Digital Commons Network^™

Phased-Array Feed Instrumentation And Processing For Astronomical Detection, Interference Mitigation, And Transient Parameter Estimation, Richard Allen Black

Theses and Dissertations

Radio astronomy, the survey and study of naturally occurring astronomical radio signals, is a challenging field in terms of engineering requirements. The typical astronomical signal of interest is incredibly faint, resulting in very low signal-to-noise ratios (SNRs) on the order of -30 dB or lower. To detect such signals, one must have an uncommonly low and stable receiver noise temperature, high gain through large aperture reflectors, and state-of-the-art signal processing algorithms. One must also be able to mitigate the effects of interference, the presence of which, even if extremely weak, can completely mask the faint astronomical signals of interest. To …

Evaporated Aluminum Fluoride As A Barrier Layer To Retard Oxidation Of Aluminum Mirrors, Margaret Miles

Theses and Dissertations

The aluminum oxide growth rate for aluminum protected with 2.4 nm of aluminum fluoride has been determined. We show that a 2.4 nm aluminum fluoride layer does not prevent aluminum from oxidation but does significantly retard the oxide growth – decreasing the oxide layer thickness from 1 nm in less than an hour to 0.9 nm over 116 hours. Additionally, the optical constants for aluminum oxide growing under an aluminum fluoride barrier layer have been determined – showing an increase in absorption at high energies for Al₂O₃ forming at room temperature as compared to highly ordered Al …

A Molecular Simulation Study Of Antibody-Antigen Interactions On Surfaces For The Rational Design Of Next-Generation Antibody Microarrays, Derek B. Bush

Theses and Dissertations

Antibody microarrays constitute a next-generation sensing platform that has the potential to revolutionize the way that molecular detection is conducted in many scientific fields. Unfortunately, current technologies have not found mainstream use because of reliability problems that undermine trust in their results. Although several factors are involved, it is believed that undesirable protein interactions with the array surface are a fundamental source of problems where little detail about the molecular-level biophysics are known. A better understanding of antibody stability and antibody-antigen binding on the array surface is needed to improve microarray technology. Despite the availability of many laboratory methods for …

Ground Reaction Forces For Irish Dance Landings In Hard And Soft Shoes, Sarah Elizabeth Klopp

Theses and Dissertations

Introduction: Irish dance has evolved to become more athletically demanding, thus making the art form very hard on dancers' bodies. Irish dancers must land from difficult moves without letting their knees bend or heels touch the ground, causing large amounts of force to be absorbed by the body. Past studies have found dancers landing with a range of 4.5–6 times body weight, potentially causing high amounts of overuse injury. The majority of injuries incurred by Irish dancers are due to overuse (79.6%). The landings that occur in Irish dance have been minimally evaluated in current literature. Obtaining values of vertical …

Machine Learning To Discover And Optimize Materials, Conrad Waldhar Rosenbrock

Theses and Dissertations

For centuries, scientists have dreamed of creating materials by design. Rather than discovery by accident, bespoke materials could be tailored to fulfill specific technological needs. Quantum theory and computational methods are essentially equal to the task, and computational power is the new bottleneck. Machine learning has the potential to solve that problem by approximating material behavior at multiple length scales. A full end-to-end solution must allow us to approximate the quantum mechanics, microstructure and engineering tasks well enough to be predictive in the real world. In this dissertation, I present algorithms and methodology to address some of these problems at …

Using Dr. Scratch As A Formative Feedback Tool To Assess Computational Thinking, Samuel Frank Browning

Theses and Dissertations

Scratch is one of the most popular ways to teach younger children to code in K–8 throughout the U.S. and Europe. Despite its popularity, Scratch lacks a formative feedback tool to inform students and teachers of a student's progress in coding ability. Dr. Scratch was built to fill this need. This study seeks to answer if using Dr. Scratch as a formative feedback tool accelerates the students' progress in coding ability and Computational Thinking (CT). Forty-one 4th-6th grade students participated in a 1-hour/week Scratch workshop for nine weeks. We measured pre- and posttest results of the Computational Thinking Test (CTt) …

Copper Mineralogy In The Oxide Zone Of The Lone Star Porphyry Copper Deposit, Eastern Arizona, Jeff G. Selck

Theses and Dissertations

The Lone Star porphyry copper deposit in the Safford District of southeastern Arizona was discovered in the late 1800's but never mined on a large scale. In addition to typical copper oxide species such as chrysocolla, the upper part of the deposit has zones of mineralization in which the chemical assays of core samples have higher amounts of copper than can be visually assigned to the observed copper-bearing minerals. The goal of this study is to identify the Cu-bearing minerals, which is crucial because the efficiency of the extraction processes is strongly dependent upon the mineralogy. Samples from seven cores …

Multiple Target Tracking In Realistic Environments Using Recursive-Ransac In A Data Fusion Framework, Jeffrey Dyke Millard

Theses and Dissertations

Reliable track continuity is an important characteristic of multiple target tracking (MTT) algorithms. In the specific case of visually tracking multiple ground targets from an aerial platform, challenges arise due to realistic operating environments such as video compression artifacts, unmodeled camera vibration, and general imperfections in the target detection algorithm. Some popular visual detection techniques include Kanade-Lucas-Tomasi (KLT)-based motion detection, difference imaging, and object feature matching. Each of these algorithmic detectors has fundamental limitations in regard to providing consistent measurements. In this thesis we present a scalable detection framework that simultaneously leverages multiple measurement sources. We present the recursive random …

The Role Of Wisdom Leadership In Increasing Job Performance: Evidence From The Egyptian Tourism Sector., My Haddoud, Elbaz Ahmed

Plymouth Business School

The paper aims to explore the intervening role of wisdom leadership in the link between leadership styles and employees’ team performance, in the context of travel agents. Drawing on the leadership theory and the strategic leadership model, we develop an integrative model exploring the relationships between four distinct leadership styles and their influence on employees’ satisfaction and team performance, through the mediating role of wise leadership. Using data collected from 505 travel agents operating in Egypt, we show that not all leadership styles have a positive influence on employees’ satisfaction. We also show that a positive influence takes place through …

"What More Could I Have Done?" A Graduate Student's Experience Teaching Writing About Writing, Lena May Harper

Theses and Dissertations

As writing about writing (WAW) research enters its "second wave," characterized not only by an increase in data-driven studies that theorize and assess the effectiveness of WAW curricula (Downs) but also by an increase in its prominence and adaptation, particularly among emerging writing studies scholars and teachers (e.g., Bird et al.), a space has opened for more and varied types of research, especially empirical research, to determine its effectiveness and to produce more solid recommendations for training and curriculum development, especially for those who are new to the field. This case study, which highlights how a novice teacher responds to …

Reliability Of Feqdrain For Modeling Performance Of Sand Treated With Large-Diameter Prefabricated Drains For Liquefaction Mitigation, Travis Hatch Meservy

Theses and Dissertations

Finite element modeling of laminar shear box testing that consisted of loose sand treated with large diameter prefabricated vertical drains (PVDs), was performed. The objective of the modeling was to evaluate the reliability of the computer program FEQDrain for predicting excess pore pressure ratios (Ru) at sites treated with prefabricated drains. FEQDrain was found to be capable of successfully modeling measured excess pore pressure ratio time histories from the laminar shear box experiment, as long as an appropriate combination of €˜number of equivalent cycles and €˜shaking duration was chosen, and sensitive parameters were in the range of measured values. Hydraulic …

Faculty Perceptions Of Open Educational Resources Quality By Peer Review, Olga Maria Belikov

Theses and Dissertations

In this paper, 936 faculty free response reviews of open textbooks from the Open Textbook Library were analyzed for content and themes. The reviews were completed by faculty members at institutions in the United States and Canada. The textbooks were evaluated regarding their comprehensiveness, content accuracy, relevance longevity, clarity, consistency, modularity, organization structure flow, interface, grammatical errors, and cultural relevance. The results of the reviews found that the across 9360 comments regarding the quality of open textbooks, of these comments 97.3% reflected adequate or exceptional reviews of the textbooks. Faculty often compared the texts to traditional textbooks and in all …

Response Inhibition To High Calorie Food Cues Among Adolescents Following Active And Sedentary Video Game Play Using A Go/No-Go Task: A Randomized Crossover Study, Joshua L. Smith

Theses and Dissertations

Sedentary behaviors, such as leisure time computer use and sedentary video games, are significant barriers to regular physical activity and contribute to high rates of overweight and obesity among adolescents. Sedentary screen time can adversely affect food intake and food selection. Active video games may be a promising way of increasing daily physical activity levels among adolescents. Active video games may help modulate response inhibition and food intake. PURPOSE: Compare the effects of an acute bout of active and sedentary video gaming on N2 amplitudes (while viewing high calorie and low calorie images), Stroop Color Word Test (Stroop test) performance …

Remember The Country And The Age In Which We Live": The British Gothic Novel In The Age Of Enlightenment, 1764-1798, Garland David Beasley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Remember the Country and the Age in Which We Live” argues that the British Gothic novels produced in the late eighteenth century were not, as has traditionally been assumed, written in reaction against Enlightenment values in the face of rising political and social discord. Instead, I contend that eighteenth-century Gothic novels take part in a larger tradition of the novel that sought to impart the values of Enlightenment into a modernist genre still on the rise. By exploring the influence of Samuel Richardson on the development of the Gothic novel, the role of formal and informal educational structures, representations of …

"Already Writers": A Case Study In Assessment And Visual Rhetoric Connections In Digital Multimodal Composition, Fawn Elise Canady

UNLV Theses, Dissertations, Professional Papers, and Capstones

English language arts must respond to shifts in literacy practices that reflect changes in ‘college and career ready’ that are more than technologically mediated, but also emphasize creative and social skills. The case study in this dissertation is a small part of a larger, ongoing formative experiment in digital multimodal composition (DMC). A formative experiment is a methodological approach that favors a collaborative, iterative research process that is centered on an instructional goal in authentic classroom settings (Reinking & Bradley, 2008). The intention of the larger research study was to support students’ learning through DMC. This dissertation explored one of …

Co-Navigating The U.S. Educational System: A Multiple Case Study Of The Social And Academic Pressures Experienced By Iranian Immigrant Parents And Their 1.5-Generation Immigrant Children, Shahla Fayazpour

UNLV Theses, Dissertations, Professional Papers, and Capstones

The United States of America is a complex, diverse nation, and the number of immigrant families grows daily. Since parents and family play central roles in their children’s future and academic achievements, the purpose of this study is to examine how immigrant parents navigate their children’s education in the United States. The goal of this research is to amplify the voices of immigrant families while informing policymakers and individuals about the racial issues and barriers that immigrant families face in society and school, and about how this affects their parenting and their children’s academic performance. This research aims to reduce …

Parents' Perceptions Of Smartphone Use And Parenting Practices, David Jackson Johnson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The present study is a qualitative examination aiming to gain insight into parents’ perceptions of their smartphone use and the effects it may be having on their children as well as parenting practices. Participants (N=12) were smartphone using parents that consisted mostly of young college-educated females. Thematic analysis of individual interviews resulted in five primary themes: (1) Disengagement, (2) Concern for Future, (3) Change in Social Norms, (4) Boundaries, and (5) Cognitive Dissonance. These findings indicate significant effects parental smartphone use is having in the lives of study participants. These thematic findings call for additional research examining the impact parental …

The Effect Of Oil Prices On Workforce In Selected Organization For Economic Cooperation And Development (Oecd) Countries, Amjad Kisswani

UNLV Theses, Dissertations, Professional Papers, and Capstones

Oil prices have greatly increased and decreased over the past few years, and have constantly been responsible for causing undesirable world economic performance and employment effects. The increase of oil prices usually leads to the rising prices of services such as production costs, energy bills, and petroleum products. Therefore, the increase will lower the productivity level, which affects interest rates and inflation rates, investments, product selling prices, consumption levels, unemployment rates, and real wage rates (Loungani, 1986). The oil price shocks since the 1970s have had a significant impact on the economy and are considered an important element of economic …

Acute Salivary Steroid Hormone Responses During Coalitional And Dyadic Competitions In Hong Kong Juvenile Children, Timothy Mchale

UNLV Theses, Dissertations, Professional Papers, and Capstones

A large body of research links testosterone and cortisol responses to competition during adulthood. Little psychoneuroendocrine research has explored salivary steroid hormone responses to competition during middle childhood. This project investigated the relationship between acute salivary steroid hormone change, performance, competitor type, and outcome effects in three different field studies, while controlling for Body Mass Index (BMI) and pubertal development, in a population of ethnically Chinese, Hong Kong juvenile children, 8-11 years of age. The relative dynamics of salivary steroid change were assessed during a 1) coalitional physical competition (soccer) in boys, 2) a non-physical mixed-sex coalitional competition (math contest), …

Latino Lgbq Young Adults' Coming-Out Experiences, Monica Munoz

UNLV Theses, Dissertations, Professional Papers, and Capstones

There is limited research on Latino LGBQ individuals and their coming-out experiences. To understand the coming out process of Latino LGBQ individuals, interviews were conducted with 10 Latino LGBQ young adults between the ages of 18 and 30 years old. Using Moustakas (1994) phenomenological approach, six themes derived from the study: (a) The disclosure process impacts family closeness and distance, (b) Latino LGBQ individuals’ family members enter a state of disbelief about their sexual orientation, (c) control of disclosure influences Latino LGBQ young adults’ perception of their coming-out experience, (d) the experience of coming-out for Latino LGBQ individuals is influenced …

Subjective Beat Perception In Musical Rhythms In Adult Listeners, Karli M. Nave

UNLV Theses, Dissertations, Professional Papers, and Capstones

Synchronization to rhythmic stimuli is an everyday experience, whether it is exercising to the beat of music, dancing salsa, or rocking a baby to sleep. Commonly, humans synchronize their movements with the frequency of the beat (a quasi-isochronous pattern of prominent time points). Previous research has shown that the intended beat periodicity of a rhythmic stimulus can be observed in periodic neural activity; however, the extent to which this reflects robust perception of musical rhythm versus purely stimulus-driven activity is unknown. In Experiment 1 and 2, I investigated how long listeners can maintain a percept of the beat once the …

The Effects Of Distributed Trials On Behaviors Of Students With Significant Disability, Mona Nasir-Tucktuck

UNLV Theses, Dissertations, Professional Papers, and Capstones

Teaching academic instruction to students with significant cognitive disability (SCD) has been done with success over the past years (Browder, Mims, Spooner, Ahlgrim-Delzell, & Lee, 2008; Hudson & Test, 2011; Mims, Hudson, & Browder, 2012), However, research is scarce and further instructional strategies are needed to help align the standard-based curriculum for this population of students (Browder, Ahlgrim-Delzell, Flowers, & Baker, 2012).

The academic inclusion of students with SCD has been a topic of interest for researchers over the past few decades. In 1997, research on teaching academics to students with SCD was scarce (Nietupski, Hamre-Nietupski, Curtin, Shrikanth, 1997). The …

The Effects Of Exhaust Vent Location On Thermal Comfort Inside The Residential Buildings Equipped With An Evaporative Cooling System, Armin Saraei

UNLV Theses, Dissertations, Professional Papers, and Capstones

Inlet and outlet conditions, Including size and location, have significant effects on the air distribution, temperature, humidity and thermal comfort in the buildings. In the current study, various strategies are presented for exhaust air vents and the effects of inlet and outlet vents locations are evaluated on providing thermal comfort in the residential and industrial buildings. To provide thermal comfort, three key factors need to be investigated based on ASHRAE standard 55- 2013 as follows: Comfort Zone, Thermal Sensation and Draft Rate. Flow distribution is studied as well in order to investigate the strategies, which make more vorticity in the …

Lock-Free Self-Adjusting Binary Search Tree, Sachiko Sueki

UNLV Theses, Dissertations, Professional Papers, and Capstones

A binary search tree (BST) is a fundamental data structure for maintaining data in a way to allow fast search. As multi-core processors are widely used nowadays, such data structures require the ability to handle concurrent accesses to exploit the concurrent hardware. There are several algorithms on lock-based as well as lock-free BST with and without self-balancing. On the other hand, only a few reports can be found on lock-based self-adjusting BST. To the best of our knowledge, there are no algorithms for lock-free self-adjusting BST. Lock-free guarantees overall progress even if some processes fail, whereas lock-based algorithms fail to …

Setting The Childless Free: An Ethnographic Study Of The Practice Of The Childfree Identity, Shelly Volsche

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heeding Sherry Ortner’s call to turn anthropological analysis inward, toward one’s own culture, the following dissertation seeks to understand the identity and practice of the voluntarily childless (hereafter “childfree”) movement in the United States. How do these individuals practice their identity, and how does the identity of “childfree” interact with other roles in their lives? How do they build meaning in a society that emphasizes children as a hallmark of adulthood? What other outlets do childfree individuals have for the “nurturing” tendencies of our species?

Combining sociohistoric analysis with identity and feminist theories, I embarked on nearly two years of …

Contingency Management Interventions For Tobacco And Other Substance Use Disorders In Pregnancy., Dennis J Hand, Jennifer D Ellis, Meagan M Carr, Diane J Abatemarco, David M Ledgerwood

Department of Obstetrics and Gynecology Faculty Papers

Contingency management (CM) is an effective intervention for reducing use of licit and illicit substances in a variety of populations. Pregnant women are a vulnerable population with much to gain from effective interventions for substance use disorders, and for whom CM interventions may be especially well-suited. We reviewed the literature on CM interventions among pregnant women with tobacco and other substance use disorders with 3 aims: (a) describe the effectiveness of CM for reducing use of tobacco and other substances during pregnancy, (b) describe the effects of CM interventions on infant outcomes, and (c) identify needs for future research on …

An Evaluation Of Full-Day Kindergarten Programming, Amy Houlihan

Dissertations

The purpose of this program evaluation document is to provide a rationale and structure for implementing full-day kindergarten. The persistence of the achievement gap in the United States requires considerable and deliberate action to narrow and eliminate the gap over time. With the evolving educational landscape and the adoption of the Common Core State Standards, early education, including systematically designed and implemented full-day kindergarten are one way to afford children the opportunity to begin their education on pace to succeed. This program evaluation examines the differences between half-day kindergarten and full-day kindergarten programs including data analysis from the first year …

Utilizing Formative Assessments To Inform Teacher Instruction And Student Engagement, Kim Ontiveros

Dissertations

ABSTRACT

The purpose of this program evaluation was to gain a clear understanding of how formative assessments impact teacher instruction and engage students. I used a survey with the teachers and data taken from their math formative assessments and NWEA MAP testing results on the mathematical concepts such as: Operations and Alegebraic Thinking, Numbers and Operations, Measurement and Data and Geometry. There were gaps identified with the formative assessments, teacher reflection with instruction and the absence of student engagement throughout the process. I found that teachers were not always using formative assessments to reteach concepts or adapt their instruction. Additionally, …

Advocacy For Compliance With Existing Policy In Social Emotional Learning, Emilie Correa

Dissertations

Social Emotional Learning (SEL) standards were adopted by the state of Illinois in 2004. Local SEL policy was adopted by District 1234 in 2010. This policy advocacy work presents how findings from a district’s SEL Audit helped a team of administrators identify areas for growth and advocate for compliance of existing state and local SEL policy. This work documents how a district went from no SEL programming, to the creation of an SEL Task Force, the powering of SEL standards, and the planning for systemic implementation of SEL. According to research (Durlak, Weissberg, Dymnicki, Taylor, & Schellinger, 2011), students who …

An Evaluation Of Avid As A Supplemental Education Program At The Middle School Level, Lori Bradner

Dissertations

This is a study of AVID as a supplemental education program at the middle school level that includes a quantitative evaluation of the academic efficacy of AVID utilizing anonymized, longitudinal student achievement data. The second section is a qualitative evaluation of the AVID program at one middle school within a district to determine the perceived efficacy of the AVID program among stakeholders using surveys and interviews. This also includes a discussion of the necessary change in leadership determined by the evaluation portions of this project. The third portion outlines a policy change essential for satisfactory outcome as defined by AVID …