Physical Sciences and Mathematics Commons^™

Numerical Approximation Of Lyapunov Exponents And Its Applications In Control Systems, Nakita K. Andrews

Electronic Theses and Dissertations

The progression of state trajectories with respect to time, and its stability properties can be described by a system of nonlinear differential equations. However, since most nonlinear dynamical systems cannot be solved by hand, one must rely on computer simulations to observe the behavior of the system. This work focuses on chaotic systems. The Lyapunov Exponent (LE) is frequently used in the quantitative studies of a chaotic system. Lyapunov exponents give the average rate of separation of nearby orbits in phase space, which can be used to determine the state of a system, e.g. stable or unstable. The objective of …

Advancements In Bio-Based Novel (Co)Monomers For Polymeric Materials, Khristal Anne Monroe

Electronic Theses and Dissertations

Most current research in the area of sustainable and environmentally friendly materials relate to the use of renewable sources for the fabrication of bio-based polymers and composites. Using plant-based derivatives is a common strategy. Pine sap can be distilled into turpentines (light fraction) and pine rosin (heavy fraction). Pine rosin is obtained as a brittle solid and its major component is abietic acid. This project aims at investigating a synthetic approach for the synthesis of a pine rosin-based polymer that can be potentially used for manufacturing a collection device for pine sap. The synthetic strategy consisted in the preparation of …

Design, Synthesis And Applications Of Nanoparticles In Suppression Of Mosquito-Born Flaviviridae Viruses, Maria R. Blahove

Electronic Theses and Dissertations

Recently, nanoparticles have become an origin of exploration in the chemistry field due to their unique medical uses. The current drug delivery models of nanoparticles often include a metal base with a drug conjugated to its surface. However this raises concerns regarding toxicity. A novel approach to solving this dilemma is the development of nanosized biocompatible polymer-based micelles, created from PEG-PCL-PEG triblock polymer, and formed around a drug of choice. The goal is to create a drug carrier nanoparticle system that is labile at a specific intracellular pH, without undue toxicity to the cell. This creates a drug-loaded nanoparticle that …

The Effects Of Nacl On The Triple Helix Structure Of Collagen And The Reinforcement Of Tung Oil-Based Polymers With Collagen Peptides, Christopher Dzorkpata

Electronic Theses and Dissertations

In this research, a collagen-reinforced bio-composite from tung oil was prepared using free radical initiation and thermal polymerization, leading to polyolefinic tung oil-based matrix. Two peptides (long and short) were synthesized and their secondary features were analyzed using circular dichroism spectroscopy. After this analysis, the long peptide exhibited more triple helix characteristics as compared to the short peptide. The full protein will ultimately have a better interaction with the tung oil, was used in the synthesis of the collagen-reinforced bio-composite. The presence of NaCl in the triple helix and its overall effect on the thermal and mechanical properties of the …

Hydroamidation With Acetamides And Trifluoroacetamides, Gordon H. Whitetree

Electronic Theses and Dissertations

The hydroamidation reaction is an attractive methodology for the construction of larger functional molecules. In our research, a baseline reactivity was established for the hydroamidation reaction using a set of N-alkyl and N-aryl (trifluoro)acetamides with methyl acrylate and acrylonitrile, various bases and varying reaction conditions. The combination of alkenes, acetamides, and trifluoroacetamides with base was crucial for reaction rate. N-aryl trifluoroacetamides exhibited near quantitative conversions in neat alkene with Diazabicycloundecene (DBU) as base. The less acidic N-aryl acetamides performed much faster in the presence of KOtBu and conversions of >95% were accomplished regularly but contained a large presence …

New Results On Cyclic Compositions And Multicompositions, Silvana Ramaj

Electronic Theses and Dissertations

Integer compositions, cyclic compositions, and lately k-compositions, are an important topic in combinatorics and number theory. In this paper, we will explain, the general approach of using generating functions to study number sequences involving compositions, cyclic compositions, k-compositions, and the number of parts in each of them. After generating the data, some properties are observed and proved. Also, some interesting bijections involving Pell numbers and the Jacobsthal sequence are given.

Advanced Analytical Techniques For The Analysis Of Therapeutics Of Toxic Inhalation Agents And Pharmacokinetic Investigation, Subrata Bhadra

Electronic Theses and Dissertations

Toxic inhalation agents (TIAs), (i.e., cyanide (CN) and reduced sulfur compounds (RSCs)), including hydrogen sulfide (H2S) and methanethiol (MT)) are extremely poisonous upon exposure. Many TIAs act by inhibiting mitochondrial cytochrome c oxidase, resulting in cellular hypoxia, cytotoxic anoxia, apnea, respiratory failure, cardiovascular collapse, seizure and potentially death. CN is generated in structural fires and cigarette smoke as well as in mining, electroplating and polymer processing, whereas H2S and MT are found in petroleum, oil and natural gas, waste treatment facilities and decaying organic matter. All are common occupational gas exposure hazards in chemical industries and for first responders, including …

Detailing The Connection Between A Family Of Polar Graphs And Tremain Equiangular Tight Frames, Nicholas Brown

Electronic Theses and Dissertations

The relationship between strongly regular graphs and equiangular tight frames has been known for several years, and this relationship has been used to construct many of the most recent examples of new strongly regular graphs. In this paper, we present an explicit construction of a family of equiangular tight frames using the geometry of a quadratic space over the field of four elements. We observe that these frames give rise to a strongly regular graph on a subset of points of a quadratic space over the field with 4 elements. We then demonstrate an isomorphism between this graph and a …

Evaluating And Predicting The Risk Of Algal Blooms In A Freshwater Lake Through A 4-Dimensional Approach: A Case Study On Lake Mitchell, Sumit Kumar Ghosh

Electronic Theses and Dissertations

Excessive algal growth in freshwater lakes can negatively impact ecosystems, recreation, and human health. Though algae are a natural part of freshwater ecosystems, elevated nutrient loading from anthropogenic and natural sources can lead to algal blooms. Both algae and blue-green algae (BGA) are responsible for algal blooms; however, BGA (cyanobacteria) is more dangerous. The first objective of this research was to prepare a conceptual model to understand how various environmental variables affect algae. This conceptual model was used to choose the environmental variables that help increase or decrease algae in the water environment. The second objective was to develop empirical …

Methods For High-Dimensional Spatial Data: Dimension Reduction And Covariance Approximation, Paul May

Electronic Theses and Dissertations

In spatial statistics, because quantities are correlated based on their relative positions in space, data is modeled as a single realization of a multivariate stochastic process. Spatial data can be high-dimensional either through a large number of observed variables per location, or through a large number of observed locations. The two are often handled differently, with the former addressed through dimension reduction and the latter addressed through appropriate modeling of the spatial correlation between locations. The main body of this dissertation is a three-part work. Parts 2 and 3 pertain to the "many variables" problem, proposing novel methods of dimension …

Novel Acetylcholine Chloride Based Water Immiscible Deep Eutectic Solvent: Formulation, Characterization And Application In Drug Solubilization, Shiksha Subedi

Electronic Theses and Dissertations

Deep eutectic solvents (DESs) are the emerging class of new and inexpensive solvents composed of two or three safe components capable of self-association through hydrogen bond interaction. The depression in the melting point characterizes DESs compared to those of the individual components. These solvents have properties like the traditionally used ionic liquids (ILs), but they can offset the significant drawbacks of ILs, such as biodegradability, toxicity, and complex synthesis. Due to these remarkable advantages, the research in DESs is increasing exponentially. However, current deep eutectic solvents still have limitations to apply to the real chemical industries due to hydrophilicity and …

Development And Properties Of The Roc-Abc Bayes Factor For The Quantification Of The Weight Of Forensic Evidence, Jessie Hendricks

Electronic Theses and Dissertations

Many scholars have proposed the use of a Bayes factor to quantify the weight of forensic evidence. However, due to the complex and high-dimensional nature of pattern evidence, likelihood functions are intractable and thus, Bayes factors cannot be assigned using traditional methods. Approximate Bayesian Computation (ABC) model selection algorithms provide likelihood-free methods to assign Bayes factors. ABC Bayes factors leverage the use of the scoring functions commonly used in recent years in forensic statistics in a rigorous statistical manner. However, traditional methods for assigning ABC Bayes factors are subject of several criticisms. In this dissertation, one of the main criticisms …

The Effects Of Saline Soil On Microbiome And The Isolation Of Root-Associated Microbes To Relieve Salinity Stress, Duncan Jakubowski

Electronic Theses and Dissertations

Increasing levels of salinity in once-viable lands for crop production is a serious and growing problem in the Northern Great Plains. The objectives of this study were to determine the effects of saline soil on the microbial composition of plant roots and bulk soil, to measure metabolic changes in plant roots from saline soil, to determine the viability of root-associated microbes as inoculants to increase stress tolerance in plants, as well as determine the impact of saline soil on nitrogen cycling genes linked to greenhouse gas production. This study hypothesizes that high soil salinity levels have a significant impact on …

College Students Conceptions Of Particulate Nature Of Matter And The Impact On Research Instrumentation, Bridget Klutse

Electronic Theses and Dissertations

The main objective of this research was to explore the understanding and conceptions of Particulate Nature of Matter (PNM) with Chem 115 L students as the participants. Conceptions were defined specifically as beliefs and alternative beliefs about topics. The research also assessed the impact of analytical instrumentation in the chemistry laboratory on learning chemistry concepts. Eight questions (8) with multiple choice answers were administered to 10 students at the beginning and after the Fall 2018 semester via selective/purposeful sampling. Data were collected using surveys (pre- and post-surveys) and interviews (pre- and postinterviews), then analyzed quantitatively and qualitatively. The eight questions …

A Study Of Geographic Information System-Based Watershed Processing For Hydrologic Analysis Of Ungauged Watersheds, Philip Adanbe Adalikwu

Electronic Theses and Dissertations

The increasing application of geographic information system (GIS) technology in watershed modeling makes is necessary to further evaluate its impacts on runoff characteristics as a basis for improved hydrologic analysis in ungauged watersheds. Experts in the field of water resources and hydrology have recommended the practice of subdivision when modeling a watershed, and the use of observed data from hydrologically similar watershed to calibrate and validate an ungauged watershed’s model. However, previous studies have failed to adequately address the issues of watershed heterogeneity, spatial and temporal variability in physical parameters, GIS data resolution issues, including artifacts in automated extraction of …

Human Activity Recognition Based On Wearable Flex Sensor And Pulse Sensor, Xiaozhu Jin

Electronic Theses and Dissertations

In order to fulfill the needs of everyday monitoring for healthcare and emergency advice, many HAR systems have been designed [1]. Based on the healthcare purpose, these systems can be implanted into an astronaut’s spacesuit to provide necessary life movement monitoring and healthcare suggestions. Most of these systems use acceleration data-based data record as human activity representation [2,3]. But this data attribute approach has a limitation that makes it impossible to be used as an activity monitoring system for astronavigation. Because an accelerometer senses acceleration by distinguishing acceleration data based on the earth’s gravity offset [4], the accelerometer cannot read …

A Hydrologic Climate Study For An Arid Region, Ali Alsubeai

Electronic Theses and Dissertations

Water is the most precious natural resource in arid regions due to the limitation of water resources, expanding population, and increasing volumes of industrial and domestic waste. The purpose of this research was to evaluate methods to estimate water quantity in an arid region. The research consisted of three separate studies. In the first study, hydrologic models used to estimate water quantity were evaluated for suitability of use in arid regions. Most hydrologic models that have been used in arid regions were originally developed for humid regions. Rainfall events in arid regions can be characterized as short-term, high intense rainstorms …

Effects Of Harvest Regulations And Post-Release Hooking Mortality On Walleye Populations In South Dakota, Cade Lyon

Electronic Theses and Dissertations

Harvest regulations are commonly implemented to manipulate fisheries stocks. By regulating the size and number of fish that are harvested by anglers, managers are able to meet the goals and needs of regions. However, these management actions come with the potential for negative consequences. Overexploitation due to less restrictive harvest regulations can cause collapses in fisheries populations. In addition, indirect consequences such as hooking mortality brought on by length-based regulations can also be detrimental to populations. In this study, I investigated the effects of various harvest regulations on Walleye populations in three western South Dakota irrigation reservoirs: Angostura, Belle Fourche, …

Cascaded Deep Learning Network For Postearthquake Bridge Serviceability Assessment, Youjeong Jang

Electronic Theses and Dissertations

Damages assessment of bridges is important to derive immediate response after severe events to decide serviceability. Especially, past earthquakes have proven the vulnerability of bridges with insufficient detailing. Due to lack of a national and unified post-earthquake inspection procedure for bridges, conventional damage assessments are performed by sending professional personnel to the onsite, detecting visually and measuring the damage state. To get accurate and fast damage result of bridge condition is important to save not only lives but also costs.
There have been studies using image processing techniques to assess damage of bridge column without sending individual to onsite. Convolutional …

Pheasant Ecology In An Agricultural Landscape Of South Dakota, Sprih Harsh

Electronic Theses and Dissertations

Habitat loss and fragmentation are the greatest threats to wildlife conservation. Grasslands are among the most threatened ecosystems worldwide. The large-scale conversion of North American grasslands to cultivation has been strongly associated with declines of grassland bird populations. The ring-necked pheasant (Phasianus colchicus) is a common grassland bird which is negatively impacted by the conversion of grassland to cropland. Though pheasants are non-native to South Dakota, they have become naturalized in most of the state. However, with increases in agricultural intensification in South Dakota, indices of pheasant abundance from brood route surveys suggest that pheasant populations have declined to historically …

An Evaluation Of The Bighorn Sheep Population In Badlands National Park, Austin J. Wieseler

Electronic Theses and Dissertations

Within the last century, bighorn sheep (Ovis canadensis) in the badlands ecosystem of western South Dakota have been subjected to complete extirpation, reintroduction, disease die-offs, genetic bottlenecking, and population augmentation. Subsequently, the population in Badlands National Park (BNP) appears to have recovered, but it was unknown to what degree past events had influenced the population. From 2017-2019, we conducted research on 5 subherds within 2 management units in BNP to 1) survey for the presence of respiratory pathogens and estimate the prevalence of other potentially infectious diseases; 2) assess adult and lamb survival and cause-specific mortality; 3) estimate population size …

Exploring The Determinants Of Aspects Of Rotational Grazing In The U.S. Great Plains, Iftekhar Uddin Ahmed Chowdhury

Electronic Theses and Dissertations

Pasture and rangeland make up about 45 percent of the agricultural land in the U.S. Great Plains and one of the most common form of mismanagement of this pasture is overgrazing. Which results in many detrimental effects on environment. Many practitioners endorsed Rotational grazing (RG) as an improved grazing management practice over season-long continuous grazing. The overall goal of the current study is to assess the certain aspects of using RG in the U.S. Great Plains. Using mail survey data of the of 874 beef cattle producers of North Dakota, South Dakota, and Texas, the study found that neighborhood practice, …

A Grounded Theory Inquiry Into The Pedagogical Socialization Of Graduate Students Within Graduate Quantitative Methods Courses, Amanda Kay Thomas

Electronic Theses and Dissertations

Quantitative methods are one of the most highly technical fields of study within social sciences graduate programs. Although classroom pedagogy is an important factor connected to student success within graduate quantitative methods courses little is known on the pedagogical socialization experiences of masters and doctoral students. The purpose of this grounded theory inquiry was to discover graduate students perspectives on their pedagogical socialization experiences and the norms, values and role expectations transmitted during the teaching and learning of quantitative methods. Narrative data was collected from in-depth interviews among a theoretical sample of 31 masters and doctoral students enrolled in introductory, …

Exponential Random Graphs And A Generalization Of Parking Functions, Ryan Demuse

Electronic Theses and Dissertations

Random graphs are a powerful tool in the analysis of modern networks. Exponential random graph models provide a framework that allows one to encode desirable subgraph features directly into the probability measure. Using the theory of graph limits pioneered by Borgs et. al. as a foundation, we build upon the work of Chatterjee & Diaconis and Radin & Yin. We add complexity to the previously studied models by considering exponential random graph models with edge-weights coming from a generic distribution satisfying mild assumptions. In particular, we show that a large family of two-parameter, edge-weighted exponential random graphs display a phase …

Wind Turbine Parameter Calibration Using Deep Learning Approaches, Rebecca Mccubbin

Electronic Theses and Dissertations

The inertia and damping coefficients are critical to understanding the workings of a wind turbine, especially when it is in a transient state. However, many manufacturers do not provide this information about their turbines, requiring people to estimate these values themselves. This research seeks to design a multilayer perceptron (MLP) that can accurately predict the inertia and damping coefficients using the power data from a turbine during a transient state. To do this, a model of a wind turbine was built in Matlab, and a simulation of a three-phase fault was used to collect realistic fault data to input into …

Bias Of Rank Correlation Under A Mixture Model, Russell Land

Electronic Theses and Dissertations

This thesis project will analyze the bias in mixture models when contaminated data is present. Specifically, we will analyze the relationship between the bias and the mixing proportion, p, for the rank correlation methods Spearman’s Rho and Kendall’s Tau. We will first look at the history of the two non-parametric rank correlation methods and the sample and population definitions will be introduced. Copulas will be introduced to show a few ways we can define these correlation methods. After that, mixture models will be defined and the main theorem will be stated and proved. As an example, we will apply this …

Lack Of Plasticity In Gopher Tortoise (Gopherus Polyphemus) Nesting Behavior And Fecundity In A Translocated Population, Jennifer N. Desha

Electronic Theses and Dissertations

Lack of Plasticity in Gopher Tortoise (Gopherus polyphemus) Nesting Behavior and Fecundity in a Translocated Population

Moving Past ‘One Size Fits All’: Developing A Trajectory Deviance Index For Dynamic Measurement Modeling, Yixiao Dong

Electronic Theses and Dissertations

Dynamic Measurement Modeling (DMM) is a recently developed measurement framework for gauging developing constructs (e.g., learning capacity) that conventional single-timepoint tests cannot assess. Like most measurement models, overall model fit indices of DMM do not indicate the measurement appropriateness for each included student. For this reason, other measurement modeling paradigms (e.g., Item-Response Theory; IRT) utilize person-fit or model appropriateness statistics to indicate whether a measurement model appropriately describes the data from each individual student. However, within the extant DMM framework, no statistical index has yet been developed for this purpose. Thus, the current project advanced a person-specific DMM Trajectory Deviance …

Evaluation Of The Effect Of The Clinical-Decision-Support Systems On Diabetes Management: A Multivariate Meta-Analysis Comparison With Univariate Meta-Analysis, Abdelfattah Elbarsha

Electronic Theses and Dissertations

The advantage of using meta-analysis lies in its ability in providing a quantitative summary of the findings from multiple studies. The aim of this dissertation was first to conduct a simulation study in order to understand what factors (sample size, between-study correlation, and percent of missing data) have a significant effect on meta-analysis estimates and whether using univariate or multivariate meta-analysis would produce different estimates.

The second goal of this study was to evaluate the effect of clinical decision support systems CDSS on diabetes care management by conducting three separate univariate meta-analyses and one multivariate meta-analysis. CDSS are health information …

Zn Orbifolds Of Vertex Operator Algebras, Daniel Graybill

Electronic Theses and Dissertations

Given a vertex algebra V and a group of automorphisms of V, the invariant subalgebra V^G is called an orbifold of V. This construction appeared first in physics and was also fundamental to the construction of the Moonshine module in the work of Borcherds. It is expected that nice properties of V such as C2-cofiniteness and rationality will be inherited by V^G if G is a finite group. It is also expected that under reasonable hypotheses, if V is strongly finitely generated and G is reductive, V^G will also be strongly finitely generated. This is an analogue …