Digital Commons Network^™

Engineering Creativity: Differences In Creative Problem Solving Stages Across Domains, Lamies J. Nazzal

Doctoral Dissertations

There is a growing call for enhancing creativity in engineering education. However, research indicates that most higher education institutions still lack the needed criteria for providing students with real-world experience that will hone their creative problem solving skills. Creating such environments requires a deeper understanding of different facets of engineering creativity. One key question is how engineering students across related disciplines demonstrate different strengths across the stages of the creative problem solving process. To study this issue, a sample of 505 engineering students was recruited from one northeastern university. Using the analysis of covariance statistical technique, this study compared engineering …

Sergei Mikhailovich Lyapunov’S Piano Sonata Op. 27 (1908): Style, Structure, And Nineteenth-Century Precedents, Andrey Y. Karpyuk

Doctoral Dissertations

Sergei Mikhailovich Lyapunov (1859-1924), Russian composer, pianist, conductor, musicologist, editor and pedagogue, holds an important place in the history of Russian music.Lyapunov established his reputation as a composer and as a distinguished professor at the Saint Petersburg Conservatoire in the early 1900s. Given his prominence in Russian music history, it is surprising that his work is relatively unknown in the United States.

Lyapunov’s Op. 27 Piano Sonata, composed in 1906-08 and published in 1908, is a work of considerable merit both compositionally and pianistically. It is one of the few consequential works modeled directly after Liszt’s Sonata in B minor, …

Educational And Career Aspirations Of University Honors And Non-Honors Students, Amnah S. Hafsyan

Doctoral Dissertations

Academically talented college students who participate in honors programs are generally believed to be more involved in educationally purposeful activities and to hold higher educational and career aspirations than their peers who do not participate in honors programs. Having high educational and career aspirations is beneficial for student success after college. However, the effects of students’ involvement in an honors program on students’ aspirations is unknown. This study examined the aspirations and involvement of two groups of college students—honors students and non-honors students—by class standing (lower division compared to upper division) and gender (male and female) at a single large …

Enhancing Student Engagement And Learning In The Chemical Engineering Laboratory Through Contextually Relevant Experiments & Novel Pedagogies, Daniel Anastasio

Doctoral Dissertations

This dissertation describes the implementation of several new experiments in the chemical engineering teaching laboratory at the University of Connecticut that were developed to showcase chemical engineering fundamentals in a context that more completely reflects modern chemical engineering. Several experiments themed around membrane desalination were developed to highlight the interplay between fluid mechanics and mass transport in these processes. A third membrane-based experiment shows how salinity gradients can be used to generate power, linking concepts relevant to process thermodynamics and efficiency. Another experiment uses a 3D printer to teach students design considerations for laminar flow reactors, drawing on theory relevant …

Classification And Multiple Hypothesis Testing In Microarray And Rna-Seq Experiments, Patrick B. Harrington

Doctoral Dissertations

This thesis focuses on analyzing the type of data returned by two pieces of technology, the older and less expensive microarray, or the next generation sequencing data, RNA-Seq. Both devices return data that is extremely large in volume. Microarray analysis begins by finding genes of interest, which are called differentially expressed (DE). Genes are called DE controlling for some criteria, such as false discovery rate (FDR), and then clustered into groups. A method unifying these two steps was suggested, using a mixture of normal distributions with the appropriate EM algorithm. We compare this to a semi-parametric alternative to the unified …

Beliefs And Practices Of Teachers In Two High-Poverty Urban Schools, Susan C. Domanico

Doctoral Dissertations

This case study examined the beliefs and instructional practices of ten teachers in two high-poverty urban elementary schools. I selected these two schools since the students and staff were racially similar to help isolate the variable of social class. Data were collected on the teachers’ beliefs about low-income students and on instructional practices utilized by teachers. I used social reproduction as the theoretical framework for the research. I conducted structured interviews and announced and unannounced non-participant class observations to determine beliefs and practices used. Data were mapped to four broad concepts: beliefs influenced by social class, beliefs influenced by education …

A Delphi Study: How Counselor Educators In Career Counseling Courses Prepare School Counselors To Address Career Readiness, Nicole G. Deronck Ed.D.

Doctoral Dissertations

This goal of this study is to understand the relationship between the preparation that career counseling courses at the post-secondary level provide school counselors and the implications it has on promoting career readiness. The Delphi method was used to garner consensus of a group of experts on how to prepare pre-service school counselors to conduct career counseling, and to promote and measure career readiness in their work with K-12 students. Seventeen leaders in the field of career counseling who are also counselor educators agreed to fully participate as experts in this study (round one n=5, round two n=7, round three …

On Lowness For Isomorphism As Restricted To Classes Of Structures, Jacob D. Suggs

Doctoral Dissertations

We explore the notion of lowness for isomorphism as restricted to various classes and subclasses of structures. We present results for equivalence structures, scattered linear orders, the non-scattered linear orders known as shuffle sums, and for various restrictions of these classes, with an emphasis on examining which properties, in general terms, of these structures play a role in which results and how changes to the various constructions affect the resulting structures. Finally, we present partial information on the relationships between the various types of results and their associated subclasses of structures, with notes on how we might expect these results …

Control Strategies Of Power Electronic Converters To Improve The Reliability And Stability Of Renewable Energy Systems, Tai-Sik Hwang

Doctoral Dissertations

This dissertation discusses control strategies for power electronic converters that improve the reliability and stability of renewable energy systems. Three approaches are proposed to improve the control performance of a dc-dc converter and a distributed generation (DG) inverter under different operation modes and fault conditions.

First, a seamless control for a dc-dc converter with both discontinuous conduction mode (DCM) and continuous conduction mode (CCM) is proposed. The plant models in DCM and CCM are different in the frequency domain. Therefore, it is difficult to design a controller with stable operation and fast response in both modes. The proposed controller can …

Control And Integration Strategies For Bidirectional And Unidirectional Converters In Residential Distributed Power Systems, Sung Min Park

Doctoral Dissertations

Reactive power compensation is important not only for power system stability but also efficient use of the power transmitted through the electric grid. Although many power electronics-based technologies such as flexible alternating current transmission systems and active power filters have emerged to overcome the shortcomings of traditional passive shunt compensation methods, they may not be the best solution for improvement of power quality of an entire power system due to high capital and operating costs, as well as additional inherent power losses.

Usually, unidirectional power factor correction converters are utilized in many commercial applications as front-end circuitry in order to …

Job Analysis: Measuring Accuracy And Capturing Multiple Perspectives, Deann H. Arnold

Doctoral Dissertations

Organizations rely on job analysis to provide information about the work performed and requirements needed for a position. The use of inaccurate information may have negative outcomes, such as the misallocation of human resources or inefficient training programs. Many job analysis techniques rely on averaging responses, which may oversimplify the results. Preserving idiosyncratic variance, which reflects differences in the ways in which respondents experience and evaluate the job, may increase job analysis accuracy. To assess overall accuracy, the job analysis data in the present study was examined utilizing a practical model of accuracy (Prien, Prien, & Wooten, 2003). To detect …

Grant Proposal: Effects Of Sound Field Amplification On Standardized Test Scores, Jessica Ivey Coker

Doctoral Dissertations

Research has shown that the majority of classroom environments lack appropriate acoustical standards to ensure optimal learning conditions. During the early school grades, it is especially crucial that students overcome poor listening environments to obtain the fundamental educational skills necessary for academic success. Furthermore, the State of Louisiana conducts standardized test assessments (LEAP and iLEAP) to measure the students' knowledge and skills gained. These standardized test scores not only determine if the student progresses to the next grade, but also influences the amount of federal revenue and how the revenue is allocated to the schools. A proposed remedy to …

Sensitivity Of Mixed Models To Computational Algorithms Of Time Series Data, Gunaime Nevine

Doctoral Dissertations

Statistical analysis is influenced by implementation of the algorithms used to execute the computations associated with various statistical techniques. Over many years; very important criteria for model comparison has been studied and examined, and two algorithms on a single dataset have been performed numerous times. The goal of this research is not comparing two or more models on one dataset, but comparing models with numerical algorithms that have been used to solve them on the same dataset.

In this research, different models have been broadly applied in modeling and their contrasting which are affected by the numerical algorithms in different …

Increasing Career Exploratory Behavior Through Message Framing, Lauren Elizabeth Tressler

Doctoral Dissertations

Career indecision is a growing problem for present day college students. As more and more students attend college right out of high school, rates of' indecision are also rising. The consequences of this include increased time to graduation, increased student loans, and decreased likelihood of career satisfaction and fit. While most institutions of higher learning offer services to help students choose a major and career path, these services remain underutilized. Research in this area has focused on investigating the effectiveness of these interventions, with little attention given to methods of increasing utilization of these services as well as career exploratory …

Electrochemical Fatigue Crack Treatment, Konstantin Dolgan

Doctoral Dissertations

Fatigue is responsible for at least 50% of all mechanical and 90% of all metallic failures. Fatigue cracks often start at stress concentrations, and without timely and appropriate remediation, tend to exhibit relatively fast propagation that leads to property damage and sometimes serious accidents.

The objective of this research was to develop a new method of fatigue crack treatment in steel structures and estimate its efficiency and limitations. The method was based on placing fatigue cracks under compression by depositing nickel onto the surfaces of the cracks. The proposed method was applied to ASTM E399 compact-tension specimens machined from ASTM …

Multivariate Longitudinal Data Analysis For Actuarial Applications, Priyantha K. Hewa Katuwandeniyage

Doctoral Dissertations

Analysis of longitudinal data has increased in popularity in recent years for several disciplines that is commonly used to understand the dynamic nature and the heterogeneity within and among subjects. There has been a much more rapid progress of longitudinal analysis for univariate data. However, there is a developing interest of extending the longitudinal framework to handle multivariate responses for obvious reasons: to capture dependence structure of the responses and thereby to increase the efficiency of the model. Actuarial applications in this area are very limited at the moment and it is our hope to contribute to this developing literature. …

Longitudinal Analysis Of Mortality Risk Factors For Actuarial Valuation, Ushani D. Kariyawasam

Doctoral Dissertations

Today, people are living longer and the world population is getting older. Recent statistics indicate that a 65-year-old female in the United States is estimated to live to 88.8 years old, while a 65-year-old male to 86.6 years old. This translates to about a two-year increase in life expectancy from birth compared to that more than a decade ago. Understanding these trends and their potential impact are ever more relevant to the insurance industry. In this thesis, we emphasize the longitudinal modeling framework of pension and long term care insurance using some advanced techniques to analyze patterns and trends in …

The Use Of A Video Self-Modeling Intervention To Decrease Disruptive Behaviors In Students With Intellectual Disability, David M. Sax

Doctoral Dissertations

The study utilized a multiple baseline design across participants to examine the effects of a video self-modeling intervention (VSM) on three middle school students showing high rates of disruptive classroom behaviors. All three students were receiving special education services through the classification of either intellectual disability or autism, and all had documented intellectual and adaptive functioning that met the criteria for an intellectual disability. The purpose of the study was to see whether VSM could reduce disruptive behaviors and if changes could be maintained after the end of treatment. Intervention procedure consisted of students watching videos exclusively showing themselves displaying …

Improving Practices In Nanomedicine Through Near Real-Time Pharmacokinetic Analysis, Isidro B. Magana

Doctoral Dissertations

More than a decade into the development of gold nanoparticles, with multiple clinical trials underway, ongoing pre-clinical research continues towards better understanding in vivo interactions. The goal is treatment optimization through improved best practices. In an effort to collect information for healthcare providers enabling informed decisions in a relevant time frame, instrumentation for real-time plasma concentration (multi-wavelength photoplethysmography) and protocols for rapid elemental analysis (energy dispersive X-Ray fluorescence) of biopsied tumor tissue have been developed in a murine model. An initial analysis, designed to demonstrate the robust nature and utility of the techniques, revealed that area under the bioavailability curve …

Sampling Of Soils With Metallic Residues Collected From Military Small-Arms Ranges, Jay L. Clausen

Doctoral Dissertations

Small-arms, artillery, mortar, and pyrotechnic military training introduces solid metallic residues into the environment. Previous energetic residue research showed conventional judgmental soil sampling and associated sample preparation methodologies are inadequate to address the heterogeneous distribution and still yield representative and reproducible results for the area of interest. Metallic residue deposition at military small-arms ranges occurs in a heterogeneous distributional pattern, similar to solid particulate energetic residue deposition.

One of the primary objectives of an environmental investigation is to estimate the mean contaminant concentration to evaluate human and ecological risk in an exposure unit (i.e., an area where the receptors are …

Nonlinear Waves On A String With Inhomogeneous Properties, Robert Arredondo

Doctoral Dissertations

Nonlinear waves on an infinite string with a rapid change in properties at one location are treated. The string is an idealized version of more complex configurations in both fluids and solids. This idealized version treats the property change as an interface with a discontinuity in properties. Packets of waves are then considered with a reduced model, here a set of nonlinear Schr¨odinger (NLS) equations. The stress and the displacement must both be matched at the interface, resulting in dynamic and kinematic interfacial conditions. The dynamic condition produces an inhomogeneous effect that cannot be treated successfully with separation-of-variables. This inhomogeneity …

A Woman's Work Is Never Done? Earlier Life Child, Marital, And Work History And Older Women's Relationship To The Paid Labor Force, Anne Shattuck

Doctoral Dissertations

In the past 40 years, women in the U.S. have experienced higher rates of labor force participation and higher rates of divorce and single motherhood. How these changes will affect women when they reach old age is not yet understood. Using a pooled sample from the Health and Retirement Study of 4,350 women born between 1931 and 1943, this dissertation assesses patterns of women’s work/retirement circumstances at age 66-68 and evaluates the relationship between those patterns and women’s earlier life marital, work, and childrearing history. Latent class analysis revealed four distinct classes of older women: the "retired well" (57.6% of …

Secondary Preservice, In-Service, And Student Teachers’ Noticing Of Mathematical Work And Thinking In Trigonometry, May Chaar

Doctoral Dissertations

Recognizing and responding to students’ work and thinking are central to reform-minded mathematics teaching; in particular, recent educational reforms advocate for instruction that builds on students’ thinking, requiring teachers’ continual assessment of students’ verbal and written strategies. Despite its significance however, little is known about how secondary mathematics teachers analyze and respond to students’ work and thinking. This study aimed to help explain how teachers carry out this work. In particular, it sought to explain what types of knowledge and other resources enable or inhibit teachers’ in-depth analysis of students’ work and thinking while more generally describing the ways in …

A Supercell, Bloch Wave Method For Calculating Low-Energy Electron Reflectivity With Applications To Free-Standing Graphene And Molybdenum Disulfide, John Francis Mcclain

Doctoral Dissertations

This dissertation reports on a novel theoretical and computational framework for calculating low-energy electron reflectivities from crystalline surfaces and its application to two layered systems of two-dimensional materials, graphene and molybdenum disulfide. The framework provides a simple and efficient approach through the matching of a small set of Fourier components of Bloch wave solutions to the Schrodinger Equation in a slab-in-supercell geometry to incoming and outgoing plane waves on both sides of the supercell. The implementation of this method is described in detail for the calculation of reflectivities in the lowest energy range, for which only specular reflection is allowed. …

Single Chain Technology: Toward The Controlled Synthesis Of Polymer Nanostructures, Christopher Kenneth Lyon

Doctoral Dissertations

A technique for fabricating advanced polymer nanostructures enjoying recent popularity is the collapse or folding of single polymer chains in highly dilute solution mediated by intramolecular cross-linking. We term the resultant structures single-chain nanoparticles (SCNP). This technique has proven particularly valuable in the synthesis of nanomaterials on the order of 5 – 20 nm. Many different types of covalent and non-covalent chemistries have been used to this end.

This dissertation investigates the use of so-called single-chain technology to synthesize nanoparticles using modular techniques that allow for easy incorporation of functionality or special structural or characteristic features. Specifically, the synthesis of …

Porous Medium Convection At Large Rayleigh Number: Studies Of Coherent Structure, Transport, And Reduced Dynamics, Baole Wen

Doctoral Dissertations

Buoyancy-driven convection in fluid-saturated porous media is a key environmental and technological process, with applications ranging from carbon dioxide storage in terrestrial aquifers to the design of compact heat exchangers. Porous medium convection is also a paradigm for forced-dissipative infinite-dimensional dynamical systems, exhibiting spatiotemporally chaotic dynamics if not ``true" turbulence. The objective of this dissertation research is to quantitatively characterize the dynamics and heat transport in two-dimensional horizontal and inclined porous medium convection between isothermal plane parallel boundaries at asymptotically large values of the Rayleigh number $Ra$ by investigating the emergent, quasi-coherent flow. This investigation employs a complement of direct …

Numerical Study On Scaling Effects And Decoupled Network-Based Simulation Of Gaseous Explosion, Liang Wang

Doctoral Dissertations

"This research seeks to improve the prediction efficiency of gaseous explosions realized by numerical simulations in a full-scale underground network using a decoupled method. To provide quick predictions of overpressure distribution of methane explosions in underground airway networks, a two-section theory is employed. The explosion space is divided into a driver section and a blast-wave section. Governing equations including conservation of mass, momentum, and energy, together with chemical reaction and turbulence models are solved for the driver and the blast-wave sections using computational fluid dynamics (CFD) solver ANSYS Fluent (3D-based) and Flowmaster (1D-based) respectively. The three dimensional (3D) and one …

Writing Program Directors' Perceptions Of Factors Promoting Writing Programs, Carole Kempler Meagher

Doctoral Dissertations

Although California grows more socially and ethnically diverse, and its public universities serve this changing population, spending in higher education has been cut over the past few years. In this context, crucial departments such as writing programs, which offer all students the opportunity to build their communication skills while bringing their unique perspectives to traditional theories, have been under pressure for their higher cost than traditional lecture-style and new online courses. Further, writing programs are not always perceived as a source of institutional prestige.

This study starts with critical pedagogy: the idea that education is social change. The study then …

Reliability And Security In Low Power Circuits And Systems, Hui Geng

Doctoral Dissertations

"With the massive deployment of mobile devices in sensitive areas such as healthcare and defense, hardware reliability and security have become hot research topics in recent years. These topics, although different in definition, are usually correlated. This dissertation offers an in-depth treatment on enhancing the reliability and security of low power circuits and systems. The first part of the dissertation deals with the reliability of sub-threshold designs, which use supply voltage lower than the threshold voltage (V_th) of transistors to reduce power. The exponential relationship between delay and V_th significantly jeopardizes their reliability due to process variation …

Iterative Ct Reconstruction From Few Projections For The Nondestructive Post Irradiation Examination Of Nuclear Fuel Assemblies, Muhammad Imran Khan Abir

Doctoral Dissertations

The core components (e.g. fuel assemblies, spacer grids, control rods) of the nuclear reactors encounter harsh environment due to high temperature, physical stress, and a tremendous level of radiation. The integrity of these elements is crucial for safe operation of the nuclear power plants. The Post Irradiation Examination (PIE) can reveal information about the integrity of the elements during normal operations and off‐normal events. Computed tomography (CT) is a tool for evaluating the structural integrity of elements non-destructively. CT requires many projections to be acquired from different view angles after which a mathematical algorithm is adopted for reconstruction. Obtaining many …