Physical Sciences and Mathematics Commons^™

Applying Data Science And Machine Learning To Understand Health Care Transition For Adolescents And Emerging Adults With Special Health Care Needs, Lisamarie Turk

Nursing ETDs

A problem of classification places adolescents and emerging adults with special health care needs among the most at risk for poor or life-threatening health outcomes. This preliminary proof-of-concept study was conducted to determine if phenotypes of health care transition (HCT) for this vulnerable population could be established. Such phenotypes could support development of future studies that require data classifications as input. Mining of electronic health record data and cluster analysis were implemented to identify phenotypes. Subsequently, a machine learning concept model was developed for predicting acute care and medical condition severity. Three clusters were identified and described (Cluster 1, n …

Mitigation Impact Of Statewide Non-Pharmaceutical Policies On Covid-19: An Application Of Infectious Disease Transmission Model And Partially Observed Markov Process To New Mexico, Xingya Ma

Mathematics & Statistics ETDs

This thesis is an application of epidemiological models for infectious disease transmission and the use of partially observed Markov process (POMP) for model fitting. It focuses on COVID-19 pandemic in the state of New Mexico. The analysis covered March 2020 to June 2021. Daily data of COVID19 cases and deaths and a daily index of eleven statewide government non-pharmaceutical intervention (NPI) policies were collected from six public sources and were validated. These data were integrated through the Susceptible-Exposed-Infected-Removed (SEIR) model. Estimated daily transmission rates between the model compartments quantify the impact of the mitigation policies, and show that transmission rates …

Investigation Of Gaas Double Heterostructures For Photonic Heat Engines, Nathan Giannini-Hutchin

Optical Science and Engineering ETDs

The creation of a laser cooled semiconductor device has been a long sought achievement. GaAs-based devices have emerged as a promising candidate for the realization of this goal. Efforts to improve the efficiency of such devices have enabled the material to exhibit external quantum efficiencies (EQE, a measure of the probability that an excitation leads to the emission of a photon) of 99.5\%. Despite this impressive feat, a laser coolable device remains elusive.

To investigate the obstacles to such a device, the material characteristics of GaAs-based double heterostructures (DHS) are theoretically and experimentally examined. Through this study, a GaAs $\vert$ …

Single-Crystal Elasticity Of Earth’S Mantle Transition Zone Minerals And High Pressure-Temperature Phase Equilibrium Experiments On Martian Basalts, Wenyi Zhou

Earth and Planetary Sciences ETDs

Wadsleyite and ringwoodite are major minerals in the Earth’s Mantle Transition Zone. Global and local seismic studies have detected strong lateral variations in seismic velocity and anisotropy in the Mantle Transition Zone, reflecting temperature and possible composition variations. Interpretation of these seismic observations requires knowledge of thermoelastic properties of wadsleyite and ringwoodite with different compositions (water and Fe contents) under high pressure-temperature conditions. In this dissertation, we have measured single-crystal elastic properties of wadsleyite and ringwoodite under high pressure-temperature conditions by Brillouin spectroscopy. Based on our measurements and previous experimental results, we further model the effects of water and Fe …

Investigation Of Laser And Nonlinear Properties Of Anderson Localizing Optical Fibers, Cody Ryan Bassett

Optical Science and Engineering ETDs

In this dissertation, I investigate the possibility of lasing and nonlinear phenomena in completely solid-state transverse Anderson localizing optical fibers (TALOFs). I examine three areas within this range of topics. The research in nonlinear phenomena focuses on four-wave mixing (FWM). FWM is of high interest in TALOFs due to the fact that guided localized modes of the fiber each have different propagation constants, and thus unique possible FWM pairs can be generated from the same input pump beam. I demonstrate the generation of FWM in the TALOF by pumping it with 532 nm light into a localized mode and observing …

Convexity Of Regularized Optimal Transport Dissimilarity Measures For Signed Signals, Christian P. Fowler

Mathematics & Statistics ETDs

Debiased Sinkhorn divergence (DS divergence) is a distance function of

regularized optimal transport that measures the dissimilarity between two

probability measures of optimal transport. This thesis analyzes the advantages of

using DS divergence when compared to the more computationally expensive

Wasserstein distance as well as the classical Euclidean norm. Specifically, theory

and numerical experiments are used to show that Debiased Sinkhorn divergence

has geometrically desirable properties such as maintained convexity after data

normalization. Data normalization is often needed to calculate Sinkhorn

divergence as well as Wasserstein distance, as these formulas only accept

probability distributions as inputs and do not directly …

Theoretical Studies Of Molecule-Surface Interactions And Dynamics, Yingqi Wang

Chemistry and Chemical Biology ETDs

Gas-surface scattering involves the conversion of energy in different forms in the impinging molecule, possible bond breaking and forming, and the energy transfer across gas-solid interface. Possible energy dissipation channels include adiabatic energy transfer to the motion of surface phonons and non-adiabatic interactions with surface electron-hole pairs. A complete understanding of the interplay of energy dissipation and physical/chemical changes in the molecule is vital for many important applications such as materials fabrication and heterogenous catalysis.

Gas-surface encounters may occur where non-adiabatic effects are negligible. Two such systems were investigated, both with ample experimental data. One is concerned with the scattering …

Science, Technology, Engineering, And Mathematics (Stem) Project-Based Learning (Pbl) Education: A New Mexico Case Study For Equity And Inclusion, Kimberly A. Scheerer

Teacher Education, Educational Leadership & Policy ETDs

This research addresses how student participation in Science, Technology, Engineering, and Mathematics (STEM) project-based learning (PBL) education activities encourages underrepresented minority student achievement in STEM career field trajectories. Seven New Mexico high school counselors and 12 STEM organization personnel were interviewed during this study. Their responses represent the nuanced professional voices where New Mexico public education intersects with STEM student interest and cultural influence.

For students, STEM PBL can foster deep integration across educational disciplines and enhance STEM career trajectory interest and readiness. STEM education converged with PBL methodologies has the ability to leverage community support while broadening student networks. …

Statistical Methods For Differential Gene Expression Analysis Under The Case-Cohort Design, Lidong Wang

Mathematics & Statistics ETDs

Differential gene expression analysis has the potential to discover candidate biomarkers, therapeutic targets, and gene signatures. How to save money when using an unaffordable sample is a practical question. The case-cohort (CCH) study design can blend the economy of case-control studies with the advantages of cohort studies. But it has not been seen in the medical research literature where high-throughput genomic data were involved.

A score test does not need to fit the Cox PH model iteratively; hence, it can save computing time and avoid potential convergence issues. We developed a score test under the CCH design to identify DEGs …

Dense Array Seismic Imaging Of Earth's Crust Using Active And Passive Sources, Evans Awere Onyango

Earth and Planetary Sciences ETDs

Imaging Earth’s crust is critical to understanding processes in the near-surface that affect civilization such as the interaction of seismic waves with the near-surface to generate natural or man-made hazards or investigating how the shallow crust affects the distribution of resources. In chapter 1, I processed and analyzed active source seismic data recorded by ~1000 geophones that were acquired over the legacy HADDOCK nuclear test at the Nevada National Security Site. Using seismic reflection and refraction methods, we image the partially collapsed post-detonation structure to better understand the velocity structure in and around the HADDOCK chimney. Results from this work …

Induced Seismicity In The Raton Basin And Global Variability Of The 410-Km Discontinuity, Margaret E. Glasgow

Earth and Planetary Sciences ETDs

Natural processes like mantle convection and plate tectonics dominate Earth’s seismic structure. Recently human activities have increasingly influenced the deformation of the shallow crust. In this dissertation, passive source seismology was used to constrain seismic discontinuities in the mantle transition zone and seismogenic structures in induced earthquake settings. Using a novel sampling method and uniform processing approach, I found the 410-km discontinuity is thermally and compositionally variable. Using a machine- learning approach, I found the three main zones of seismicity in the Raton Basin consist of short faults or fault segments with variable orientations. The zone that hosted a Mw …

Functional Data Analysis Of Covid-19, Nichole L. Fluke

Mathematics & Statistics ETDs

This thesis deals with Functional Data Analysis (FDA) on COVID data. The Data involves counts for new COVID cases, hospitalized COVID patients, and new COVID deaths. The data used is for all the states and regions in the United States. The data starts in March 1^st, 2020 and goes through March 31^st, 2021. The FDA smooths the data and looks to see if there are similarities or differences between the states and regions in the data. The data also shows which states and regions stand out from the others and which ones are similar. Also shown …

Music Genre Classification By Convolutional Neural Networks, Usame Suud

Mathematics & Statistics ETDs

In today’s world, deep learning models are widely used in a variety of fields. Audio

applications include speech recognition, audio classification, and music information

retrieval. In this paper, we will focus on the classification of music genres using an

artificial neural network. The development of audio machine learning techniques has

created an independence from traditional, more time-consuming signal processing

techniques. Starting with raw audio data, we will gain an understanding of what

audio is and its digital representation. Then, the focus will be on obtaining frequency

information from audio signals through the use of spectrograms. Transforming the

spectrograms into the …

A Rapid High-Precision Analytical Method For Triple Oxygen Isotope Analysis Of Co2 Gas Using Tunable Infrared Laser Direct Absorption Spectroscopy, Nathan Perdue, Zachary Sharp, David Nelson Jr., Rick Wehr, Christoph Dyroff

Earth and Planetary Sciences ETDs

Rationale

The simultaneous analysis of the three stable isotopes of oxygen – triple oxygen isotope analysis – has become an important analytical technique in natural sciences. Determination of the abundance of the rare ¹⁷O isotope in CO₂ gas using magnetic sector isotope ratio mass spectrometry is complicated by the isobaric interference of ¹⁷O by ­¹³C (¹³C¹⁶O¹⁶O and ¹²C¹⁶O¹⁷O both have mass 45 amu). A number of analytical techniques have been used to measure the ¹⁷O/¹⁶O ratio of CO₂ gas. They …

Determining The Idealizers Of Principal Monomial Ideals Over A Rational Normal Curve, Perla A. Maldonado Cortez

Mathematics & Statistics ETDs

Given an ideal J generated by an element of the form sm1 tm2 , where
m1 ≥ 2 and m2 ≥ 0, we illustrate how to compute the idealizer I(J) over the ring
of the rational normal curve of degree n and we give a formula for it using the
graded pieces of the sets of differential operators.

Distance Estimates To Evolved Stars Using Infrared Emission And Verification And Validation Of The Plasma Code Empire, Brandon M. Medina

Physics & Astronomy ETDs

Gaining insight into the structure and dynamics of the Milky Way is important for understanding the universe on a large scale. Evolved stars on the Asymptotic Giant Branch are useful for studying the Milky Way because their emission is peaked in the infrared, where interstellar extinction effects are not as dominant. To further understand the physical properties of these objects like luminosity and investigate the Galaxy's structure, we need distance estimates. Obtaining distance estimates for these evolved stars via trigonometric parallax measurements is time-consuming, so infrared surveys studying Asymptotic Giant Branch stars can benefit from other distance estimate methods. In …

Rock Climbing And Conservation In Land Management: Can They Coexist?, Marissa Heller

Geography ETDs

As participation in outdoor recreation is growing in the U.S., a dilemma is presented for conservation planners and land area managers who must manage the increasing demand for recreation while simultaneously working to protect species. Rock climbers and other outdoor recreationalists have asserted that a relationship exists between recreation and the conservation of public lands. However, mounting evidence suggests that rock climbing continues to cause a multitude of negative impacts to ecosystems. Here, I investigate the extent to which land management practices allow for rock climbing and conservation to coexist, and how it is that well developed plans protect ecologically …

Machine Learning Model Comparison And Arma Simulation Of Exhaled Breath Signals Classifying Covid-19 Patients, Aaron Christopher Segura

Mathematics & Statistics ETDs

This study compared the performance of machine learning models in classifying COVID-19 patients using exhaled breath signals and simulated datasets. Ground truth classification was determined by the gold standard Polymerase Chain Reaction (PCR) test results. A residual bootstrapped method generated the simulated datasets by fitting signal data to Autoregressive Moving Average (ARMA) models. Classification models included neural networks, k-nearest neighbors, naïve Bayes, random forest, and support vector machines. A Recursive Feature Elimination (RFE) study was performed to determine if reducing signal features would improve the classification models performance using Gini Importance scoring for the two classes. The top 25% of …

Robust Uncertainty Quantification With Analysis Of Error In Standard And Non-Standard Quantities Of Interest, Zachary Stevens

Mathematics & Statistics ETDs

This thesis derives two Uncertainty Quantification (UQ) methods for differential equations that depend on random parameters: (\textbf{i}) error bounds for a computed cumulative distribution function (\textbf{ii}) a multi-level Monte Carlo (MLMC) algorithm with adaptively refined meshes and accurately computed stopping-criteria. Both UQ approaches utilize adjoint-based \textit{a posteriori} error analysis in order to accurately estimate the error in samples of numerically approximated quantities of interest. The adaptive MLMC algorithm developed in this thesis relies on the adjoint-based error analysis to adaptively create meshes and accurately monitor a stopping criteria. This is in contrast to classical MLMC algorithms which employ either a …

Ultrashort Pulse Laser Filamentation Electrical And Optical Diagnostic Comparison, James E. Wymer

Optical Science and Engineering ETDs

Results presented here examine the effect of changing gas pressure on the radio frequency (RF) emissions of an ultrashort pulse laser filament plasma and how those emissions vary longitudinally in the laser focal region. We use a WR284 rectangular waveguide with a 1.5 cm hole that allows the beam through. A 3.2 GHz microwave signal is emitted in the waveguide, and signals are received through a waveguide-to-coax antenna connected to an HP8470B Schottky diode. By enabling and disabling the 3.2 GHz signal, we measure both the self-emitted RF from a USPL filament and subsequently the degree of attenuation a filament …

The Changing Urban Forest In Gallup, New Mexico: Contextualizing Urban Tree Programs And Planning Processes, Joseph A. Scala

Geography ETDs

Tree plantings are often proposed as a solution to a variety of urban problems. The purpose of this project is to investigate the historical formation of urban tree cover in Gallup, New Mexico, and the extent to which urban tree plantings can benefit areas with inequitable urban tree distribution. To do this, I employ a mixed methods approach that includes correlation analysis, historical analysis, and analysis of urban tree canopy change from 1972-2005. The findings from this study indicate that Gallup’s history of tree plantings is heavily influenced by its history of economic development. Additionally, the findings demonstrate that if …

Atomic Gradiometry Based On The Interference Of Microwave Optical Sidebands, Kaleb L. Campbell

Optical Science and Engineering ETDs

We describe a novel pulsed magnetic gradiometer based on the optical interference of sidebands generated using two spatially separated alkali vapor cells. The sidebands are produced with high efficiency using parametric frequency conversion of a probe beam interacting with Rubiduim 87 atoms in a coherent superposition of magnetically sensitive hyperfine ground states. First, experimental evidence of the sideband process is described for both steady-state and pulsed operation. Then, a theoretical framework is developed that accurately models sideband generation based on density matrix formalism. The gradiometer is then constructed using two spatially separated vapor cells, and a beat-note is generated. The …

Computational, Synthetic And Spectroscopic Studies On Donor Acceptor Transition Metal Complexes, Ranjana Dangi

Chemistry and Chemical Biology ETDs

Fundamental advances in our ability to design and construct electronic components at the nanoscale will require new design paradigms. One proposed nanoscale electronic component is the molecular rectifier. Molecular and molecule-based electronic components are advantageous due to their ease of synthetic manipulation, and the fact that the size dimensions of molecules are inherently at the nanoscale (0.5 - 3nm). Our group has shown how the Donor-Bridge-Acceptor biradical approach can be used to derive key structure-property relationships that allow insight into the choice of bridge fragments for molecular rectification by using constitutional isomers of the donor-bridge-acceptor biradical (NN-Th-Py-SQ) (S=1/2 ortho-semiquinonate, …

Fiesta And Shock-Driven Flows, Brian E. Romero

Mechanical Engineering ETDs

In this study, the interaction of a shock with various gas and particle interfaces is analyzed through simulations using a new, GPU capable, multi-species flow solver, FIESTA (Fast, Interface Evolution, Shocks, and Transport in the Atmosphere), de- veloped for this research. The cases studied include the interaction between a shock and i) a two-dimensional (2D), circular cloud of a dense gas; ii) a 2D curtain of a dense gas; iii) a three-dimensional (3D) cylinder of a dense gas, and iv) a 3D curtain of solid particles.

In simulations of a 2D gas curtain and a 3D gas column, the curtain …

Effect Of Phylogeny Misestimation On Estimating Trait Evolution Parameters, Tabytha Ariel Perez

Mathematics & Statistics ETDs

Biologists are interested in estimating trait evolution models from phylogenies. However, phylogenies are imperfectly estimated, generally from DNA sequence data. In this study, true phylogenies are simulated to understand whether errors in phylogeny estimation affect inference of the trait evolution model. Given the tree, DNA sequences as well as traits are then simulated from the true phylogeny; both are simulated independently from the other. After the simulation, the DNA sequences were used to estimate trees using the UPGMA method without utilizing the trait information. The estimated trees combined with the traits are used to infer the evolutionary trait models, specifically …

Human-Centered Avalanche Susceptibility Mapping, Lindsey L. Rotche

Geography ETDs

With backcountry winter travel increasing in popularity, the importance of accessible avalanche safety information is crucial. Widely accessible avalanche backcountry maps use slope shading to show where avalanches are likely to start. Instead of focusing on the hazard of an avalanche starting in a specific location, this project shifted the cartographic emphasis of avalanche susceptibility maps to show risk to a human traveling in the terrain. I developed a methodology to incorporate possible avalanche runouts, terrain traps, and connected slopes while reducing false certainty of the visualization. To provide a more comprehensive representation of susceptible terrain, I integrated aspect, distance …

Halogen And Non-Traditional Isotope Geochemistry Of Planetary And Terrestrial Materials, Anthony Gargano, Zachary Sharp, Justin Simon, Charles Shearer, Adrian Brearley, James Day

Earth and Planetary Sciences ETDs

This dissertation presents the advances in non-traditional isotope geochemistry of planetary and terrestrial materials encompassing chlorine, sulfur, and zinc isotopes, as well as halogen geochemistry. A wide breadth of materials was studied throughout the completion of this work including iron meteorites, achondrites, chondrites, Apollo lunar samples, as well ancient marine chert, and carbonate sediments. Much of the focus involved the development of a method capable of simultaneously measuring the halogen contents and chlorine isotope compositions of geological materials. Here, I present these data sets to broadly characterize the process of devolatilization of planetary materials, and specifically the problem of ‘halogen-poisoning’ …

Relating Plant Community Structure To Carbon Dynamics In Semiarid Grasslands, Theodore D. Roper

Biology ETDs

Understanding how fine-scale changes in soil characteristics and plant community composition affect ecosystem functioning is key to predicting how biome shifts will affect regional and global carbon cycling. This is crucial in the dryland biomes of the US Southwest, projected to be one of the regions most affected by climate change. We examined fine-scale drivers of ecosystem function within two biomes – a Chihuahuan Desert grassland and Plains/Chihuahuan Desert ecotone – via long-term vegetation data, micrometeorological data, eddy covariance carbon flux measurements, and soil water and texture, finding that the ecotone site had over 30% higher soil water content, over …

Deformation Of Antigorite + Olivine Aggregates: Implications For Mantle Wedge Dynamics, Roselyn K. Hurlow

Earth and Planetary Sciences ETDs

Aggregates with varying volume proportions of antigorite and olivine were deformed at mantle wedge conditions of high-pressure (P) (2.5-7.6 GPa), -temperature (T) (675 K), and strain rates from ~1.0*10^-5 to ~1.0*10^-4 s^-1 using the deformation-DIA (D-DIA) to investigate deformation mechanisms and stress/strain partitioning. Macroscopic strain, lattice strain, and texture were measured in situ using synchrotron x-ray diffraction and radiography and were modeled for olivine using Elasto-Viscoplastic Self-Consistent (EVPSC) simulations. These modeled results are coupled with microstructure images and electron backscatter diffraction (EBSD) measurements results to determine stress and deformation mechanisms. Previous to this study, investigations have been …

The Obata First Eigenvalue Theorem On A Seven Dimensional Quaternionic Contact Manifold, Abdelrahman Mohamed

Mathematics & Statistics ETDs

We prove an Obata-type rigidity result for the first eigenvalue of the sub-Laplacian on a compact seven dimensional quaternionic contact (QC) manifold which satisfies a Lichnerowicz-type bound on its QC-Ricci tensor, and has a non-negative Paneitz P -function. In particular, under the stated conditions, the lowest possible eigenvalue of the sub-Laplacian is achieved if and only if the manifold is QC-equivalent to the standard 3-Sasakian sphere.