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Full-Text Articles in Physical Sciences and Mathematics

Devops Education: An Interview Study Of Challenges And Recommendations, Marcelo Fernandes, Samuel Ferino, Anny K. Fernandes, Uirá Kulesza, Eduardo Aranha, Christoph Treude May 2022

Devops Education: An Interview Study Of Challenges And Recommendations, Marcelo Fernandes, Samuel Ferino, Anny K. Fernandes, Uirá Kulesza, Eduardo Aranha, Christoph Treude

Research Collection School Of Computing and Information Systems

Over the last years, the software industry has adopted several DevOps technologies related to practices such as continuous integration and continuous delivery. The high demand for DevOps practitioners requires non-trivial adjustments in traditional software engineering courses and educational methodologies. This work presents an interview study with 14 DevOps educators from different universities and countries, aiming to identify the main challenges and recommendations for DevOps teaching. Our study identified 83 challenges, 185 recommendations, and several association links and conflicts between them. Our findings can help educators plan, execute and evaluate DevOps courses. They also highlight several opportunities for researchers to propose …


Pasture Biomass Estimation Using Crop Surface Modeling And Vegetation Indices, Brendan Macinnis May 2022

Pasture Biomass Estimation Using Crop Surface Modeling And Vegetation Indices, Brendan Macinnis

All Theses

Biomass estimations are a critical function of any grazing or haylage system. Determination of ideal harvesting or grazing times help optimize the quality and quantity of above-ground biomass (AGB). The objective of this study was to evaluate the use of unmanned aerial vehicles (UAVs) for Alfalfa and Tall Fescue biomass estimations. Using a DJI Mavic Pro, RGB and NDVI images were taken and used to create orthomosaic images. Structure-from-motion (SfM) techniques were used to developed digital elevation models to evaluate the change in canopy height (∆H) between pre- and post-harvests. Change in canopy height (∆H) was shown to provide the …


Floating Treatment Wetlands For Brackish Waters: Plant Selection And Nutrient Uptake Potential., Andrea Landaverde May 2022

Floating Treatment Wetlands For Brackish Waters: Plant Selection And Nutrient Uptake Potential., Andrea Landaverde

All Theses

Brackish water bodies in coastal regions provide critical ecosystem services that support human and environmental health. Anthropogenic activities such as agricultural and industrial activities, construction, urban settlements, and tourism contribute to increased inputs of nitrogen (N) and phosphorus (P) in brackish coastal ecosystems. Excess nutrients can lead to impaired water quality and affect marine organisms. Floating treatment wetlands (FTWs) are a vegetated-base technology used to remove contaminants from water column, that has been mainly studied and applied in freshwater systems. Application of FTWs in brackish systems requires further investigation, as high salinity in brackish waters could result in toxicity to …


Understanding User Perceptions Of Voice Personal Assistants, Ha Young Kim May 2022

Understanding User Perceptions Of Voice Personal Assistants, Ha Young Kim

All Theses

As the artificial intelligence (AI) technique improves, voice assistant (smart speaker) such as Amazon Alexa and Google Assistant are quickly, surely permeating into people's daily lives. With its powerful and convenient benefits and the circumstances that people started to stay at their home longer due to the pandemic, reliance on smart speakers has increased rapidly. But at the same time, concerns of security on smart speakers have increased.

In this thesis, we conducted an online user survey of smart speaker users with five different perspectives – 1) Users’ engagement with privacy policy; 2) Awareness of different policy requirements defined by …


Identifying Noisy Labels In The Ground Truth Of Eating Episodes Self-Reported By Button Press On A Wrist-Worn Device, Tianyi Zhang May 2022

Identifying Noisy Labels In The Ground Truth Of Eating Episodes Self-Reported By Button Press On A Wrist-Worn Device, Tianyi Zhang

All Theses

This thesis considers the problem of identifying noisy labels in the ground truth of eating episodes (meals, snacks) as self-reported by participants collecting data in the wild. Participants wore a smartwatch-like device that tracked their wrist motion all day. They were instructed to press a button on the device at the start and end of each eating episode. The device and instructions were designed to be as simple to use as possible, but post-review of the ground truth provided by participants revealed a strong likelihood that a significant portion of the button presses may contain errors. For example, an error …


A Performance Evaluation Of Architectural Coatings To Preserve Aerosol Paint On Concrete, Riley Morris May 2022

A Performance Evaluation Of Architectural Coatings To Preserve Aerosol Paint On Concrete, Riley Morris

All Theses

The growing movement of assigning cultural and heritage value to graffiti and street art is one without a preservation solution to ensure the longevity of these works in-situ in an outdoor environment. The goal of this thesis was to provide a comprehensive evaluation of six architectural topcoats’ performance when applied as a conservation treatment to outdoor aerosol graffiti and street art on concrete substrate. An artist’s quality, durable, color-fast spray-paint was applied to twenty-eight concrete test panels to mimic the application of graffiti or street art. Six topcoats, Prosoco SC-1, Prosoco Gloss n’ Guard WB, Keim Faceal Oleo HD®, Keim …


A Contribution To The Statistical Analysis Of Climate-Wildfire Interaction In Northern California, Adam Diaz May 2022

A Contribution To The Statistical Analysis Of Climate-Wildfire Interaction In Northern California, Adam Diaz

All Theses

Wildfires are extreme weather events that exist at the interface of atmospheric, ecological, and human processes. Ongoing anthropogenic climate change is expected to impact the distribution, frequency, and behavior of wildfires on a grand scale, however the exact nature of this change remains shrouded in a great deal of uncertainty. This study takes a statistical approach to the question over the fire-prone Northern California region of the western United states. Climate model projections are analyzed to investigate changes in a major driver of fire weather in the region. The relationship between wildfire severity and climate factors is then explored separately, …


Fate And Transport Of Toxoplasma Gondii Oocysts In Saturated Porous Media: Effects Of Electrolytes And Natural Organic Matter, Christian Pullano May 2022

Fate And Transport Of Toxoplasma Gondii Oocysts In Saturated Porous Media: Effects Of Electrolytes And Natural Organic Matter, Christian Pullano

All Theses

Toxoplasma gondii is a pathogenic microorganism that is currently a threat to public health. Understanding the fate and transport of T. gondii through the soil and groundwater is vital in determining the risk it poses to water resources and human health. The physico-chemical interactions between the groundwater and the bio colloid within an aquifer will dictate its mobility and its ability to infect humans. This research examines how various naturally occurring groundwater chemistries containing organic compounds and monovalent and divalent salt solutions will alter the fate and transport of T. gondii. Solutions containing various concentrations of humic acid, fulvic …


Effects Of Invasive Wild Pigs And Supplemental Feeding On Wildlife In The Piedmont Region Of South Carolina, Elizabeth A. Saldo May 2022

Effects Of Invasive Wild Pigs And Supplemental Feeding On Wildlife In The Piedmont Region Of South Carolina, Elizabeth A. Saldo

All Theses

Wild pigs (Sus scrofa), which are invasive in much of the world, can alter ecosystems and compete with native species through interference competition and resource exploitation. We assessed the potential for interspecific interactions between invasive wild pigs and other wildlife in the Piedmont region of South Carolina by examining their spatiotemporal overlap in a correlational field study and an experimental field study. Our correlational study used data from wildlife cameras in seasonal occupancy, N-mixture, and temporal overlap analyses. Both deer (Odocoileus virginianus) and coyote (Canis latrans) site use were negatively associated with wild pig …


Advancing Hymenocallis Coronaria Conservation And Restoration For Improved Habitat Management In Fall Line Streams Of The Southeast, Andrew Paul Grunwald May 2022

Advancing Hymenocallis Coronaria Conservation And Restoration For Improved Habitat Management In Fall Line Streams Of The Southeast, Andrew Paul Grunwald

All Theses

The rocky shoals spider lily (Hymenocallis coronaria) is a culturally and ecologically important emergent macrophyte endemic to the biodiverse shoals of fall line streams in the southeastern United States. H. coronaria has declined throughout its range as shoal habitat has become increasingly threatened by flow modification and other anthropogenic stressors. The genetics and botany of H. coronaria have been given considerable attention, but quantitative habitat research has been lacking. Furthermore, despite substantial need, public interest, and its status as an indicator species for fall line streams, no research has been conducted on H. coronaria restoration. Our main objectives …


A Conservative Numerical Scheme For The Multilayer Shallow Water Equations, Evan Butterworth May 2022

A Conservative Numerical Scheme For The Multilayer Shallow Water Equations, Evan Butterworth

All Theses

An energy-conserving numerical scheme is developed for the multilayer shallow water equations (SWE’s). The scheme is derived through the Hamiltonian formulation of the inviscid shallow water flows related to the vorticity-divergence variables. Through the employment of the skew-symmetric Poisson bracket, the continuous system for the multilayer SWE’s is shown to preserve an infinite number of quantities, most notably the energy and enstrophy. An energy-preserving numerical scheme is then developed through the careful discretization of the Hamiltonian and the Poisson bracket, ensuring the skew-symmetry of the latter. This serves as the groundwork for developing additional schemes that preserve other conservation properties …


Balancing Data- Vs. Art-Driven Decisions In Video Game Design, Jaden D. Goter May 2022

Balancing Data- Vs. Art-Driven Decisions In Video Game Design, Jaden D. Goter

Honors Theses

Video games, like software, need to be designed. Video game development studios tend to use data-driven or art-driven decision-making to design their games. Data-driven decision-making is where active and passive data is collected in order to make informed decisions about the design of a game. Art-driven decision-making is when designers use their artistic intuition to design games, potentially ignoring player data. This paper elaborates on the advantages and disadvantages of both approaches and provides case studies of games designed under both approaches. Based on these studies, for a game to be successful, a combined approach of data- and art-driven decision-making …


Control Of Irradiation Wavelength And Quantum Yield Of Photocleavable Cages, Jingxuan Ma May 2022

Control Of Irradiation Wavelength And Quantum Yield Of Photocleavable Cages, Jingxuan Ma

Theses and Dissertations

An important component of biological research is the precise regulation of biomolecules in their physiological environment. Recent advances in neuroscience, have made it possible to regulate the activity of neurotransmitters using photocleavable protecting groups (PPGs), which are also known as cages. This enables the use of light as a trigger to activate selected neurons via photo release of agonists with precise control of timing as well as synaptic site, popularly referred to as spatiotemporal control. In recent years, a variety of PPGs have been developed and applied to biomolecular cages. PPGs can be classified according to their absorption wavelengths (from …


A Co-Evolutionary Approach To Test Case Generation For Safety-Critical Systems, Brad Thomas Costa May 2022

A Co-Evolutionary Approach To Test Case Generation For Safety-Critical Systems, Brad Thomas Costa

Theses and Dissertations

Safety-critical software development is a costly and time-consuming process that involves thousands of hours dedicated to test development. Tests must meet stringent developmental guidelines to verify the correct and complete implementation of their parent requirements. Further compounding any such effort is the tendency towards requirement churn or the frequent change to the software and other system requirements. This thesis presents a solution, PyTcGen, that alleviates these challenges by processing natural language requirements and programmatically generating the requisite test cases to ensure the software meets all of the conditions of that requirement. The solution uses template matching to marry requirements to …


Development Of Diagnostic Tools And Analysis Of The Density Functional Theory Zoo, Pierpaolo Morgante May 2022

Development Of Diagnostic Tools And Analysis Of The Density Functional Theory Zoo, Pierpaolo Morgante

Theses and Dissertations

The main goal of this dissertation is to give an overview of existing and new databases for density functional theory (DFT). It describes the procedures used to introduce A Collection of Chemistry DataBases (ACCDB) and its reduction to a smaller and statistically significant database called A Small(er) Collection of DataBase (ASCDB). Also, it presents an application of such databases in chemical education through the introduction of a notebook of twelve exercises that can easily complement a computational chemistry class. In addition, a new database of molecules having carbon-carbon long bonds (CLB18) is presented. Last, the databases are used in the …


A Spatiotemporal Bayesian Model For Population Analysis, Mohamed Jaber May 2022

A Spatiotemporal Bayesian Model For Population Analysis, Mohamed Jaber

Theses and Dissertations

Spatiotemporal population analysis based on incomplete, redundant, and unidentified observations is critically important, yet it is a very challenging problem. Different approaches have been proposed and several methods have been implemented to address this problem. Capture-recapture methods have been widely used and have become the standard sampling and analytical framework for ecological statistics with applications to population analysis. Despite the fact that capture-recapture methods have been commonly used, these methods do not consider the spatial structure of the population. Moreover, conventional capturerecapture methods do not use any explicit spatial information with regard to the spatial nature of the sampling and …


Assessment Of Soil Health Under Native Warm-Season Grasses And Different Grazing Management, Kara Leigh Grosso May 2022

Assessment Of Soil Health Under Native Warm-Season Grasses And Different Grazing Management, Kara Leigh Grosso

Masters Theses

This research uses analysis of soil quality indicators (SQIs) to compare vegetation species and grazing management over the 2021 grazing season. The soil health effect of the native warm-season grasses (NWSG) big bluestem (BB) (Andropogon gerardii) mixed with indian grass (IG) (Sorghastrum nutans) (BBIG), and switchgrass (SG) (Panicum virgatum), inter-seeded with a 12 species biodiversity mix was investigated in a 5 pressure grazing system (no graze (NG), no rest (NR), early, middle, and late rest (ER, MR, LR)). Additionally, there is a need for inexpensive tools for land owners to assess soil quality, and a validation study …


An Empirical Investigation Into The Impact Of Automated Grading, Alex James St. Aubin May 2022

An Empirical Investigation Into The Impact Of Automated Grading, Alex James St. Aubin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Context: Computer Science enrollment has seen increases in recent years. At the University of Nevada, Las Vegas we have seen an average year to year growth rate of 17.33% in the spring and 13.71% in the fall over the past 10 years in our entry level programming course. These enrollment increases have led to considerable additional costs for grading course material.Objective: The goal of this study is to determine the impact of automatic grading systems on students. If automatic grading is at least as effective as manual grading in practice, it may reduce cost under the context of at least …


Towards Highly Sensitive Capacitance Measurements Of A Quantum Anomalous Hall Phase In Van Der Waal Heterostructures, Kayla Cerminara May 2022

Towards Highly Sensitive Capacitance Measurements Of A Quantum Anomalous Hall Phase In Van Der Waal Heterostructures, Kayla Cerminara

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the pioneering achievements in condensed matter physics of the 20th century is the observation of the quantum Hall e↵ect (QHE) in which the Hall resistance in a two-dimensional (2D) sample takes on quantized values in the presence of a strong perpendicular magnetic field. The precise quantization of the hall resistance to one part in a billion has provided a practical, worldwide resistance standard. A long-standing goal has been to realize a similar state of matter but without the need of a strong quantizing magnetic field. The quantum anomalous Hall e↵ect (QAHE) is such a state that is predicted …


Radiomic Features To Predict Overall Survival Time For Patients With Glioblastoma Brain Tumors Based On Machine Learning And Deep Learning Methods, Lina Chato May 2022

Radiomic Features To Predict Overall Survival Time For Patients With Glioblastoma Brain Tumors Based On Machine Learning And Deep Learning Methods, Lina Chato

UNLV Theses, Dissertations, Professional Papers, and Capstones

Machine Learning (ML) methods including Deep Learning (DL) Methods have been employed in the medical field to improve diagnosis process and patient’s prognosis outcomes. Glioblastoma multiforme is an extremely aggressive Glioma brain tumor that has a poor survival rate. Understanding the behavior of the Glioblastoma brain tumor is still uncertain and some factors are still unrecognized. In fact, the tumor behavior is important to decide a proper treatment plan and to improve a patient’s health. The aim of this dissertation is to develop a Computer-Aided-Diagnosis system (CADiag) based on ML/DL methods to automatically estimate the Overall Survival Time (OST) for …


Built Environment, Land Use, And Crime: A Las Vegas Study, Stacey Lynn Clouse May 2022

Built Environment, Land Use, And Crime: A Las Vegas Study, Stacey Lynn Clouse

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study examined land use and crime against persons and crime against property in Las Vegas, Nevada at varying spatial levels of analysis. Using crime data provided by the Las Vegas Metropolitan Police Department and the Clark County Assessor’s office, results at the macro-level of analysis reveal that property crime rates concentrated on commercial, transportation, communication and utilities, and industrial land use, whereas violent crime concentrated at commercial, multi-residential, and civic, institutional, and recreational land use. Upon examining the subtypes of land use that generate or radiate more crime, property crime concentrated on transportation land use, class 1 resorts, and …


Enigma - Ongoing Development Towards Novel Beta-Decay Spectroscopy Station At Isolde, Philipp Wagenknecht May 2022

Enigma - Ongoing Development Towards Novel Beta-Decay Spectroscopy Station At Isolde, Philipp Wagenknecht

Masters Theses

Beta decay and collinear laser spectroscopy are proven efficient tools to study nuclear structure far from stability. Two areas of significance are investigations into nuclear deformation and shape coexistence, as well as delayed neutron emissions used in nuclear energy applications. This contribution presents the ongoing development towards a novel beta-decay spectroscopy station for the VITO experiment at CERN’s radioactive ion beam facility ISOLDE. The setup will utilize both collinear laser spectroscopy and beta-decay spectroscopy to measure the energy and spin-parities of the ground and excited states of radioactive beams. Initial designs of the support structure, magnetic field, and detector array …


Path Planning And Flight Control Of Drones For Autonomous Pollination, Chapel R. Rice May 2022

Path Planning And Flight Control Of Drones For Autonomous Pollination, Chapel R. Rice

Masters Theses

The decline of natural pollinators necessitates the development of novel pollination technologies. In this thesis, a drone-enabled autonomous pollination system (APS) that consists of five primary modules: environment sensing, flower perception, path planning, flight control, and pollination mechanisms is proposed. These modules are highly dependent upon each other, with each module relying on inputs from the other modules. This thesis focuses on approaches to the path planning and flight control modules. Flower perception is briefly demonstrated developing a map of flowers using results from previous work. With that map of flowers, APS path planning is defined as a variant of …


Quality Assurance Procedures Implementation For Varian Truebeam, Yongquan Jiang May 2022

Quality Assurance Procedures Implementation For Varian Truebeam, Yongquan Jiang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Department of radiation oncology of Oncology Nevada updated its linear accelerator (LINAC) from Varian Clinac iX to a newer model known as Varian TrueBeam. The Varian TrueBeam LINAC includes 6x, 6xFFF (i.e., 6x without flattening filter known as flattening filter free), 10x, 10xFFF, 15x photon beams and 6e, 9e, 12e MeV electron beams. This system is also equipped with a 6 degree of freedom (DOF) couch, RapidArc, kV on board imager, MV portal imager and Cone Beam CT (CBCT) imaging. This system allows the clinical delivery of modern image guided radiation therapy (IGRT) modalities such as IMRT/VMAT, and SRS/SRT/SBRT. The …


Aberrant Responding With Underlying Dominance And Unfolding Response Processes: Examining Model Fit And Performance Of Person-Fit Statistics, Jennifer A. Reimers May 2022

Aberrant Responding With Underlying Dominance And Unfolding Response Processes: Examining Model Fit And Performance Of Person-Fit Statistics, Jennifer A. Reimers

Graduate Theses and Dissertations

Researchers have recognized that respondents may not answer items in a way that accurately reflects their attitude or trait level being measured. The resulting response data that deviates from what would be expected has been shown to have significant effects on the psychometric properties of a scale and analytical results. However, many studies that have investigated the detection of aberrant data and its effects have done so using dominance item response theory (IRT) models. It is unknown whether the impacts of aberrant data and the methodology used to identify aberrant responding when using dominance IRT models apply similarly when scales …


Cyanobacterial And Microcystin Response To Nutrient Additions At Lake Fayetteville Throughout The 2021 Growing Season, Lillie Haddock May 2022

Cyanobacterial And Microcystin Response To Nutrient Additions At Lake Fayetteville Throughout The 2021 Growing Season, Lillie Haddock

Graduate Theses and Dissertations

Harmful Algal Blooms (HABs) are becoming a global concern due to their increasing distribution, frequency, intensity, and the occurrence of toxins. While it is known that eutrophication influences algal blooms, there is less known about what triggers these HABs to produce toxins, especially microcystin. In this study, we conducted 21 community bioassays at Lake Fayetteville, a hypereutrophic reservoir in Fayetteville, Arkansas, from April-November 2021 to examine how the addition of phosphorous and nitrogen influence cyanobacteria concentrations, microcystin concentrations, and microcystin toxin production. These experiments included a control, nitrogen (1.0 mg/L as KNO3), low phosphorus (0.025 mg/L as K2HPO4), high phosphorus …


Fabrication Of Mof Films Of Uio Or Pcn Type Through Layer-By-Layer Molecular Deposition As Well As Bulk Deposition For Catalytic Applications, John Ozdemir May 2022

Fabrication Of Mof Films Of Uio Or Pcn Type Through Layer-By-Layer Molecular Deposition As Well As Bulk Deposition For Catalytic Applications, John Ozdemir

Graduate Theses and Dissertations

Metal-organic frameworks (MOFs) are crystalline, porous materials comprised of symmetric organic linkers coordinated to positively charged metal atoms or metal oxide nodes. This dissertation uses strategies in crystal engineering to advance the study of functional MOFs with emphasis on thin film deposition. The first chapter of this dissertation will introduce the field of reticular chemistry to the reader and describe synthetic efforts to develop useful building blocks for MOF materials: namely porphyrin macrocycles and carboxylate capped zirconium-oxo and hafnium-oxo clusters. The building blocks for MOFs developed in the first chapter will be employed in the second and third chapters through …


Ab Initio Studies Of Structure And Properties Of Group-Iv Monochalcogenide Monolayers, Shiva Prasad Poudel May 2022

Ab Initio Studies Of Structure And Properties Of Group-Iv Monochalcogenide Monolayers, Shiva Prasad Poudel

Graduate Theses and Dissertations

The goal of this dissertation is to study the structure of ferroelectric group-IV monochalcogenide monolayers (MMLs) and their material properties. This work also established a new buckled honeycomb phase of these monolayers. Chapter 1 serves as an introduction where the motivation for these studies is established. In chapter 2, I used eight different exchange-correlation functionals (XC) to study the structure of these 2D ferroelectrics and found that their properties are independent of the choice of XC functionals. These findings reveal that the ground-state ferroelectric unit cell can be described by only five independent parameters, whereas their paraelectric (square or rectangular) …


Diederich-Fornæss Index On Boundaries Containing Crescents, Jason Demoulpied May 2022

Diederich-Fornæss Index On Boundaries Containing Crescents, Jason Demoulpied

Graduate Theses and Dissertations

The worm domain developed by Diederich and Fornæss is a classic example of a boundedpseudoconvex domains that fails to satisfy global regularity of the Bergman Projection, due to the set of weakly pseudoconvex points that form an annulus in its boundary. We instead examine a bounded pseudoconvex domain Ω ⊂ C2 whose set of weakly pseudoconvex points form a crescent in its boundary. In 2019, Harrington had shown that these types of domains satisfy global regularity of the Bergman Projection based on the existence of good vector fields. In this thesis we study the Regularized Diederich-Fornæss index of these domains, …


Optimized Damage Assessment And Recovery Through Data Categorization In Critical Infrastructure System., Shruthi Ramakrishnan May 2022

Optimized Damage Assessment And Recovery Through Data Categorization In Critical Infrastructure System., Shruthi Ramakrishnan

Graduate Theses and Dissertations

Critical infrastructures (CI) play a vital role in majority of the fields and sectors worldwide. It contributes a lot towards the economy of nations and towards the wellbeing of the society. They are highly coupled, interconnected and their interdependencies make them more complex systems. Thus, when a damage occurs in a CI system, its complex interdependencies make it get subjected to cascading effects which propagates faster from one infrastructure to another resulting in wide service degradations which in turn causes economic and societal effects. The propagation of cascading effects of disruptive events could be handled efficiently if the assessment and …