Physical Sciences and Mathematics Commons^™

Sybil Defense Using Efficient Resource Burning, Diksha Gupta

Computer Science ETDs

In 1993, Dwork and Naor proposed using computational puzzles, a resource burning mechanism, to combat spam email. In the ensuing three decades, resource burning has broadened to include communication capacity, computer memory, and human effort. It has become a well-established tool in distributed security. Due to the cost attached to utilizing resource burning mechanism, these have not been popularized in domains apart from cryptocurrency.

In this dissertation, we design efficient resource burning based Sybil defense techniques for permissionless systems. As a first step, we identify existing resource burning mechanisms in literature in Chapter 2. Additionally, we enumerate numerous open problems …

Microstructural Constraints On The Nebular And Asteroidal Histories Of Calcium-Aluminum-Rich Inclusions From Cv3 Chondrites, Shaofan Che

Earth and Planetary Sciences ETDs

The petrology and mineralogy of calcium-aluminum-rich inclusions (CAIs) from CV3 carbonaceous chondrites have been investigated using transmission electron microscopy (TEM). The goal of this dissertation is twofold: (1) to gain new insights into the nebular processes, such as vapor-solid reactions, accretion, transport, that are responsible for the formation of non-igneous CAIs, and (2) to better understand the role of fluid in the secondary alteration of CAIs on the CV3 chondrite parent body. This work represents the first systematic microstructural study of CAIs from CV3 chondrites.

Chapter 2 presents the microstructural observations of primary mineralogies of fine-grained, spinel-rich inclusions (FGIs) from …

Monitoring The Low Frequency Radio Transient Sky With The Long Wavelength Array, Savin Shynu Varghese

Physics & Astronomy ETDs

Transient searches in radio astronomy have discovered some of the most extreme astrophysical phenomena in our universe. This has enabled us to study the physics of these explosive and dynamic sources. Most of the transient searches over the past 70 years have been at frequencies higher than 100 MHz leaving the transient sky below 100 MHz unexplored. The Long Wavelength Array (LWA) telescope offers an excellent opportunity to study the transient sky below 100 MHz with its wide field of view, high sensitivity and fast imaging at shorter timescales. This dissertation presents the transient searches carried out using the all-sky …

Niche Dynamics Of The Felid Guild Following The Pleistocene Megafaunal Extinction, Nicholas A. Freymueller

Biology ETDs

The loss of large carnivores is fundamentally restructuring modern mammal communities. However, large carnivore removal is not exclusively a modern trend. The Pleistocene Megafaunal Extinction (PME) resulted in a near-eradication of hyper-carnivorous felids such as saber-toothed cats. However, it is unclear if smaller surviving meso-felids began to infill this ecological vacuum post-PME. I apply Ecological Niche Modeling (ENM) to test evaluate whether surviving felids filled in vacant niches post-extinction, and hypothesize that they ought to have shown increased niche-overlap patterns with mega-felids post-extinction. I model species’ fundamental niches using a multi-temporal approach, and develop a novel test to model realized …

Understanding The Role Of Atom Trapping In The Evolution Of Hydrocarbon Transformation Catalyst Morphology, Griffin Canning

Chemistry and Chemical Biology ETDs

Converting alkanes to other, more chemically and economically valuable molecules requires catalysts that can survive elevated temperatures and highly reducing environments. These environments can cause many metal-nanoparticle based catalysts to sinter rapidly, causing a loss of activity. They must also tolerate the coke formation, as well, since coke can restrict access to active sites by gas phase molecules, thus lowering catalytic activity. While there are routes to improve both the sinter and coke resistance of catalysts, an alternative strategy is to develop a protocol for regenerating the activity of the catalyst in question when coke formation or sintering becomes problematic. …

Monte Carlo Simulations Of Awkward Actions, David John Amdahl

Physics & Astronomy ETDs

Time derivatives of scalar fields occur quadratically in textbook actions. A simple Legendre transformation turns the Lagrangian into a Hamiltonian that is quadratic in the momentum. The partition function over the momentum is Gaussian. Mean values of operators are basically euclidian path integrals of their classical counterparts with positive weight functions. Monte Carlo simulations can estimate such mean values. This familiar framework falls apart when the time derivatives do not occur quadratically. The Legendre transformation becomes difficult or so intractable that the Hamiltonian can’t be determined. Even if the Hamiltonian is found, it usually is so complicated that the partition …

An Analysis Of Growth Of The Community Integration Psychological Score In An Ethnically Diverse Population Experiencing Homelessness In A Permanent Supportive Housing Program Using Hierarchical Mixed Modeling, Leah Hollis Puglisi

Mathematics & Statistics ETDs

Hierarchical models are becoming increasingly common in epidemiological and psychological research. When analyzing data from such studies, the nested structure of the data must be taken into account. Mixed modeling in conjunction with hierarchical mixed modeling allows researchers to ask broad questions about the population of interest. Modeling under restricted maximum likelihood estimation (REML), as opposed to full maximum likelihood estimation (ML), increases the accuracy of estimates for the random effects in the model. We use hierarchical mixed modeling under REML estimation to analyze which factors increase “community integration”, a concept and a construct developed and used in the mental …

Boron Adsorption In Clay Minerals: Implications For Martian Groundwater Chemistry And Prebiotic Processes, Matthew A. Nellessen, Laura Crossey, Patrick J. Gasda, Horton Newsom, Abdulmehdi Ali, Eric J. Peterson, Nina Lanza, Adriana Reyes-Newell, Dorothea Delapp, Chris Yeager, Andrea Labouriau, Roger C. Wiens, Samuel Clegg, Shelbie Legett, Debarati Das

Earth and Planetary Sciences ETDs

Boron has been detected on Mars [Gasda et al., 2017, Das et al., 2019, 2020] within calciumsulfate veins found within clay-rich rocks on Mars by the Mars Science Laboratory (MSL) rover using Laser Induced Breakdown Spectroscopy (LIBS) analysis. Boron plays a vital role in stabilizing ribose on Earth and has been suggested as a key requirement for life [Scorei et al., 2006, 2012; Furukawa et al., 2013, 2017; Becker et al., 2019]. Additionally, boron readily adsorbs to phyllosilicate clay minerals and is often associated with biologic processes in clay soils. The discovery of boron on Mars in proximity to phyllosilicate …

Atom Trapping And Its Role On The Nucleation & Growth Of Platinum Nanoparticles, Deepak Kunwar

Chemistry and Chemical Biology ETDs

Diesel oxidation catalysts deactivate due to Pt sintering, a major problem in automotive industries. To make sure they operate effectively throughout the lifetime of the vehicle, automotive industries are putting an excessive amount of Pt. There is a need to develop a catalyst that serves long term performance with minimal use of Pt. Jones et al^.1 demonstrated that ceria traps Pt atoms. His work generated some logical and valid questions such as what is the mechanism for the formation of anomalously large Pt particles? What is the upper limit of Pt metal loading in the form of single atoms …

Radial Basis Densities And The Density Functional-Based Atom-In-Molecule: Designing Charge-Transfer Potentials, Godwin Amo-Kwao

Nanoscience and Microsystems ETDs

Classical potentials that are capable of describing charge transfer and charge polarization in complex systems are of central importance for classical atomistic simulation of biomolecules and materials. Current potentials—regardless of the system—do not generalize well, and, with the exception of highly-specialized empirical potentials tuned for specific systems, cannot describe chemical bond formation and breaking. The charge-transfer embedded atom method (CT-EAM), a formal, DFT-based extension to the original EAM for metals, has been developed to address these issues by modeling charge distortion and charge transfer in interacting systems using pseudoatom building blocks instead of the electron densities of isolated atoms. CT-EAM …

A Bayesian Network Analysis Of The Human Exposure To Escherichia Coli Bacteria In The Environment, Brandon G. De Flon

Mathematics & Statistics ETDs

Diarrhea is a leading cause of death worldwide because a lack thereof in household sanitization exposes humans to high concentrations of pathogenic Escherichia coli. In 2016, the University of New Mexico’s Nepal Study Center collected cross-sectional survey data using proportional random sampling on three communities in Western Nepal. Structural and parameter learning estimation and approximate inference of Bayesian networks studied diarrheagenic E. coli exposure while incorporating participation in sanitary behaviors, access to sanitary built-in environments, and other human characteristics. Of the reported sickness, hand washing resulted in a 20 percent decrease, water treatment 8 percent, and both 28 percent. Of …

Exploring Hidden Structure Of The Nearby Universe And The Limits And Capabilities Of Two Neutral Hydrogen Surveys, Monica Sanchez Barrantes

Physics & Astronomy ETDs

We can use the 21 cm neutral hydrogen (HI) emission line to detect galaxies in optically obscured regions, but it is also a faint line that is difficult to detect at higher redshifts. This work presents two HI surveys. The ALFAZOA Survey maps new and predicted large-scale structure across the Galactic plane, and finds a total of 217 completely new galaxies across both of the survey phases. The completeness limits for ALFAZOA Shallow and Deep are presented. Follow-up observations of confused galaxies in ALFAZOA using the VLA determine that confusion in this survey will not cause significant deviations for the …

Integrating Deep Learning And Augmented Reality To Enhance Situational Awareness In Firefighting Environments, Manish Bhattarai

Electrical and Computer Engineering ETDs

We present a new four-pronged approach to build firefighter's situational awareness for the first time in the literature. We construct a series of deep learning frameworks built on top of one another to enhance the safety, efficiency, and successful completion of rescue missions conducted by firefighters in emergency first response settings. First, we used a deep Convolutional Neural Network (CNN) system to classify and identify objects of interest from thermal imagery in real-time. Next, we extended this CNN framework for object detection, tracking, segmentation with a Mask RCNN framework, and scene description with a multimodal natural language processing(NLP) framework. Third, …

Numerical Simulations Of Nonlinear Waves And Their Stability: Stokes Waves And Nonlinear Schroedinger Equation, Anastassiya Semenova

Mathematics & Statistics ETDs

The present work offers an investigation of dynamics and stability of nonlinear waves in Hamiltonian systems. The first part of the manuscript discusses the classical problem of water waves on the surface of an ideal fluid in 2D. We demonstrate how to construct the Stokes waves, and how to apply a continuation method to find waves in close vicinity to the limiting Stokes wave. We provide new insight into the stability of the Stokes waves by identifying previously inaccessible branches of instability in the equations of motion for the fluid. We provide numerical evidence that pairs of unstable eigenvalues of …

From Wave Propagation To Spin Dynamics: Mathematical And Computational Aspects, Oleksii Beznosov

Mathematics & Statistics ETDs

In this work we concentrate on two separate topics which pose certain numerical challenges. The first topic is the spin dynamics of electrons in high-energy circular accelerators. We introduce a stochastic differential equation framework to study spin depolarization and spin equilibrium. This framework allows the mathematical study of known equations and new equations modelling the spin distribution of an electron bunch. A spin distribution is governed by a so-called Bloch equation, which is a linear Fokker-Planck type PDE, in general posed in six dimensions. We propose three approaches to approximate solutions, using analytical and modern numerical techniques. We also present …

Understanding Solar Wind Formation By Identifying The Origins Of In Situ Observations, Samantha Wallace

Physics & Astronomy ETDs

Over the past century, significant progress has made on the subjects of two fundamental unresolved questions in Heliophysics, namely 1) how is the solar corona heated to multi-million-degree temperatures, and 2) how is the solar wind formed, from its origin, to its release and acceleration. While the two are in many ways intertwined, this dissertation focuses on the latter. Our current understanding of solar wind formation has developed largely through relating the general origins of the observed solar wind on global spatial scales to the corresponding observed speed at 1 au. However, we are now at a point where long-standing …

Intrinsic Curvature For Schemes, Pat Lank

Mathematics & Statistics ETDs

This thesis develops an algebraic analog of psuedo-Riemannian geometry for relative schemes whose cotangent sheaf is finite locally free. It is a generalization of the algebraic differential calculus proposed by Dr. Ernst Kunz in an unpublished manuscript to the non-affine case. These analogs include the psuedo-Riemannian metric, Levi-Civit´a connection, curvature, and various existence theorems.

Quaternary Shelf-Slope Development In The Northern Gulf Of Alaska From Combined Geophysical And Geomorphologic Analysis, Wesley A. Clary

Earth and Planetary Sciences ETDs

This dissertation follows the hybrid format as defined by the Office of Graduate Studies at the University of New Mexico. The three chapters defined herein were prepared as manuscripts to be submitted for publication in peer reviewed journals in the field of Earth sciences. A version of chapter 1 was published in Proceedings of the Integrated Ocean Drilling Program, 2017, Volume 41. Chapter 2 was submitted to Marine Geology in Feb 2020, and is under revision as of this date. A version of chapter 3 will be submitted to the Journal of Geophysical Research. In chapter 1, I …

Lattice Of Maximal-Primary Ideals In Quadratic Orders, Ryan Bridges

Mathematics & Statistics ETDs

An order is a subring of the ring of integers of an algebraic extension, Peruginelli and Zanardo classified the lattices of orders with prime index inside te ring of integers of quadratic extensions of the rational numbers. The lattices are quite striking and have different layered structure depending on whether the prime is inert, split, or ramified. This thesis considers the orders which have prime power index inside the Gaussian integers. This is a nice generalization of the work of Peruginelli and Zanardo, and succeeds in a few classifications of specific instances of orders derived from inert primes.

Bayesian Analysis Of Single Molecule Fluorescence Microscopy Data, Mohamadreza Fazel

Physics & Astronomy ETDs

The diffraction limit can be circumvent by creating and exploiting independent behaviors of the sample at lengths scale below the diffraction limit. In fluorescence microscopy, the independence arises from individual fluorescent labels switching between dark and fluorescence states. The fluorophores can then be localized employing the generated sparse image frames. Finally, the resulting list of coordinates is utilized to generate high resolution images or to gain quantitative insight into the underlying biological structures. Therefore image processing and post-processing are essential stages of SMLM techniques.

In this dissertation, Reversible Jump Markov Chain Monte Carlo was employed to implement Bayesian analysis of …

"A Comparison Of Variable Selection Methods Using Bootstrap Samples From Environmental Metal Mixture Data", Paul-Yvann Djamen

Mathematics & Statistics ETDs

In this thesis, I studied a newly developed variable selection method SODA, and three customarily used variable selection methods: LASSO, Elastic net, and Random forest for environmental mixture data. The motivating datasets have neuro-developmental status as responses and metal measurements and demographic variables as covariates. The challenges for variable selections include (1) many measured metal concentrations are highly correlated, (2) there are many possible ways of modeling interactions among the metals, (3) the relationships between the outcomes and explanatory variables are possibly nonlinear, (4) the signal to noise ratio in the real data may be low. To compare these methods …

Advanced Parallel Algorithms In Computational Electromagnetics, Shu Wang

Electrical and Computer Engineering ETDs

The rapid development of high performance computing has pushed the computational electromagnetic(CEM) towards high accuracy, high fidelity and extreme computational scales. There is a great need for existing CEM solvers to have enhanced parallelism and scaling capability. The purpose of this dissertation is to investigate advanced parallel algorithms for both frequency and time domain solvers.

In frequency domain, this work first develop the underpinnings of parallel preconditioning technique and high-order transmission condition in the context of multi-solver scheme. The result is a computing resource-aware and implementation wise compact solver. Then this work targeted at developing efficient algorithms for cases where …

Arithmetic Differential Operators On Z_P^R, Marshall Brandenburg

Mathematics & Statistics ETDs

Given a prime, p, we prove that if a function can be represented as a restricted power series, then the function is analytic.

Methods Of Uncertainty Quantification For Physical Parameters, Kellin Rumsey

Mathematics & Statistics ETDs

Uncertainty Quantification (UQ) is an umbrella term referring to a broad class of methods which typically involve the combination of computational modeling, experimental data and expert knowledge to study a physical system. A parameter, in the usual statistical sense, is said to be physical if it has a meaningful interpretation with respect to the physical system. Physical parameters can be viewed as inherent properties of a physical process and have a corresponding true value. Statistical inference for physical parameters is a challenging problem in UQ due to the inadequacy of the computer model. In this thesis, we provide a comprehensive …

Small Molecule Analog Studies Of Paramagnetic Dmso Reductase Enzyme Family Intermediates, Khadanand Kc

Chemistry and Chemical Biology ETDs

Pyranopterin molybdenum and tungsten enzymes are expressed in numerous organisms from all domains of life. These enzymes catalyze a variety of atom, hydride, and electron transfer reactions. The enzymes are of great importance in the biogeochemical cycles of nitrogen, carbon, and sulfur. In recent years, chemists have investigated applications for some of these enzymes as industrial biocatalysts. The dimethylsulfoxide reductase (DMSOr) enzyme family is the broadest family of pyranopterin Mo enzymes. The first coordination sphere of the Mo or W-containing active site for each member of this family is made up of 4 sulfur donors from the two pyranopterin dithiolenes …

Fluvial Geomorphic And Hydrologic Evolution And Climate Change Resilience In Young Volcanic Landscapes: Rhyolite Plateau And Lamar Valley, Yellowstone National Park, Benjamin Newell Burnett

Earth and Planetary Sciences ETDs

Quaternary volcanism associated with the last caldera cycle in Yellowstone National Park included emplacement of ash-flow tuffs, massive rhyolite flows ranging from 79 to 484 ka, and valley-filling basalts. This study examines (1) the evolution of spring hydrology with flow age on the Rhyolite Plateau, (2) initial development and evolution of stream networks on the rhyolite flows, and (3) the impact of the 630 ka caldera formation and volcanic flow emplacement on Lamar Valley incision rates.

Integrated stream networks formed within 79 kyr on the Rhyolite Plateau. Incision is focused on steep flow margins and knickpoints and is dependent on …

Maximum Likelihood Estimation Of Species Trees And Anomaly Zone Detection Using Ranked Gene Trees, Anastasiia Kim

Mathematics & Statistics ETDs

A phylogenetic tree represents the evolutionary relationships among a set of organisms. Gene trees can be used to reconstruct phylogenetic trees. The methods in this dissertation focus on the gene tree topologies with emphasis on ranked gene tree topologies. A ranked tree depicts the order in which nodes appear in the tree together with topological relationships among gene lineages. One challenge that arises during phylogenetic inference is the existence of the anomaly zones, the regions of branch-length space in the species tree that can produce gene trees that have topologies differing from the species tree topology but are more probable …

Assessing The Validity Of Sentiment Analysis Measures Through Polychoric Correlation, Kelli N. Kasper

Mathematics & Statistics ETDs

Sentiment analysis methods extract the attitude of a text via systematic algorithms. To evaluate the validity of common sentiment analysis methods, we use polychoric correlation to compare computer-mediated methods and human-rated analogues. Our main topics of interest are the internal consistency of the raters' scores, the level of consensus among raters, and how well raters' scores correlate with those given by sentiment analysis methods for randomly collected Twitter data.

Our analysis found that there is good validity for methods that measure negative and positive sentiments in short texts, both in terms of inter-rater consistency and when comparing raters to computer-mediated …

Neogene Drainage Reversal And Colorado Plateau Uplift In The Salt River Area, Jordan Curtis Anderson

Earth and Planetary Sciences ETDs

The modern Salt River flows southwest from the Colorado Plateau, through the Arizona Transition Zone and into to the Basin and Range. Rivers in this area flowed northeast during the Paleogene from the Laramide Mogollon Highlands into structural basins of the topographically lower southern Colorado Plateau area. One of these rivers carved the Salt River paleocanyon through a portion of the Mogollon Highlands known as the Apache Uplift to similar depths as the modern Grand Canyon. This study refines the timing of this drainage reversal in the Salt River area by constraining the ages of paleoriver sediments deposited during the …

Triple Oxygen Isotope Composition Of Carbonates, Jordan A.G. Wostbrock

Earth and Planetary Sciences ETDs

This dissertation presents a method of analyzing the triple oxygen isotope compositions of carbonates, presents an empirical calibration of the carbonate-water equilibrium fractionation line, presents a triple oxygen isotope equipped fluid-rock mixing model for carbonates to see-through diagenesis, and applies all these findings to ancient carbonate samples. Using modern carbonates and associate water, the following equations are calculated to describe equilibrium triple oxygen isotope fractionation of carbonates:

1000lnalpha¹⁸O_cc-wt=2.84x10⁶/T²-2.96 1),

Theta_cc-wt=-1.39/T+0.5305 2).

Using these fractionation equations provides an extremely useful tool to determine whether a carbonate sample is altered or preserves …