Digital Commons Network^™

Estimating Wildfire Potential On A Mojave Desert Landscape Using Remote Sensing And Field Sampling, Peter F. Van Linn Iii

UNLV Theses, Dissertations, Professional Papers, and Capstones

Landscape level wildfire prediction can be used to allocate wildfire resources and guide land management practices. Wildfire prediction in arid habitats in the Southwestern United States is of specific concern because of the negative ecological impacts of fire on desert habitats and the current lack of accurate fire prediction tools for such areas. This study examines the ability to predict previous fire occurrences and estimate future fire potential using satellite imagery and on the ground field survey techniques along with ignition potential data (lightning strikes and distance to roads), topographical data (elevation and aspect), and climate information (maximum and minimum …

Statistical Inference Of A Measure For Two Binomial Variates, Serena Petersen

UNLV Theses, Dissertations, Professional Papers, and Capstones

We study measures of a comparison for two independent binomial variates which frequently occur in real situations. An estimator for measure of reduction (MOR) is considered for two sample proportions based on a modified maximum likelihood estimation. We study the desirable properties of the estimator: the asymptotic behavior of its unbiasedness and the variance of the estimator. Since the measure ρ is approximately normally distributed when sample sizes are sufficiently large, one may establish approximate confidence intervals for the true value of the estimators. For numerical study, the Monte Carlo experiment is carried out for the various scenarios of two …

Dispersion Of The Hyperpolarizability Of The Carbon Tetrachloride Molecule, Scott Wilde

UNLV Theses, Dissertations, Professional Papers, and Capstones

The second hyperpolarizability of a molecule is the microscopic version of the third order susceptibility. Direct measurements of the ratio of the second hyperpolarizability of carbon tetrachloride to diatomic nitrogen are made possible through electric field induced second harmonic generation. Whenever the dispersion of the second hyperpolarizability is not negligible, there should be deviations from Kleinman symmetry. Previous experimental data for second hyperpolarizability of this molecule have only been at two frequencies and theory predicts the zero frequency value. In order to provide for a better extrapolation to zero frequency, additional gas phase measurements of this ratio at optical frequencies …

Relationships Of Exotic Plant Invasions With Biological Soil Crust, Desert Pavement, And Soil Carbon In The Eastern Mojave Desert, Adria Decorte

UNLV Theses, Dissertations, Professional Papers, and Capstones

In a matter of 50 years, exotic annual plants have become widespread in the Mojave Desert, contributing to drastic landscape changes such as those caused by recent fires. Invasions by exotics threaten native Mojave Desert plant communities by altering community functions (e.g. fire regimes) and by reducing plant diversity. Because it is not practical, or even possible, to eradicate these exotics, developing effective prevention techniques is the key to controlling these invasions.

This thesis used a greenhouse experiment, a field experiment, and a correlational field study to examine the affect soil surface types have on the establishment of three exotic …

Arima Models For Bank Failures: Prediction And Comparison, Fangjin Cui

UNLV Theses, Dissertations, Professional Papers, and Capstones

The number of bank failures has increased dramatically over the last twenty-two years. A common notion in economics is that some banks can become "too big to fail." Is this still a true statement? What is the relationship, if any, between bank sizes and bank failures? In this thesis, the proposed modeling techniques are applied to real bank failure data from the FDIC. In particular, quarterly data from 1989:Q1 to 2010:Q4 are used in the data analysis, which includes three major parts: 1) pairwise bank failure rate comparisons using the conditional test (Przyborowski and Wilenski, 1940); 2) development of the …

The Relationship Between Participation In Extracurricular Activities And Utah's Proficiency Assessments Of Students In A Suburban School District, Everett N. Kelepolo

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to discover whether a relationship exists between participation in extracurricular activities and meeting Utah proficiency assessment standards. This study took place in a suburban school district in the state of Utah.

Throughout the history of public education, economic hardships have wreaked havoc on school systems that depend on public sources of income. Schools today are managing these budget restraints by reducing or eliminating extracurricular programs.

The relationship between academic success and participating in extracurricular activities is found concretely in the research data. However, schools must make budget decisions which place activities and academics in …

Telework Within The Bureau Of Reclamation Lower Colorado Region Office, Theresa Lee, Lynne Arnold, John Wagner, Elias Samorano, Anita Morgan

UNLV Theses, Dissertations, Professional Papers, and Capstones

A team of researchers from The University of Nevada, Las Vegas were invited by management to observe, assess, and offer recommendations. It was determined by the research team that the first step to improving participation would be to observe the functional telework policy, compare and contrast it with the Department of the Interior standards, and offer recommendations to generate data necessary to develop an updated telework policy by management. The recommendations made by this group include creating an employee eligibility list, tracking actual participation by creating a renewal policy for employees choosing to telework. It is also recommended that a …

Modeling Gamma-Ray Bursts, Amanda Maxham

UNLV Theses, Dissertations, Professional Papers, and Capstones

Discovered serendipitously in the late 1960s, gamma-ray bursts (GRBs) are huge explosions of energy that happen at cosmological distances. They provide a grand physical playground to those who study them, from relativistic effects such as beaming, jets, shocks and blastwaves to radiation mechanisms such as synchrotron radiation to galatic and stellar populations and history. Through the Swift and Fermi space telescopes dedicated to observing GRBs over a wide range of energies(from keV to GeV), combined with accurate pinpointing that allows ground based follow-up observations in the optical, infrared and radio, a rich tapestry of GRB observations has emerged. The general …

Climate Change In Rural Nevada: The Influence Of Vulnerability On Risk Perception And Environmental Behavior, Ahmad Safi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this research, I examine the impact of vulnerability on risk perception, stated willingness to adopt individual mitigation behavior, and support for climate change mitigation policies. My major research question is, "Does vulnerability to climate change increase risk perception, encourage more energy-efficient individual behavior, and enhance support for climate change mitigation policies?" But to understand the role of vulnerability I also pursue answers to questions regarding its three components: Physical vulnerability; sensitivity and adaptive capacity. I investigate the following sub-questions:

• Do physical vulnerability, and sensitivity to climate change increase risk perception, encourage more energy-efficient individual behavior, and enhance support for …

Topic Detection And Tracking Using Hidden Markov Models, Aditya S. Tatavarty

UNLV Theses, Dissertations, Professional Papers, and Capstones

There is a continuous progress in automatic recording of broadcast speech using speech recognition. With the increasing use of this technology, a new source of data is added to the pool of information available over web. This has increased the need to categorize the resulting text, based on their topic for the purpose of information retrieval.

In this thesis we present an approach to automatically assign a topic or track a change of topic in a stream of input data. Our approach is based on the use of Hidden Markov Models and language processing techniques. We consider input text as …

Effectiveness Of Earthtec ® On Killing Invasive Quagga Mussels (Dreissena Rostriformis Bugenis) And Preventing Their Colonization In The Western U.S., Ashlie Watters

UNLV Theses, Dissertations, Professional Papers, and Capstones

Dreissena rostriformis bugensis, an invasive species, also known as the quagga mussel, was discovered in Lake Mead, NV in January of 2007. In the four years since detection, quagga mussels have created tremendous economical, ecological, and human health impacts. The mussels clog pipes, ruin boat motors, and damage recreational equipment, and once established in the lake, routine maintenance is necessary to avoid further damage. Because of quagga mussels' high fecundity, planktonic veliger stage, and ability to attach to substrates with byssal threads, they have easily and swiftly spread to other lakes and reservoirs in the Lower Colorado River Basin. …

Pleistocene Climate In Alaska From Stable Isotopes In An Ice Wedge, Corinne Y. Griffing

UNLV Theses, Dissertations, Professional Papers, and Capstones

The CRREL permafrost tunnel offers a unique opportunity to sample ice wedges in a climate-controlled environment, penetrating frozen silts which host massive ground ice that may record Dansgaard-Oeschger (D-O) and Heinrich Events. Ice wedges in the tunnel have been dated to approximately 36-22 ka (Hamilton et al., 1988), allowing the paleoclimate of the region to be reconstructed during MIS 3, when D-O and Heinrich events were documented in various other records. These climate cycles are rapid climate oscillations that have been recognized in records from the Arctic and subarctic, and suggest that climate can rapidly shift by 10°C over millennial …

A Multi-Wavelength Study On Gamma-Ray Bursts And Their Afterglows, Binbin Zhang

UNLV Theses, Dissertations, Professional Papers, and Capstones

During the prompt emission and afterglow phases, GRBs(Gamma-Ray Bursts) release their huge amount of energy not limited in gamma-ray, but in a wide range of muti-wavelengths, from radio band to GeV gamma-rays. Thanks to the recent missions of Swift and Fermi, I was able to use their multi-wavelength observation data of GRBs and study their physical natures. I have processed all the Swift BAT/XRT and Fermi GBM/LAT GRB observation data. Based on the Swift data, I have studied the following comprehensive topics: (1) high-latitude "curvature effect" of early X-ray tails of GRBs Swift XRT afterglow (2) diverse physical origins of …

Learning Middle School Mathematics Through Student Designed And Constructed Video Games, Camille M. Mccue

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mathematics achievement is an area in which American precollege students are faltering. Emerging research suggests that making mathematics instruction relevant and applicable in the lives of youth may impact math achievement, especially when it capitalizes on high-interest technologies such as video games.

Employing a quasi-experimental and descriptive approach, this study examined the mathematics (i.e., numbers and operations, algebra, geometry, measurement, and probability) that middle school students employed during their design and construction of video games. First, it examined the mathematics content learned by 19 sixth and seventh graders during their analysis, synthesis, and programming of three video game projects over …

Investigating The Effects Of A Combined Problem-Solving Strategy For Students With Learning Difficulties In Mathematics, Dustin B. Mancl

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many students, specifically those with learning difficulties in mathematics, struggle when presented with word problems to solve. With this in mind, the purpose of this research was to examine the effects of the READER Strategyon word problem performance of students with mathematics disabilities and students who are at-risk to fail in mathematics. There were two parts to this research. Part One was implemented using a single-subject design (i.e., multiple-probe across participants) and Part Two was implemented using a group design (i.e., 2 x 4 factorial design). The single-subject design included three participants identified as having mathematics disabilities. There were two …

Gamma-Ray Burst Populations, Francisco J. Virgili

UNLV Theses, Dissertations, Professional Papers, and Capstones

Over the last fifty years the field of gamma-ray bursts has shown incredible growth, but the amassing of data has also left observers and theorists alike wondering about some of the basic questions surrounding these phenomena. Additionally, these events show remarkable individuality and extrema, ranging in redshift throughout the observable universe and over ten orders of magnitude in energy. This work focuses on analyzing groups of bursts that are different from the general trend and trying to understand whether these bursts are from different intrinsic populations and if so, what can be said about their progenitors. This is achieved through …

Complex Vs Profiles To 100 M Depth From Rayleigh Waves And 3-D Vs Model For Las Vegas Valley, Helena Murvosh

UNLV Theses, Dissertations, Professional Papers, and Capstones

A three-dimensional (3-D) shear wave velocity (VS) model was developed for the heterogeneous shallow sediments (to nearly 400 m) of the Las Vegas Valley (LVV), Nevada. The model was based on more than 200 VS profiles and 1400 geologic well logs. Five sediment units including a cemented unit were defined from geologic log descriptions. A characteristic VS profile for four of the units was obtained by correlating between closely spaced pairs of VS and sediment data; a constant VS was assigned to the cemented unit. VS profiles were then assigned to each well location based on type of sediment according …

Shop Problems In Scheduling, James Andro-Vasko

UNLV Theses, Dissertations, Professional Papers, and Capstones

The shop problems in scheduling will be discussed in this thesis. The ones I'll be discussing will be the flow shop, open shop, and job shop. The general idea of shop problems is that you're given a set of jobs and a set of machines. Each job is predeterminely broken into parts and there are rules to how each part is executed on a machine. In this thesis, several shop problems and their algorithms will be introduced that I have researched. There are several examples and counter examples that I have constructed. Also I will discuss how an arbitrary problem …

The Effect Of Working Memory And Math Ability On Decision Making, Jeremy A. Krause

UNLV Theses, Dissertations, Professional Papers, and Capstones

Previous research has indicated that people use various strategies when making decisions. A majority of the research has involved the idea that people use a heuristic when making decisions. Kahneman and Tversky have illustrated that there are instances that people respond with an answer that appears to be indicative of usage of the representativeness heuristic. One of the purposes of the current paper is to gain insight into the actual strategies that are used in these instances. Another purpose of the current experiment is to see if math ability and working memory capacity influence the strategy that a person selects …

Sharp Feature Identification In A Polygon, Joseph P. Scanlan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis presents an efficient algorithm for recognizing and extracting sharp-features from polygonal shapes. As used here, a sharp-feature is a distinct portion of a polygon that is long and skinny. The algorithm executes in O(n^2) time, where n is the number of vertices in the polygon. Experimental results from a Java implementation of the algorithm are also presented.

Consensus On The Colorado: Issues In The Allocation Of A Limited Resource, Jeffrey D. Tilton

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to identify current issues in water allocation in the Lower Colorado River Basin and to locate existing areas of consensus among its stakeholders. Surveys, both paper and web-based provided the data required to measure overwhelming agreement on issues. The data analysis served to locate the areas of agreement within and between interest groups. While overwhelming agreement between all groups proved to be a relatively rare occurrence, the existence of issue specific agreement between two or more groups was more common than expected. Accord was demonstrated in all four major areas: allocation, augmentation, conservation, and …

Analyzing The Relative Efficiency Of Nevada Secondary Schools, Jesse Welsh

UNLV Theses, Dissertations, Professional Papers, and Capstones

A definitive answer to how to allocate school-level expenditures to yield the greatest "bang for the buck" has continually eluded education finance researchers. With increased regulation, oversight, and sanctions resulting from the No Child Left Behind Act, paired with financial strains on states' education budgets, measuring schools' production and efficiency has become urgent.

The methodology for this study was comprised of two phases. Phase I analyzed the per-pupil expenditures of middle and high schools over a three-year period and developed descriptive statistics that revealed the expenditure patterns by category. Phase II used a micro-level economic approach, data envelopment analysis, to …

Molecular Organic Geochemistry Of The Oil And Source Rocks In Railroad Valley, Eastern Great Basin, Nevada, United States, Laode Ahdyar

UNLV Theses, Dissertations, Professional Papers, and Capstones

A comprehensive geochemical study of oils from Railroad Valley, Nevada and two candidate source rock intervals from the nearby Egan Range, was conducted in order to establish oil-oil and oil-source rock correlations. Analyses consisted of total organic carbon, Rock-Eval pyrolysis, and vitrinite reflectance for source rock samples, as well as biomarker, diamondoids, and stable carbon isotope analyses on source rock extracts and oil samples.

Total organic carbon analyses showed high organic content in the Mississippian Chainman Shale. However, outcrop samples of the Paleogene Sheep Pass Formation Member B are organically lean. Strata in both of these units are immature to …

Self-Assembling Organic Semiconductors With Tunable Electronic Properties Based On Novel Asymmetric Phenazine And Bisphenazine, Kyoungmi Jang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Current demands in the area of organic semiconductors focus on both electronic and self-assembling properties. Particularly, one-dimensionally grown nanostructures of small organic semiconductors have drawn much attention for nanodevice fabrication. Self-assembly through various intermolecular interactions has been widely used to produce one-dimensionally grown nanostructures which can be induced by various methods such as rapid solution dispersion, a phase transfer method, vapor annealing, crystallization, and organogelation in conjunction with proper molecular design. Controlling the morphology of the nanostructures plays an important role in achieving desirable properties in optoelectronic device applications. While significant advancements have been made in developing molecular architectures for …

Finding Acronyms And Their Definitions Using Hmm, Lakshmi Vyas

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we report on design and implementation of a Hidden Markov Model (HMM) to extract acronyms and their expansions. We also report on the training of this HMM with Maximum Likelihood Estimation (MLE) algorithm using a set of examples.

Finally, we report on our testing using standard recall and precision. The HMM achieves a recall and precision of 98% and 92% respectively.

Extraction Chromatographic Studies Of Rutherfordium And Dubnium Homologs, Megan E. Bennett

UNLV Theses, Dissertations, Professional Papers, and Capstones

Studying the chemistry of transactinide elements does not only allow for these elements to be properly placed in the Periodic Table, but it also permits for the extrapolation of the electronic structure based upon the position of the element in the Periodic Table. In addition it enable for the assessment of the role that relativistic effects play in the chemical behavior of the heaviest elements. An improved understanding of the role of relativistic effects in chemistry of the heaviest elements allows for a better understanding of the fundamentals principles that govern the Periodic Table. In order to investigate the chemistry …

Bilingualism And Math Cognition, Michelle M. Guillaume

UNLV Theses, Dissertations, Professional Papers, and Capstones

Within cognitive psychology, the fields of bilingualism and math cognition have been investigated relatively separately from one another. Although there has been a substantial amount of research conducted in both areas, few studies have examined mathematical processes as they relate to bilinguals. A couple of the traditional effects found in the math cognition literature, the problem size and associative confusion effects, have been studied with bilinguals; however, bilingual categorization was not carefully controlled for in those studies. There have also been mathematical models applied to bilingual samples; one such model is the encoding-complex model, which has been extended to Chinese-English …

A Change Of Heart: A Phenomenographic Study Of Conversation, Marjorie Kay Meckes Conner

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study investigated the use of a school-level leadership model intended to explore the institutionalization of principal-teacher conversations as a tool in leading and learning. An elementary principal and two teachers at five elementary schools were selected for the study. Over an eight-week time, the principal and each teacher held a series of at least four conversations. The investigator interviewed each of the fifteen participants prior to any conversations, at the mid-point of the conversations and at the conclusion of all conversations. The purposes of this exploratory study were to document participant perceptions of the usefulness and importance of principal-teacher …

The Road Traveled To Becoming A Safe High School, Monica J. Pufky Cortez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many urban school districts share a common profile of high dropout rates, low graduation rates, high discipline statistics and acts of school violence, and low student achievement on assessments. Researchers have argued high schools are teaching students in ways that are not only ineffective but also fail to provide the requisite tools for students to achieve success in the 21st century (Gates Foundation, 2010). Additional voices claim urban high schools are not adequately preparing students to become successful citizens for a knowledge-based society (Cuban, 2007).

Using qualitative methodology, this naturalistic study revealed five factors that contribute to creating a safe …

Implementation Of Hidden Semi-Markov Models, Nagendra Abhinav Dasu

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the most frequently used concepts applied to a variety of engineering and scientific studies over the recent years is that of a Hidden Markov Model (HMM). The Hidden semi-Markov model (HsMM) is contrived in such a way that it does not make any premise of constant or geometric distributions of a state duration. In other words, it allows the stochastic process to be a semi-Markov chain. Each state can have a collection of observations and the duration of each state is a variable. This allows the HsMM to be used extensively over a range of applications. Some of …