Digital Commons Network^™

Mesoscale Studies Of Nanostructured Multi-Functional Materials, Lukasz Kuna

Doctoral Dissertations

In this dissertation, multiple studies centered around functional properties of materials for applications in devices and novel technologies are carried out utilizing a mesoscale modeling approach. The studies involve simulating the properties of dielectric nano/microstructures with coupled polar and elastic degrees of freedom and developing a greater understanding of their dependence on the structure size, morphology and applied external conditions. Of particular focus in this work are optical properties of electroactive materials including zero- and one-dimensional structures such as nanoparticles and nanowires, as well as mesoscopic functional properties of larger structures such as polycrystalline ceramics (with submicron grain sizes) and …

Effects Of Stereotype Threat On Intra- And Interpersonal Coordination Dynamics, Andrew Tucker

Doctoral Dissertations

Great progress has been made on both intra- and interpersonal coordination by recasting them as the product of distributed parts and processes, in terms closer to those of physics than psychology. However, insofar as coordination is an a posteriori product of competing and cooperating forces defined across an organism-environment system, the full breadth of forces present must be considered. This requires approaching the consequences of the organism’s embedding within higher-level social and cultural systems.

Across three experiments, Stereotype Threat (ST) manipulations were used to affect the sociocultural context or meaning of coordination. These experiments were intended to address complementary issues …

How Average Is "Average?" Making Sense Of A Machine Learning Analysis Of Personality Types, Colin Lee Omori

Doctoral Dissertations

In light of a study by Gerlach and colleagues (2018) claiming to have found four personality types (a potential subset of a larger, yet-undiscovered pool, the article clarifies), the goal of the present study was to identify the percentage of people in Johnson’s Big Five IPIP-120 and -300 data sets (N = 555,764) who fall into each type. Analyses found that over 87% of cases in both samples did not fall into any personality type. Of those who fell into a personality type in the IPIP-120 data (N = 53,243), 15.17% fell into multiple types. In the ‘typed’ sample within …

The Parity-Violating Asymmetry In The N→Δ Transition At Low Q2, Thamraa A. Alshayeb

Doctoral Dissertations

Qweak has used the parity violating asymmetry to test the Standard Model (SM) by constantly flipping helicity states of a longitudinally polarized electron beam that scatters in the unpolarized LH2 target. The main focus of the Qweak experiment at Jefferson Lab was the recently published determination of the proton’s weak charge. In order to make corrections to the measured asymmetry at low 𝑄 2 due to inelastically scattered electrons, dedicated measurements were made of the parity violating asymmetry in the N→∆ transition at two different beam energies.

The measured inelastic asymmetries are used to extract the low energy constant dΔ, …

The School Leader's Role In Co-Teaching And It's Impact On The Academic Achievement For Students With Disabilities, Laquina Chanel Dove-Cummings

Doctoral Dissertations

iii ABSTRACT The purpose of this research study was to analyze the role of school leaders in the implementation of co-teaching as an instructional model on teacher collaboration and academic outcomes for students with disabilities. Federal guidelines and provisions forged the increase of mainstreaming students with disabilities into the full inclusion setting. As a result, school administrators are increasingly implementing co-teaching as an instructional model to provide opportunities to access the general education curriculum while receiving special education supports and services in the full inclusion setting. A mix-method study of semi-structured interviews with school leaders and coteachers and data analyses …

Multi-Model Network Intrusion Detection System Using Distributed Feature Extraction And Supervised Learning, Sangam Mulmi

Doctoral Dissertations

Intrusion Detection Systems (IDSs) monitor network traffic and system activities to identify any unauthorized or malicious behaviors. These systems usually leverage the principles of data science and machine learning to detect any deviations from normalcy by learning from the data associated with normal and abnormal patterns. The IDSs continue to suffer from issues like distributed high-dimensional data, inadequate robustness, slow detection, and high false-positive rates (FPRs). We investigate these challenges, determine suitable strategies, and propose relevant solutions based on the appropriate mathematical and computational concepts.

To handle high-dimensional data in a distributed network, we optimize the feature space in a …

Abc Method And Fractional Momentum Layer For The Fdtd Method To Solve The Schrödinger Equation On Unbounded Domains, Joshua Paul Wilson

Doctoral Dissertations

The finite­difference time­domain (FDTD) method and its generalized variant (G­FDTD) are efficient numerical tools for solving the linear and nonlinear Schrödinger equations because not only are they explicit, allowing parallelization, but they also provide high­order accuracy with relatively inexpensive computational costs. In addition, the G­FDTD method has a relaxed stability condition when compared to the original FDTD method. It is important to note that the existing simulations of the G­FDTD scheme employed analytical solutions to obtain function values at the points along the boundary; however, in simulations for which the analytical solution is unknown, theoretical approximations for values at points …

Relative And Absolute Price Efficiency In Stock Markets: Could Behavioral Finance And Efficient Markets Both Be Correct?, James Ryan Hickey

Doctoral Dissertations

Prior research on stock prices has found that most variation in stock prices is attributable to variation in expected returns rather than cash flows. Prices exhibit “excess volatility” and are too persistent to be explained in terms of cash flows. This finding has contributed to the divergence between the so-called “behavioral finance” school of research and advocates of “efficient markets.” I examine whether the relation between fundamentals and prices is stronger in relative stock prices than absolute stock prices. I also explore whether the reasons for the excess volatility and persistence problems may be attributable to structural change.

Chapter 1 …

Human And Climate Impacts On Flooding Via Remote Sensing, Big Data Analytics, And Modeling, Eunsang Cho

Doctoral Dissertations

Over the last 20 years, the amount of streamflow has greatly increased and spring snowmelt floods have occurred more frequently in the north-central U.S. In the Red River of the North Basin (RRB) overlying portions of North Dakota and Minnesota, six of the 13 major floods over the past 100 years have occurred since the late 1990s. Based on numerous previous studies as well as senior flood forecasters’ experiences, recent hydrological changes related to human modifications [e.g. artificial subsurface drainage (SSD) expansion] and climate change are potential causes of notable forecasting failures over the past decade. My dissertation focuses on …

An Asymptotic Self-Sustaining Process Theory For Uniform Momentum Zones And Internal Interfaces In Unbounded Couette Flow, Brandon Montemuro

Doctoral Dissertations

Meinhart \& Adrian (Phys. Fluids, vol. 7, 1995, p 694) were the first investigators to document that the wall-normal ($y$) structure of the instantaneous streamwise velocity in the turbulent boundary layer exhibits a staircase-like profile: regions of quasi-uniform momentum are separated by internal shear layers across which the streamwise velocity jumps by an O(1) amount when scaled by the friction velocity $u_\tau$. This sharply-varying instantaneous profile differs dramatically from the well-known long-time mean profile, which is logarithmic over much of the boundary layer, and prompted Klewicki (Proc. IUTAM, vol. 9, 2013, p. 69--78) to propose that the turbulent boundary layer …

The Impact Of Fine Scale Drivers On Upwelling Processes, David Kenward

Doctoral Dissertations

Ionospheric upwelling and outflow are large-scale processes which affect the dynamics of the greater magnetosphere-ionosphere-thermosphere system. Though these terms historically refer to the propensity of ions to increase in scale height and escape Earth's gravity due to a the collective effect of energization processes; that same behaviour is frequently observed to occur with neutral species within the cusp regions of the ionosphere. Although many different driving mechanisms have been identified which contribute to the energization and increase in scale height of the ionosphere, the relative energy budget of these individual drivers is debated. In this dissertation, data from the Rocket …

Synthesis And Characterization Of Biomimetic Model Systems For The Study Of Diiron Hydrogenase And Porphyrin Enzymes, Brian Francis Patenaude

Doctoral Dissertations

The branch of biomimetic chemistry aims to imitate natural reactions and enzymatic processes in order to advance many other areas of chemistry, including inorganic and organic catalysis as well as materials science. To study the mechanisms of enzyme activity and the effect of secondary coordination sphere interactions, the synthesis and characterization of two artificial metallo-enzymes were pursued.

In order to further understand the mechanism of [FeFe]-hydrogenase and the effect of secondary coordination sphere interactions within the protein binding pocket, the synthesis of an optimized biotin-avidin [FeFe] artificial enzyme was pursued. This dissertation describes the synthesis and characterization of the small …

Am I A Math Or Science Person? How High School Students’ Attitudes Towards Mathematics And Science Influence Their Decision To Major In Stem, Dalton Dayne Marsh

Doctoral Dissertations

Motivated by an innovation-driven economy, critical emphasis has been placed on the science, technology, engineering, and mathematics (STEM) workforce in the United States. Education has been charged to prepare a diverse population of young people qualified to take up these jobs and lead the nation into a rapidly evolving technological future. How to best approach this goal is still being negotiated. While past research and efforts focused largely on improving students’ achievement in mathematics and science, more recent research points to the need to also consider students’ attitudes towards STEM subjects. However, what types of attitudes (e.g., self-efficacy, identity, interest, …

The Equitable Leadership Practices Of Teacher Leaders In Secondary Science Instruction, Latanya T. Brandon

Doctoral Dissertations

The purpose of this case study is to investigate science teacher leadership for educational equity at the secondary school level during a period of reform. The current reform in science education acknowledges inequity and calls for significant changes in instruction (NRC, 2012). This study is designed to address two research questions: (1) ‘How do participants describe science teacher leaders’ educational practices for equity?’ and (2) ‘How are science teacher leaders’ equitable practices related to organizational structures and social norms within secondary schools?’. Three data sources: interviews, field observations, and artifacts, were collected and analyzed qualitatively. A social justice leadership framework …

Three Essays On Econometrics, Zhonghui Zhang

Doctoral Dissertations

This dissertation contains three chapters. In the first chapter, I investigate why there exists considerable variation in estimates of the coefficient of relative risk aversion (CRRA) and the elasticity of intertemporal substitution (EIS) in the consumption-based asset pricing model with Epstein and Zin (1989) preferences. I find the Epstein and Zin (1989) structure collapses to the time-separable structure when returns are within a reasonable range. I also show the choice of parameters might lead to an "ill-behaved" conditional moment, which might cause either the GMM method to get "stuck," or the estimates do not move much from the starting points. …

On Brownian Motion Governed By Telegraph Process, Chaoran Hu

Doctoral Dissertations

Statistical modeling of animal movement is of critical importance in addressing fundamental questions about space use, movement, resource selection, and behavior in animal ecology. The explosion of telemetry data on animal movement from the recent advancements in tracking and observation technologies presents a storm of opportunities and challenges.

A moving-resting-handling (MRH) process is introduced to allow predators to have two different motionless states, resting, and handling. In essence, it is a Brownian motion whose infinitesimal variance changes according to a three-state continuous-time Markov Chain. The Markov Chain can be viewed as a telegraph process with one on state and two …

Finding Critical And Gradient-Flat Points Of Deep Neural Network Loss Functions, Charles Gearhart Frye '09

Doctoral Dissertations

Despite the fact that the loss functions of deep neural networks are highly non-convex, gradient-based optimization algorithms converge to approximately the same performance from many random initial points. This makes neural networks easy to train, which, combined with their high representational capacity and implicit and explicit regularization strategies, leads to machine-learned algorithms of high quality with reasonable computational cost in a wide variety of domains.

One thread of work has focused on explaining this phenomenon by numerically characterizing the local curvature at critical points of the loss function, where gradients are zero. Such studies have reported that the loss functions …

The Impact Of Middle School Scheduling Practices On Adolescent Math Achievement In Louisiana Public Schools, Deborah Lynn Gegg

Doctoral Dissertations

Research on middle-level schools and student achievement revealed a drop in academic performance when students transitioned from elementary school to a traditional middle school. In the United States, the middle school years have historically seen a decline in student achievement following a transition from elementary school.

According to the National Center for Education Statistics, the performance of United States eighth-grade students in mathematics continued to lag behind globally based on the 2015 Trends in International Mathematics and Science Study (U.S. Department of Education, 2017). Specifically, United States eighth graders were ranked 12th in mathematics, which was three notches down from …

Philippine Jesuit Schools Of Education: Heroic Institutions Of Learning And Leadership In Mission, Joaquin Jose Mari Casimiro Sumpaico

Doctoral Dissertations

Philippine Jesuit schools of education are important training sanctuaries for future teachers. These schools help build a nation by nurturing educators in their student years so that these said teacher-students may be equipped as they pursue their vocation of journeying with the Philippine youth towards meaningful and heroic learning. There is limited research on these Philippine Jesuit schools of education and how these have created an impact in Philippine nation-building. The qualitative research draws attention to the four pillars of Heroic Leadership in these schools of education. It will look for practices of Self-awareness, Ingenuity, Love, and Heroism in the …

Dynamic Resource Management In Lossy Real-Time Wireless Networks, Tao Gong

Doctoral Dissertations

Along with the rapid development of real-time wireless network (RTWN) technologies in a wide range of time- and safety-critical industrial applications, packet scheduling algorithms have been playing a critical role in RTWNs to achieve desired Quality of Service (QoS) for real-time sensing and control, especially in the presence of unexpected disturbances. Most existing solutions focus on communication schedule construction to meet the desired QoS but have common assumptions that all wireless links are reliable, and the network topologies are prior known. Although these assumptions simplify the algorithm design and analysis, they are not realistic in real world.

To relax the …

Correlative Framework Of Techniques For The Inspection, Evaluation, And Design Of Micro-Electronic Devices, Joseph Favata

Doctoral Dissertations

Trillions of micro- and nano-electronic devices are manufactured every year. They service countless electronic systems across a diverse range of applications ranging from civilian, military, and medical sectors. Examples of these devices include: packaged and board-mounted semiconductor devices such as ceramic capacitors, CPUs, GPUs, DSPs, etc., biomedical implantable electrochemical devices such as pacemakers, defibrillators, and neural stimulators, electromechanical sensors such as MEMS/NEMS accelerometers and positioning systems and many others. Though a diverse collection of devices, they are unified by their length scale. Particularly, with respect to the ever-present objectives of device miniaturization and performance improvement. Pressures to meet these objectives …

Replicative Bypass Of A Dna-Peptide Cross-Link And Oxidative Single And Tandem Dna Lesions In Human Cells, Spandana Naldiga

Doctoral Dissertations

DNA harbors the genetic information in all living organisms and plays a pivotal role in passing the genetic information to the next generation. All living cells are exposed to numerous exogenous and endogenous agents that damage the DNA to form different lesions or adducts in DNA. Fortuitously, diverse DNA repair mechanisms exist in the living cells, which repair these DNA adducts before the replication apparatus of the cell copies the DNA. However, frequently extensive DNA damage or slow repair may allow replication bypass of a DNA lesion. As a result, cells adapt a DNA damage tolerance mechanism, termed as translesion …

Social Media Based Algorithmic Clinical Decision Support Learning From Behavioral Predispositions, Radhika V. Medury

Doctoral Dissertations

Behavioral disorders are disabilities characterized by an individual’s mood, thinking, and social interactions. The commonality of behavioral disorders amongst the United States population has increased in the last few years, with an estimated 50% of all Americans diagnosed with a behavioral disorder at some point in their lifetime. AttentionDeficit/Hyperactivity Disorder is one such behavioral disorder that is a severe public health concern because of its high prevalence, incurable nature, significant impact on domestic life, and peer relationships. Symptomatically, in theory, ADHD is characterized by inattention, hyperactivity, and impulsivity. Access to providers who can offer diagnosis and treat the disorder varies …

Poisoning Attacks On Learning-Based Keystroke Authentication And A Residue Feature Based Defense, Zibo Wang

Doctoral Dissertations

Behavioral biometrics, such as keystroke dynamics, are characterized by relatively large variation in the input samples as compared to physiological biometrics such as fingerprints and iris. Recent advances in machine learning have resulted in behaviorbased pattern learning methods that obviate the effects of variation by mapping the variable behavior patterns to a unique identity with high accuracy. However, it has also exposed the learning systems to attacks that use updating mechanisms in learning by injecting imposter samples to deliberately drift the data to impostors’ patterns. Using the principles of adversarial drift, we develop a class of poisoning attacks, named Frog-Boiling …

A Framework Of Multi-Dimensional And Multi-Scale Modeling With Applications, Zilong Li

Doctoral Dissertations

In this dissertation, a framework for multi-dimensional and multi-scale modeling is proposed. The essential idea is based on oriented space curves, which can be represented as a 3D slender object or 1D step parameters. SMILES and Masks provide functionalities that extend slender objects into branched and other objects. We treat the conversion between 1D, 2D, 3D, and 4D representations as data unification. A mathematical analysis of different methods applied to helices (a special type of space curves) is also provided. Computational implementation utilizes Model-ViewController design principles to integrate data unification with graphical visualizations to create a dashboard. Applications of multi-dimensional …

Towards Efficacy And Efficiency In Sparse Delay Tolerant Networks, Douglas John Mcgeehan

Doctoral Dissertations

"The ubiquitous adoption of portable smart devices has enabled a new way of communication via Delay Tolerant Networks (DTNs), whereby messages are routed by the personal devices carried by ever-moving people. Although a DTN is a type of Mobile Ad Hoc Network (MANET), traditional MANET solutions are ill-equipped to accommodate message delivery in DTNs due to the dynamic and unpredictable nature of people's movements and their spatio-temporal sparsity. More so, such DTNs are susceptible to catastrophic congestion and are inherently chaotic and arduous. This manuscript proposes approaches to handle message delivery in notably sparse DTNs. First, the ChitChat system [69] …

Acoustic Confinement And Characterization Of A Microwave Plasma, Seth Lee Pree '09

Doctoral Dissertations

High amplitude acoustic fields are used to confine, characterize, and manipulate collisional plasmas with temperatures of a few thousand Kelvin. This dissertation describes the theory, experimental techniques, and apparatus necessary both to generate high amplitude sound in a few thousand Kelvin plasma and to use that sound field to manipulate the plasma within a resonant acoustic cavity. The acoustic field in a spherically symmetric oscillating plasma has been measured to have a Mach number of .03, which is sufficient to cause acoustic radiation pressure effects to confine the plasma to the center of its container. This field also generates convection …

Development Of Lightweight Materials By Meso- And Microstructure Control, Myranda Shea Spratt

Doctoral Dissertations

”In this work, two lightweight structures – lattice structures and metal matrix syntactic foams (MMSF) – were studied. Honeycomb lattices were manufactured by powder bed selective laser melting (SLM) from 304L stainless steel. The wall thicknesses of these structures ranged from 0.2 to 0.5 mm. Surface roughness was the primary cause of dimensional mismatch between the expected and as-built structures with an average wall thickness increase of 0.12 mm. The strength of the honeycombs increased with increasing wall thickness. A feature of the SLM microstructure, the melt pool boundary, was also studied as a part of this work. 3D models …

Isospin Dependence Of Nucleon-Nucleon Short-Range Correlations In Inclusive Scattering With Tritium And Helium-3, Shujie Li

Doctoral Dissertations

The nucleon-nucleon (NN) potential has a strong repulsive core. When a two-nucleon (sub)system falls into this range, they will interact strongly at short distance, and move away from each other with momenta above the Fermi level. This is called the NN Short-range Correlations (SRCs).

Previous experiments reported a neutron-proton pair (isosinglet) dominance in high-momentum nucleons. In inclusive electron scattering, this np dominance will cause a scaling behavior of cross sections at 1.4

Becoming ‘We’: Disembodied Trauma And A Community Of Globalized Reading In Contemporary Asian American Novels And Graphic Narratives, Jin Lee

Doctoral Dissertations

Historical narratives often focus on the victors of major global conflicts and leave out the mention of the oppressed. But trauma theorists note that literary arts can effectively offer insight to unremarked histories. My dissertation examines how contemporary Asian American novels and graphic narratives represent underrepresented historical trauma, with a particular focus on Maxine Hong Kingston’s The Woman Warrior, Lois-Ann Yamanaka’s Blu’s Hanging, GB Tran’s Vietnamerica, Fred Chao’s Johnny Hiro, and Gene Luen Yang’s American Born Chinese. I focus on what I call “disembodied trauma,” a phenomenon which encourages readers to recognize silenced histories in the texts. Specifically, “disembodied trauma,” …