Operations Research, Systems Engineering and Industrial Engineering Commons^™

Detecting Non-Axisymmetric Instabilities In Fluid-Based Manufacturing Via Multi-View Tensor Analysis., Bidusi Khadka

Electronic Theses and Dissertations

Fluid-based manufacturing processes, such as inkjet printing and electrospinning, fabricate micro- and nano-scale structures with high precision, but are prone to complex fluid dynamics exhibiting axisymmetric and non-axisymmetric instabilities. Conventional monitoring often relies on single-camera inputs and symmetry assumptions, limiting the detection of three-dimensional anomalies like jet deflection. This study presents a novel multi-view streaming video-based anomaly detection framework to address this gap. The framework employs a modified Tensor Sequential Sampling (TSS) algorithm with edge-based sampling to capture geometric spatiotemporal features of each camera view using the videos obtained from an orthogonally positioned dual-camera setup. These features are fused with …

Trauma Network Design Considering Patient Safety And Cost., Lin Lin

Electronic Theses and Dissertations

Trauma, as the leading cause of mortality and morbidity for those under the age of 45 in the US, incurs trillions in annual economic costs. The time-sensitive nature of trauma treatment necessitates an effective, coordinated regional trauma system to optimize patient safety. However, the financial burden associated with trauma care, especially due to low-insured population, presents a significant challenge to the financial health of trauma centers (TCs). To address critical challenges in this domain and provide much-needed insights to trauma decision-makers regarding their trauma system cost, network design, and subsidy policy, this dissertation proposes 3 contributions. First, we introduce an …

Optimization And Simulation Models For Integrating Social Determinants In Assessing And Optimizing The Accessibility And Efficiency Of Community Pharmacy Networks., Md Morshedul Alam

Electronic Theses and Dissertations

Community pharmacies are essential components of the healthcare system, serving not only as points of medication access but also as providers of health consultations and preventive care. However, disparities in pharmacy access persist due to a combination of geographic, socioeconomic, and behavioral factors. This dissertation develops a comprehensive methodological framework to evaluate and improve accessibility to community pharmacies, integrating optimization, choice modeling, and discrete event simulation. First, we develop an Optimal Community-Pharmacy Assignment (OCPA) model to quantify geographic accessibility across a regional population network. The model minimizes risk-adjusted travel distances between population centers and pharmacies, incorporating social determinants of health …

A Causal Model Of Performance Shaping Factors For Human Reliability Analysis In Manufacturing., Prameet Ranjan Jha

Electronic Theses and Dissertations

Human reliability analysis is a critical component of probabilistic risk assessment, aimed at predicting and mitigating human errors in complex systems. This dissertation develops a novel approach to human reliability analysis in manufacturing by integrating structural equation modeling and Bayesian networks to improve the estimation of human error probabilities. Traditional human reliability assessment methods, such as the Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) and the Technique for Human Error Rate Prediction (THERP), provide structured techniques for estimating human error probabilities. However, these methods often fail to capture the complex interdependencies among performance shaping factors (PSFs), limiting their applicability in …

Engineering Solutions For The Transplant Supply Gap: Social Network Analysis, Artificial Intelligence, And Optimization In Living Kidney Donation., Joshua Nielsen

Electronic Theses and Dissertations

Kidney transplantation is the gold standard for treating end-stage renal disease, yet over 90,000 patients remain on the transplant waitlist. This dissertation introduces engineering-driven solutions to help reduce the transplant supply gap by addressing three challenges: illicit trafficking, donor recruitment, and evaluation inefficiencies. First, we model illicit organ trafficking networks using social network analysis. We demonstrate that targeting transplant clinics alone is insufficient to disrupt operations. Instead, disrupting the network requires detaining brokers who organize behind-the-scenes logistics—offering a more effective strategy for intervention. Second, we seek to identify a latent population of potential living donors who face barriers such as …

The Food Truck: A Multi-Product Newsvendor With Trans-Shipment Cost, Samuel Ajibola

Electronic Theses and Dissertations

The Newsvendor Problem is a key model in supply chain management that focuses on determining the optimal order quantity to minimize costs under uncertain demand. This thesis introduces the Food Truck Problem, an extension of the Newsvendor model that incorporates nonlinear transshipment costs for inventory transportation. In this context, a Food Truck must determine the optimal stock levels for multiple products while minimizing costs related to stock shortages, excess inventory, and transportation. Unlike traditional Newsvendor models, our approach explicitly considers a quadratic transshipment cost, which necessitates the use of Lagrangian duality and Karush-Kuhn-Tucker (KKT) conditions for analysis. Moreover, we apply …

Sensitive Grip Mounting Surfaces For Physical Human-Robot Interaction., Branden Shay

Electronic Theses and Dissertations

As the development of robotics becomes ever increasingly present in our society, the need for studying how humans and robots interact with each other becomes more of a necessity to be properly integrated in the changing world around us. In this thesis, we undertake the study and development of how to create a tactile human-robot operator interface to guide a robot perform a physical task. The implementation of tactile interfaces such as SkinCell sensor arrays emulating skin, and of a robotic handlebar fitted with tactile sensors are critical examples of the challenges that come with mounting and packaging such sensors …

Virtual Engagement: Can Law Enforcement Benefit From Utilizing Extended Reality In Their Training Systems?, Jacob Maxwell Read

Electronic Theses and Dissertations

Introduction: Extended reality (XR) technologies offer innovative training solutions for various industries, including healthcare, manufacturing, aviation, sports, military, and law enforcement. XR can provide a solution for training where job tasks are difficult or near impossible to train in real-life. A human factors research and design approach could provide an effective, low-risk, and cost and time-efficient option for integrating the use of XR technology into training for many industries. To advance this goal, this research answered two main research questions: (1) What training needs/challenges are best suited for an XR training system designed for law enforcement officers (LEOs)? (2) …

A Design Science And Implementation Framework For Studying Interruptions And Its Application In A Dental Clinic., Carsten Ziegler

Electronic Theses and Dissertations

Interruptions during dental treatment are frequent, and often have detrimental effects on quality of care, patient safety and processing times, and have an impact on provider satisfaction and performance. Interruptions can significantly increase the cognitive load on dental providers, making it hard for them to concentrate on complex procedures. Frequent interruptions also disrupt the workflow in general, leading to delays in treatment, which can reduce the overall throughput of a clinic. Unfortunately, there is no comprehensive approach to collectively (i) analyze interruptions in dental healthcare, (ii) design an intervention, and (iii) implement and sustain it. This research proposes a comprehensive …

A Study Of Group Effectiveness In A Virtual Reality Environment., Dalton Clay Sparks

Electronic Theses and Dissertations

Virtual Reality (VR) technology has revolutionized the study of team effectiveness, yet many studies in this domain lack a comprehensive approach, focusing narrowly on performance metrics. This thesis investigates VR team effectiveness by integrating traditional Team Effectiveness frameworks with VR-specific dynamics. Utilizing Data Envelopment Analysis (DEA) and Group Style Inventory (GSI), this study assesses teams within a VR environment, specifically a multiplayer submarine simulation game, IronWolfVR. Fifteen groups, totaling 45 participants, were observed for their collaborative gameplay, incorporating physiological measures (Heart Rate and Electrodermal Activity), team coordination dynamics, and various survey-based assessments (demographics, System Usability Scale, Simulator Sickness Questionnaire, and …

Automated Usability Evaluation Utilizing Log Files And Data Mining Techniques., Sima Shafaei

Electronic Theses and Dissertations

Usability evaluation is one of the essential aspects of software production. This evaluation should be done during the entire life cycle of a software application, from pre-production to production and post-production. However, the collection and evaluation of usability data can be a very challenging, time-consuming, and expensive task to be conducted manually, particularly for certain types of products and working conditions. These challenges may include the need to recruit participants fully engage and motivate them during evaluation, and factor in environmental conditions. Other challenges may include collecting data in real-world environments, especially when the users are geographically dispersed, minimizing evaluator …

Visibility Based Hospital Inpatient Unit Design., Uttam Karki

Electronic Theses and Dissertations

Patient fall is one of the adverse events in an inpatient unit of a hospital that can lead to disability and/or mortality. Healthcare literature suggests that increased visibility of patients by unit nurses is essential to improve patient monitoring and, in turn, reduce falls. However, such research has been descriptive in nature and does not provide an understanding of the characteristics of an optimal inpatient unit layout from a visibility-standpoint. This dissertation fills significant voids in this domain and adds much-needed realism to develop insights that hospital decision-makers can use to design their inpatient unit layout. Our first contribution (Chapter …

Experimental And Numerical Studies Of Laser Powder-Bed Fusion Process With Ti-6al-4v Powder: (1) Porosity And Mechanical Properties, And (2) Transient Phenomena In One- And Two-Dimensional Fabrications., Santosh K. Rauniyar

Electronic Theses and Dissertations

Laser powder bed fusion (L-PBF) process represents a form of metal additive manufacturing (AM) where micron-level powdered material is selectively melted and fused layer by layer to create intricate three-dimensional parts. This process involves rapid melting and solidification, leading to intense thermocapillary convection within the molten pool. The melt pool is a crucial element of the L-PBF process and refers to the localized region where the powder particles are melted and solidified to form each layer of the printed part. The shape and dimensions of the melt pool directly influence the accuracy and surface finish of the printed part. Precise …

Simulating The Impact Of Emissions Control On Economic Productivity Using Particle Systems And Puff Dispersion Model, Najam Khan

Electronic Theses and Dissertations

A simulation platform is developed for quantifying the change in productivity of an economy under passive and active emission control mechanisms. The program uses object-oriented programming to code a collection of objects resembling typical stakeholders in an economy. These objects include firms, markets, transportation hubs, and boids which are distributed over a 2D surface. Firms are connected using a modified Prim’s Minimum spanning tree algorithm, followed by implementation of an all-pair shortest path Floyd Warshall algorithm for navigation purposes. Firms use a non-linear production function for transformation of land, labor, and capital inputs to finished product. A GA-Vehicle Routing Problem …

Models And Algorithms For Trauma Network Design., Sagarkumar Dhirubhai Hirpara

Electronic Theses and Dissertations

Trauma continues to be the leading cause of death and disability in the US for people aged 44 and under, making it a major public health problem. The geographical maldistribution of Trauma Centers (TCs), and the resulting higher access time to the nearest TC, has been shown to impact trauma patient safety and increase disability or mortality. State governments often design a trauma network to provide prompt and definitive care to their citizens. However, this process is mainly manual and experience-based and often leads to a suboptimal network in terms of patient safety and resource utilization. This dissertation fills important …

Forecasting Hypotension By Learning From Multivariate Mixed Responses.., Jodie Ritter

Electronic Theses and Dissertations

Blood Pressure is the main determinant of blood flow to organs. Hypotension is defined as a systolic blood pressure less than 90 mmHg or a diastolic blood pressure less than 50 mmHg. The severity and duration of hypotension is associated with low blood flow to organs often result in organ damage and a high mortality rate. Predicting hypotension prior to surgery and during the surgery can reduce the incidence and duration resulting in better patient outcomes. This thesis uses preoperative bloodwork and vital signs as well as perioperative vital signs in 5-minute increments as inputs to forecast hypotension. Hypotension can …

Efficient Numerical Optimization For Parallel Dynamic Optimal Power Flow Simulation Using Network Geometry, Rylee Sundermann

Electronic Theses and Dissertations

In this work, we present a parallel method for accelerating the multi-period dynamic optimal power flow (DOPF). Our approach involves a distributed-memory parallelization of DOPF time-steps, use of a newly developed parallel primal-dual interior point method, and an iterative Krylov subspace linear solver with a block-Jacobi preconditioning scheme. The parallel primal-dual interior point method has been implemented and distributed in the open-source PETSc library and is currently available. We present the formulation of the DOPF problem, the developed primal dual interior point method solver, the parallel implementation, and results on various multi-core machines. We demonstrate the effectiveness our proposed block-Jacobi …

Drone Location And Scheduling Problems In Humanitarian Logistics., Zabih Ghelichi

Electronic Theses and Dissertations

Unmanned Aerial Vehicles (UAVs), commonly referred to as drones, are a promising technology for the last-mile delivery of medical and aid items in humanitarian logistics. In emergency scenarios, like disasters, where transportation networks are destroyed and people are stranded, drones can accelerate the delivery of urgently needed items, e.g., food and water, insulin shots and blood pressure pills, to those trapped in the disaster-affected areas. Drones can also provide logistics services in many non-emergency situations by delivering medical items, e.g., vaccine shots and lab specimens, to remote communities and hard-to-access locations. The contribution of using UAVs goes beyond merely having …

High-Density Parking For Autonomous Vehicles., Parag J. Siddique

Electronic Theses and Dissertations

In a common parking lot, much of the space is devoted to lanes. Lanes must not be blocked for one simple reason: a blocked car might need to leave before the car that blocks it. However, the advent of autonomous vehicles gives us an opportunity to overcome this constraint, and to achieve a higher storage capacity of cars. Taking advantage of self-parking and intelligent communication systems of autonomous vehicles, we propose puzzle-based parking, a high-density design for a parking lot. We introduce a novel method of vehicle parking, which leads to maximum parking density. We then propose a heuristic method …

Machine Learning Models For Lodi Indices., Lucas A. Bruns

Electronic Theses and Dissertations

Two indices published monthly by the Logistics and Distribution Institute (LoDI) predict changes in logistics and distribution activity levels nationally and regionally and are useful for organizations when planning projects and expenses. This research validates the current linear regression model, updates the index conversion method, and introduces machine learning models.

New source data are introduced to the models to validate the current linear regression model and a comparative analysis verifies that the current source data are robust. A rolling average is used for index conversion in place of a fixed reference month to reflect recent changes in employment levels.

Three …

Optimization With Interval Data: New Problems, Algorithms, And Applications., Mohsen Mohammadi Dehcheshmeh

Electronic Theses and Dissertations

The parameters of real-world optimization problems are often uncertain due to the failure of exact estimation of data entries. Throughout the years, several approaches have been developed to cope with uncertainty in the input parameters of optimization problems, such as robust optimization, stochastic optimization, fuzzy programming, parametric programming, and interval optimization. Each of these approaches tackles the uncertainty in the input data with different assumptions on the source of uncertainty and imposes different requirements on the returned solutions. In this dissertation, the approach we take is that of interval optimization, and more specifically, interval linear programming. The two main problems …

An Investigation Of Barriers And Facilitators To Living Kidney Donation, Rachel E. Crenshaw

Electronic Theses and Dissertations

There is strong interest in increasing living kidney donation, as the need for kidney transplants is quite high. Although previous studies outline some barriers and facilitators associated with donating, living kidney donation comprises only a small percentage of overall kidney transplants and thus further research on factors influencing the decision to donate is needed to find ways to increase the donor pool. Ten semi-structured interviews of living kidney donors were completed and analyzed for common themes that either support the current literature or surface additional barriers and facilitators. In addition, a systematic review and analysis of social medial support groups …

Designing An Autonomous Goods-To-Person Order Picking System: From Storage To Pick., Mina Shekari Ashgzari

Electronic Theses and Dissertations

In recent years, there has been an increased growth in e-commerce, which is a special case of a business-to-customer model. Among all the operations for fulfilling online orders, order picking has been the concern of many researchers and practitioners in the field of warehousing and material handling. This is due to very different technical assumptions and service expectations for online retailers compared to the case of business-to-business models. The most fundamental change in order processing, imposed by business-to-customer models, is shipping individual items or “eaches,” instead of cases and pallets, which is typical of business-to-business models. As a result, the …

Mathematical Models And Analysis For Demand Side Management In Residential Electricity Distribution Networks., Arnab Roy

Electronic Theses and Dissertations

Development of smart grids along with communication technologies have led to the increased attention and adoption of demand side management (DSM) in the residential sector. Among various DSM schemes, demand response (DR) is a market- based mechanism to shave peak electricity consumption at the system level. In the past decade, the academia has seen a growing literature studying load management methodologies for residential consumers. A typical demand response program has three important facets: the energy cost, comfort of the consumers and overall system efficiency. In this dissertation, we investigate and develop models for effective load control to minimize energy cost …

Gridhub: A Grid-Based, High-Density Material Handling System., Gang Hao

Electronic Theses and Dissertations

In the past twenty years, the share of e-commerce has increased (FRED, 2019). Since more and more activities, such as picking and sorting customers’ orders, are done in warehouses, high efficiency warehouses are in demand. Furthermore, the efficiency of warehouses is related to customer satisfaction (Colla and Lapoule, 2012). Storage systems are key components in warehouses, which are related to the efficiency of warehouse operations. In this dissertation, we address an automatic puzzle-based storage system under decentralized control. We call this system GridHub. GridHub meets standards of Industry 4.0 (Lasi et al., 2014), and it features high throughput with parallel …

A Machine Learning Approach For Allocating Route Cost To Customers For Transportation And Logistics Services., Alison Davis

Electronic Theses and Dissertations

Advancements in big data enabled management practices inspire logistics companies to study deeper into their transportation operations with a data driven approach. One such question asks: How can a logistics firm identify high-cost customers in their service network? In the presence of rich data on routes involving many customers, this thesis develops a framework to allocate a route cost among customers that the route serves, where each route is associated with multiple route features related to the transportation cost. Cost is allocated using the proportional allocation approach in combination with the random forest method in machine learning. First, this framework …

Effects Of Design Autonomy On The Flow Experience, Antonio F Coriano

Electronic Theses and Dissertations

Most modern workplace settings are laden with operating procedures aimed at standardizing action in the name of efficiency. The cost of this standardization is the autonomy of the operator. Mihaly Csikszentmihalyi stated the problem concisely in his 1975 work Beyond Boredom and Anxiety “… [M]ost of the institutions that take up our time…are organized around the assumption that serious work is grim and unpleasant. Because of this assumption, most of our time is spent doing unpleasant things”. An experiment was created to study and better understand how to redress this harmful situation. Sixteen subjects were given a SolidWorks computer-aided design …

Determining The Efficacy Of Additive Manufacturing For The Aerospace Spare Parts Supply Chain, Kyle O'Brien

Electronic Theses and Dissertations

This thesis investigates how additive manufacturing (AM) based on-demand part production can supplement or replace the traditional production and inventory in typical aerospace’s spare parts supply chain systems. This study focuses on the operational characteristics of AM and its impacts on the overall logistics of plant-level operations. To capture the microscopic operational aspects of the AM production, a discrete-event simulation based approach was adopted, with key AM operation resources (e.g. AM system, operator) and attributes (e.g. AM manufacturing speed, individual part characteristics and demands) accounted for in the modeling process. In addition, a benchmark warehouse inventory model was also established …

Joint Location And Inventory Models And Algorithms For Deployment Of Hybrid Electric Vehicle Charging Stations., Jie Zhang

Electronic Theses and Dissertations

This thesis describes a study of a novel concept of hybrid electric vehicle charging stations in which two types of services are offered: battery swapping and fast level-3 DC charging. The battery swapping and fast-charging service are modeled by using the M/G/s/s model and the M/G/s/$\infty$ model, respectively. In particular, we focus on the operations of joint battery swapping and fast charging services, develop four joint locations and inventory models: two for the deployment of battery swapping service, two for the deployment of hybrid electric vehicle charging service. The first model for each deployment system considers a service-level constraint for …

Optimization And Simulation Models To Improve Access To Organ Transplantation In The United States., Fatemeh Karami

Electronic Theses and Dissertations

Organ allocation in the U.S. is administrated by the United Network of Organ Sharing (UNOS). UNOS’s mission is to ensure fair and equitable allocation of organs as stated in the Code of Federal Regulations, which reads "neither place of residence nor place of listing shall be a major determinant of access to transplant". Despite the regulations, there has been endless controversy surrounding the disparity in access to organ transplants. In this context, the primary research goal in this dissertation was to reduce geographic disparity in access to transplants in the U.S., with a focus on heart and kidney transplants. To …