulation Experiments, Mousumi Mitra Hazra
Dissertations, Theses, and Masters Projects
Frequency Domain Experiments (FDEs) were first used in discrete-event simulation to perform system parameter sensitivity analysis for factor screening in stochastic system simulations. FDEs are based on the intuitive assertion that if one or more system parameters are oscillated at fixed frequencies throughout a simulation run, then oscillations at the same frequencies will be induced in the system's response. Spectral (Fourier) analysis of these induced oscillations is then used to characterize and analyze the system. Since their introduction 12 years ago, significant work has been done to extend the applicability of FDEs to regression analysis, simulation optimization and gradient estimation. …