Digital Commons Network^™

Routing Problems Through The Lens Of Hybrid Algorithms, Sasan Mahmoudinazlou

USF Tampa Graduate Theses and Dissertations

This dissertation explores novel approaches to address complex combinatorial optimization challenges in transportation and routing scenarios. Three sets of contributions are presented, each encapsulated in a chapter. The first set of contributions introduces a pioneering hybrid genetic algorithm meticulously crafted to address the intricacies of the Traveling Salesman Problem with Drone (TSPD) and the Flying Sidekick Traveling Salesman Problem (FSTSP). These emerging problems involve the strategic use of both ground-based trucks and aerial drones for efficient package delivery. Our algorithm stands out by leveraging sophisticated chromosomes and dynamic programming, allowing for broad exploration by the genetic algorithm and effective exploitation …

Knowledge Integration In Domain-Informed Machine Learning And Multi-Scale Modeling Of Nonlinear Dynamics In Complex Systems, Phat K. Huynh

USF Tampa Graduate Theses and Dissertations

Nonlinear dynamical systems have been extensively used to model various phenomena in the changing world around us, especially in science and engineering fields. Thanks to breakthrough advancements in sensing technologies, an increasingly high volume of multi-modal sensor data has been collected, which enables us gain better insights into complex systems dynamics and build sophisticated data-driven machine-learning-based dynamic models without having the access to the underlying governing equations. However, integrating domain-specific knowledge in machine learning algorithms remains pivotal for various reasons: it promises enhanced predictive accuracy, better model interpretability, and increased generalizability. This dissertation delves into three core research questions, each …

The Aging Workforce: How It Relates To Incident Rates Within A Distribution Warehouse And A Chemical Manufacturing Building, Elisabeth V. Jones

USF Tampa Graduate Theses and Dissertations

Over the past 20 years or so, the average age of the global population has slowly increased. This is due to low birth rates as well as increased life expectancy. With this global population aging, there has also been a shift in the global labor market causing a trend termed the “aging workforce.” However, with the aging workforce comes a new set of issues for the health and safety professional because they create new hazards. This is due mostly because of the body undergoing physical, psychological, and cognitive decline as someone ages which causes decreased capabilities. Thus, the purpose of …

Cyber-Physical Multi-Robot Systems In A Smart Factory: A Networked Ai Agents Approach, Zixiang Nie

USF Tampa Graduate Theses and Dissertations

This dissertation focuses on addressing the technical challenges of non-stationarity in smart factories through the use of cyber-physical AI agents. Industry 4.0 and smart manufacturing with smart factories as a central role, have a growing demand for Just-in-Time (JIT) and on-demand production, as well as mass customization—all while maintaining high productivity, resource efficiency and resilience. This research positions Multi-Robot Systems (MRS)-driven smart factories. The heterogeneous production and transportation robots in an MRS collaborate to form multiple real-time adjusted production flows achieving the flexibility to accommodate such on-demand, mass customization.

However, the implementation of MRS introduces new sets of challenges, including …

Process Automation And Robotics Engineering For Industrial Processing Systems, Drake Stimpson

USF Tampa Graduate Theses and Dissertations

Automation in industrial systems applications has emerged as the fundamental solution for improving quality, production rate, and efficiency of a process. Much of the recent popularity surrounding the transition of processes from manually operated tasks to automated systems can be attributed to the concept of Industry 4.0, which outlines the fundamental guidelines for integrating cyber-physical systems into industrial processes. Due to rapid advancement of technology in robotics and automation as well as the increase in accessibility of resources to this technology, the capability to develop automated systems has become feasible for small-scale enterprise. This work presents a two-part initiative to …

Stochastic Models For Resilience Assessment And Improvement, Weimar Ardila Rueda

USF Tampa Graduate Theses and Dissertations

Resilience refers to the ability of a system to absorb and mitigate the impact of potential disruptions and return to normal operational conditions. The above notion of resilience allows us to distinguish two stages in a system's post-disruption response, the absorptive dimension and the recovery dimension. The absorptive dimension is related to a system's robustness and capacity to mitigate initial loss posterior to a disruption. Meanwhile, the recovery dimension is the system's rapidity to return and reach an acceptable level of functionality after the disruption occurrence.

A social-physical (SP) system's post-disruption response is related to its resilience capacity so building …

Degradation Performance Modeling And Optimal Maintenance Planning Of Deteriorating Critical Infrastructures, Hung Q. Nguyen

USF Tampa Graduate Theses and Dissertations

Serving as the backbone of the nation’s economy, a large and growing number of deteriorating critical infrastructures, such as transportation and water infrastructures, are underperforming, aging, becoming structurally deficient, and must be repaired or replaced. Due to the influence of a variety of factors (e.g., material structure, design, operation, and environmental conditions) at different phases of lifecycle and the costly data acquisition process, field degradation of deteriorating infrastructures is highly uncertain with limited degradation data. The co-location and spatial proximity between many infrastructures, such as road and water infrastructures, further makes them physically and operationally interdependent. The sheer deterioration of …

Computational Methods For Solving The Combinatorial Optimization Problems In Transportation, Xufei Liu

USF Tampa Graduate Theses and Dissertations

This dissertation discusses three transportation problems. The first problem is a bi-level optimization problem that simultaneously optimizes facility locations and network design in hazardous materials transportation. In the upper level, the leader intends to reduce the facility setup cost and the hazmat exposure risk, by choosing facility locations and road segments to close for hazmat transportation. When making such decisions, the leader anticipates the response of the followers who want to minimize the transportation costs. A robust optimization approach with multiplicative uncertain parameters and polyhedral uncertainty sets is applied to deal with the uncertain risk and demand.

The second problem …

Statistical Monitoring The Quality Of Healthcare Services, Yanqing Kuang

USF Tampa Graduate Theses and Dissertations

In today’s healthcare industry, quality of care is a growing focus in the delivery of healthcare. To improve the quality of care in healthcare delivery, many studies focus on the longterm operational decision making to meet the expectations of healthcare providers and users, such as medical resource allocation, bed planning, staff scheduling, etc. These problems are typically parts of long-term operational decision making, however, time is essential in healthcare system. To ensure the adherence to a high quality of care and detect deterioration in real time, the quality of service should be measured over days or hours instead of just …

Healthcare Data Analytics For Predicting Health Outcomes Of Older Adults And Emergency Responses Of Aged Care Facilities, Nazmus Sakib

USF Tampa Graduate Theses and Dissertations

The United States (US) is experiencing rapid growth in its older adult population, who may suffer from multiple chronic diseases, injuries, and impairments. To meet with the excess demand without compromising the quality of care for older adults, the current aged care systems, such as nursing home systems, will face unprecedented challenges of healthcare resource shortage with rising costs. Accurate prediction of health outcomes of individual older adults will facilitate the aged care professionals to better prioritize healthcare resources for the most at-risk individuals with more focused care and provide more proactive and individualized treatment and care delivery. In addition, …

Analysis And Modeling Of Strategic Interactions In Health Systems To Improve Patient Care Access, Jorge A. Acuña Melo

USF Tampa Graduate Theses and Dissertations

Affordable health care access that provides well-coordinated and high-quality services on time is a goal that governments and health organizations strive for. Regrettably, most countries deal with access problems that affect the population's health, such as long waiting lists for specialized medical services, overcrowding of emergency departments, and high health prices. In the present doctoral dissertation, I model and analyze the strategic interactions that inhabit the health system machinery to uncover possible structural problems that led to the aforementioned issues. The study involves operation research, data science, and game theory techniques to address the health care access predicament.

Each research …

Data-Informed Decision Support To Improve Pediatric And Maternal Care Quality Under Medicaid Managed Care Settings, Hasan Symum

USF Tampa Graduate Theses and Dissertations

Over the last two decades, the United States has spent almost twice as much per person in healthcare compared to most other wealthy countries. However, this higher spending has not necessarily transformed into improved quality of care; According to World Health Organization reports, the US now ranks 39th for child health and wellbeing and worst in maternal care among developed nations. In terms of proportion of preventable hospital visits, low-risk cesarean sections, and avoidable maternal morbidity/death, the U.S. is among the highest compared with the peer nations. The prevalence of these adverse outcomes in pediatric and obstetric care is particularly …

Strategies For Achieving The United States Health System's Quadruple Aim By Enhancing The Primary Care Level, Jennifer L. Mendoza-Alonzo

USF Tampa Graduate Theses and Dissertations

The quadruple aim is an approach to optimize the performance of the health system in the United States and consists of four dimensions. The main objective is to improve the population's health, followed by reducing cost, improving patients' experience, and increasing providers' satisfaction. In the present doctoral dissertation, I explore three strategies that help accomplish the quadruple aim at the primary care level. The analysis combines data science and operation research principles to address health system engineering questions.

Each strategy proposed in this document emphasizes one objective more than another; however, all of them in conjunction serve to attain the …

Heterogeneous Performance Modeling With Applications In Healthcare And Reliability Engineering, Xuxue Sun

USF Tampa Graduate Theses and Dissertations

In both health systems engineering and reliability engineering, individual units, such as patients and product units, often exhibit highly heterogeneous performance due to the influences of various observed individual characteristics and unobserved/unknown factors. Successful modeling of the heterogeneous performance of individual units is of great importance. It will not only facilitate the identification and quantification of influencing factors for improving performance of individual units, but also improve prediction accuracy of their future performance. This will further facilitate better decisions, such as cost-effective and adaptive healthcare resource planning decision, and proactive maintenance policy at reduced cost. However, due to the highly …

The Utilization Of Shared Energy Storage In Energy Systems: Design, Modeling And Optimization, Rui Dai

USF Tampa Graduate Theses and Dissertations

Energy storage (ES) plays a significant role in modern smart grids and energy systems. With the advances of ES technologies, efficiently applying ES to energy systems has become the bottleneck for achieving the benefits of ES. The traditional approach of utilizing ES is the so-called distributed framework in which there is a separate ES for each individual user. Due to the inherent limits in the distributed framework such as cost inefficiency and space limitations, many studies have promoted to utilize a shared ES in energy systems to further exploit the potentials of ES. However, current studies always focus on maximizing …

Efficient Neural Architecture Search With Multiobjective Evolutionary Optimization, Maria Gabriela Baldeón Calisto

USF Tampa Graduate Theses and Dissertations

Deep neural networks have become very successful at solving many complex tasks such as image classification, image segmentation, and speech recognition. These models are composed of multiple layers that have the capacity to learn increasingly higher-level features, without prior handcrafted specifications. However, the success of a deep neural network relies on finding the proper configuration for the task in hand. Given the vast number of hyperparameters and the massive search space, manually designing or fine-tuning deep learning architectures requires extensive knowledge, time, and computational resources.

There is a growing interest in developing methods that automatically design a neural network´s architecture, …

Using Optimization Methods For Solving Problems In Sustainable Urban Mobility And Conservation Planning, Zulqarnain Haider

USF Tampa Graduate Theses and Dissertations

This dissertation considers three separate optimization problems related to sustainable urban and environmental systems. The first problem relates to the nightly relocation and recharging operations for Free-floating electric vehicle sharing (FFEVS) systems. Such operations involve a crew of drivers to move the shared electric vehicles (EVs), and a fleet of shuttles to transport those drivers. Mixed integer programs are used to model the relocation and recharging operations. Two approaches are devised: sequential and synchronized approaches. In the sequential approach, the movement of EVs is first decided, then the routing of shuttles and drivers is determined. In the synchronized approach, all …

Identification Of Patterns And Disruptions In Ambient Sensor Data From Private Homes, Yan Wang

USF Tampa Graduate Theses and Dissertations

The world’s population is rapidly aging and the increasing demand for home and health care services from this aging population brings unprecedented challenges to the economy and society. Ambient-assisted smart homes, residences equipped with ambient sensors to monitor the resident’s daily activities in a continuous and unobtrusive way, present great potential to manage the growing care service needs of this older population segment, and enable them to age-in-place.

Despite growing research, using ambient sensor data from private homes to monitor daily activities, health and wellness still faces significant challenges. To study ambient sensor data from private homes where annotated data …

Some Recent Advances In Design Of Bayesian Binomial Reliability Demonstration Tests, Suiyao Chen

USF Tampa Graduate Theses and Dissertations

Reliability demonstration test (RDT) is one of important reliability assurance activities to demonstrate products' quality over time. Binomial RDT (BRDT) is one class of RDTs with appealing features, such as less failure monitoring efforts and fewer reliability modeling assumptions. Integrating with Bayesian method further allows prior knowledge incorporation for potential test sample size reduction. However, conventional designs often assume the binary failure states (i.e., success and failure) and consider a single objective of minimizing the testing cost with limited planning horizon. In this dissertation, a series of RDT designs are proposed and studied by advancing the conventional Bayesian BRDT designs …

On The Convergence Of Transportation And Power Systems In Smart And Connected Communities, Kevin A. Melendez

USF Tampa Graduate Theses and Dissertations

Even though the total number of light-duty vehicles in the U.S. is expected to increase by 2030, total fuel consumption is expected to significantly decrease in the same timeframe. This contradictory behavior is in part explained by the increasing utilization of electricity as the primary source of energy in the transportation sector. Due to its potential to decrease dependency on fossil fuels, electric transportation has become a promising approach to alleviate the increasing environmental crisis. Passenger car markets are expected to experience a flood of new Electric vehicles (EVs) in the next few years. EVs are considered effective resources to …

Algorithms For Multi-Objective Mixed Integer Programming Problems, Alvaro Miguel Sierra Altamiranda

USF Tampa Graduate Theses and Dissertations

This thesis presents a total of 3 groups of contributions related to multi-objective optimization. The first group includes the development of a new algorithm and an open-source user-friendly package for optimization over the efficient set for bi-objective mixed integer linear programs. The second group includes an application of a special case of optimization over the efficient on conservation planning problems modeled with modern portfolio theory. Finally, the third group presents a machine learning framework to enhance criterion space search algorithms for multi-objective binary linear programming.

In the first group of contributions, this thesis presents the first (criterion space search) algorithm …

Dynamic Pricing Of Electricity And Demand Response In Smart Communities, Vignesh Subramanian

USF Tampa Graduate Theses and Dissertations

Grid modernization using advanced metering infrastructure (AMI) will continue to enhance timely communication among the system operator (SO), producers, and consumers. This will further empower the vision of dynamic pricing and demand side management (DSM). The phrase dynamic pricing in this dissertation refers to the practice of disclosing binding prices of electricity just ahead of consumption. As regards DSM, the focus is on collective demand response (DR) by aggregators managing consumers’ loads in smart and connected communities (households, businesses, industries and aggregation of electric vehicle batteries). However, practitioners and researchers alike have expressed the fear that dynamic pricing may cause …

Statistical Monitoring Of Queuing Networks, Yaren Bilge Kaya

USF Tampa Graduate Theses and Dissertations

Queuing systems are important parts of our daily lives and to keep their operations at an efficient level they need to be monitored by using queuing Performance Metrics, such as average queue lengths and average waiting times. On the other hand queue lengths and waiting times are generally random variables and their distributions depend on different properties like arrival rates, service times, number of servers. We focused on detecting the change in service rates in this report. Therefore, we monitored queues by using Cumulative Sum(CUSUM) charts based on likelihood ratios and compared the Average Run Length values of different service …

Physical And Social Systems Resilience Assessment And Optimization, Daniel Romero Rodriguez

USF Tampa Graduate Theses and Dissertations

Resilience has been measured using qualitative and quantitative metrics in engineering,economics, psychology, business, ecology, among others. This dissertation proposes a resilience metric that explicitly incorporates the intensity of the disruptive event to provide a more accurate estimation of system resilience. A comparative analysis between the proposed metric and average performance resilience metrics for linear and nonlinear loss and recovery functions suggests that the new metric enables a more objective assessment of resilience for disruptions with different intensities. Moreover, the proposed metric is independent of a control time parameter. This provides a more consistent resilience estimation for a given system and …

Analysis Of A Potential A(H7n9) Influenza Pandemic Outbreak In The U.S., Walter A. Silva Sotillo

USF Tampa Graduate Theses and Dissertations

This dissertation presents a collection of manuscripts that describe development of models and model implementation to analyze impact of potential A(H7N9) pandemic influenza outbreak in the U.S. Though this virus is still only animal-to-human transmittable, it has potential to become human-to-human transmittable and trigger a pandemic. This work is motivated by the negative impact on human lives that this virus has already caused in China, and is intended to support public health officials in preparing to protect U.S. population from a potential outbreak of pandemic scale.

An agent-based (AB) simulation model is used to replicate the social dynamics of the …

Decision Support Models For A Few Critical Problems In Transportation System Design And Operations, Ran Zhang

USF Tampa Graduate Theses and Dissertations

Transportation system is one of the key functioning components of the modern society and plays an important role in the circulation of commodity and growth of economy. Transportation system is not only the major influencing factor of the efficiency of large-scale complex industrial logistics, but also closely related to everyone’s daily life. The goals of an ideal transportation system are focused on improving mobility, accessibility, safety, enhancing the coordination of different transportation modals and reducing the impact on the environment, all these activities require sophisticated design and plan that consider different factors, balance tradeoffs and maintaining efficiency. Hence, the design …

Strategies For Reducing Preventable Hospital Readmissions On Medicare Patients, Andres Patricio Garcia-Arce

USF Tampa Graduate Theses and Dissertations

The high expenditure of healthcare in the United States (U.S.) does not translate into better quality of care. Indeed, the U.S. healthcare system is recognized by its lack of efficiency and waste (which represents about 20% of the country’s healthcare expenses). Lack of coordination is one of the most referenced causes of waste in the U.S. healthcare system, and preventable hospital readmissions have been acknowledged to be evidence of poor coordination of care. In fiscal year 2013, the Centers for Medicare and Medicaid Services (CMS) established financial penalties for inpatient care reimbursements in hospitals with excessive readmissions. All the same, …

Optimal Bidding Strategy For A Strategic Power Producer Using Mixed Integer Programming, Sayed Abdullah Sadat

USF Tampa Graduate Theses and Dissertations

The thesis focuses on a mixed integer linear programming (MILP) formulation for a bi-level mathematical program with equilibrium constraints (MPEC) considering chance constraints. The particular MPEC problem relates to a power producer’s bidding strategy: maximize its total benefit through determining bidding price and bidding power output while considering an electricity pool’s operation and guessing the rival producer’s bidding price. The entire decision-making process can be described by a bi-level optimization problem. The contribution of our thesis is the MILP formulation of this problem considering the use of chance constrained mathematical program for handling the uncertainties.

First, the lower-level poor operation …

Oversampling Methods For Imbalanced Dataset Classification And Their Application To Gynecological Disorder Diagnosis, Iman Nekooeimehr

USF Tampa Graduate Theses and Dissertations

In many applications, the dataset for classification may be highly imbalanced where most of the instances in the training set may belong to some of the classes (majority classes), while only a few instances are from the other classes (minority classes). Conventional classifiers will strongly favor the majority class and ignore the minority instances. The imbalance problem can occur in both binary data classification and also in ordinal regression. Ordinal regression is a supervised approach for learning the ordinal relationship between classes. Extensive research has been performed for addressing imbalanced datasets for binary classification; however, current methods do not address …

Rule-Based Risk Monitoring Systems For Complex Datasets, Mona Haghighi

USF Tampa Graduate Theses and Dissertations

In this dissertation we present rule-based machine learning methods for solving problems with high-dimensional or complex datasets. We are applying decision tree methods on blood-based biomarkers and neuropsychological tests to predict Alzheimer’s disease in its early stages. We are also using tree-based methods to identify disparity in dementia related biomarkers among three female ethnic groups. In another part of this research, we tried to use rule-based methods to identify homogeneous subgroups of subjects who share the same risk patterns out of a heterogeneous population. Finally, we applied a network-based method to reduce the dimensionality of a clinical dataset, while capturing …