Physical Sciences and Mathematics Commons^™

Information And Hardness Quantification Of Graphs: A Computational Study, Brent Dutson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

New techniques to measure the information contained within a network of interconnected nodes (such as links between computers in the Internet) have recently been developed. This work studies the relationship between the computer time needed to solve a common network problem and the information contained within the given network.

Multiplicity Results Of Periodic Solutions For Two Classes Of Nonlinear Problems, Kazuya Hata

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We investigate the existences and qualitative properties of periodic solutions of the following two classes of nonlinear differential equations:

I) (Special) Relativistic Pendulum Equations (RPEs);

II) (2-coupled) Gross-Pitaevskii Equations (GPEs).

The pendulum equation describes the motion of a pendulum. According to Special Relativity, which was published by A. Einstein in 1905, causality is more fundamental than constant time-space, thus time will flow slower and space will distort to keep causality if the speed of motion is near the speed of light. In such high speed situations, the pendulum equation needs to be revised due to Special Relativity. The revised equation …

Improving Reuse And Maintainability Of Communication Software With Conversation-Aware Aspects, Ali Raza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Inter-process communications (IPC) are ubiquitous in today’s software systems, yet they are rarely treated as first-class programming concepts. Implementing crosscutting concerns for message-based IPC are difficult, even using aspect-oriented programming languages (AOPL) such as AspectJ. Many of these challenges are because the context of a communication-related crosscutting concern is often a conversation consisting of message sends and receives. Hence, developers typically have to implement communication protocols manually using primitive operations, such as connect, send, receive, and close. This dissertation describes an extension to AspectJ, called CommJ, with which developers can implement communication-related concerns in cohesive and loosely coupled aspects. It …

Understanding Local Perceptions And The Role Of Historical Context In Ecotourism Development: A Case Study Of St. Kitts, Amber Greening

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecotourism is a popular tool for the conservation of fragile ecosystems and local development of the communities surrounding them. It is widely argued that the key to effective and sustainable ecotourism programs relies on the depth of community involvement and support. This research reveals a better understanding of community members’ perceptions of ecotourism and conservation, and how these perceptions potentially influence participation in current and future ecotourism projects within the villages of Cayon and Keys on the Caribbean island of St. Kitts. Data were collected through several qualitative methods including: face-to-face surveys with Cayon and Keys villagers; interviews with government …

Exploring Visitor Attitudes Toward The Proposed Greater Canyonlands National Monument: A Survey In Utah's Indian Creek Corridor, Chase C. Lamborn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In August of 2012, the Outdoor Industry Association (OIA) sent a letter to President Barack Obama asking him to designate the Greater Canyonlands National Monument (GCNM). The proposed 1.4 million acre national monument would surround the already present 337,570 acre Canyonlands National Park, and would include public lands/waterways from five Utah counties. The OIA’s goal for the GCNM is to preserve the landscape for quality outdoor recreation by decreasing the amount of off-highway vehicle use and to eliminate the possibility of oil/gas drilling and mining. Given the proposal highlights outdoor recreation use benefits as the main catalyst for justification of …

Rock Strength Of Caprock Seal Lithologies: Evidence For Past Seal Failure, Migration Of Fluids And The Analysis Of The Reservoir Seal Interface In Outcrop And The Subsurface, Elizabeth Sandra Petrie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Scientists have proposed that in order to avoid damaging climate change further accumulations of anthropogenic atmospheric carbon dioxide (CO₂) must be limited. One of several proposed techniques for reducing the amount CO₂ reaching the atmosphere is carbon capture and storage (CCS). This emerging technology stores CO₂ Emissions captured from large point sources (i.e. power plants or industrial facilities), in deep geologic formations, including depleted hydrocarbon reservoirs and saline aquifers. For successful CCS design, implementation and appropriate site selection and subsurface trapping mechanisms must be ensured over the 100's to 1000's of year timescale.

A key component …

Traditional Lecture Versus An Activity Approach For Teaching Statistics: A Comparison Of Outcomes, Jennifer L. Loveland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many educational researchers have proposed teaching statistics with less lecture and more active learning methods. However, there are only a few comparative studies that have taught one section of statistics with lectures and one section with activity-based methods; of those studies, the results are contradictory. To address the need for more research on the actual effectiveness of active learning methods in introductory statistics, this research study was undertaken.

An introductory, university level course was divided into two sections. One section was taught entirely with traditional lecture. The other section was taught using active learning methods and a minimal amount of …

Detailed Analysis Of The Domains Of Mtr4 And How They Regulate Helicase Activity, Lacy Leigh Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The central dogma states that DNA is transcribed into RNA, which is then translated into protein. This concept conveys a minimal view of the role of RNA, portraying it simply as an intermediary between DNA and protein. However, it is now known that the role of RNA in the cell is critical in regulating protein expression both directly and indirectly. RNA in the cell typically goes through modifications to become active (on) and inactive (off) to eventually become targeted for degradation and start the cycle all over again. The protein complex that regulates the proper maturation and degradation of RNA …

Computational Topics In Lie Theory And Representation Theory, Thomas J. Apedaile

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The computer algebra system Maple contains a basic set of commands for working with Lie algebras and matrices. The purpose of this thesis was to extend the functionality of these Maple packages in a number of important areas. First, programs for defining multiplication in several different types of algebras were created to allow users to perform a wider variety of calculations. Second, commands were created for calculating some basic properties of matrix representations of semisimple Lie algebras. This allows a user to identify a given matrix representation by a collection of integers which do not change when the basis of …

Hamiltonicity, Pancyclicity, And Cycle Extendability In Graphs, Deborah C. Arangno

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A significant portion of Graph Theory is devoted to determining the characteristics which guarantee the existence of long cycles.

Long cycles have roles in applications to civil engineering, chemistry, and communications, among many others, but the problem, in and of itself, of determining whether a graph has a cycle of some fixed and typically large length is one of the most important problems of both pure Mathematics and Computer Science.

A cycle containing all the vertices of the graph is called a Hamiltonian cycle, and a graph which possesses such a cycle is said to be Hamiltonian. If …

A Computer-Aided Training (Cat) System For Short Track Speed Skating, Chenguang Liu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Short track speed skating was adopted by the International Skating Union in 1967, and upgraded to full winter Olympic sport status in 1992. Even though its history is short compared with long track speed skating, it became popular around the world because it is more intense and more entertaining for audiences. The demands of having a CAT system for gathering and analyzing competition data automatically is raising drastically due to its growing popularity all around the world.

There have been some commercial systems for some other sports, which are able to provide extrinsic feedback information to coaches and athletes. However, …

Pathway Pioneer: A Web-Based Metabolic Network Layout Extension, Harsh Dosi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The number and complexity of genome-scale metabolic networks have seen a rapid growth in the past 10 years. Today, more than 450 genome-scale metabolic reconstructions of biological systems are characterized and existing models are extended. With the growing influence of these reconstructions on biomedical and biological research, the field has observed a shift from an inward focus on method development to an outward focus on application development.

Static state analysis of metabolic networks in textual format is too cumbersome and time consuming. In addition, visualization and arrangement of these networks to facilitate their analysis is an open research problem. A …

Network Applications And The Utah Homeless Network, Michael A. Snyder

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Graph theory is the foundation on which social network analysis (SNA) is built. With the flood of "big data," graph theoretical concepts and their linear algebraic counterparts are essential tools for analysis in the burgeoning field of network data analysis, in which SNA is a subset. Here we begin with an overview of SNA. We then discuss the common descriptive measures taken on network data as well as proposing new measures specific to homeless networks. We also define a new data structure which we call the location sequence matrix. This data structure makes certain computational network analyses particularly easy. …

A 576-Year Weber River Streamflow Reconstruction From Tree Rings For Water Resource Risk Assessment In The Wasatch Front, Utah, Matthew F. Bekker, R. Justin Derose, Brendan Buckley, Roger Kjelgren, Nathan S. Gill

Wasatch Dendroclimatology Research

We present a 576-year tree-ring-based reconstruction of streamflow for northern Utah's Weber River that exhibits considerable interannual and decadal-scale variability. While the 20th Century instrumental period includes several extreme individual dry years, it was the century with the fewest such years of the entire reconstruction. Extended droughts were more severe in duration, magnitude, and intensity prior to the instrumental record, including the most protracted drought of the record, which spanned 16 years from 1703 to 1718. Extreme wet years and periods are also a regular feature of the reconstruction. A strong early 17th Century pluvial exceeds the early 20th Century …

Tree-Ring Reconstruction Of The Level Of Great Salt Lake, Usa, R. Justin Derose, Shih-Yu (Simon) Wang, Brendan M. Buckley, Matthew F. Bekker

Wasatch Dendroclimatology Research

Utah’s Great Salt Lake (GSL) is a closed-basin remnant of the larger Pleistocene-age Lake Bonneville. The modern instrumental record of the GSL-level (i.e. elevation) change is strongly modulated by Pacific Ocean coupled ocean/atmospheric oscillations at low frequency, and therefore reflects the decadalscale wet/dry cycles that characterize the region. A within-basin network of seven tree-ring chronologies was developed to reconstruct the GSL water year (September–August) level, based upon the instrumental record of GSL level from 1876 to 2005. The result was a 576-year reconstruction of the GSL level that extends from 1429 to 2005; all calibration-verification tests commonly used in dendroclimatology …

Lessons Learned From The Statistical Analysis Of Measurements Of The Energetic Electron Bombardment Of Epoxy ‘Glue Dots, Justin Christensen, Justin Dekany, Jr Dennison

Presentations

No abstract provided.

Perihelion Precession In General Relativity, Charles G. Torre

Charles G. Torre

This is a Maple worksheet providing a relatively quick and informal sketch of a demonstration that general relativistic corrections to the bound Kepler orbits introduce a perihelion precession. Any decent textbook will derive this result. My analysis aligns with that found in the old text "Introduction to General Relativity", by Adler, Bazin and Schiffer. The plan of the analysis is as follows. * Model the planetary orbits as geodesics in the (exterior) Schwarzschild spacetime. * Compute the geodesic equations. * Simplify them using symmetries and first integrals. * Isolate the differential equation expressing the radial coordinate as a function of …

Stochastic Variations Of Cathodoluminescent Intensity Of Bisphenol/Amine Epoxy Exposed To Energetic Electron Bombardment, Justin Christensen, Justin Dekany, Jr Dennison

Presentations

When highly disordered insulating materials are subjected to energetic electron bombardment they can emit photons. This process is termed “cathodoluminescence.” This occurs in the space plasma environment and is an important phenomenon to understand when designing any object to be put into space. Light emitted from spacecraft materials can affect optical detection, and can cause stray-light contamination in space-based observatories. The Materials Physics Group at Utah State University uses an ultra-high vacuum chamber equipped with electron guns and a cryostat to control the sample temperature to simulate the space environment and to observe its affects on sample materials. Previous studies …

Simulation Of Uv Radiation Degradation Of Polymers On Misse-6 In The Low Earth Orbit Environment, Philip Lundgreen, Justin Dekany, Jr Dennison

Presentations

Using a high-Voltage Battery power Supply, we measured the time dependent conductivity for highly disorganized materials, and were able to model the complete conductivity curve for said materials. Previous methods were utilized and improved upon to decrease the error found in conductivity measurements through an “extremely resistive” materials. The data was subsequently analyzed using various curve fitting techniques to measure time taken for a sample to reach conductive equilibrium. The fittings were also used to predict the amount of time required for a sample to completely discharge after it had been fully charged. The objective of this study was to …

Electrostatic Discharge Breakdown Analyses, Sam Hansen, Jr Dennison, Allen Andersen

Presentations

Electrostatic discharge (ESD) and the associated material breakdown is the primary cause for spacecraft damage due to space environment interactions. This phenomenon occurs when the space plasma fluxes charge a craft to high voltages where insulating materials then break down and conduct current. This can damage or destroy onboard electrical systems. This project deals with how suspect materials break down under high voltage exposure. The USU Material Physics Group has acquired hundreds of samples that underwent ESD. The ESD damage sites of these samples have been analyzed for parameters including breakdown size, shape, coloring, and location and material characteristics such …

Mapping The Lower Bear River Cross Section, Megan Gordon, Jordan Floyd, Ayman Alafifi, David E. Rosenberg

Spring Runoff Conference

The lower Bear River plays a large agricultural and socioeconomic role within the Cache Valley. Studying changes in the River’s flow, depth, surrounding vegetation, and river cross section is absolutely imperative in that these changes can have large impacts on the valley’s agricultural and economic well-being. The purpose of this cross section data study is to map the geometry of different portions of the Lower Bear River to be able to compare the data from year to year to understand how the changes in the river cross section correlate with seasonal variation of river flow. We obtained data through setting …

Stage-Flow Relationship And Seasonal Fluctuations In Flow Of The Lower Bear River, Taylor Dudunake, Isaac Robertson, Ayman Alafifi, David E. Rosenberg

Spring Runoff Conference

The Bear River Fellows Program within the Department of Civil and Environmental Engineering at Utah State University was funded through the National Science Foundation. We extended the data analysis of the previous year’s research at three different sites within the Lower Bear River Basin between the Idaho-Utah state line and Cutler Reservoir on two separate occasions, August 13-16, 2013 and November 16, 2013. Our work included collecting river stage, flow, and water pressure measurements using standard surveying equipment, an Acoustic Doppler Current Profiler (ADCP), and pressure transducers. Part of the objective of each trip was to fill out the relationship …

Mapping Inflows, Diversions, And Vegetation Along The Lower Bear River Basin, Amberlee Burrows, Leah Langdon, Ayman Alafifi, David E. Rosenberg

Spring Runoff Conference

The Department of Civil and Environmental Engineering at Utah State University (USU), through a National Science Foundation project, has partnered with the Outdoor Recreation, and Parks and Recreation programs at USU to offer the Bear River Fellows Program - a unique river-based experiential learning opportunity for 6 freshmen Fellows to receive first-hand experience in collecting, synthesizing and analyzing environmental and ecological data. Part of these objectives included observing plant composition over time as well as measuring inflows to and diversions from the river. We collected field measurements such as flow measurements and channel cross section topology and examined environmental and …

Shaping Carbon Nanotube Forests For Field Emission, Benjamin Pound

Student Showcase

Field emission is a phenomenon where electrons are extracted from a conducting material by an external electric field. This effect has been used for electron sources for many applications, from electron microscopes to flat-panel displays. One undesirable feature of field emitters is that they often require high turn-on voltages. One way to improve the field emission is to decrease the tip size. In previous works, single carbon nanotubes (CNTs) with nanometer tip sizes have been used as field emitters, and have achieved currents comparable or higher than commercial field emitters at relatively low operating voltages. However, the single CNT field …

Faraday Cup Designs For High Efficiency Determination Of Energy- And Angular-Resolved Charged Particle Fluxes, Kent Hartley, Jr Dennison

Senior Theses and Projects

In order to build a spacecraft, we must understand how the construction materials will behave in the space environment (i.e. when subjected to the solar wind). The USU Materials Physics Group performs electron emission tests on spacecraft materials in an Ultra-high vacuum (UHV) test chamber (Fig.1). The chamber utilizes Faraday cups (Fig.2) in order to quantify electron flux at a location within the chamber. This measurement is important in characterizing beam profiles of electron guns used in UHV experiments. Perhaps more importantly, the Faraday cups are used to detect secondary electrons (SE) and back-scattered electrons (BSE) emitted from the surface …

Creating An Electronic Analog Of A Stomatal Network, David Berg

Physics Capstone Projects

Stomata are microscopic variable aperture pores on the surfaces of leaves. In response to different environmental stimuli, they control the exchange rate of both water vapor and carbon dioxide between the air and the leaf interior, making their role an important determination of the status of plant life on Earth. This study is based on a recently developed stomatal model in which the aperture size is governed by vapor phase humidity. The study describes an electronic analog of the stomatal unit; in it, current models water flow, a transistor represents the variable resistance of the stomatal aperture, capacitor voltages represent …

Ensemble Modeling With Data Assimilation Models: A New Strategy For Space Weather Specifications, Forecasts, And Science, Robert W. Schunk, Ludger Scherliess, V. Eccles, Larry Gardner, Jan Josef Sojka, L. Zhu, X. Pi, A. J. Mannucci, B. D. Wilson, A. Komjathy, C, Wang, G. Rosen

All Physics Faculty Publications

The Earth’s Ionosphere-Thermosphere-Electrodynamics (I-T-E) system varies markedly on a range of spatial and temporal scales and these variations have adverse effects on human operations and systems, including high-frequency communications, over-the-horizon radars, and survey and navigation systems that use Global Positioning System (GPS) satellites. Consequently, there is a need to elucidate the underlying physical pro- cesses that lead to space weather disturbances and to both mitigate and forecast near-Earth space weather.

Ionospheric Ion Temperature Forecasting In Multiples Of 27 Days, Jan Josef Sojka, Robert W. Schunk, Michael J. Nicholls

All Physics Faculty Publications

he ionospheric variability found at auroral locations is usually assumed to be unpredictable. The magnetosphere, which drives this ionospheric variability via storms and substorms, is at best only qualitatively describable. In this study we demonstrate that over a 3 year period, ionospheric variability observed from Poker Flat, Alaska, has, in fact, a high degree of long-term predictability. The observations used in this study are (a) the solar wind high speed stream velocity measured by the NASA Advanced Composition Explorer satellite, used to define the corotating interaction region (CIR), and (b) the ion temperature at 300 km altitude measured by the …

Simulation Of Uv Induced Discoloration On Space Polymers, Kelby T. Peterson, Jr Dennison

Presentations

No abstract provided.

Coordinated Investigation Of Midlatitude Upper Mesospheric Temperature Inversion Layers And The Associated Gravity Wave Forcing By Na Lidar And Advanced Mesospheric Temperature Mapper In Logan, Utah, Tao Yuan, Pierre-Dominique Pautet, Y. Zhao, Xuguang Cai, Michael J. Taylor, Neal R. Criddle

All Physics Faculty Publications

Mesospheric inversion layers (MIL) are well studied in the literature but their relationship to the dynamic feature associated with the breaking of atmospheric waves in the mesosphere/lower thermosphere (MLT) region are not well understood. Two strong MIL events (ΔT ~30 K) were observed above 90 km during a 6 day full diurnal cycle Na lidar campaign conducted from 6 August to 13 August Logan, Utah (42°N, 112°W). Colocated Advanced Mesospheric Temperature Mapper observations provided key information on concurrent gravity wave (GW) events and their characteristics during the nighttime observations. The study found both MILs were well correlated with the development …