Physical Sciences and Mathematics Commons^™

Was 2015 The Summer Of The Shark? Evidence From The Coastal Carolina University Shark Project, Brooke Anderson

Honors Theses

Winyah Bay is a 65-km2 estuary in northeast South Carolina and is considered essential habitat and nursery ground for several shark species of the western North Atlantic. As a result of a number of shark bites/attacks during the summer of 2015, many concluded there was higher abundance of sharks than in previous years. The objective of this study was to test this hypothesis using surveys of shark populations from Winyah Bay in the summer of 2015, and comparing the diversity and abundance of sharks from this survey to those of previous years from the same survey. From July to August …

Abundance And Distribution Of Microplastic Particles In Winyah Bay, S.C. ‌, Dillon King

Honors Theses

Plastics are incredibly durable synthetic polymers used in a wide variety of consumer products. Microplastics are generally defined as plastic debris ranging from 0.33 to 5 millimeters in size. Microplastic pollution in the environment is a global concern because of their propensity to serve as a vector for bioaccumlation and the spread of harmful bacteria. This study characterized the concentrations of floating microplastics in Winyah Bay, South Carolina, the surrounding freshwater river systems, and 10 miles offshore of Winyah Bay. Samples were collected according to NOAA standard techniques for microplastic collection in water using a 335 µm and 153 µm …

Development Of A [2]-Catenane Synthetic Method And A Student Beliefs Survey For A Hybrid Organometallics Course, Jourdan E. Lakes

Honors Theses

In this study, the value-added of a new upper-level chemistry course, CHEM 372-Organometallics, was defined using a Student Beliefs Survey that was answered by students in CHEM 372 and by faculty who teach upper-level chemistry courses at Coastal Carolina University. The laboratory portion of CHEM 372 focused on the synthesis of a [2]-catenane, which is a molecularly interlocked molecule (MIM). The intention was to give the CHEM 372 students a goal to work toward over the course of the semester instead of different, unrelated, experiments each week. Using this style of lab teaching, the students were introduced to graduate school-level …

Seismic Studies Of The Tonga Subduction Zone And The Lau Back-Arc Basin, Songqiao Wei

Arts & Sciences Graduate Student Theses and Dissertations

This dissertation utilizes multiple techniques of seismic tomography and earthquake location to investigate the upper mantle structure and intermediate-depth seismicity of the Tonga subduction zone, the Lau back-arc basin, and adjacent regions. Data for these studies consist of broadband records from 49 ocean bottom seismographs and 17 island-based seismic stations deployed for one year in 2009-2010, as well as more limited earlier datasets. I conducted tomographic studies of Rayleigh wave velocity and body wave attenuation to examine the thermal variations and the distribution of partial melt in the mantle wedge. The shear-wave velocity structure is first determined using only teleseismic …

No-Slip Billiards, Christopher Lee Cox

Arts & Sciences Graduate Student Theses and Dissertations

We investigate the dynamics of no-slip billiards, a model in which small rotating disks may exchange linear and angular momentum at collisions with the boundary. A general theory of rigid body collisions in is developed, which returns the known dimension two model as a special case but generalizes to higher dimensions. We give new results on periodicity and boundedness of orbits which suggest that a class of billiards (including all polygons) is not ergodic. Computer generated phase portraits demonstrate non-ergodic features, suggesting chaotic no-slip billiards cannot easily be constructed using the common techniques for generating chaos in standard billiards. However, …

Examining Cost Functionality And Optimization: A Case Study On Testing The Reasonableness Of New Aircraft Using Historical Aircraft Data, Katherine Jozefiak

Arts & Sciences Graduate Student Theses and Dissertations

When pursuing business by competing for government contracts, proving the submitted price is reasonable is often required. This proof is called a test of reasonableness. This study analyzes data from historical aircraft programs in relation of a new aircraft program in order to demonstrate the estimated cost of the new program is reasonable. The purpose of this study is to investigate three questions. Is the new program cost reasonable using current industry and government parameters? Is it better to look at programs from a total cost perspective or break the total cost into subcategory levels? Finally, this study applies a …

Spot Volatility Estimation Of Ito Semimartingales Using Delta Sequences, Weixuan Gao

Arts & Sciences Graduate Student Theses and Dissertations

This thesis studies a unifying class of nonparametric spot volatility estimators proposed by Mancini et. al.(2013). This method is based on delta sequences and is conceived to include many of the existing estimators in the field as special cases. The thesis first surveys the asymptotic theory of the proposed estimators under an infill asymptotic scheme and fixed time horizon, when the state variable follows a Brownian semimartingale. Then, some extensions to include jumps and financial microstructure noise in the observed price process are also presented. The main goal of the thesis is to assess the suitability of the proposed methods …

Revelation Of Yin-Yang Balance In Microbial Cell Factories By Data Mining, Flux Modeling, And Metabolic Engineering, Gang Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

The long-held assumption of never-ending rapid growth in biotechnology and especially in synthetic biology has been recently questioned, due to lack of substantial return of investment. One of the main reasons for failures in synthetic biology and metabolic engineering is the metabolic burdens that result in resource losses. Metabolic burden is defined as the portion of a host cells resources either energy molecules (e.g., NADH, NADPH and ATP) or carbon building blocks (e.g., amino acids) that is used to maintain the engineered components (e.g., pathways). As a result, the effectiveness of synthetic biology tools heavily dependents on cell capability to …

Theory Of Carrier Transport From First Principles: Applications In Photovoltaic And Thermoelectric Materials, Alireza Faghaninia

McKelvey School of Engineering Graduate Student Theses & Dissertations

New sources of energy that are environmentally friendly, cost-effective, and renewable are essential if we are to combat the effects of global climate change. Two of these sources are solar photovoltaic (PV) cells to convert sunlight into electricity and thermoelectric (TE) devices to convert heat to electricity. To be practical on a large scale, the properties (e.g. electrical conductivity, band gap, Seebeck coefficient, etc) of the the underlying materials must be improved significantly through judicious control of structure and composition. Significant understanding of materials properties is required to design and engineer new high-performing materials. First principles calculations using density functional …

Goggle Augmented Imaging And Navigation System For Fluorescence-Guided Surgery, Suman Bikash Mondal

McKelvey School of Engineering Graduate Student Theses & Dissertations

Surgery remains the only curative option for most solid tumors. The standard-of-care usually involves tumor resection and sentinel lymph node biopsy for cancer staging. Surgeons rely on their vision and touch to distinguish healthy from cancer tissue during surgery, often leading to incomplete tumor resection that necessitates repeat surgery. Sentinel lymph node biopsy by conventional radioactive tracking exposes patients and caregivers to ionizing radiation, while blue dye tracking stains the tissue highlighting only superficial lymph nodes. Improper identification of sentinel lymph nodes may misdiagnose the stage of the cancer. Therefore there is a clinical need for accurate intraoperative tumor and …

Cyclotron Production And Biomedical Imaging Applications Of The Pet Isotope Manganese-52, Andrew Lake Wooten

McKelvey School of Engineering Graduate Student Theses & Dissertations

Manganese is an important element for biomedical research because of its roles as an essential micronutrient and as a neurotoxin from chronic elevated exposure, as well as the role of manganese(II) as a paramagnetic core for contrast agents in T1-weighted magnetic resonance imaging (MRI). Using a radiotracer of manganese provides excellent sensitivity for studying these phenomena, but only 52Mn met the criteria for our experiments: (1) a half-life (t1/2=5.6 days) that was long enough to examine timepoints over several days, (2) a half-life that was short enough to emit sufficient counts for a realistic scan time, and (3) emitted radiation …

A General Framework Of Large-Scale Convex Optimization Using Jensen Surrogates And Acceleration Techniques, Soysal Degirmenci

McKelvey School of Engineering Graduate Student Theses & Dissertations

In a world where data rates are growing faster than computing power, algorithmic acceleration based on developments in mathematical optimization plays a crucial role in narrowing the gap between the two. As the scale of optimization problems in many fields is getting larger, we need faster optimization methods that not only work well in theory, but also work well in practice by exploiting underlying state-of-the-art computing technology.

In this document, we introduce a unified framework of large-scale convex optimization using Jensen surrogates, an iterative optimization method that has been used in different fields since the 1970s. After this general treatment, …

Automatically Characterizing Product And Process Incentives In Collective Intelligence, Allen Brockhurst Lavoie

McKelvey School of Engineering Graduate Student Theses & Dissertations

Social media facilitate interaction and information dissemination among an unprecedented number of participants. Why do users contribute, and why do they contribute to a specific venue? Does the information they receive cover all relevant points of view, or is it biased? The substantial and increasing importance of online communication makes these questions more pressing, but also puts answers within reach of automated methods. I investigate scalable algorithms for understanding two classes of incentives which arise in collective intelligence processes. Product incentives exist when contributors have a stake in the information delivered to other users. I investigate product-relevant user behavior changes, …

Distributed Target Tracking And Synchronization In Wireless Sensor Networks, Jichuan Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Wireless sensor networks provide useful information for various applications but pose challenges in scalable information processing and network maintenance. This dissertation focuses on statistical methods for distributed information fusion and sensor synchronization for target tracking in wireless sensor networks.

We perform target tracking using particle filtering. For scalability, we extend centralized particle filtering to distributed particle filtering via distributed fusion of local estimates provided by individual sensors. We derive a distributed fusion rule from Bayes' theorem and implement it via average consensus. We approximate each local estimate as a Gaussian mixture and develop a sampling-based approach to the nonlinear fusion …

Learning With Scalability And Compactness, Wenlin Chen

McKelvey School of Engineering Graduate Student Theses & Dissertations

Artificial Intelligence has been thriving for decades since its birth. Traditional AI features heuristic search and planning, providing good strategy for tasks that are inherently search-based problems, such as games and GPS searching. In the meantime, machine learning, arguably the hottest subfield of AI, embraces data-driven methodology with great success in a wide range of applications such as computer vision and speech recognition. As a new trend, the applications of both learning and search have shifted toward mobile and embedded devices which entails not only scalability but also compactness of the models. Under this general paradigm, we propose a series …

Exploiting The Weak Generational Hypothesis For Write Reduction And Object Recycling, Jonathan Andrew Shidal

McKelvey School of Engineering Graduate Student Theses & Dissertations

Programming languages with automatic memory management are continuing to grow in popularity due to ease of programming. However, these languages tend to allocate objects excessively, leading to inefficient use of memory and large garbage collection and allocation overheads.

The weak generational hypothesis notes that objects tend to die young in languages with automatic dynamic memory management. Much work has been done to optimize allocation and garbage collection algorithms based on this observation. Previous work has largely focused on developing efficient software algorithms for allocation and collection. However, much less work has studied architectural solutions. In this work, we propose and …

Classification Trees And Rule-Based Modeling Using The C5.0 Algorithm For Self-Image Across Sex And Race In St. Louis, Rohan Shirali

Arts & Sciences Graduate Student Theses and Dissertations

The study population comprised children, adolescents, and adults who were residents of the city of St. Louis at the time of data collection in 2015. The data collected includes sex, age, race, measured height and weight, self-reported height and weight, zip code, educational background, exercise and diet habits, and descriptions and strategies of participants' weight (i.e. overweight and trying to lose weight, respectively). I use the C5.0 algorithm to create classification trees and rule-based models to analyze this population. Specifically, I model a binary self-image variable as a function of sex, age, race, zip code, and a ratio of reported …

Visualization Of Deep Convolutional Neural Networks, Dingwen Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Deep learning has achieved great accuracy in large scale image classification and scene recognition tasks, especially after the Convolutional Neural Network (CNN) model was introduced. Although a CNN often demonstrates very good classification results, it is usually unclear how or why a classification result is achieved. The objective of this thesis is to explore several existing visualization approaches which offer intuitive visual results. The thesis focuses on three visualization approaches: (1) image masking which highlights the region of image with high influence on the classification, (2) Taylor decomposition back-propagation which generates a per pixel heat map that describes each pixel's …

Environmental Fullerene Chemistry: Elucidating Critical Reaction Pathways And Resulting Products In The Aqueous Phase, Jiewei Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

As the production of fullerenes and fullerene-based materials approaches industrial scale, there are increasing interests/concerns regarding their (potential) environmental impact(s) upon release. To date, a number of critical, aqueous-based fullerene transformation pathways under environmentally relevant conditions remain poorly understood. Comprehensive, fundamental, and quantitative understanding of the potential (major) reaction pathways and resulting products of fullerene materials, particularly in aquatic systems, is now crucial for their accurate fate, transport, life cycle, risk assessment(s), and thus ultimate material sustainability.

Herein, this dissertation is focused on identifying and elucidating aqueous transformation pathways of fullerene materials, focused on C60 as a model fullerene, under …

Modeling, Simulation, And Analysis Of Lithium-Ion Batteries For Grid-Scale Applications, Matthew Thomas Lawder

McKelvey School of Engineering Graduate Student Theses & Dissertations

Lithium-ion batteries have become universally present in daily life, being used across a wide range of portable consumer electronics. These batteries are advantageous compared to other forms of energy storage due to their high energy density and long cycle life. These characteristics make lithium-ion batteries advantageous for many new and developing applications that require large scale energy storage such as electric vehicles and the utility grid. Typical uses for lithium-ion batteries require consistent cycling patterns that are predictable and easy to approximate across all uses, but new large scale applications will have much more dynamic demands. The cycling patterns for …

Three Problems In Operator Theory And Complex Analysis, Cheng Chu

Arts & Sciences Graduate Student Theses and Dissertations

This thesis concerns three distinct problems in operator theory and complex analysis. In Chapter 2, we study the following problem: On the Hardy space H^2, when is the product of a Hankel operator and a Toeplitz operator compact? We give necessary and sucient conditions for when such a product H_fT_g is compact. In Chapter 3, we discuss hyponormal Toeplitz operators. We show that for those operators, there exists a lower bound for the area of the spectrum. This extends the known estimate for the spectral area of Toeplitz operators with an analytic symbol. This part is joint work with Dmitry …

Lead Poisoning In United States Children, Zeren Zhou

Arts & Sciences Graduate Student Theses and Dissertations

We investigate factors related to blood lead levels of children ages 1 to 5 in the United States for the years 2007-2014. We use data from the National Health and Nutrition Examination Survey (NHANES). The goal is to explore predictors of lead in childrens' blood and to develop a multivariate model using as many predictors as possible. The analysis is conducted using SAS survey regression procedures that account for weighting, stratification, and clustering of the data.

Can Climate-Driven Change Influence Silicon Assimilation By Cereals And Hence The Distribution Of Lepidopteran Stem Borers In East Africa?, P. A. Calatayud, E. Njuguna, S. Mwalusepo, M. Gathara, G. Okuku, A. Kibe, B. Musyoka, D. Williamson, G. Ong'amo, G. Juma, T. Johansson, S. Subramanian, E. Gatebe, B. Le Ru

All Peer-Reviewed Publications

In East Africa, lepidopteran stemborers such as Chilo partellus and Busseola fusca are major constraints to production of maize, which is the main staple food crop in the region. Cereals depend on silicon (Si)-based defences to fight off herbivores. Using altitudinal ranges in the East African highlands as ecological surrogates for inferring climate change, it was shown that Si concentrations in soil and maize decreased with altitude. This was attributed, in part, to low temperatures at high altitudes, which negatively affected Si assimilation by maize. Experiments showed that B. fusca was more susceptible to Si than C. partellus. Hence the …

On The Limiting Behavior Of Variations Of Hodge Structures, Genival Francisco Fernandes Da Silva Jr.

Arts & Sciences Graduate Student Theses and Dissertations

In this dissertation we will address three results concerning the limiting behavior of variations of Hodge structures. The first chapter introduces the main concepts involved and fixes some notation. In chapter two we discuss extension classes representing LMHS, compute them for a class of toric families and introduce an alternative method for the computation of VHS arising from middle convolution. The next chapter is concerned with the so called Apery constants; we provide a method of computing such constants by using higher normal functions coming from geometry. Finally, in the last chapter we analyze a family of surfaces with geometric …

High-Valent Organometallic Palladium And Nickel Complexes And Their Roles In Carbon-Carbon And Carbon-Heteroatom Bond Formation Reactions, Jason Wesley Schultz

Arts & Sciences Graduate Student Theses and Dissertations

The development of palladium catalysis has been influential in a wide range of organic transformations, in particular C-C coupling, C-Heteroatom coupling and C-H functionalization reactions. These catalytic transformations normally proceed through the Pd0/II catalytic cycle. These reactions are remarkably useful, however, they suffer from two major problems: -hydride elimination and palladium black deposition. To circumvent these problems, recent reports have been focused on developing novel organic transformations proceeding through high-valent palladium and nickel catalytic cycles. To this point, we recently reported the isolation and characterization of various mononuclear PdIII complexes using the tetradentate ligands, N,N-di-alkyl-2,11-diaza[3.3](2,6)pyridinophane (RN4, R = tBu, iPr, …

Plate Tectonics Initiation On Earth-Like Planets: Insights From Numerical And Theoretical Analysis Of Convection-Induced Lithospheric Failure, Teresa Wong

Arts & Sciences Graduate Student Theses and Dissertations

Plate tectonics is central to many aspects of the geology and evolution of terrestrial planets, yet it is only observed on the Earth while all other known planets are covered with a stagnant lithosphere. Plate motions on the Earth are mostly driven by the pull of subducting slabs, therefore understanding the initiation of subduction is crucial to understanding plate tectonics initiation. On a one-plate planet which lacks the forces due to plate motions, some other mechanisms will have to cause the first episode of subduction to mobilize the surface. Sublithospheric convection has been proposed as a possible mechanism that induce …

Investigation Of Lung Structure-Function Relationships Using Hyperpolarized Noble Gases, Robert P. Thomen

Arts & Sciences Graduate Student Theses and Dissertations

Magnetic Resonance Imaging (MRI) is an application of the nuclear magnetic resonance (NMR) phenomenon to non-invasively generate 3D tomographic images. MRI is an emerging modality for the lung, but it suffers from low sensitivity due to inherent low tissue density and short T₂*. Hyperpolarization is a process by which the nuclear contribution to NMR signal is greatly enhanced to more than 100,000 times that of samples in thermal equilibrium. The noble gases ³He and ¹²⁹Xe are most often hyperpolarized by transfer of light angular momentum through the electron of a vaporized alkali metal to the noble …

Noncommutative Borsuk-Ulam Theorems, Benjamin Passer

Arts & Sciences Graduate Student Theses and Dissertations

The Borsuk-Ulam theorem in algebraic topology shows that there are significant restrictions on how any topological sphere interacts with the antipodal action of reflection through the origin (which maps x to -x). For example, any map f from a sphere to itself which is continuous and odd (f(-x) = -f(x)) must be homotopically nontrivial. We consider various equivalent forms of the theorem in terms of the function algebras on spheres and examine which forms generalize to certain noncommutative Banach and C*-algebras with finite group actions. Chapter 1 contains background material on C*-algebras, K-theory, and group actions. Next, in Chapter 2, …

Seismic Array Studies Of Antarctica And Madagascar, Martin James Pratt

Arts & Sciences Graduate Student Theses and Dissertations

The scope of this dissertation is broad, involving seismic array studies from Antarctica and Madagascar, and includes aspects of glaciology and oceanography as well as solid Earth geophysics. Chapter 2 focuses on the study of stickslip motion of the Whillans Ice Stream, West Antarctica. It includes methods combining seismic array and GPS time series, from ice stream based-sensors, to determine source dynamics in the framework of an earthquake source. The source characteristics are then analyzed to explain far-field seismic observations of ice stream- sourced surface waves detected throughout West Antarctica. Locations of asperities, or sticky- spots, that cause the Whillans …

Heart Failure Outcomes With Empagliflozin In Patients With Type 2 Diabetes At High Cardiovascular Risk: Results Of The Empa-Reg Outcome® Trial., David Fitchett, Bernard Zinman, Christoph Wanner, John M. Lachin, Stefan Hantel, Afshin Salsali, Odd Erik Johansen, Hans J Woerle, Uli C Broedl, Silvio E Inzucchi

Epidemiology Faculty Publications

AIMS: We previously reported that in the EMPA-REG OUTCOME(®) trial, empagliflozin added to standard of care reduced the risk of 3-point major adverse cardiovascular events, cardiovascular and all-cause death, and hospitalization for heart failure in patients with type 2 diabetes and high cardiovascular risk. We have now further investigated heart failure outcomes in all patients and in subgroups, including patients with or without baseline heart failure.

METHODS AND RESULTS: Patients were randomized to receive empagliflozin 10 mg, empagliflozin 25 mg, or placebo. Seven thousand and twenty patients were treated; 706 (10.1%) had heart failure at baseline. Heart failure hospitalization or …