Physical Sciences and Mathematics Commons^™

Improving Children's Authentication Practices With Respect To Graphical Authentication Mechanism, Dhanush Kumar Ratakonda

Boise State University Theses and Dissertations

A variety of authentication mechanisms are used for online applications to protect user’s data. Prior literature identifies that adults and children often utilize weak authentication practices and our own initial research corroborates that children often create weak usernames and passwords. One reason children adopt weak authentication practices is due to difficulties in remembering their usernames and passwords. Existing literature suggests that people are better at remembering graphical information than text and words. In this dissertation, my research goal is to improve the usability and security of children’s authentication mechanisms. My research includes designing, developing, and evaluating a new graphical …

Automated Detection Of Sockpuppet Accounts In Wikipedia, Mostofa Najmus Sakib

Boise State University Theses and Dissertations

Wikipedia is a free Internet-based encyclopedia that is built and maintained via the open-source collaboration of a community of volunteers. Wikipedia’s purpose is to benefit readers by acting as a widely accessible and free encyclopedia, a comprehensive written synopsis that contains information on all discovered branches of knowledge. The website has millions of pages that are maintained by thousands of volunteer editors. Unfortunately, given its open-editing format, Wikipedia is highly vulnerable to malicious activity, including vandalism, spam, undisclosed paid editing, etc.

Malicious users often use sockpuppet accounts to circumvent a block or a ban imposed by Wikipedia administrators on the …

Understanding Water Security In Portland, Oregon: Using Newspapers As Tools For Science Communication And Education, Julian Roth

University Honors Theses

Water insecurity is faced by a large percentage of the global population, particularly in urban areas, which face greater and more complex needs for water resources. Better tools are needed to be able to recognize and communicate water security issues in a way that reinforces water systems, engages all stakeholders, and recognizes early warnings of environmental injustice. This research examines utilizing public newspaper articles to produce these tools. Using a case-study approach, this thesis explores newspaper articles about water from 2014-2020 in the urban center of Portland, Oregon, to understand local water security issues and to build a system of …

Emotion Detection Using An Ensemble Model Trained With Physiological Signals And Inferred Arousal-Valence States, Matthew Nathanael Gray

Electrical & Computer Engineering Theses & Dissertations

Affective computing is an exciting and transformative field that is gaining in popularity among psychologists, statisticians, and computer scientists. The ability of a machine to infer human emotion and mood, i.e. affective states, has the potential to greatly improve human-machine interaction in our increasingly digital world. In this work, an ensemble model methodology for detecting human emotions across multiple subjects is outlined. The Continuously Annotated Signals of Emotion (CASE) dataset, which is a dataset of physiological signals labeled with discrete emotions from video stimuli as well as subject-reported continuous emotions, arousal and valence, from the circumplex model, is used for …

Development Of High Quantum Efficiency Strained Superlattice Spin Polarized Photocathodes Via Metal Organic Chemical Vapor Deposition, Benjamin Belfore

Electrical & Computer Engineering Theses & Dissertations

Spin polarized photocathodes are necessary to examine parity violations and other fundamental phenomena in the field of high energy physics. To create these devices, expensive and complicated growth processes are necessary. While integral to accelerator physics, spin polarized electrons could have other exciting applications in materials science and other fields of physics. In order to explore these other applications feasibly, the relative supply of spin polarized photocathodes with a high rate of both polarization and photoemission needs to be increased. One such way to increase this supply is to develop the means to grow them faster and at a larger …

A Gpu Accelerated Genetic Algorithm For The Construction Of Hadamard Matrices, Andras Balogh, Raven Ruiz

School of Mathematical & Statistical Sciences Faculty Publications

We use a genetic algorithm to construct Hadamard Matrices. The initial population of random matrices is generated to have a balanced number of +1 and −1 entries in each column except the first column with all +1. Several fitness functions are implemented in order to find the most effective one. The crossover process creates offspring matrix population by exchanging columns of the parent matrix population. The mutation process flips +1 and −1 entry pairs in random columns. The use of CuPylibrary in Python on graphics processing units enables us to handle populations of thousands of matrices and matrix operations in …

Joint Invariants Of Primitive Homogenous Spaces, Illia Hayes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Joint invariants are motivated by the study of congruence problems in Euclidean geometry, where they provide necessary and sufficient conditions for congruence. More recently joint invariants have been used in computer image recognition problems. This thesis develops new methods to compute joint invariants by developing a reduction technique, and applies the reduction to a number of important examples.

Pesticide-Leaf Interactions And Their Implications For Pesticide Fate Modeling, Ashlie Kinross

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work described here provides measured data to improve the understanding of the interaction between a pesticide and leaf surface after application. Two methods were developed, one using a newly introduced instrument, for the extraction of pesticides from leaves. This is required to measure the concentration of pesticide in the leaves. Using one of the developed extraction methods, measurements were made to determine how a pesticide equilibrates between a leaf and the air above it. These measurements were incorporated into a pesticide fate model that predicts how a pesticide moves through the environment after application to an agricultural field. The …

An Introduction To Combinatorics Via Cayley's Theorem, Jaylee Willis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this paper, we explore some of the methods that are often used to solve combinatorial problems by proving Cayley’s theorem on trees in multiple ways. The intended audience of this paper is undergraduate and graduate mathematics students with little to no experience in combinatorics. This paper could also be used as a supplementary text for an undergraduate combinatorics course.

Invigorating Seventh-Day Adventist Science Education With Chemical Knowledge Of God's Creation, Ryan T. Hayes, D. David Nowack

Faculty Publications

No abstract provided.

Multi-Technique Characterization Of Superconducting Materials For Particle Accelerator Applications, Junki Makita

Physics Theses & Dissertations

We investigated the performance limitations of superconducting radio-frequency (SRF) cavities and materials using multiple experimental techniques. In particular, this study focuses on understanding the surface properties of nitrogen-doped Nb cavities and superconducting thin films with higher T_c such as Nb₃Sn. The main goal of this work is to use different techniques to better understand each aspect of the complex loss mechanism in superconductors to further improve the already highly efficient SRF cavities.

Nitrogen doping applied to a Nb SRF cavity significantly improves the quality factor Q₀ compared to a conventional Nb cavity, at an expense of …

Nestedness And Modularity Of Avian Metacommunities Across Gradients Of Chesapeake Bay Island Characteristics, Grant Walter Bowers

Biological Sciences Theses & Dissertations

Islands are not only great models for understanding the ways in which communities are linked by the dispersal of their members to form metacommunities, but are of particular interest to conservationists. One important aspect of metacommunity structure is the degree of nestedness—whether or not less speciose communities are perfect subsets of more speciose communities. Another important metric of metacommunity structure is modularity—the degree to which communities belong to modules composed of other communities that share the same species but have little species overlap with communities from different modules. Environmental gradients have received insufficient attention as predictors of metacommunity nestedness and …

Bidirectional Testing For Repairable Systems Reliability: Power Asymmetries, Panel Of Control Charts, And Reliability Graphics, Sung Keun Koo

UNLV Theses, Dissertations, Professional Papers, and Capstones

To a practitioner who chooses to be on the safe side, we offer an option between a cocktail of tests and a solo one-size-fits-all test as a needed antidote to power asymmetries. Two bidirectional tests are first established to empower a basic pair of tests as asymmetrical performances. Unsurprisingly, we’ve seen either bidirectional device championing in one alternative setting, but also being turned against the very setting altered with just one of the composed elements. Progressing by filtering out the bad and enhancing the good, we assemble a hybrid from the empowered pair to restore power symmetries that are thought …

Current Ecotoxicity Testing Needs Among Selected U.S. Federal Agencies, Patricia Ceger, Natalia Garcia-Reyero Vinas, David Allen, Elyssa Arnold, Raanan Bloom, Jennifer C. Brennan, Carol Clarke, Karen Eisenreich, Kellie Fay, Jonathan Hamm, Paula F.P. Henry, Katherine E. Horak, Wesley Hunter, Donna Judkins, Patrice Klein, Nicole Kleinstreuer, Kara Koehrn, Carlie A. Lalone, James P. Laurenson, Jessica K. Leet, Anna Lowit, Scott G. Lynn, Teresa Norberg-King, Edward J. Perkins, Elijah J. Petersen, Barnett A. Rattner, Catherine S. Sprankle, Thomas Steeger, Jim E. Warren, Sarah Winfield, Edward Odenkirchen

United States Department of Agriculture Wildlife Services: Staff Publications

U.S. regulatory and research agencies use ecotoxicity test data to assess the hazards associated with substances that may be released into the environment, including but not limited to industrial chemicals, pharmaceuticals, pesticides, food additives, and color additives. These data are used to conduct hazard assessments and evaluate potential risks to aquatic life (e.g., invertebrates, fish), birds, wildlife species, or the environment. To identify opportunities for regulatory uses of non-animal replacements for ecotoxicity tests, the needs and uses for data from tests utilizing animals must first be clarified. Accordingly, the objective of this review was to identify the ecotoxicity test data …

Defining An Epidemiological Landscape That Connects Movement Ecology To Pathogen Transmission And Pace-Of-Life, Kezia Manlove, Mark Wilber, Lauren White, Guillaume Bastille-Rousseau, Anni Yang, Marie L.J. Gilbertson, Meggan E. Craft, Paul C. Cross, George Wittemyer, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Pathogen transmission depends on host density, mobility and contact. These components emerge from host and pathogen movements that themselves arise through interactions with the surrounding environment. The environment, the emergent host and pathogen movements, and the subsequent patterns of density, mobility and contact form an ‘epidemiological landscape’ connecting the environment to specific locations where transmissions occur. Conventionally, the epidemiological landscape has been described in terms of the geographical coordinates where hosts or pathogens are located. We advocate for an alternative approach that relates those locations to attributes of the local environment. Environmental descriptions can strengthen epidemiological forecasts by allowing for …

Polar Alignment Of Massive Retrograde Circumbinary Discs, Charles Abod

UNLV Theses, Dissertations, Professional Papers, and Capstones

To understand the observed circumbinary planetary systems, we must first explain the dynamics of the circumbinary discs in which they formed. Observations of circumbinary discs show that misalignments to the binary orbital plane may be common. Here we investigate these systems by exploring the orbital dynamics of three-body systems and circumbinary discs. A test particle orbit around an eccentric binary has two stationary states in which there is no nodal precession: coplanar and polar. Nodal precession of a misaligned test particle orbit centres on one of these stationary states. A low mass circumbinary disc undergoes the same precession and moves …

Monte Carlo Simulation Of Thallium-Bromide Semiconductor Detector For Range Verification Of A Carbon Ion Radiotherapy Beam Through Prompt Gamma-Ray Detection, Peter Dimpfl

UNLV Theses, Dissertations, Professional Papers, and Capstones

Thallium-Bromide is a semiconductor material which is well suited for photon detection. Composed of high atomic number elements and a high mass density of 7.56 g/cm3, TlBr has superb photon stopping power. External beam radiation therapy is an ever-changing environment with technology rapidly improving. With proton therapy facilities becoming more widely available, and carbon ion facilities showcasing the benefits of carbon ion radiation therapy, there is an industry need toprovide accurate dosimetric treatment plans to verify patients are receiving proper care. Current clinical practices apply safety margins to clinical target volumes to safe treatment. Through research to improve detection techniques, …

Antler Foreland Basin Evolution Recorded In Detrital Zircon U-Pb Geochronology, James Duncan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Antler orogeny was a Devonian-Mississippian (375-320 Ma) mountain building event that occurred along the western Laurentian margin. The initiation of the Antler orogeny is marked by the emplacement of the Roberts Mountain Allochthon (RMA) that thrust Cambrian-Devonian deep water marine siliciclastic rocks 100 km eastward onto the western Laurentian margin. Shortening related to the Antler orogeny deformed RMA strata and caused a flexural response in the continental crust that resulted in the formation of the adjacent Antler Foreland basin. The paleogeographic history of the RMA strata and tectonic drivers for the Antler orogeny are still debated. Proposed models suggest …

Dissolution And Electrochemical Recovery Of Uo2, Uo3, And U3o8 In Ionic Liquids, Katherine Iolani Thornock Luebke

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research explores a novel method of increasing the solubility of uranium oxides and other actinide oxides in room temperature ionic liquids (IL) using direct dissolution. The goal is to further expand our knowledge of actinide dissolution and possible nuclear fuel cycle material applications using ionic liquids. The novelty of the methods is focused on the use of oxidizing gas generated using air passed through an ozone generator. While examples of dissolution exist in IL using acidic functionalized ionic liquids, the solubility of all possible oxide species was not demonstrated. Also, the addition of aqueous acid to IL containing actinide …

Hyperspectral Image Analysis Of Food For Nutritional Intake, Shirin Nasr Esfahani

UNLV Theses, Dissertations, Professional Papers, and Capstones

The primary object of this dissertation is to investigate the application of hyperspectral technology to accommodate for the growing demand in the automatic dietary assessment applications. Food intake is one of the main factors that contribute to human health. In other words, it is necessary to get information about the amount of nutrition and vitamins that a human body requires through a daily diet. Manual dietary assessments are time-consuming and are also not precise enough, especially when the information is used for the care and treatment of hospitalized patients. Moreover, the data must be analyzed by nutritional experts. Therefore, researchers …

Source And Parental Melts Of Poikilitic Shergottites: Implications For Martian Magmatism, Evan W. O'Neal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Martian poikilitic shergottite meteorites are cumulate rocks that can be used to understand melt evolution on Mars from the bottom of the crust (~10 kbar) all the way up to near-surface shallow depths (~1 kbar). There is a general lack of knowledge regarding shergottites including, parental magma compositions, crystallization ages, and the location of the enriched geochemical source of the shergottites in the martian mantle. Through a comprehensive petrographic and geochemical study, we have attempted to better understand poikilitic shergottite formation and the evolution of the martian interior during the Amazonian period (~3 Ga – present day). We studied a …

The Application Of Detrital Zircon Geochronology, Pressure-Temperature Modeling, Monazite Petrochronology, And Quartz-In-Garnet Elastic Geobarometry To The Tectonic Evolution Of The Funeral Mountains And Related Metamorphic Core Complexes, Suzanne Renae Mulligan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation investigates and applies different techniques for studying mid-crustal metamorphic rocks including detrital zircon geochronology, monazite petrochronology, thermodynamic pressure-temperature modeling, and elastic geobarometry. The first chapter reconstructs stratigraphy in deformed metamorphic rocks from the Funeral Mountains metamorphic core complex in Death Valley, California, and the Bullfrog Hills, Nevada, using U-Pb detrital zircon (DZ) geochronology. This study documents another successful application of stratigraphic techniques applied to metamorphic rocks and migmatites. DZ geochronology identified Pahrump Group metasediments in rocks that were previously interpreted to be Paleoproterozoic basement gneisses, providing insights into the distribution of Rodinia rift basins. This analysis has shown …

Reachability And Turn Constraint Paths, Sabrina Wallace

UNLV Theses, Dissertations, Professional Papers, and Capstones

Problems dealing with the development of efficient algorithms for constructing collision-free paths have been explored extensively. We review existing algorithms for constructing collision-free paths under turn-angle constraints. We examine the problem of computing collision-free paths in the presence of polygonal obstacles. We present an algorithm for identifying the placement of a source vertex so that the maximum number of obstacle vertices can be reached via the shortest path tree under turn-angle requirements. We also present some experimental results on the construction of collision-free paths in the presence of polygonal obstacles.

Toward A Conceptual Approach To The Coriolis Force: Cataloging Intuitive Knowledge Elements In Intermediate Physics Learners, Jared B. Arnell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In Physics, the topic of the Coriolis force is often confusing and difficult to teach. I conducted a series of interviews with undergraduate physics students to understand how they would use their prior knowledge and personal experiences to interact with and navigate through a new conceptual teaching approach for the Coriolis force. Many students applied their intuitive understanding of balance to interpret and make predictions about the Coriolis force. Some students displayed a strong conviction that rotating objects will naturally get pulled outward, which suggests that this impression may be a useful tool for novice physics learners to use in …

A Dynamic Relationship With Wilderness: Comparing Day And Multi-Day Visitors' Indicators Of Quality In Wilderness Settings, Caleb Meyer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The length of stay in wilderness areas is declining and, in many areas, day visitors comprise most of all use. Most prior research exploring this trend took place in the 1990s and few studies of wilderness visitation account for the increase in outdoor recreation participation over the last decade. Lack of understanding surrounding this trend raises questions about managerial and philosophical approaches to the recreation-wilderness relationship. This study explored these topics within visitor use management approaches used by the National Park Service, which manages the proposed Glen Canyon Wilderness, near Escalante, Utah, where this research took place.

Results of this …

Syntax Exercises And Their Effect On Computational Thinking, Marina Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Abstract—Job opportunities and the need for programmers are increasing. Companies are looking for new hires who have the ability to learn how to learn, who have computational thinking skills. Student dropout rate in computer science is the highest among college majors. Educators are striving to find a way to teach efficiently and effectively the technical and the problem solving skills students need. In this paper we will be studying the effects of syntax exercises on a subject’s ability to think computationally and precisely. We tested our process on professionals and students. Half of the professionals were in the computer science …

Extensions To The Syrjala Test With Eye-Tracking Data Analysis Applications In R, Eric D. Mckinney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Eye tracking is a process for measuring the movement of an individual’s eye(s) when that individual is looking at something. Many eye-tracking technologies exist to aid in calculating and recording data associated with what a person focuses their visual attention on. For example, eye-tracking technology can record points on an image that a person is looking at. Often the question arises as to whether two people, or groups of people, are looking at the same thing(s). This dissertation presents a new way (or test) to quantify those differences while taking into consideration the randomness associated with such data. Hence, the …

The Effect Of Species Choice, Seed Mix Composition, And Microtopography On Native Plant Restoration In Great Salt Lake Wetlands, Coryna Hebert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wetlands are important ecosystems that improve water quality, prevent floods, and provide wildlife habitat. As such, restoring native plants that promote wetland health is a high priority for land managers. However, there are many challenges to the restoration of native plants. In our study system (Great Salt Lake wetlands), many areas are invaded by the European grass, Phragmites australis. Phragmites grows in dense stands and displaces native plants. The reduction of native plant communities in Great Salt Lake wetlands is a major concern because these ecosystems provide habitat for millions of native birds. Managers have made successful efforts to …

On Continuity Of Multiplication In The Fundamental Group, Eric Steadman

Theses and Dissertations

For a topological space X, the fundamental group can be topologized as a quotient of the path space with the compact-open topology. For one-dimensional or planar Peano continua, the fundamental group with this topology is a topological group if and only if it is semilocally simply connected. In particular, we demonstrate that the group operation is not continuous in this setting.

Identification And Quantitation Of Unspecified Impurities Discovered In Novel Oral Irinotecan By Lc-Ms/Ms And Uhplc, Laura B. Miller

Forensic Science Master's Projects

Irinotecan is a cancer medication approved for medical use in the United States in 1996. It is currently administered via intravenous injection. However, intravenous dosing has disadvantages such as requirement of administration by a trained professional in a medical facility, possible severe adverse effects, pain at the injection site, and possible hemolysis if injected too rapidly. Previously oral administration was not feasible because the p-glycoprotein (p-GP) on the cell membrane of stomach cells acts as a defense mechanism against harmful substances by pumping the irinotecan back into the intestinal lumen for excretion. With the discovery of the p-GP inhibitor encequidar …