Physical Sciences and Mathematics Commons^™

An Introduction To Federated Learning And Its Analysis, Manjari Ganapathy

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the onset of the digital era, data privacy is one of the most predominant issues. Decentralized learning is becoming popular as the data can remain within local entities by maintaining privacy. Federated Learning is a decentralized machine learning approach, where multiple clients collaboratively learn a model, without sharing raw data. There are many practical challenges in solving Federated Learning, which include communication set up, data heterogeneity and computational capacity of clients. In this thesis, I explore recent methods of Federated Learning with various settings, such as data distributions and data variability, used in several applications. In addition, I, specifically, …

Extreme Event Reconstructions For The Upper Fraser River Basin, British Columbia, Canada, Inga K. Homfeld

UNLV Theses, Dissertations, Professional Papers, and Capstones

Spring freshets and summer droughts have recently worsened in the Fraser River Basin, British Columbia, Canada, with significant impacts to the keystone Pacific salmon populations, the food and economic sovereignty of over eighty First Nations, and the western Canadian economy. These extreme events present a potential risk since, unlike many large and less hydroclimatically-complex and/or empounded watersheds, the Fraser River Basin is susceptible to a combination of unregulated spring freshet and summer drought events even within the same year. A major limitation for understanding past and future extreme event risk in the Fraser River Basin is that observational streamflow datasets …

Climate And Soil Moisture Dynamics Inform Potential Climate Change Impacts On Available Moisture And Juvenile Tree Survival In Semiarid Forests, Carolyn R. Koehn

UNLV Theses, Dissertations, Professional Papers, and Capstones

Trees in semiarid forests and woodlands of the western United States need soil moisture to transpire and function. Juvenile trees are especially vulnerable during periods of low soil moisture as their rooting zones are smaller and shallower than those of adult trees. This thesis focuses on two soil moisture-driven aspects of semiarid forests that may be modified by climate change: seasonal soil moisture patterns and juvenile tree survival.

In chapter 1, I investigated the influence of precipitation on soil moisture across seasons, elevations, soil layers, and periods of low and high precipitation. I developed time-varying definitions of winter (snow accumulation), …

Exploring The Choiceless Cardinal Hierarchy, David Linkletter

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 1971, Kunen proved that the Axiom of Choice imposes a ceiling on the large cardinal hierarchy [7]. Much like the assumption V ≠ L unlocks measurable cardinals and beyond, dropping the Axiom of Choice enables Reinhardt cardinals and stronger cardinals to be explored. Some major notions of large cardinals beyond choice have recently been standardized by Woodin et. al. [2], with questions raised regarding their interconnectedness. Part 1 of this dissertation partially answers two of those questions, while conjecturing, with a partial solution, a much stronger answer which would simplify the existing cardinal charts - that Regular Berkeley Cardinals …

A Fusion Of Remotely Sensed Data To Map The Impervious Surfaces Of Growing Cities Of Punjab, Pakistan, Binita Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Urban population is expected to exceed 70% of the world’s total by the middle of the 21st century. Thus, growth in number as well as the sizes of the cities are certain in the near future. The urbanization rates will be much higher in the developing countries than the developed. Such phenomena are accompanied by conversion of land cover from its natural use to built up environment to accommodation growing population. Built up surfaces include road networks, buildings, parking lots and pathways. They are permanently impervious and hydrologically active surfaces. Large volume and discharges of runoff characterize impervious surfaces with …

Accretion And Debris Disc Dynamics Around Single And Higher-Order Star Systems, Jeremy L. Smallwood

UNLV Theses, Dissertations, Professional Papers, and Capstones

My research deals with highly topical areas of astrophysics, such as planet habitability, stellar evolution, the origin of fast radio bursts, the evolution of debris discs, and the dynamics of accretion discs in binary and higher-order star systems. Accretion discs around binary star systems are ubiquitous in the galaxy and planet formation is thought to occur within these discs. Circumbinary discs are commonly observed to be misaligned with respect to the binary orbital plane. A misaligned circumbinary disc eventually evolve to a stable orientation, either coplanar or polar with the binary orbital plane. The process of disc alignment has important …

Does Social Support Moderate The Association Between Income And Food Security Status Among Seniors Living In Southern Nevada?, Adugna Teka Siweya

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: Income is the strongest predictor of food insecurity among seniors, and social support also an essential factor to help mitigate the effects of food insecurity. However, little is known about the potential role that social support may play as a moderator of the association between income and food insecurity. Thus, we aim to examine social support as a moderator for the relationship between income and food insecurity among seniors. Methods: Logistic regression models were used to analyze data collected in 2019 from seniors residing in Southern Nevada. Predictors of food insecurity, sociodemographic factors, social support variables, and income and …

Pectin And Alginate Extraction To Treat Liquid Cafo Manure, Clare Sunderman

Honors Projects

For this project, various extraction methods were used to extract pectin from Pastinaca Sativa and alginate from Macrocystis. These extractions were then dried and used in treating 250mL of manure along with a CaCl₂ or FeCl₃ coagulant. It was found that CaCl₂ was not as effective as FeCl₃ in coagulating manure. But the results obtained suggest that pectin and alginate obtained with a simpler extraction method is just as effective as the highly purified and refined pectin and alginate produced for the food industry, in the treatment of CAFO manure. The liquid portion of the …

Food Hubs And Rebuilding Missing Middle Market Structure In Agriculture: The Social In Supply Chain Development, Stephen Luoni

Community Design Center Faculty Publications and Presentations

Tens of millions of Americans became food insecure during the COVID-19 pandemic as independent farmers dumped millions of tons of food due to economic lockdowns. Yet contract growers looped into vertically integrated monopoly supply chains escaped system breakdowns. Food provisioning is often seen as polarized between local scale and continental/ global market scale. Food supply and consumption are functions more of market structure than scale. Farmers reliant on direct sales to local restaurants, schools, universities, and hospitals saw their markets evaporate overnight. This Food Away from Home market constitutes 54 percent of food consumed nationally yet is vulnerable since direct-to-consumer …

A Hyperelastic Porous Media Framework For Ionic Polymer-Metal Composites And Characterization Of Transduction Phenomena Via Dimensional Analysis And Nonlinear Regression, Zakai J. Olsen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ionic polymer-metal composites (IPMC) are smart materials that exhibit large deformation in response to small applied voltages, and conversely generate detectable electrical signals in response to mechanical deformations. The study of IPMC materials is a rich field of research, and an interesting intersection of material science, electrochemistry, continuum mechanics, and thermodynamics. Due to their electromechanical and mechanoelectrical transduction capabilities, IPMCs find many applications in robotics, soft robotics, artificial muscles, and biomimetics. This study aims to investigate the dominating physical phenomena that underly the actuation and sensing behavior of IPMC materials. This analysis is made possible by developing a new, hyperelastic …

Linking Extreme High Air Temperature Events To Wildfire And Environmental Variation To Water Balance Partitioning In The Western Us, Neil Savage

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chapter 1

Wildfire activity has increased across the western United States in recent decades, causing significant damage to ecosystem services and human communities. The Sierra Nevada region, in particular, has experienced substantial increases in the ignition frequency, severity, and extent of large wildfires. To partly disentangle the complex processes underlying wildfire risk, I developed a simple approach to link natural wildfire ignition patterns to changing seasonal temperatures and extreme high and low air temperature events across the Sierra Nevada region from 1992—2015. Extreme event analyses focused on the association between the magnitude and frequency of occurrence of extreme temperature events …

Food Insecurity And Adiposity Among Children And Adults Nhanes 2015-2016, Denise Vidal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: Obesity is a preventable disease that has been associated with many adverse health outcomes. A possible factor that may influence adiposity development is food insecurity. Although several epidemiological studies have been conducted examining the association between food insecurity and adiposity among children and adults, results have been inconsistent. Objective: This cross-sectional study investigates the relationship between food insecurity and adiposity among children and adults using recent data from a representative sample of the US population. Methods: We examined 3,391 adults and 2,837 children from the National Health and Nutrition Examination Survey (NHANES) 2015-2016. Household food insecurity was assessed using …

Recommender App Development For Essential Health Products : Covid And Beyond, Jessica Lourenco

Theses, Dissertations and Culminating Projects

The COVID-19 pandemic has affected all of our lives in many ways and as a result people have become more health conscious. Now more than ever it is critical to take cautious steps to prevent being infected and spreading the virus. It is important to be supplied with the right products that maintain us all safe and healthy. Although many stores have health related products, sometimes it is a hassle to find them and even to pick out the best ones. With that, the Health Essentials app was developed to facilitate the findings of health products. The app is solely …

Comparing A New Algorithm For The Traveling Salesman Problem To Previous Deterministic And Stochastic Algorithms, Edward Friesema

UNLV Theses, Dissertations, Professional Papers, and Capstones

The challenges of drone navigation have driven many advances in the development of autonomous systems. Unmanned Autonomous Vehicles(UAVs) operate in a rapidly changing flight space and have to balance a complex set of constraints and objectives. Many of these objectives can be represented in variations of the classic Traveling Salesman Problem. Numerous approximate solutions to TSP have been proposed over the years, but these approaches have difficulty when adding new constraints that require rapid recalculation of the solution. Either they are fast but do not provide solutions that are close to the optimum, or they provide excellent solutions but they …

Effect Of Boundary Approximation On Visibility, Samridhi Jha

UNLV Theses, Dissertations, Professional Papers, and Capstones

The problem of simplifying a complex shape with simpler ones is an important research area in computer science and engineering. In this thesis, we investigate the effect on the visibility properties of polygons when their boundaries are approximated to make them simpler. We present two algorithms for approximating a restricted class of polygons called 1.5 D terrain. We also present experimental investigations on the performance of reviewed and proposed approximation algorithms.

Chronicling Magma Transit Beneath Hawaiian Volcanoes: Every Isotope A Word, Every Crystal A Story, Jonathan Pinko

UNLV Theses, Dissertations, Professional Papers, and Capstones

At many oceanic volcanoes, such as Hawaii, mantle-derived magmas migrate to crustal level magma chambers, where they accumulate before eruption. Understanding the magma chamber residence times, or the time gaps between the arrivals of new magmas and eruptions, is important in volcanic hazard mitigation. Here I apply iron and magnesium isotope effects in olivines to constrain these times at Hawaiian volcanoes. Combined with published data, I present bulk ?56Fe (-1.706 to 0.489) and ?26Mg (-0.400 to 0.356) in 108 Hawaiian olivines erupted from the pre-shield, shield, and post-shield stages. The Hawaiian olivine ?56Fe and ?26Mg represent the largest Fe-Mg isotope …

Prograde Metamorphism And Upper-Crustal Cooling In The Northern Panamint Range, California: New Insights Into The Jurassic And Mid-Cretaceous Evolution Of The Southern Sevier Fold-Thrust Belt, Elijah A. Turner

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Jurassic-Cretaceous southern Sevier fold-thrust belt, which experiences changes in orientation and structural style as it approaches intersection with the Mesozoic continental arc, has been pervasively overprinted by Neogene-Quaternary faulting, rendering its evolution enigmatic. Raman spectroscopy of carbonaceous material (RSCM) thermometry data from 14 samples and zircon (U-Th)/He (ZHe) thermochronology data from 23 samples collected in the northern Panamint Range illuminate the history of metamorphism and upper-crustal cooling associated with this belt of shortening structures. Best estimate peak temperatures derived from RSCM thermometry increase from 166 ± 19°C at 2.5 km structural depth (measured from the top of the exposed …

Crystal Structure Of Tris, Colin T. Hartgerink, Richard J. Staples, Carolyn E. Anderson

University Faculty Publications and Creative Works

The title ketenyl­idene, [Au3(C2O)(C26H35O2P)3](C2F6NO4S2), was obtained upon exposure of [2-(di­cyclo­hexyl­phosphino)-2′,6′-dimeth­oxy-1,1′-biphen­yl]gold(I) bis­(tri­fluoro­methane­sulfon­yl)imide to acetic anhydride at elevated temperature. The ketenyl­idene bridge caps the tri-gold cluster. The title compound has provided crystals that upon analysis represent the first tri-gold ketenyl­idene with atomic distances indicative of bonding inter­action between the gold atoms.

A Careful Reassessment Of Globular Cluster Multiple Population Radial Distributions With Sloan Digital Sky Survey And Johnson-Cousins Broadband Photometry, Willem B. Hoogendam, Jason P. Smolinski

University Faculty Publications and Creative Works

Inconsistencies regarding the nature of globular cluster (GC) multiple population radial distributions is a matter for concern given their role in testing or validating cluster dynamical evolution modeling. In this study, we present a reanalysis of eight GC radial distributions using publicly available ground-based ugriz and UBVRI photometry; correcting for a systematic error identified in the literature. We detail the need for including and considering not only Kolmogorov-Smirnov (K-S) probabilities but critical K-S statistic values as well when drawing conclusions from radial distributions, as well as the impact of sample incompleteness. Revised cumulative radial distributions are presented, and the literature …

Expanding Band Parameter Analysis Methods For Hed Meteorites And V-Type Asteroids, Noah Adm Haverkamp Frere

Masters Theses

Vesta and Vesta-like asteroids have been convincingly linked, through visible and near-infrared (VNIR; 0.7 - 2.5 µm [micron]) spectral analysis, to a clan of basaltic achondritic meteorites – howardites, eucrites, and diogenites (HEDs). VNIR reflectance spectra of V-type asteroids and HED meteorites have two absorption features centered near 1 µm (Band I) and 2 µm (Band II) caused primarily by Fe²⁺ [iron] and Ca²⁺ [calcium] cations in pyroxene. Previous studies have shown a correlation between the mol% Fs and Wo with the central wavelengths of Band I and Band II, hereafter called Band I Center (BIC) and Band …

Association Between Stream Impairment By Mercury And Superfund Sites In The Conterminous Usa, Karessa L. Manning

Masters Theses

Mercury is a natural element that can cause harm to the brain, heart, kidneys, lungs, and immune system, especially to fetuses developing in the womb. Many natural and anthropogenic factors contribute to mercury in the environment, such as geologic deposits, landfills, gold and silver mining operations, cement production, and atmospheric deposition. Mercury has been identified as a contaminant of concern at many National Priority List (NPL) sites, however, studies on contamination at NPL sites are often only conducted on a local level. This study was to analyze the potential connection between mercury-contaminated NPL sites and the presence of mercury impaired …

A Fully-Automated, Deep Learning-Based Framework For Ct-Based Localization, Segmentation, Verification And Planning Of Metastatic Vertebrae, Tucker Netherton, Tucker James Netherton

Dissertations & Theses (Open Access)

Palliative radiotherapy is an effective treatment for the palliation of symptoms caused by vertebral metastases. Visible evidence of disease is localized on medical images as part of the treatment planning process. However, complicating factors such as time pressures, anatomic variants in the spine, and similarities in adjacent vertebrae are associated with wrong level treatments of the spine. In addition, erroneous manual contouring of anatomic structures is a major failure mode in radiotherapy treatment planning.

The purpose of this study is to mitigate the challenges associated with treatment planning of the spine by automating the treatment planning process for three-dimensional conformal …

Measurement Of The Top Quark Mass Using Leptonic Observables In Tt Events Produced In Pp Collisions At Sqrt S = 13 Tev With The Cms Experiment At The Lhc, Mark Douglas Saunders

Theses and Dissertations

A novel method is presented for the measurement of the top-quark mass using only leptonic observables in tt events produced in pp collisions at SQRT(s)= 13 TeV.Data, corresponding to an integrated luminosity of 35.9 fb−1, were collected with the CMS detector during LHC Run II in 2016. The measurement uses the top-quark mass dependence of multiple kinematic distributions comprised from the dilepton eμ final state of tt events. The top-quark mass dependence of each kinematic distribution is calibrated using events generated with a NLO Monte Carlo simulation, and for the first time, with a second simulation that includes the exact …

Timing Properties Of Active Galactic Nuclei, Evan Arnold Smith

Theses and Dissertations

Timing properties of Active Galactic Nuclei (AGN) are investigated primarily using archival data from the Rossi X-ray Timing Explorer (RXTE) satellite collected between 1996 and 2011. The main emphasis is to search for quasi-periodic oscillations (QPOs). This search was motivated by the uniqueness of the RXTE AGN database, which contains a gold-mine of information on the long-term light curves of AGN, as well as the fact that QPOs are a common feature in the light curves of stellar mass black hole (BH) and neutron star (NS) X-ray Binaries (XRBs).In stellar mass systems, QPOs have been used as strong diagnostics about …

Metastable State Photoacids And Ultrasound Responsive Carbon Monoxide Releasing Polymer Micelle, Osamah Zaid Saleh Alghazwat

Theses and Dissertations

This dissertation described my Ph.D. work on the development of a novel metastable state photoacids (mPAH), which can be activated by near infrared light and a reversible mPAH switched by different wavelengths of light. Also, it described the development of a micelle that responded to ultrasound to localized carbon monoxide CO delivery. An introduction of metastable state photoacid is given in Chapter 1. In Chapter 2, described my work on the development of a novel mPAH, which can be activated by near infrared light is an important factor for various biological functions. mPAH was designed and synthesized with a donor-acceptor-donor …

The Brezis-Nirenberg Problem For The Generalized Kirchhoff Equation, Erisa Hasani

Theses and Dissertations

We study a class of critical Kirchhoff problems with a general nonlocal term. The main difficulty here is the absence of a closed-form formula for the compactness threshold. First we obtain a variational characterization of this threshold level. Then we prove a series of existence and multiplicity results based on this variational characterization.

Pattern Based Classification Of Chronic Kidney Disease Patients, Melissa Megan Moreno Cole

Theses and Dissertations

We apply a pattern-based classification method to identify clinical and genomic features associated with the progression of Chronic Kidney Disease (CKD). We analyze the African-American Study of Chronic Kidney Disease with Hypertension (AASK) dataset and construct a decision-tree classification model, consisting 15 combinatorial patterns of clinical features and single nucleotide polymorphisms (SNPs), seven of which are associated with slow progression and eight with rapid progression of renal disease among AASK patients. We identify four clinical features and two SNPs that can accurately predict CKD progression. These features are validated with using sophisticated machine learning techniques including Random Forest, Nearest Neighbor, …

Schur Complement Algebra And Operations With Applications In Multivariate Functions, Realizations, And Representations, Anthony Dean Stefan

Theses and Dissertations

We provide a new approach to the following multidimensional realizability problem: Can an arbitrary square matrix, whose entries are from the field of multivariate rational functions over the complex numbers, be realized as a Schur complement of a linear matrix pencil with symmetries? To answer this problem, we prove the main theorem of M. Bessmertny˘ı,“On realizations of rational matrix functions of several complex variables,” in Vol. 134 of Oper. Theory Adv. Appl., pp. 157-185, Birkh¨auser Verlag, Basel, 2002 and have included additional symmetries as an extension to his results. Furthermore, we were so thorough in our constructive approach that we …

Stability Results For Special Solutions Of Scalar-Field Equations With Variable Coeffcients, Mashael Ibrahiem Alammari

Theses and Dissertations

We study the long-time behavior of general semilinear scalar-field equations on the real line with variable coefficients in the linear terms. In the first part of the dissertation, we take the coefficients to be uniformly small, but slowly decaying, perturbations of a constant-coefficient operator. We are motivated by the question of how these perturbations of the equation may change the stability properties of kink solutions (one-dimensional topological solitons). We prove existence of a stationary kink solution in our setting, and perform a detailed spectral analysis of the corresponding linearized operator, based on perturbing the linearized operator around the constant-coefficient kink. …

Machine Learning Approach To Predict Mortality Rates Based On Hospital Clinical Data, Rebecca Smith

Theses and Dissertations

This thesis integrates fundamental concepts from conventional statistics with the more explanatory, algorithmic, and computational techniques offered by machine learning to predict early mortality risk of surgical patients. Well-known classification methods, including Random Forest, Decision Trees, Nearest Neighbor, Stochastic Gradient Descent, Logistic Regression, Na¨ıve Bayes, Bayes Network, Neural Networks, and Support Vector Machines, are utilized to predict mortality risk of elective general surgical patients treated between January 2005 and September 2010 at the Cleveland Clinic [33]. Clinical factors include surgery type, age, gender, race, BMI, underlying chronic conditions, surgical risk indices, surgical timing predictors, the 30-day mortality, and in-hospital complication …