Engineering Commons^™

Adversarial Attacks, Coarse Robustness, And Dataless Neural Networks: Novel Techniques For Improved Classification And Combinatorial Optimization, Ismail Alkhouri

Electronic Theses and Dissertations, 2020-2023

Neural networks (NN) have become a central component in most machine learning systems. However, studies have shown that these models are not robust against adversarial attacks. As such, in this dissertation, we explore four directions. In the first direction, we investigate adversarial attacks on two hierarchical classification (HC) models: the Flat HC (FHC), and the Top-Down HC (TDHC). In particular, we formulate attacks against these models by using convex programming. Through experimental results, it is shown that FHCs are more robust than TDHCs. Second, we formalize a new notion of coarse robustness that is defined with respect to a specified …

Bench- And Pilot-Scale Corrosion Control Inhibitor Effectiveness Studies For A Community's Blended Surficial And Brackish Groundwater Supply, Paula Campesino

Electronic Theses and Dissertations, 2020-2023

The United States Environmental Protection Agency regulates the lead and copper content of a public water system's finished water at the consumer's tap, through the Safe Drinking Water Act's Lead and Copper Rule (LCR), promulgated in 1991. This rule was recently changed through the LCR Revisions (LCRR), that took effect in 2021. The more stringent requirements of the LCRR motivated the City of Sarasota, Florida (City), to work with the University of Central Florida (UCF) on a study of the municipality's finished water corrosivity. Initially, this evaluation investigated the City's existing finished water corrosivity using linear polarization resistance (LPR) measurements …

The Development Of Computational Models For Melting-Solidification Applications Using The Volume-Of-Fluid Method, Brendon Cavainolo

Electronic Theses and Dissertations, 2020-2023

Fluids-related issues in the Aerospace industry are often multiphase in scope. Numerical modeling, such as computational fluid dynamics, is used to describe these problems, as they are difficult or impossible to describe analytically. This research uses computational fluid dynamics to describe multiphase problems related to melting-solidification and particle impingement. Firstly, a numerical model was established that uses the Volume-of-Fluid method to resolve a melting/solidifying particle. This model was verified against experiments and simplified analytical models, and a mesh independence study was done to ensure the results were independent of the mesh sizing. Next, the model was applied to two separate …

A Framework To Define And Quantify Leadership Styles Within Navy Engineering Units, Megan Praschak

Electronic Theses and Dissertations, 2020-2023

This study aimed to develop a framework for the U.S. Navy's leadership styles by assessing self-perceived leadership styles in a sample of reserve Engineering Duty Officers (EDOs) and the Senior Enlisted Leaders (SELs) in these technical units. Transformational and transactional leadership styles were examined using the Multifactor Leadership Questionnaire (MLQ) Form (Avolio & Bass, 2004), while the servant leadership style was analyzed using the Servant Leadership Self-Assessment Questionnaire (SLSQ) (Sandling, 2021). The effect of rank and the triad leadership position on leadership style was explored in this study. The survey was made available to all EDOs and SELs (n = …

Design And Control Of A Dual Active Bridge Converter For Electric Vehicle (Ev) And Photovoltaic (Pv) Applications, Md Safayatullah

Electronic Theses and Dissertations, 2020-2023

With the growing concerns of climate change due to fossil fuel-based electricity generation, solar integration to the grid is swiftly increasing. However, the intermittency of solar power is a major obstacle to harness it efficiently. Energy storage system (ESS) with its declining price over the last few years is a viable solution to address this issue. Another source of greenhouse gas emission is fossil fuel-based transportation system which is likely to be replaced by electric vehicles (EVs) in near future. To match the driving range of EVs with the internal combustion engine-based vehicle, fast and extreme fast charging infrastructure in …

Leveraging Signal Transfer Characteristics And Parasitics Of Spintronic Circuits For Area And Energy-Optimized Hybrid Digital And Analog Arithmetic, Adrian Tatulian

Electronic Theses and Dissertations, 2020-2023

While Internet of Things (IoT) sensors offer numerous benefits in diverse applications, they are limited by stringent constraints in energy, processing area and memory. These constraints are especially challenging within applications such as Compressive Sensing (CS) and Machine Learning (ML) via Deep Neural Networks (DNNs), which require dot product computations on large data sets. A solution to these challenges has been offered by the development of crossbar array architectures, enabled by recent advances in spintronic devices such as Magnetic Tunnel Junctions (MTJs). Crossbar arrays offer a compact, low-energy and in-memory approach to dot product computation in the analog domain by …

Examining Direct Load Control Within Demand Response Programs, Maria Bonina Zimath

Honors Undergraduate Theses

The power system is a complex entity with unique plant designs, control systems, and market strategies. For many years, engineers have developed advanced technology to keep the grid efficient and balanced. With the rise of renewable sources, some new technology and programs must be developed to keep the quality of the power system. Unlike traditional power plants, renewable energy is highly dependent on environmental factors, such as sunlight and wind, meaning the generation depends on an unpredictable source of fuel. As the grid moves to more sustainable sources, the power market faces a growing challenge of less control over the …

Understanding Changes In Land Use Patterns At A Parcel Level In Central Florida Counties (Orange, Seminole, Osceola), Youssef Mohamed Abdelaziz Elsebaie

Electronic Theses and Dissertations, 2020-2023

In Florida, a state with significant population growth, it is essential to understand how land use change and transportation interact. Understanding these interactions between land use and transport is useful for transportation planners and land use modelers. Hence, in this research, we attempt to quantify the impact of the transportation system on land use and vice-versa. The research, using high-resolution land use data from 2011 to 2019, builds a binary logistic regression model of land use change. The model accounts for various independent variables, including socio-demographic attributes, built environment characteristics, and transportation network variables. The data set covers GIS data …

Detonability Of A Rotating Detonation Combustor Seeded With Carbon/Hydrocarbon Particles At Fringe Operating Conditions, Matthew Hopwood

Electronic Theses and Dissertations, 2020-2023

The Rotating Detonation Combustor (RDC) has, in recent years, been a subject of great interest in the pressure-gain combustion research community. Researchers have been investigating the RDC as a potential improvement over current combustors in today's turbomachinery-based power generation systems. With the theoretical efficiency boost that detonations provide over deflagrating combustors, RDCs have the promise to be a next step in fuel/cost savings in the power generation industry. One mode of research to push an RDCs capabilities is the potential use of combustible carbon/hydrocarbon solid particles in addition to liquid or gaseous fuels. These particles are a source of high …

A Generalized Accelerated Failure Time Model To Predict Restoration Time From Power Outages, Tasnuba Binte Jamal

Graduate Thesis and Dissertation 2023-2024

Major disasters such as wildfire, tornado, hurricane, tropical storm, flooding cause disruptions in infrastructure systems such as power outage, disruption to water supply system, wastewater management, telecommunication failures, and transportation facilities. Disruptions in electricity infrastructures have negative impacts on sectors throughout a region, including education, medical services, financial, and recreation sectors. In this study, we introduce a novel approach to investigate the factors which can be associated with longer restoration time of power service after a hurricane. Considering restoration time as the dependent variable and utilizing a comprehensive set of county-level data, we have estimated a Generalized Accelerated Failure Time …

Enabling Large-Scale Transportation Electrification For Shared And Connected Mobility Systems, Md Rakibul Alam

Graduate Thesis and Dissertation 2023-2024

Owing to advancements in technology, substantial investments within the automotive industry, and the formulation of supportive state policies, the future landscape of the transportation sector is poised to witness a shift from traditional internal combustion engine vehicles (ICEVs) to electric vehicles (EVs). While EVs have made inroads in the market, they still face significant hurdles in the form of range anxiety and prolonged charging durations, inhibiting their widespread adoption. To tackle these challenges, a comprehensive approach to smart transportation electrification is proposed, emphasizing the pivotal roles of infrastructure development, particularly in the allocation of charging stations, and strategic operational decisions, …

Optimizing Biomechanical Models: Estimation Of Muscle Tendon Parameters And Ankle Foot Orthosis Stiffness, Sepehr Ramezani

Electronic Theses and Dissertations, 2020-2023

The complexity of the human musculoskeletal system presents challenges in accurately identifying its characteristics, particularly due to the presence of redundant actuators on a single joint. Non-invasive measures are necessary to overcome these challenges. Optimization algorithms have emerged as a crucial tool to advance subject-specific musculoskeletal modeling allows a more realistic representation of biomechanical behaviors, enhancing our understanding of human movement and enabling better clinical decision-making. Furthermore, optimization algorithms play a vital role in customizing rehabilitation and assistive devices, such as orthoses and prostheses. The current ankle-foot orthosis (AFO) stiffness measurement methods require bulky, complex designs, and often permanent modification …

Assessment Of Midblock Pedestrian Crossing Facilities Using Surrogate Safety Measures And Vehicle Delay, Nafis Anwari

Graduate Thesis and Dissertation 2023-2024

This dissertation has contributed to the pedestrian safety literature by assessing and comparing safety benefits and traffic efficiency among midblock Rectangular Rapid Flashing Beacon (RRFB) and Pedestrian Hybrid Beacon (PHB) sites. Video trajectory data were used to calculate pedestrian Surrogate Safety Measures (SSMs) and vehicles' delay. Regression models of SSMs and vehicles' delay revealed that PHB sites offer more safety benefits, at the expense of increased vehicles' delay, compared to RRFB sites. The presence of the PHB, weekday, signal activation, lane count, pedestrian speed, vehicle speed, land use mix, traffic flow, time of day, and pedestrian starting position from the …

Modeling Behavior And Vaccine Hesitancy For Predicting Daily Vaccination Inoculations Using Trends, Case, Death, And Twitter Sentiment Data, Talal Daghriri

Electronic Theses and Dissertations, 2020-2023

Over the past 100 years, epidemiological models have evolved to incorporate greater facets of the process. With the advent of social networking, massive computational power, population sentiment analysis can now be added to the epidemiological modeling process. Sentiment analysis is greater understanding of the fears, uncertainties, motivation, and trends of the public with respect to vaccination and associated events. Lack of public confidence in the efficacy of models, safety of vaccines, and appropriateness of policies confounds vaccine inoculation prediction. Sentiment analysis of social media is a seminal technique that accesses shared users' contents and tweets on the Twitter platform for …

Time-Specific Safety Performance Functions For Different Advanced Traffic Management Strategies, Jingwan Fu

Electronic Theses and Dissertations, 2020-2023

Time-specific Safety Performance Functions (SPFs) were proposed to achieve accurate and dynamic crash frequency predictions and bridge the gap between annual crash frequency prediction and real-time crash likelihood prediction. This research proposed time-specific SPFs considering the temporal variation in crashes and traffic characteristics. Firstly, the developed time-specific SPFs that include different ATM strategies (i.e., HOV, merge, diverge and reversible lanes segments) were investigated in this study. The results indicate that the traffic turbulence during specific hours would relate to crash occurrence. Further, the variables that represent the speed and occupancy differences between the HOV lanes/reversible lanes and general-purpose lanes were …

Optical Design Study Of A High-Resolution Spectrograph Utilizing Photonic Lanterns For A Large Fiber Array Telescope, Richard D'Alo

Graduate Thesis and Dissertation 2023-2024

Large area fiber array telescopes are a relatively modern development in the long history of telescope design and effectively create a single large equivalent aperture by combining many smaller unit telescopes at a fraction of the cost. In this study a spectrograph optical design is demonstrated that utilizes photonic lanterns in the input fiber feed for the Large Fiber Array Spectroscopic Telescope (LFAST) design concept, where photonic lanterns provide a simplified approach to the fiber feed originally proposed for LFAST. Conservation of etendue is applied to derive the relationship between slit size and photonic lantern ratio, and classical echelle spectrograph …

Spatial Ensemble Distillation Learning Based Real-Time Crash Prediction And Management Framework, Md Rakibul Islam

Graduate Thesis and Dissertation 2023-2024

Real-time crash prediction is a complex task, since there is no existing framework to predict crash likelihood, types, and severity together along with a real-time traffic management strategy. Developing such a framework presents various challenges, including not independent and identically distributed data, imbalanced data, large model size, high computational cost, missing data, sensitivity vs. false alarm rate (FAR) trade-offs, estimation of traffic restoration time after crash occurrence, and real-world deployment strategy. A novel spatial ensemble distillation learning modeling technique is proposed to address these challenges. First, large-scale real-time data were used to develop a crash likelihood prediction model. Second, the …

Acausal Modeling Of Wind Turbines With Validation And Control Studies, Kazi Ishtiak Mohsin

Graduate Thesis and Dissertation 2023-2024

This thesis involves the modeling, validation, and control studies of a Control-Oriented, Reconfigurable, and Acausal Floating Turbine Simulator (CRAFTS), that is currently under development. CRAFTS uses Modelica®, an object-oriented, declarative, multi-domain modeling language for physical system modeling in the Dymola environment. The CRAFTS simulator facilitates rapid dynamic simulation of wind turbines with various model variants and enables control co-design.

A major emphasis of this thesis is in the validation of the CRAFTS simulator for a 15-MW land-based wind turbine through several test cases. These test cases were collaboratively developed in conjunction with other participating research entities. CRAFTS has undergone rigorous …

Safety Considerations For Setting Variable Speed Limits On Freeways, Md Tarek Hasan

Graduate Thesis and Dissertation 2023-2024

This thesis focuses on evaluating the appropriate speed at which vehicles should travel under different traffic conditions on freeways and its impact on crash frequency. The common belief is that the lower speed results in fewer crashes as reduced speed provides drivers with more time to react effectively and avoid collisions. However, this perspective overlooks the interplay among traffic speed, average spacing between consecutive vehicles, and the distance available for stopping a vehicle. Hence, we propose a safety parameter termed ‘Safety Correlate' (SCORE), which is defined as the proportion of average spacing relative to the stopping distance. To determine the …

Understanding Workforce Agility At Nasa Kennedy Space Center, Ledlyne H. Vazquez

Graduate Thesis and Dissertation 2023-2024

This study aims to define workforce agility via a literature review and a conducted research survey of the Kennedy Space Center (KSC) Engineering workforce. The survey results will help us determine the workforce agility of the KSC engineering team and understand what has allowed them to transition from the Space Shuttle Program to the new Exploration Ground System (EGS) program. Structural Equation Modeling was used to develop a model of relationships to test the hypotheses. The results show that organizational practices and psychological empowerment significantly support workforce agility. The implications of this study for understanding the characteristics of workforce agility …

Ocean Vector Wind Measurement Potential From The Global Precipitation Measurement Mission Using A Combined Active And Passive Algorithm, Alamgir Hossan

Electronic Theses and Dissertations, 2020-2023

Ocean surface vector wind (OVW) is an essential parameter for understanding the physics and dynamics of the ocean-atmosphere system, thereby improving weather forecasting and climate studies. Satellite scatterometers, synthetic aperture radars, and polarimetric microwave radiometers have provided almost global coverage of ocean surface vector wind for the last four decades. Nonetheless, a consistent and uninterrupted long-time data record with the capability of resolving sub-diurnal variability has remained a critical challenge over the years. The Global Precipitation Measurement Mission (GPM) is a satellite mission designed to provide space-based precipitation information on a global scale with complete diurnal sampling. This dissertation presents …

Designing A Loving Robot: A Social Construction Analysis Of A Sex Robot Creator’S Vision, Annette Masterson

Human-Machine Communication

In 2018, one of the world’s first sex robots was released by CEO Matt McMullen and his company, RealDoll. With artificial intelligence capabilities, the Harmony model is meant to support and converse with users. Using a social construction of technology theory lens, this study develops the theory’s fourth level of analysis, emphasizing mass media’s construction abilities. A critical discourse analysis of 38 publicity interviews found a tendency to emphasize the companionship of sex robots while envisioning a future where integration is normalized, and a sentient robot is possible. As the creator, McMullen’s vision could determine the future of robotic design, …

The Evolution Of Gendered Software: Products, Scientific Reasoning, Criticism, And Tools, Victoria A. E. Kratel

Human-Machine Communication

Over the past 7 decades, gendered software has become globally established. In this theoretical distribution, I outline the evolution of gendered software. The journey of gendered software started with the raw idea fueled by Alan Turing’s imitation game in the 1950s. And only shortly thereafter, in the 1960s and 1970s, the first gendered software products like Joseph Weizenbaum’s ELIZA were developed. Thus, academia took its time to not only explore technological aspects, but to further investigate the matter of gender in the 1990s CASA-paradigm (Nass et al., 1994) and Media Equation (Reeves & Nass, 1996). As these theories reasoned the …

Do People Perceive Alexa As Gendered? A Cross-Cultural Study Of People’S Perceptions, Expectations, And Desires Of Alexa, Leopoldina Fortunati, Autumn P. Edwards, Anna Maria Manganelli, Chad Edwards, Federico De Luca

Human-Machine Communication

Mainly, the scholarly debate on Alexa has focused on sexist/anti-woman gender representations in the everyday life of many families, on a cluster of themes such as privacy, insecurity, and trust, and on the world of education and health. This paper takes another stance and explores via online survey methodology how university student respondents in two countries (the United States, n = 333; and Italy, n = 322) perceive Alexa’s image and gender, what they expect from this voice-based assistant, and how they would like Alexa to be. Results of a free association exercise showed that Alexa’s image was scarcely embodied …

Gender And Human-Machine Communication: Where Are We?, Leopoldina Fortunati, Autumn P. Edwards

Human-Machine Communication

In this introduction to the fifth volume of the journal Human-Machine Communication, we present and discuss the five articles focusing on gender and human-machine communication. In this essay, we will analyze the theme of gender, including how this notion has historically and politically been set up, and for what reasons. We will start by considering gender in in-person communication, then we will progress to consider what happens to gender when it is mediated by the most important ICTs that preceded HMC: the telephone, mobile phone, and computer-mediated communication (CMC). We outline the historical framework necessary to analyze the last section …

Data-Driven Power System Stability Analysis And Control, Jian Xie

Electronic Theses and Dissertations, 2020-2023

In recent years, with the expansion of power system size, the increase of interconnection and the use of large-scale renewable energy, power system stability and safe operations have become more prominent, causing challenges to the normal operation of power grid. Traditional analysis rely on detailed models of the system. But for real power systems, the operating state of the system is variable, and the model-based analysis methods may not accurately reflect the real operating state of the system. Therefore, this dissertation is focused on data-driven stability analysis and control. First, a method for locating the oscillation source of multi-machine systems …

High Voltage Aqueous Electrolyte Based Structural Supercapacitors For Electric Vehicles, Deepak Pandey

Electronic Theses and Dissertations, 2020-2023

The current electric vehicles (EVs) face many challenges like limited charge capacity, low miles/charge, and long charging times. Herein, these issues are addressed by developing "energized composite," which is a multifunctional supercapacitor-based energy-storing carbon fiber reinforced polymer composite that can store supplemental electric energy and function as the body shell of EV's. This is achieved by developing a unique design, vertically aligning graphene sheets on carbon fiber electrodes and depositing metal oxides to obtain high energy density electrodes. A high-strength multilayer composite is fabricated using an alternate layer pattern configuration of epoxy and polyacrylamide gel electrolyte. The composite so developed …

Ceria Defect Engineering Using Thin-Films/Ald And Biological Applications, Udit Kumar

Electronic Theses and Dissertations, 2020-2023

Ceria nanostructures have been utilized for various engineering applications due to their unique defect structure, enabling them to have regenerative redox properties. The ability to shuttle between Ce3+ and Ce4+ oxidation states extends to unique properties. Defect level in ceria is usually expressed in the Ce3+/Ce4+ ratio. It can be achieved by varying the size(0 to 3D), morphologies, dopants, hetero-nanostructures, and external stimuli. However, it is still a challenge to have precise control over defect structures in the ceria lattice. The current study aims to explore the thin film deposition techniques for cerium oxide using ALD (Atomic layer deposition) and …

Adaptive Analytic Continuation For The State Transition Tensors Of The Two-Body Problem, Tahsinul Haque Tasif

Electronic Theses and Dissertations, 2020-2023

In the past few decades, Kessler syndrome (named after Donald J. Kessler) has become a point of concern in the field of Space Situational Awareness and the future of space missions. It refers to a scenario, where space debris in Earth's orbits collides and creates an exponential increase in space debris numbers leading to more collisions and more debris. In order to handle the resulting challenges like conjunction analysis, tracking, and probability of collisions, the State Transition Matrix (STM) and Tensors (STTs) of the orbit problem play a significant role. In addition, STM and STTs are ubiquitous in spaceflight dynamics, …

Processing And Characterization Of Ultra High Temperature And High Conductive Composites, Haonan Song

Electronic Theses and Dissertations, 2020-2023

There are significant challenges for materials in extreme environments for a variety of applications such as aircraft engines, gas turbines, nuclear reactors, re-entry vehicles, and hypersonic structures. Ceramic matrix composites (CMCs) could be ideal candidates to meet these stringent requirements for materials due to their high melting temperatures, high oxidation, corrosion and ablation resistance, low creep, and thermal cycling behavior in such extreme environments. Particularly, continuous fibers can bridge cracks in CMCs and therefore improve the strength and fracture toughness of composites. Metal matrix ceramics are important materials in various industries, such as aerospace and automobile. MMCs have excellent mechanical …