Digital Commons Network^™

Design And Preliminary Evaluation Of A Supercritical Carbon Dioxide Brayton Cycle For Solar Dish Concentrator Clean Energy Production, Danielle Nobles-Lookingbill

UNLV Theses, Dissertations, Professional Papers, and Capstones

As we move toward energy independence and more ambitious clean energy goals, solar energy research must push the efficiency limits of traditional energy generation systems. Increases in efficiency can be achieved by increasing the hot temperature of the power cycle. Recent research demonstrates the potential for increased efficiency and a vastly smaller component size when supercritical carbon dioxide Brayton power cycles are used. Concentrated solar and nuclear heat sources are capable of achieving the high working fluid temperatures needed for significant efficiency gains. This NSF EPSCoR funded, experimental research system is designed to exploit the uniquely immense solar irradiance of …

Factors That Impact Direct Democracy And Voter Turnout: Evidence From A National Study On American Counties, Michael Joseph Biesiada

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation examines factors that impact citizen initiatives and voter turnout. The dissertation contains two parts that build upon each other with fitting theoretical frameworks. The first part investigates the decision for a county government to permit citizen initiatives. This part applies new institutionalism theory as a framework to examine county governance, autonomy, and decision-making. County governments play a vital role in American politics, yet little is known about why some counties permit citizen initiatives while others do not. I address a gap in the literature that focuses on policy outcomes that vary at the county-level due to election laws. …

Disastrous Voting, Moritz Peter Rissmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

The central question of this study is ’Is there an observable general trend of electorates punishing incumbents for natural disasters across countries and elections?’ Many scholars have argued for the existence of such behavior, yet the empirical evidence rests mostly on single-country and even single-election studies. I look for a generalizable trend in two original data sets with country-election and country-constituency-election as the unit of analysis respectively. I test the punishment hypothesis by correlating the occurrence of natural disasters to the performance of incumbent parties in national lower house elections. Furthermore, I propose that the effect of natural disasters on …

Corporate Social Responsibility And Consumer Purchase Behavior: The Moderating Role Of Self-Presentation, Mandy May Walsh

UNLV Theses, Dissertations, Professional Papers, and Capstones

In recent years, companies have experienced increasing pressure to integrate corporate social responsibility (CSR) into their organizational structure. The relationship between a company's investment in CSR and overall revenue, however, is still under debate in the current literature as research has focused on correlations and consumer purchase intentions (e.g., Auger, Burke, Devinney, & Louviere, 2003; Dutta & Singh, 2013; Klein & Dawar, 2004; Maignan, 2001; Mohr & Webb 2005; Mohr, Webb, & Harris, 2001; Nanda, 2015; Wigley, 2008). Findings from previous studies have not yet assessed actual purchase behavior or potential moderating variables impacting this relationship. Therefore, this dissertation examined …

Employee Perceptions Of Organizational Corporate Responsibility And Their Effect On Employee Organizational Commitment, Lisa R. Davis

UNLV Theses, Dissertations, Professional Papers, and Capstones

The debate over whether organizations play a part in society beyond economic profit has been a major focus of research in corporate social responsibility (CSR). These debates have been mainly looked at from the macro (societal) or the meso (institutional) level. Very little research has been done on the role of the firm and looking at CSR from the micro (individual) level. Questions regarding the role of work for employees, securing economic benefits or making a difference in the world, would vary greatly depending on the individual and the importance they place on these areas in their own lives. Scholars …

Personality Patterns Of Students Who Make A Threat Of Targeted School Violence, Tawnya Michelle Ayim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Although school shootings date back to the 1760’s (Dixon, 2005), recent attacks at schools in our country have raised awareness of school violence. This study investigates how students from one large school district responded to the personality pattern items on the Millon Adolescent Clinical Inventory, Second Edition after having made a threat to harm another student or staff member. Personality patterns were investigated in the overall sample, as well as within groups designated to be at a Low/Moderate risk level and High/Imminent risk level following a threat assessment. The minimal Differences between the sample for the current study and the …

Design And Analysis Of First And Second Order K-Delta-1-Sigma Modulators In Multiple Fabrication Processes, Shada Sharif

UNLV Theses, Dissertations, Professional Papers, and Capstones

Analog to digital converters (ADC) are an important category of electronic circuits that are required in order to convert real-world analog signals into the digital domain. One of the main trade-offs in ADC design is between data conversion speed and resolution. Delta Sigma ADCs are commonly used for high precision data conversion of low bandwidth signals such as those found in audio, industrial and biomedical applications. A major disadvantage of traditional Delta Sigma ADC architectures is that they have limited signal bandwidth and are not suited for high speed applications such as communication systems. The continuous time K-Delta-1-Sigma (KD1S) modulator …

Examining The Training Transfer Practice Of A Financial Institution: An Action Research Study, Maria Lourdes Lourdes Gutierrez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many organizations rely on training to improve the skills and knowledge of its human resources. The underlying assumption is that employees will use what they learned when they return to the workplace. Although there is evidence that learning occurred it does not always result in transfer (Mosel, 1957). Transfer is an issue of concern for training practitioners. If despite the significant investment no return is realized, then the training is not effective and the investment is wasted. This action research study was conducted in a financial institution in the Southwestern United States. The purpose of this study was to (1) …

Studies Of Inner-Shell Chemistry Of Mercury Based Compounds At Extreme Conditions, Sarah Schyck

UNLV Theses, Dissertations, Professional Papers, and Capstones

It has been theoretically predicted that when mercury difluoride (HgF2) is pressurized to above 50 GPa in the presence of molecular fluorine, it will most likely transform into mercury tetrafluoride (HgF4), thus mercury will behave as a transition element at high pressure. However, there is no experimental evidence verifying this prediction yet. To begin with, the crystalline properties of pure HgF2 at high pressure were not experimentally established. In this thesis, the high pressure structural properties of HgF2 are investigated by means of synchrotron X-ray powder diffraction. Our results reveal that the predicted, ambient cubic structure of HgF2 with the …

Application Of Machine Learning Techniques In Credit Card Fraud Detection, Ronish Shakya

UNLV Theses, Dissertations, Professional Papers, and Capstones

Credit card fraud is an ever-growing problem in today’s financial market. There has been a rapid increase in the rate of fraudulent activities in recent years causing a substantial financial loss to many organizations, companies, and government agencies. The numbers are expected to increase in the future, because of which, many researchers in this field have focused on detecting fraudulent behaviors early using advanced machine learning techniques. However, the credit card fraud detection is not a straightforward task mainly because of two reasons: (i) the fraudulent behaviors usually differ for each attempt and (ii) the dataset is highly imbalanced, i.e., …

A Qualitative Multiple Case Study Of The Transition Experiences Of Parents And Service Providers Of Individuals With Intellectual/Developmental Disabilities (Idd) In A Postsecondary Educational Program, Rebecca S. Rogers

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this qualitative case study was to explore the transition experiences of parents of young adults with IDD who are currently enrolled in a postsecondary educational

program in the Southwest part of the United States. This qualitative multiple-case study used Schlossberg’s transition theory to frame the cases for this report. Schlossberg’s transition theory examines the way in which adults move through various transitions in their lives and what strategies they use to cope with the transitions. The theory identifies three different types of transitions: anticipated transitions, unanticipated transitions, and nonevent transitions. In addition, the theory identifies four coping …

Bayesian Model Comparisons In Planetary Science, John Henry Boisvert

UNLV Theses, Dissertations, Professional Papers, and Capstones

Model comparison in the modern era allows us to use statistical methods that were previously difficult with older machines. I present a state-of-the-art model comparison code that uses modern Bayesian statistics to measure the Bayes factor between two competing models. The Bayes factor is the ratio of the probability of the data given one model to the probability of the data given another model. My code was used to compare models in five problems in planetary science. The first three pertain to radial velocity exoplanet data. There is a degeneracy in the radial velocity exoplanet signal between a single planet …

Effect Of Curing Conditions On Mechanical Properties And Durability Of Concrete, Edgar Lazaro Salas-Borrero

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis presents the results for three different concrete mix designs with compression strengths of 4500 psi. The experiment was conducted in the Las Vegas area during the summer, from August 16th to October 12th, 2018, where temperatures and relative humidity was recorded daily, three times a day. In total, 135 concrete specimens (4” x 8”) were taken on site and were subjected to five different curing conditions.

For each concrete mix design, three concrete samples (4” x 8”) were taken and submitted for each curing condition, resulting in 45 cylinders for each concrete mix design. The same number of …

The Influence Of Opponent Strategy And Psychopathic Traits On Point Gains And Cooperation In The Iterated Prisoner’S Dilemma, Mary Baggio

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Prisoner’s Dilemma game is a paradigm used to model and measure social cooperation. Uncooperative behavior may be one manifestation of the unstable interpersonal functioning in psychopathy. I investigated the effect of opponent strategy as well as psychopathic traits of fearless dominance (FD) and impulsive antisociality (IA) on cooperation rates and total and competitive point gains in a sample of 177 undergraduates playing long, finitely iterated Prisoner’s Dilemma games against computerized opponents who varied in their interpersonal styles from very harsh to very lenient. I analyzed rates of cooperation during each game, participants’ total points gained, and the difference in …

The Roles Of Biophilic Attitudes And Auditory Stimuli Within Attention Restoration Theory, Jason B. Boggs

UNLV Theses, Dissertations, Professional Papers, and Capstones

Attention Restoration Theory indicates that interacting with nature allows one’s fatigued, directed attention to be restored. This effect has been documented and produced through directed interaction with nature, such as a walk in the park, as well as through indirect interactions (e.g., photographs). The current dissertation was designed to: 1) investigate whether and how biophilic attitudes affect the attention-restoring effects incurred from interactions with nature, and 2) extend the research on ART by assessing the impact of nature-related audio stimuli. A total of 184 participants completed an assessment of biophilic attitudes, engaged in attention fatiguing exercises, and participated in one …

Combinatorial Ant Optimization And The Flowshop Problem, Tasmin Chowdhury

UNLV Theses, Dissertations, Professional Papers, and Capstones

Researchers have developed efficient techniques, meta-heuristics to solve many Combinatorial Optimization (CO) problems, e.g., Flow shop Scheduling Problem, Travelling Salesman Problem (TSP) since the early 60s of the last century. Ant Colony Optimization (ACO) and its variants were introduced by Dorigo et al. [DBS06] in the early 1990s which is a technique to solve CO problems. In this thesis, we used the ACO technique to find solutions to the classic Flow shop Scheduling Problem and proposed a novel method for solution improvement. Our solution is composed of two phases; in the first phase, we solved TSP using ACO technique which …

Performance-Based Economical Seismic Design Of Multistory Reinforced Concrete Frame Buildings And Reliability Assessment, Chunyu Zhang

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the next generation of seismic design methodology, performance-based seismic design (PBSD) method requires a structure satisfy multiple preselected performance levels under different hazard levels. Optimal PBSD methods provide different strategies to design the numerous variables, including strength, stiffness and ductility of each structural component. The overall goal of this study is to develop a new optimal PBSD method for multi-story RC moment frames. This method is capable of overcoming the deficiencies of existing optimal PBSD methods and can be implemented by the U.S. design practice. The proposed method minimizes construction cost and takes the limit of member plastic rotation …

Associations Between Opioid-Related Hospitalizations And Intravenous Drug Users, Jacklynn De Leon

UNLV Theses, Dissertations, Professional Papers, and Capstones

The opioid epidemic has led to a chain reaction of public health concerns, including an increase in heroin usage, injection drug abuse, incidence of hepatitis C virus (HCV), and HIV transmission. There have been few population-based studies investigating the clinical and socio- demographic data associated with opioid use in Nevada (Feng et al., 2016; Frank, 2000) and few studies investigating the intravenous drug user (IDU) population in Clark County. On February 2017, Clark County’s first syringe exchange program (SEP) opened its doors to the IDU population. This study provides an updated analysis of opioid-related injuries within Nevada and provides a …

Efficient And Practical Composition Of Lock-Free Data Structures, Neha Bajracharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

A concurrent data object is lock-free if it guarantees that at least one, among all concurrent operations, finishes after a finite number of steps. In other words, a lock free technique guarantees that some thread always makes progress. Lock-free data objects offer several advantages over their blocking counterparts, such as being immune to deadlocks and priority inversion, and typically provide high scalability and performance, especially in shared memory multiprocessor architectures.

Composition of data structures is a powerful approach to combine simple data structures to create more complex ones. It works as a building block for many advanced useful data structures. …

Surface Resistivity For Concrete Quality Assurance, Stanley Tat

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this study was to determine the effectiveness of SRT for concrete quality assurance and to evaluate the relationship between SRT and the three chloride ion ingress methods currently used by various State DOTs. Additionally, the influence of binder type and content, concrete age, and water-to cementitious materials ratio on the experimental results were also examined.

In this study, Type V Portland and three SCMs; namely fly ash, slag, and silica fume were used. Fine and coarse, aggregates were supplied by a local quarry. To evaluate the transport properties of the studied concretes, RMT, RCPT, and ACT were …

A Framework To Capture Dynamic Traffic Trends From Historical Sensor Data, Carlos Gaviria

UNLV Theses, Dissertations, Professional Papers, and Capstones

The typical approach of increasing infrastructure to alleviate traffic issues such as congestion is becoming unviable due to limited space, high cost, and associated externalities. Control and management strategies using Intelligent Transportation Systems (ITS) seek to maximize the use of existent infrastructure. Many ITS strategies, such as the deployment of information, require or benefit from knowledge about traffic patterns and trends. This study proposes a mathematical programming formulation and solution algorithm that considers multiple time intervals for the estimation of network-wide traffic states and calculation of the corresponding transition probabilities. The proposed solution enables the determination of sections of the …

A Phenomenological Study On The Professional Development Of African American Male Administrators At Predominately White Post-~Secondary Institutions, Arnold Shmorn Bell

UNLV Theses, Dissertations, Professional Papers, and Capstones

As of today, African Americans continue to face a daunting endeavor when seeking to become executive administrative leaders at predominately White post-secondary institutions, even though, according to Tillman (2001), “Mentoring was identified as a technique to assist the professional advancement of African American faculty. In doing so, their numbers will increase at predominantly White institutions” (p. 295). Literature steadily indicates that mentorship contributes to one’s career development in the post-secondary environment. The influential aspects of mentorship on one’s professional development is supported by numerous studies that examines mentoring relationships across various academic disciplines and businesses in corporate America (Brown, 2005). …

Identifying Youth At Risk For Problematic Absenteeism Using Nonparametric Modeling: The Impact Of Youth Psychopathology And Family Environment Risk Factors, Mirae Fornander

UNLV Theses, Dissertations, Professional Papers, and Capstones

The best cutoff to differentiate problematic school absenteeism from nonproblematic school absenteeism has yet to be identified in the literature (Lyon & Cotler, 2007). Contemporary classification systems, including Multi-Tiered Systems of Support (MTSS), depend upon cutoffs to clearly define the various tiers (Jimerson, Burns, & VanDerHeyden, 2016). The current study aimed to inform the MTSS approach while also contributing to early identification, assessment, and intervention methods for those youth and families at the highest risk of problematic school absenteeism and its negative consequences. The current study identified subgroups of youth at the highest risk of problematic absenteeism, defined as equal …

Uas-Based Object Tracking Via Deep Learning, Marc Dinh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Tracking is the task of identifying an object of interest and detect its position over time, and has numerous applications like surveillance, security and traffic control. In present times, unmanned aerial vehicles (UAV) have been more and more common which provides us with a new and less explored domain, with an ideal vantage point for surveillance and monitoring applications.. Aerial tracking is a particularly challenging task as it introduces new environmental variables such as rapid motion in 3D space. We propose a new deep learned tracker architecture catered to aerial tracking.

First, a study of six state-of-the-art deep learned trackers …

Influencing Hawai‘I Hotel Patrons To Use Reef-Safe Sunscreens, Rochelle Good

UNLV Theses, Dissertations, Professional Papers, and Capstones

The health of Hawaiian coral reefs is threatened by pollution from common sunscreen ingredients such as oxybenzone. Hawai‘i hotel patrons using sunscreens with harmful ingredients contaminate coral reefs when these products wash off while swimming or bathing. Reef-safe sunscreens are alternative sunscreens that provide effective sun protection while averting damage to coral reefs. The purpose of this research was to determine the dominant factors leading to the pro-environmental behavior of using reef-safe sunscreen and identify practices that Hawai‘i hotel operators could implement to influence patrons to engage in this behavior. This research applied an integrative conceptual framework to model pro-environmental …

Development Of The Emotional Verbal Learning Test - Spanish (Evlt-S), Davor Nicolas Zink

UNLV Theses, Dissertations, Professional Papers, and Capstones

Emotional disturbances are common features of clinical disorders and are often present in individuals who have neurodevelopmental or acquired brain disorders. The Hispanic population is the largest and fastest growing ethnic minority group in the United States (U.S.) and by 2050 is projected to be the largest. However, few instruments are available to evaluate emotional functioning in individuals who speak Spanish. Fewer still are available to assess cognitive disturbances resulting from brain dysfunction that impact emotion processing. Normal processing of emotion is critical for social functioning. In recent years it has become apparent that cognitive abilities specialized to process social …

Confirmatory Factor Analysis Of Oppositional Defiant Disorder Within Clinically Referred Youth, Breanna Garcia

UNLV Theses, Dissertations, Professional Papers, and Capstones

Each new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; APA, 2013) has been met with substantial criticism. Particularly, in DSM-5, two disorders were defined by very similar criteria. Oppositional defiant disorder (ODD) was defined as consisting of three dimensions - irritability, noncompliance, and spiteful/vindictive. Additionally, ODD has duration criteria that indicate its symptoms must be present for at least 6 months suggesting the presence of chronic irritability. DSM-5 also included disruptive mood dysregulation disorder (DMDD) as a disorder marked by the presence of chronic irritability in childhood and adolescence. The question of whether chronic irritability (i.e., …

A Distributed Real-Time Short-Term Solar Irradiation Forecasting Network For Photovoltaic Systems, Michael Adelbert Gacusan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solar irradiation forecasting is essential for PV connected electrical grids to maintain reliability, stability, and effective matching of real-time demand to power distribution. This research paper develops and evaluates proposed forecasting methods using wireless sensor networks. Each node of the network is capable of monitoring illuminance data and communicate it through RF and/or WiFi. The nodes are calibrated with respect to irradiance data from an industry-standard pyranometer. Power consumption of each node type is also collected at different operating states. The proposed sensor network can estimate a cloud motion vector or a cloud shadow’s speed and direction from the data …

Effects Of Ambient Air Pollution On Asthma-Related Emergency Department Visits Within The Las Vegas Metropolitan Area, Loiren E. Monardes

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this research was to evaluate the risk for asthma-related Emergency Department visits and their association with ambient air pollution within the Las Vegas metropolitan area. All data were aggregated by date and ZIP Code. The association was analyzed by applying the distributed lag non-linear model in an attempt to identify elevated concentrations of specific air pollutants

as triggers and their delayed effects (lag days). Relative Risk (RR) and 95% confidence intervals were produced, while adjusting for socioeconomic status. This ecological population-based study analyzed daily asthma counts of Emergency Department visits from January 1st, 2009 to December 31st, …

Design, Layout, And Testing Of Sige Apds Fabricated In A Bicmos Process, Dane Laurence Gentry

UNLV Theses, Dissertations, Professional Papers, and Capstones

This Thesis is concerned with the design, layout, and testing of avalanche photodiodes (APDs). APDs are a type of photodetector and, thus, convert light signals into electrical signals (current or voltage). APDs can be fabricated using silicon (Si). In this Thesis, however, three integrated circuit (IC) chips containing various silicon-germanium (SiGe) APDs with different sizes, structures, and geometries were designed, laid out, and fabricated using the Austriamicrosystems (AMS) 0.35μm SiGe BiCMOS (S35) process. This was done in order to compare SiGe APDs to Si only APDs and investigate the hypothesis that SiGe APDs are capable of detecting longer wavelengths than …