Digital Commons Network^™

Subnational Map Of Poverty Generated From Remote-Sensing Data In Africa: Using Machine Learning Models And Advanced Regression Methods For Poverty Estimation, Lionel N. Hanke

Master's Theses

According to the 2020 poverty estimates from the World Bank, it is estimated that 9.1% - 9.4% of the global population lived on less than $1.90 per day. It is estimated that the Covid-19 pandemic further aggravated the issue by pushing more than 1% of the global population below the international poverty line of $1.90 per day (WorldBank, 2020). To provide help and formulate effective measures, poverty needs to be located as exact as possible. For this purpose, it was investigated whether regression methods with aggregated remote-sensing data could be used to estimate poverty in Africa. Therefore, five distinct regression …

An Examination Of The Fuzzy Inference System On Probabilistic Roadmap Path Planning, Brandon Replogle

Master's Theses

In recent years, multi-robot systems have been widely used in many applications such as warehouse inventory tracking and automatic search and rescue operations. Probability roadmap (PRM) is a typical path planning algorithm that can determine an optimal trajectory once the robot start and goal positions are specified. However, when the number of robots in the system increases, it converges slowly and may even fail to find the solution.

In this thesis, a fuzzy inference system is proposed and combined with the probability roadmap algorithm for robot path planning. Computer simulation results in five different environments show this approach is very …

The Relationship Between Vitamin D Intake, Sun Exposure, Handgrip Strength And Hg Alc Levels In College-Age Adults, Janelle Melancon

Master's Theses

Vitamin D is known for its importance to bone health and calcium metabolism and plays a role in insulin resistance. Recent research has recognized its role in insulin secretion, inflammatory response, and adipose tissue changes as possible reasons for its association with insulin resistance and cardiovascular disease. The CDC (2019) reported that 20% of adolescents are now living with prediabetes. Most individuals with prediabetes progress to type 2 diabetes within ten years. Because many studies have focused on adults of all ages, it is important to research young adults. This study aimed to determine prevention efforts; therefore, the younger adult …

Predict Trend Of Unemployment Rate By Observing The Nasdaq Composite Index Using Hidden Markov Model, Li Liu

Master's Theses

In this paper, we present how to use Hidden Markov Models (HMM) to predict the change in Unemployment Rate. By observing the NASDAQ price difference, we will predict the Unemployment Rate will rise or fall in the next month using the Hidden Markov Model. We will use the NASDAQ price and the unemployment rate from 2016 to 2020 monthly data for this paper. When we check the relation between the NASDAQ price and the unemployment rate, we find out that whenever the NASDAQ price goes up, the unemployment rate will drop for a time. So we are interested in how …

Design And Analysis Of A Single-Stage Inverter Using Parallel Dc-Dc Converters For Solar Cell Application, Gabriel Leonides

Master's Theses

This thesis introduces the design and analysis of a single-stage inverter. A circuit was designed and simulated as a proof of concept to investigate the possibility of using boost and buck-boost converters to provide an AC output. The proposed circuit utilizes non-synchronous boost and buck-boost converters due to their simplicity in control signals as opposed to synchronous converters. The application of the proposed inverter is for use with individual solar cells. The aim of the inverter for a single cell is to improve the efficiency of a solar panel, whose performance is limited to the performance of the least efficient …

Interior Point Optimization Of Low-Thrust Spacecraft Trajectories, Jordan D. Frederiksen

Master's Theses

Low-thrust interplanetary spacecraft trajectory optimization poses a uniquely difficult problem to solve because of the inherent nonlinearities of the dynamics and constraints as well as the large size of the search space of possible solutions. Tools currently exist that optimize low-thrust interplanetary trajectories, but these tools are rarely openly available to the public, and when they are available they require multiple interfaces between multiple different packages. The goal of this work is to present a new piece of low-thrust interplanetary spacecraft trajectory optimization software that is open-source and entirely self-contained so that more people can have access to the ability …

Subclinical Atherosclerosis Quantified Through Cumulative Shear Measurement, Margaret Lynne Papka

Master's Theses

With the high mortality rate of cardiovascular disease, it is important to study the early signs. The early detection of cardiovascular disease can lead to saved lives. Currently the most prevalent detection methods are the Framingham Risk Score and the carotid intima media thickness, both of which are insufficient. The necessary tool for early detection requires a uniform quantification system. The stimulus leading to endothelial dysfunction, the most significant predictor of a major adverse cardiovascular event (MACE)—and subsequently subclinical atherosclerosis—is reduced shear stress. Increased surface relative roughness affects the flow profile transition from laminar to turbulent resulting in reduced shear …

Snr: Software Library For Introductory Robotics, Spencer F. Shaw

Master's Theses

This thesis introduces "SNR," a Python library for programming robotic systems in the context of introductory robotics courses. Greater demand for roboticists has pressured educational institutions to expand robotics curricula. Students are now more likely to take robotics courses earlier and with less prior programming experience. Students may be attempting to simultaneously learn a systems programming language, a library API, and robotics concepts. SNR is written purely in Python to present familiar semantics, eliminating one of these learning curves. Industry standard robotics libraries such as ROS often require additional build tools and configuration languages. Students in introductory courses frequently lack …

Nonlinear Model Development And Validation For Ball And Plate Control System, Zachary Richter

Master's Theses

Ball and plate balancing control systems are commonly studied due to the complex dynamics associated with the instability of the system in open-loop. For simplicity, mathematical models describing the ball and plate dynamics are often linearized and the effects of complex motion are assumed to be negligible. These assumptions are rarely backed with evidence or explanations validating the simplified form of the dynamical equations of motion. This thesis focuses on developing a nonlinear model that more accurately defines the dynamics of the system, in order to quantify the error of linear and nonlinear models when compared to a Simscape physical …

Take The Lead: Toward A Virtual Video Dance Partner, Ty Farris

Master's Theses

My work focuses on taking a single person as input and predicting the intentional movement of one dance partner based on the other dance partner's movement. Human pose estimation has been applied to dance and computer vision, but many existing applications focus on a single individual or multiple individuals performing. Currently there are very few works that focus specifically on dance couples combined with pose prediction. This thesis is applicable to the entertainment and gaming industry by training people to dance with a virtual dance partner.

Many existing interactive or virtual dance partners require a motion capture system, multiple cameras …

Long Term Recovery From Cattle Grazing Disturbance And Climate Impacts At Capitol Reef National Park, Utah, Erin Tessens

Master's Theses

Cattle grazing has influenced the environment in the western United States since European settlement in the 1800’s. Continuous and heavy grazing on arid and semi-arid rangelands has resulted in decreased biodiversity, changes in vegetation structure, and vulnerability to exotic plant invasion. Heavy grazing has also been linked to decreased cryptobiotic soil due to trampling and susceptibility to erosion. With a lack of effective means of successful habitat restoration, there is a rising concern among land managers to maintain these intricate systems, notably under the threat of climate change. Consequently, there is a critical need to understand these system’s response to …

Haunted And Hunted: The Gothic And The Ghostly In The Light And Asylum, Adam Dunnells

Master's Theses

Young adult Gothic horror fiction acts as a coming-of-age story wherein the protagonists must confront the metaphorical and literal ghosts while simultaneously attempting to establish a sense of identity. Applying Gothic theory and ghost theory to the ghostly stories in young adult Gothic horror demonstrates how certain young adult Gothic stories represent the struggle of adolescents as they mature into adulthood and search for their identities. I use Madeline Roux’s Asylum (2013) and D.J. MacHale’s The Light (2010) as case studies to analyze how ghostly antagonists directly oppose adolescent protagonists on their coming-of-age journeys. Analyzing these young adult Gothic horror …

Polycyclic Aromatic Hydrocarbons And The Microbiomes Of Two Benthic Species, Samantha Ells

Master's Theses

The presence of oil has been shown to affect the microbiomes of the water column, sediments, and organisms, both by altering the diversity and the composition of those microbial communities. If the microbiome is altered it may no longer provide benefits to its host organism, impacting its ability to survive. Thus, it is important to understand the effects of large-scale contamination events including the Deepwater Horizon oil spill. This study set out to examine the effects of oil exposure on the microbiome of two benthic species, southern flounder (Paralichthys lethostigma) and eastern oysters (Crassostrea virginica) to further understand the effects …

Sedimentology And Shallow Groundwater Responses Of A Coastal Marsh Along A Salinity Gradient: A Case Study In Grand Bay National Estuarine Research Reserve, Mississippi, James Thompson

Master's Theses

Climate change and relative sea level rise is resulting in saltwater intrusion and inundation of coastal marshes. This study investigates factors affecting marsh hydrology, including sediment composition, seasonal variability, and coastal storms in Grand Bay National Estuarine Research Reserve (NERR) near Pascagoula, Mississippi. Analysis of sediment includes color, organic matter, carbonate, magnetic susceptibility, and particle size. Shallow groundwater hydrologic trends between Summer 2015 and Fall 2016 are established along a salinity gradient at four sites using water levels, temperature, and conductivity monitored at the surface and in piezometers at depths of 0.75m, 1.5m, and 2.25m.

Sediment analysis indicates reducing conditions …

A Modified Preconditioned Conjugate Gradient Method For Approximating The Scattering Amplitude, Samson Ayo

Master's Theses

In this thesis, we look at an iterative method for approximating the scattering amplitude that involves solving two linear systems: a forward system Ax=b and an adjoint system A^Ty=g. Once these two systems are solved, the scattering amplitude, defined by g^Tx=y^Tb is easily obtained.

We derive a conjugate gradient-like iteration for a nonsymmetric saddle point matrix that is constructed to have a real positive spectrum. We investigate the use of Schur Complement preconditioners with block-diagonal factorization to speed up the convergence of our method and compare …

Spatial And Seasonal Patterns Of Above- And Belowground Vegetation Biomass And Potential Drivers In The Pascagoula River Delta, Ms, Evan Grimes

Master's Theses

Coastal wetlands provide a valuable wealth of services to the greater coastal ecosystem and human communities. However, threats such as sea level rise and conservation projects, such as freshwater diversions, have the potential to alter coastal wetlands in different ways. In this thesis, I describe the effects of inundation and nitrogen on vegetation productivity using a field-sampling approach and an in situ controlled mesocosm experiment, called a marsh organ. The West Channel of the Pascagoula River contained significantly higher belowground biomass than the East Channel, which is more anthropogenically modified. Vertical distribution of belowground biomass did not strongly vary between …

Population Parameter Estimation And Stable Isotope Analysis Of Gulf Sturgeon (Acipenser Oxyrinchus Desotoi) In The Pascagoula River, Alfonso Cohuo

Master's Theses

Gulf Sturgeon (GS), Acipenser oxyrinchus desotoi, are a threatened, anadromous fish species in the northern Gulf of Mexico. Their range is from the Pearl River, LA, in the west to the Suwannee River, FL, in the east with a longitudinal divide at Mobile Bay, AL, creating a western population unit (WPU) and an eastern population unit (EPU). Sturgeon belonging to the WPU exhibit lower abundances, higher mortality rates, and are overall less studied than their EPU counterparts. Notable data gaps for the WPU includes the absence of recent population parameter estimations and confirmed feeding habitat. My thesis aims to …

Exploring The Influence Of Diurnal Forcing On Tidal Inlet Exchange And The Impact On The Movement Of Oxygen Depleted Waters In The Mississippi Sound And Bight Region, Courtney Bouchard

Master's Theses

A small yet notable hypoxic event manifests east of the Birdfoot Delta in the Mississippi Sound and Bight (MSAB). The shallow shelf environment of the MSAB is affected by a host of complex physical interactions and separating the influences of each process is difficult to accomplish with in-situ data alone. A physical model using high-resolution atmospheric forcing has been developed which provides insights into the physical interactions in this coastal marine system heavily influenced by freshwater plumes and diurnal wind forcing. Twin experiments using a high temporal (hourly) and spatial (0.01 deg) resolution meteorological analysis product, along with a temporally …

Design, Synthesis, And Characterization Of Glycodendrons Through Small Molecule And Linear Polymer Models, Molly Jones

Master's Theses

This thesis focuses on the design, synthesis, and characterization of glycopolymer-dendron thiol-ene coupling reactions with the long-term goal of increasing biocompatibility of near infrared (NIR) fluorophores for bioimaging applications. A design of experiments was used with small molecule model compounds to determine the parameters for successful thiol-ene click reactions that would lead to success of more complicated amphipathic polymer-polymer coupling reactions. The first chapter provides an introductory overview of the importance and applications of glycopolymers, bioimaging, and Janus dendrimersomes. The second chapter presents the synthetic methods for creating a glucose-functionalized glycopolymer with an acrylamide backbone, the exploration of thiol-ene coupling …

Assessing The Rates Of Post-Depositional Change Within 2004 Indian Ocean Sediments: Implications For Long-Term Records Of Paleotsunamis, Lillian Pearson

Master's Theses

Foraminifera are commonly used to examine patterns of tsunami inundation occurring over centennial to millennial timescales, but the impacts of post-depositional change on geologic reconstructions are unknown. In Sumatra, the taphonomic character (i.e., test surface condition) of a foraminifer can deteriorate over time, rendering them unidentifiable, and even dissolve them entirely. Here I investigate the rates of post-depositional change of foraminiferal assemblages found within the 2004 Indian Ocean Tsunami (IOT) deposit over a 15-year time interval in Aceh, Indonesia in a vegetated open coastal plain (Site 1: Pulot) and an unvegetated protected coastal cave (Site 2). I identified two zones …

Noninvasive Measurement Of Arterial Compliance With A Blood Pressure Cuff Using A Surrogate Arm Bench Top Model For Oscillometric Use, Shane Wilsey

Master's Theses

A surrogate arm model was created that is capable of being used for oscillometry. This model is capable of being used as a bench top model for blood pressure cuff devices. The arm consists of endplates and internal supports that are 3D printed with ABS, a silicone rubber outer sleeve, and interchangeable arteries made from two silicone rubber strips glued together at the edges. The interchangeable arteries have varying compliances that can be used as different inputs for oscillometric testing. A process was established to measure the artery compliances with a curve fit correlation of 0.95. However, testing revealed that …

Comparison Of Two Advanced Oxidation Processes For Their Production Of Hydroxyl Radicals And Evaluation Of A Uv/Ozone Aop At Varying Uv Fluence For Treating Diclofenac, Alexandra Cass

Master's Theses

This study explores the efficacy of two advanced oxidation processes for generation of hydroxyl radicals to promote degradation of emerging contaminants. Drought and water shortage have become pressing issues caused by our world’s changing climate. Water reclamation and reuse are increasingly important options for relieving this water stress. Water reuse runs the risk of reintroducing recalcitrant compounds that can accumulate in our bodies and environment. Advanced treatment methods that degrade these compounds are vital to protect our health and the health of the environment while providing necessary water resources. Advanced oxidation processes (AOPs) have shown great promise for removing recalcitrant …

Development Of A Low-Cost, Photovoltaic-Powered, Automated Water Recovery System, David E. Daley

Master's Theses

An existing water filtration system at the Channel Islands Marine & Wildlife Institute (CIMWI) wastes approximately 25 gallons of water per day rinsing out solid waste under light load. To reduce CIMWI’s water and energy consumption, an automated system was designed and built to recover the rinse water and return it to the existing filtration loop. Models for fluid system requirements, basic energy needs, and photo- voltaic energy generation were created to aid in component selection. Basic sensors and electronics were programmed in Python for use with a Raspberry Pi single board computer to collect and process water recovery data …

Integral Boundary Layer Methods In Python, Malachi Joseph Edland

Master's Theses

This thesis presents a modern approach to two Integral Boundary Layer methods implemented in the Python programming language. This work is based on two 2D boundary layer methods: Thwaites' method for laminar boundary layer flows and Head's method for turbulent boundary layer flows. Several novel enhancements improve the quality and usability of the results. These improvements include: a common ordinary differential equation (ODE) integration framework that generalizes computational implementations of Integral Boundary Layer methods; the use of a dense output Runge-Kutta ODE solver that allows for querying of simulation results at any point with accuracy to the same order as …

High Voltage Dc-Dc Converter Design For Submarine Application, Oscar Ambriz

Master's Theses

In this work a proof of concept for a step-down DC-DC converter used in a high voltage submarine application is presented. The purpose of the converter is to step down a 5000V-6000V input to a 24V output which can serve as an input to a submarine sensor. The completed system consists of two stages where the first stage is an unregulated switched capacitor converter to step down the initial input to a voltage range more appropriate for the selected second stage. The second stage is a regulated flyback converter topology which regulates the final output to the desired 24V. Performance …

Analysis Of Multi Resonant Switched Capacitive Converter With Imbedded Pcb Elements, Adel Lahham

Master's Theses

The data center industry is headed towards a lower point of load voltages with increased load demands contributing to higher I2R losses in power busses. Raising the bus voltage from 12V to 48V is a popular area investigated today for reducing power delivery losses. Switched capacitive converters (SCCs) are a popular topology used for this purpose. However, SCCs suffer from low tolerance for operating conditions and are unregulated. The proposed multi resonant switched capacitor buck converter (MRSCBC) can resolve these challenges while also providing output regulation. Switch mode power supplies exhibit high electromagnetic noise and with an increased number of …

Quantification Of Red Blood Cell Deformability And Distribution In Venous Valve Mimics, Zyrina Alura Calderon Sanchez

Master's Theses

Red blood cells (RBCs) are vital to sustaining life as they are necessary for microvascular oxygenation and tissue perfusion, as well as inflammation and hemostasis. RBC deformability plays a key role in their distribution in blood vessels, and hence directly influences pathophysiology of sickle cell disease and deep vein thrombosis. In this study, we tested the hypothesis that RBC deformability will affect their distribution in venous valve pockets, the location of venous thrombosis. To test this hypothesis, we used confined microfluidic flows to quantify RBC deformability, and manipulated membrane cholesterol to alter RBC deformability. The effect of RBC deformability changes …

Deep Reinforcement Learning With Accelerated Reward Function Technique For Robotics Task Planning, Shifabanu Mohammed Rafiq Shaikh

Master's Theses

The objectives of this research are to investigate, design, develop, and implement a DRL-based reward function enhanced robotics technique to achieve ”human-like” operations for a six DoF robot. Technical challenges for robotics applications arise nowadays with a need to achieve human-like intelligence. DRL can formulate human-likeintelligence by maximizing a long-term reward function. However, the design of states, actions, policies, and reward functions having continuous values turns out to be quite tricky. Lastly, to reach a target position, control motion behavior without calculating inverse kinematics, and update state space for actions and policy optimizations are also challenging. Inspired by Google Deepmind’s …

Examination Of Flow Patterns During Droplet Formation And In Venous Valve Mimic Using Μ-Piv, Vignesha Vijayananda

Master's Theses

In this work, particle image velocimetry (PIV) was used for fluid flow visualization in both continuous and segmented-flow microfluidics. Droplet microfluidics is known for its precise and consistent volume dispersion between microliters and picoliters in volume for application ranging from molecular synthesis, drug discover, and diagnostics. But the influence of junction geometry on the process of drop formation has not been investigated. In this study, µ-PIV was used to study the internal flow during the drop formation process in flow-focus microfluidic device with and without constriction. It was found that in case of flow-focus with constriction, the shear force on …

Analyzing The Scalability Of Parallel Microwire Arrays For Neural Recording, Yeena Ng

Master's Theses

Brain-computer interfaces (BCI) improve the quality of life for patients with severe motor disabilities and sensory impairment by providing them a direct way to communicate with the outside world through computers. To gain higher temporal resolution for better devices, intracortical neural electrodes, such as microwire arrays, are used. Microwire electrode arrays bonded to CMOS sensors, for intracortical neural recordings, have been claimed to be scalable. Microwire electrode arrays of varying diameters and densities were constructed and evaluated for percentage connectivity after interfacing with a custom-made CMOS sensor. The results demonstrate that there is no significant difference in the mean connectivity …