Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 8 of 8

Full-Text Articles in Systems Engineering

Decision-Analytic Models Using Reinforcement Learning To Inform Dynamic Sequential Decisions In Public Policy, Seyedeh Nazanin Khatami Mar 2022

Decision-Analytic Models Using Reinforcement Learning To Inform Dynamic Sequential Decisions In Public Policy, Seyedeh Nazanin Khatami

Doctoral Dissertations

We developed decision-analytic models specifically suited for long-term sequential decision-making in the context of large-scale dynamic stochastic systems, focusing on public policy investment decisions. We found that while machine learning and artificial intelligence algorithms provide the most suitable frameworks for such analyses, multiple challenges arise in its successful adaptation. We address three specific challenges in two public sectors, public health and climate policy, through the following three essays. In Essay I, we developed a reinforcement learning (RL) model to identify optimal sequence of testing and retention-in-care interventions to inform the national strategic plan “Ending the HIV Epidemic in the US”. …


Optimization Of Islanded Utility-Microgrids After Natural Disasters, Rodney Kizito Aug 2021

Optimization Of Islanded Utility-Microgrids After Natural Disasters, Rodney Kizito

Doctoral Dissertations

Natural disasters can cause widespread disturbances/power outages within distribution networks and hinder a utility’s ability to provide uninterrupted power supply to the critical public buildings (e.g., hospitals, grocery stores, fire, police and gas stations) within the utility’s serviced region. Backup generators, which are typically relied on during power interruptions, have limited capacities and have been reported to experience failures during usage. Microgrids, defined as localized power grids that incorporate distributed generators (DGs) and energy storage systems (ESSs) to allow them to operate independent of the main grid (i.e., island mode), can help utilities provide disaster relief power supply to critical …


Theory And Practice Of Supply Chain Synchronization, Michael Prokle Nov 2017

Theory And Practice Of Supply Chain Synchronization, Michael Prokle

Doctoral Dissertations

In this dissertation, we develop strategies to synchronize component procurement in assemble-to-order (ATO) production and overhaul operations. We focus on the high-tech and mass customization industries which are not only considered to be very important to create or keep U.S. manufacturing jobs, but also suffer most from component inventory burden. In the second chapter, we address the deterministic joint replenishment inventory problem with batch size constraints (JRPB). We characterize system regeneration points, derive a closed-form expression of the average product inventory, and formulate the problem of finding the optimal joint reorder interval to minimize inventory and ordering costs per unit …


Modeling The Economic And Environmental Performance Of Offshore Wind Energy, Alexana Cranmer Jul 2017

Modeling The Economic And Environmental Performance Of Offshore Wind Energy, Alexana Cranmer

Doctoral Dissertations

Offshore wind is a growing source of energy globally. Like any energy technology, it has impacts on the environment. In the case of renewable energy, we need a way to consider the environmental benefits as well as the environmental costs. This dissertation develops a set of models to examine the economic and environmental costs and benefits and the trade-offs between them. We ask how much offshore wind energy should be sited, and where should that offshore wind energy be located? The first model estimates the economic impact of wake interactions between wind farms. Wind farm sites are chosen through a …


Developing An Optimal Model For Infant Home Visitation, Isaac Atuahene Aug 2015

Developing An Optimal Model For Infant Home Visitation, Isaac Atuahene

Doctoral Dissertations

The United States, Great Britain, Denmark, Canada and many other countries have accepted home visitation (HV) as a promising strategy for interventions for infants after births and for their mothers. Prior HV studies have focused on theoretical foundations, evaluations of programs, cost/benefit analysis and cost estimation by using hospital/payer/insurance data to prove its effectiveness and high cost. As governments and private organizations continue to fund HVs, it is an opportune time to develop and formulate operations research (OR) models of HV coverage, quality and cost so they might be used in program implementation as done for adult home healthcare (HHC) …


Stochastic Models For Capacity Planning In Healthcare Delivery: Case Studies In An Outpatient, Inpatient And Surgical Setting, Asli Ozen Aug 2014

Stochastic Models For Capacity Planning In Healthcare Delivery: Case Studies In An Outpatient, Inpatient And Surgical Setting, Asli Ozen

Doctoral Dissertations

U.S. healthcare system has become far too complex and costly to sustain and operations research has much to contribute in improving health systems by addressing a large spectrum of problems. We study capacity planning in healthcare while considering the case-mix of patients, using stochastic modeling in different application areas: primary care, inpatient bed allocation and (spine) surgery scheduling. This body of work was developed over four years of collaborative research with hospitals and healthcare providers. The main objective of our research in primary care is to optimize the patient mix of primary care physicians in a group practice to maximize …


Interpreting, Stephanie Jo Kent Aug 2014

Interpreting, Stephanie Jo Kent

Doctoral Dissertations

What do community interpreting for the Deaf in western societies, conference interpreting for the European Parliament, and language brokering in international management have in common? Academic research and professional training have historically emphasized the linguistic and cognitive challenges of interpreting, neglecting or ignoring the social aspects that structure communication. All forms of interpreting are inherently social; they involve relationships among at least three people and two languages. The contexts explored here, American Sign Language/English interpreting and spoken language interpreting within the European Parliament, show that simultaneous interpreting involves attitudes, norms and values about intercultural communication that overemphasize information and discount …


Multi-Modular Integral Pressurized Water Reactor Control And Operational Reconfiguration For A Flow Control Loop, Sergio Ricardo Pereira Perillo Dec 2010

Multi-Modular Integral Pressurized Water Reactor Control And Operational Reconfiguration For A Flow Control Loop, Sergio Ricardo Pereira Perillo

Doctoral Dissertations

This dissertation focused on the IRIS design since this will likely be one of the designs of choice for future deployment in the U.S and developing countries. With a net 335 MWe output IRIS novel design falls in the “medium” size category and it is a potential candidate for the so called modular reactors, which may be appropriate for base load electricity generation, especially in regions with smaller electricity grids, but especially well suited for more specialized non-electrical energy applications such as district heating and process steam for desalination. The first objective of this dissertation is to evaluate and quantify …