Digital Commons Network^™

Analysis Of Lubricants At Trace Levels Using Infrared Spectroscopy, Tanmai Bandarupalli

Honors Undergraduate Theses

Analysis of trace evidence involved in sexual assault investigations holds considerable potential as a newer avenue of identification when bulk, larger evidence is not found or unreliable. Trace analysis of forensic materials involves common findings such as strands of hair, residues left on clothing, shards of paint or glass, etc. In recent research focused on the analysis of trace materials found as evidence in a sexual assault, there has been promise in condom and bottled lubricant classification based on their chemical profiles that can provide an associative link in an investigation. Few studies have considered the examination of lubricant evidence …

Liquid Crystal Flat Optics For Near-Eye Displays, Tao Zhan

Electronic Theses and Dissertations, 2020-2023

Augmented reality (AR) and virtual reality (VR) displays, considered as the next-generation information platform, have shown great potential to revolutionize the way how we interact with each other and the digital world. Both AR and VR are disruptive technologies that can enable numerous applications in education, healthcare, design, training, entertainment, and engineering. Among all the building blocks of these emerging devices, near-eye displays (NEDs) play a critical role in the entire system, through which we can perceive the virtual world as the real one. However, the visual experience offered by existing NED technologies is still far from satisfying the human …

Unsupervised Meta-Learning, Siavash Khodadadeh

Electronic Theses and Dissertations, 2020-2023

Deep learning has achieved classification performance matching or exceeding the human one, as long as plentiful labeled training samples are available. However, the performance on few-shot learning, where the classifier had seen only several or possibly only one sample of the class is still significantly below human performance. Recently, a type of algorithm called meta-learning achieved impressive performance for few-shot learning. However, meta-learning requires a large dataset of labeled tasks closely related to the test task. The work described in this dissertation outlines techniques that significantly reduce the need for expensive and scarce labeled data in the meta-learning phase. Our …

Mathematical Knowledge For Teaching: Instructional Reasoning In High-Density Black Populations, Desheila Rumph

Electronic Theses and Dissertations, 2020-2023

To be economically competitive, U.S. citizens must be mathematically competent (Wang et al., 2010). However, students in the United States have consistently underperformed those in other industrialized nations in mathematics (Program for International Student Assessment [PISA], 2018), which threatens the economic health of the nation (Achieve, 2013; Auguste et al., 2009; Harbour et al., 2018; Mickelson et al., 2013). Federal education reform was implemented and failed to improve the mathematics achievement of U.S. pupils (Cheong Cheng, 2020). Researchers have found links between teacher knowledge and student achievement; however, factors mediate this relationship (Hatisauri & Erbas, 2017). As a result, non-significant …

Examining The Effects Of Implementation Of I-Ready To Fidelity On Reading And Its Effects On Free Or Reduced Lunch Students In Seven Middle Schools, Ryan Martin

Electronic Theses and Dissertations, 2020-2023

The purpose of this study was to contribute to the literature and to policy and practice in the educational field on how individual student diagnostic scores was affected in the area of reading. This study specifically examined full or partial fidelity of implementation of the iReady reading instructional and computerized program was applied in seven middle schools in a school district in Central Florida for all students in intensive reading courses. Additionally, this study contributed to how individual student diagnostic scores was affected in the area of reading for students on free or reduced lunch. Data were analyzed from the …

Qualitative Reconceptualizations Of Success In Physics From A Feminist Lens, Brian Zamarripa Roman

Electronic Theses and Dissertations, 2020-2023

To address the critical issue of the underrepresentation of women in physics, the Physics Education Research community has focused on exploring the factors contributing to student success; however, few studies have explored the meaning of success in physics as seen by women and other marginalized populations. This study, guided by Feminist Standpoint Theory and Critical Race Nepantlera Methodologies, incorporates qualitative methods to explore the central question, "how do women in physics conceptualize the meaning of success in physics?" We begin with an analysis of metaphors of success in physics constructed by nine women studying physics at a single institution, followed …

Exergoeconomic Analysis And Optimization Of Novel Cogeneration Systems For Freshwater Production, Power And Cooling, Sattam Alharbi

Electronic Theses and Dissertations, 2020-2023

Global consumption of energy and freshwater is increasing continuously due to population growth and improving living standards. The world energy consumption is anticipated to increase by around 50% by 2050 according to the U.S Energy Information Administration (EIA). There is also very limited access to freshwater and cooling in many developing countries. Therefore, developing an efficient energy system, recovering the waste heat (cogeneration system or multigeneration) to produce freshwater and cooling, and using a renewable energy source are promising solutions to meet the energy demand and to reduce environment pollution associated with fossil fuels. In this study, several novel cogeneration …

Self-Governed Iot Networks: A Blockchain-Based Framework, Mehrdad Salimitari

Electronic Theses and Dissertations, 2020-2023

In the modern-day, IoT-enabled devices and sensors are growingly deployed in a variety of applications in consumer, commercial, industrial, and infrastructure spaces. Thus, decentralization of such networks for reducing the maintenance and repair costs is significantly gaining attention. In this dissertation, we investigate a variety of mathematical tools and technological advancements to design a secure, fully decentralized, and self-governed IoT network. On this path, the main challenge is ensuring the data integrity in IoT networks, securing the devices against a variety of attack scenarios, and preserving the privacy of the users. We begin by proposing a prospect theoretic method for …

Measurement And Mitigation Of Optical, Recombination And Resistive Losses In Silicon Photovoltaics, Mohammad Jobayer Hossain

Electronic Theses and Dissertations, 2020-2023

Today, most of the photovoltaic cells in the market are made of silicon. Great achievements are being attained every year in terms of reducing the price of this kind of cells and improving their efficiency, reliability and durability. However, further improving the cell performance is a challenging task because of the presence of optical, recombination and resistive loss mechanisms in the cell. This work is focused on the measurement and mitigation of these losses. Mitigation of the optical, recombination and resistive losses at first require quantifying those losses and their impacts on the cell performance metrics accurately. Traditionally, solar cells …

Online Organizational Citizenship Behavior: An Exploration Of New Avenues For Prosocial Behavior In The Digital Age, Sarah Rabon

Electronic Theses and Dissertations, 2020-2023

Internet use has changed modern workplaces and introduced new options for employee behavior, including organizational citizenship behavior (OCB). While prior research suggests the internet is a unique social environment, and not a simple extension of a traditional in-person workplace, OCB has not been studied in this context. This thesis aimed to identify and document the nature of online OCB and identify how it differs in form and function from traditional in-person OCB. This thesis used a mixed methods approach, with self-report data from 201 participants. Results indicate workers engage in OCB online at a lower rate than in person. Some …

Fabrication Of High-Frequency Piezoelectric Resonant Micro-Accelerometers Based On Capacitive Loading Effect, Ankesh Todi

Electronic Theses and Dissertations, 2020-2023

In this thesis, a high-frequency resonant accelerometer is presented. This novel sensor was designed to operate in 10's of MHz frequency range utilizing an out-of-plane capacitive mechanism for acceleration sensing. The sensor is comprised of a 2-port RF MEMS piezoelectric resonator, operating at 27MHz, and a Capacitive Mass-spring structure. One of the resonator ports is electrically connected to the variable capacitor in the mass-spring structure. The acceleration is measured utilizing a piezoelectric stiffening mechanism, where a change in the termination impedance of a piezoelectric resonant body would result in a shift in the resonance frequency of the resonator. The acceleration …

A Quasi-Experimental Study Of The Relationship Between Teaching Intensive Reading Using Novels And Student Skills In English Language Arts, Sarah Brevoort

Electronic Theses and Dissertations, 2020-2023

Many research-based reading interventions exist, but little literature examines teaching secondary reading using entire novels as an intervention. This quasi-experimental study examined the relationship between whether entire novels were included in secondary intensive reading and students' English language arts skills. Data were collected through an online survey of eight reading teachers from one Florida school district. Data collected by the survey were teacher qualifications, inclusion of entire novels in reading curriculum, and implementation of research-based teaching strategies. Survey data, Florida Standards Assessment of English Language Arts (FSA ELA) student scores, student demographics and reading placement data were analyzed to answer …

Parameter Calibration And Optimization In Smart Grid For Synchronous Generators And Converters, Seyyed Rashid Khazeiynasab

Electronic Theses and Dissertations, 2020-2023

In power systems, monitoring, protection, and control are usually model based; an accurate dynamic model for either synchronous generators or power electronic converters is essential. Besides, renewable energies, smart loads, energy storage, and new market behavior add new sources of uncertainty to power systems. Therefore, planning in real-time and developing high-quality models is crucial to adapt to uncertainties. In this thesis, we propose a framework for validating and calibrating power system models using novel methods. At the first step, we developed the nonlinear sensitivity-based method to find the critical parameters. Then, we propose an Approximate Bayesian Computation (ABC) based method …

Dynamic Analysis Of The Implementation Of The Blockchain Technology In The Supply Chain, Rehab Ali

Electronic Theses and Dissertations, 2020-2023

Blockchain technology is a new digital technology that has been disrupting the way businesses are performing. It is a decentralized and distributed ledger that enables transactions of any form of value. As blockchain technology provides visibility, transparency, and security through the multi-agent system, the supply chain sector is one of its critical and promising applications. In a highly dynamic environment, the supply chain's efficiency needs to be measured from a blockchain perspective. As the main benefit of blockchain technology is the visibility and real-time access to data, blockchain technology's preeminent affected areas within the supply chain are the responsiveness to …

Evaluating Source Water Quality, Pretreatment, And Particulate Mass Transport In A Nanofiltration Membrane Process, Courtney Powell

Electronic Theses and Dissertations, 2020-2023

This document details the source and occurrence of particulates in a nanofiltration (NF) process, considers the implementation of additional pretreatment to improve feedwater quality, and investigates the impact of submicron particles on membrane performance. Much of this research was performed in cooperation with the City of Boynton Beach (City) at the West Water Treatment Plant (WTP) and stemmed from particulate fouling concerns in the pretreatment and NF membrane processes. The water quality of the individual wells that supply the West WTP was evaluated to identify the source of particulates which overload the pre-filters (5-μm cartridge filters) and may contribute to …

Race-Based Adjustment In Egfr Algorithms: An Integrative Literature Review, Leah E. Utt

Honors Undergraduate Theses

Background: There is a 3-fold risk of developing end stage kidney disease in Non-Hispanic African Americans compared to Non-Hispanic White Americans (Centers for Disease Control and Prevention, 2017). Estimated glomerular filtration rate (eGFR), one of the fundamental algorithms for coordinating treatment for kidney disease which factors in age, race, gender, and levels of creatinine, may pose an issue in this vulnerable population. Currently African Americans receive a correction factor between 1.21 and 1.16 to their eGFR to adjusting the value higher, potentially impacting appropriate kidney disease classification, and delaying beneficial interventions (National Kidney Foundation, 2020).

Methods: A systematic literature search …

Simulating Ejecta Blown Off The Lunar Surface Due To Landing Spacecraft Using The Mercury N-Body Integrator, Isabel Rivera

Electronic Theses and Dissertations, 2020-2023

The experiences of the Apollo lunar landings revealed the danger lunar dust can pose to surrounding hardware, outposts, and orbiting spacecraft. Future lunar missions such as the Artemis program will require more information about the trajectories of ejecta blown by landers to protect orbiting spacecraft such as the Lunar Gateway. In this paper, we simulate lunar lander ejecta trajectories using the Mercury N-body integrator. We placed cones of test particles on the Moon at the North Pole, South Pole, and Equator with various ejection speeds and angles. The results show that particles ejected at speeds near the Moon's escape velocity …

Polymer-Based And Functionalized 3d Microelectrode Array (Mea) Biosensors, Nilab Azim

Electronic Theses and Dissertations, 2020-2023

Microphysiological systems are three-dimensional (3D) in vitro systems that recapitulate crucial biological aspects of cell heterogeneity and native tissue architecture by mimicking complex structures that are impossible in two-dimensional (2D) cell cultures. Microelectrode arrays (MEAs) are biosensors used to spatially and temporally monitor the activity of microphysiological systems by transducing cellular signals into electronic signals to provide quantitative data on the in vitro system. Conventional MEAs are typically planar in nature, however, 3D MEAs offer several advantages such as better simulation of an in vivo cellular environment and improved signal-to-noise ratio and cell-electrode coupling. MEA fabrication utilizing traditional cleanroom methods …

Highly Reproducible Electrochemical Sensors Towards Wearable Applications And Pharmaceutical Analysis, Mohammad Rostampour Kakroudi

Electronic Theses and Dissertations, 2020-2023

Ion-selective electrodes (ISEs) are widely used to monitor ions in various applications from environmental to clinical settings and pharmaceutical analysis. ISEs are a type of potentiometric sensor that provides a versatile, cost-effective, and efficient platform towards wearable sensing applications. Among the two different platforms of ISEs (solid-contact and liquid-contact), solid-contact ISEs are superior to ISEs with internal electrolytes (liquid-contact) since they are easy to be miniaturized, can be used in any environment and their portability is facilitated. Unfortunately, mass production and commercialization of such devices is often constrained by the requirement of sensor calibration. Thus, approaches for sensor manufacturing towards …

Seismic Soil-Structure Interaction Effects In Tall Buildings Considering Nonlinear-Inelastic Behaviors, Jaime Mercado

Electronic Theses and Dissertations, 2020-2023

Soil-structure interaction (SSI) effects are relevant for the seismic analysis of tall buildings on shallow foundations since the dynamic behavior of structures is highly affected by the interaction between the superstructure and supporting soils. As part of earthquake-resistant designs of buildings, considering SSI effects in the analysis provides more realistic estimates of its performance during a seismic event, particularly when both the structure and soil undergo large demands that can compromise serviceability. Oversimplifications of structural or soil modeling in the analysis introduces variability and biases in the computed seismic response. The main goal of this dissertation is to investigate the …

Understanding Forearm Muscle Coordination In Children, Miguel Gonzalez

Electronic Theses and Dissertations, 2020-2023

A combination of surface electromyography (EMG) and pattern recognition algorithms have led to improvements in the functionality of upper limb prosthetics. This method of control relies on user's ability to repeatedly generate consistent muscle contractions. Research in EMG based control of prosthesis has mainly utilized adult subjects who have fully developed neuromuscular control. Little is known about children's ability to generate consistent EMG signals necessary to control artificial limbs with multiple degrees of freedom. To address this gap, two experiments were designed to validate and benchmark an experimental protocol that quantifies the ability to coordinate forearm muscle contractions in able-bodied …

Solidification Cracking In Binary Al-Cu Alloys Additively Manufactured Through Laser Powder Bed Fusion, Keegan Muller

Electronic Theses and Dissertations, 2020-2023

Laser Powder Bed Fusion (LPBF) is an additive manufacturing technique with growing relevance in industry. However, alloys with a high susceptibility to micro-cracking during solidification cannot be feasibly manufactured through LPBF, such as in selected high-strength Al-alloys. The cracking susceptibility (CS) of Al-alloys varies with composition, so modeling CS with respect to composition is crucial in designing compatible alloys for LPBF. In a theoretical modeling of solidification cracking based on the Scheil equation, the relative CS is taken as the maximum value of |dT/d(fs^1/2)| when solidification is near completion. However, experimental observations of the crack density in Al-alloys suggest that …

Visual Learning Beyond Human Curated Datasets, Muhammad Abdullah Jamal

Electronic Theses and Dissertations, 2020-2023

The success of deep neural networks in a variety of computer vision tasks heavily relies on large- scale datasets. However, it is expensive to manually acquire labels for large datasets. Given the human annotation cost and scarcity of data, the challenge is to learn efficiently with insufficiently labeled data. In this dissertation, we propose several approaches towards data-efficient learning in the context of few-shot learning, long-tailed visual recognition, and unsupervised and semi-supervised learning. In the first part, we propose a novel paradigm of Task-Agnostic Meta- Learning (TAML) algorithms to improve few-shot learning. Furthermore, in the second part, we analyze the …

Spatial-Temporal Representation Learning: Concepts, Algorithms And Applications, Pengyang Wang

Electronic Theses and Dissertations, 2020-2023

Recent years have witnessed the flourish of Internet-of-Things (IoT), in which sensors connect spatial entities to constitute complex Cyber-Physical Systems (CPSs). In this setting, spatial-temporal data becomes increasingly available. Mining spatial-temporal data can reveal holistic user and system structures, dynamics, and semantics of the underlying CPSs, including identifying trends, forecasting future behavior, and detecting anomalies. However, obtaining effective representations over spatial-temporal data remains a big challenge for the following reasons: (1) on the one hand, traditional manual feature design is labor-intensive and time-consuming facing the complex and huge volumes of spatial-temporal data; (2) on the other hand, as an emerging …

Regulation Of Actin Assembly, Mechanics, And Structure By Intracellular Environmental Factors, Nicholas Castaneda

Electronic Theses and Dissertations, 2020-2023

The assembly, mechanics, and structure of actin cytoskeleton are critical for eukaryotic cellular processes such as structural support, cellular motility, and intracellular transport. Actin assembly occurs in crowded intracellular environments containing many ions and macromolecules. While the individual roles of cation and crowding on actin assembly and mechanics are well established, how the combined cation and crowding effects modulate the formation, mechanics and structural transitioning of actin filaments and bundles are not fully understood. Here, we investigate the impacts of various cation and crowded environments on the bending stiffness, length, organization, secondary structure, and kinetics of actin filaments and bundles. …

Binary State Distance Vector Routing: A Protocol For Near-Unicast Forwarding In Partitioned Networks, Ammar Farooq

Electronic Theses and Dissertations, 2020-2023

Ad-hoc networks are highly dynamic and can be disconnected/partitioned during their operations, particularly in delay-tolerant networks (DTNs) where infrastructure support is not entirely available. Even after several decades of research on DTN routing, there is still a need for routing protocols that operate effectively in network environments where disconnections, delays, and resource scarcity are common. Traditionally, DTN routing protocols use an epidemic routing strategy, where multiple copies of packets get forwarded to increase network reachability. However, these flooding-based strategies are seldom suitable in resource-constrained network settings. Other prominent DTN routing designs use distance vectors (DVs) that summarize global network reachability …

Improving Matching And Classification Through Deep Learning Of Structure And Varying Illumination, Sarah Braeger

Electronic Theses and Dissertations, 2020-2023

Convolutional networks have driven major advances in computer vision in recent years. The design of deep architectures, loss functions, and the curation of large, diverse datasets have furthered progress in many applied computer vision tasks. How data is represented to a network guides feature discovery and must be carefully considered in order to maximize performance on any applied task. We introduce novel input representations and associated architectural techniques to better utilize them such as complementary loss terms and network structure. We demonstrate the impact of these approaches on classification and matching tasks which involve shape and varied illumination. We show …

Contextual Understanding Of Sequential Data Across Multiple Modalities, Sangwoo Cho

Electronic Theses and Dissertations, 2020-2023

In recent years, progress in computing and networking has made it possible to collect large volumes of data for various different applications in data mining and data analytics using machine learning methods. Data may come from different sources and in different shapes and forms depending on their inherent nature and the acquisition process. In this dissertation, we focus specifically on sequential data, which have been exponentially growing in recent years on platforms such as YouTube, social media, news agency sites, and other platforms. An important characteristic of sequential data is the inherent causal structure with latent patterns that can be …

Mechanics Of Low Dimensional Biomimetic Scale Metamaterials, Hossein Ebrahimi

Electronic Theses and Dissertations, 2020-2023

Combination of topology and material could play an important role in giving rise to nontraditional behavior in mechanical structures and is a typical strategy in nature. Topology is concerned with the geometrical and spatial properties of the objects, which are preserved under continues mechanical deformation of the object such as stretching, bending, twisting, etc. In this work, we focus on structures based on fish scale inspired surface topology. The utilized idea for surface topology is a bioinspired design on the substrate of biological scale-covered systems. Scales are a path breaking evolutionary adaptation that accompanied vertebrate evolution for the past 500 …

Fine-Grained Lower Bounds For Problems On Strings And Graphs, Gary Thomas Hoppenworth

Honors Undergraduate Theses

The motivation of this thesis is to present new lower bounds for important computational problems on strings and graphs, conditioned on plausible conjectures in theoretical computer science. These lower bounds, called conditional lower bounds, are a topic of immense interest in the field of fine-grained complexity, which aims to develop a better understanding of the hardness of problems that can be solved in polynomial time. In this thesis, we give new conditional lower bounds for four interesting computational problems: the median and center string edit distance problems, the pattern matching on labeled graphs problem, and the subtree isomorphism problem. These …