Digital Commons Network^™

Detection, Identification And Localization Of R/C Electronic Devices Through Their Unintended Emissions, Vivek Thotla

Doctoral Dissertations

"The accurate and reliable detection of unintended emissions from radio receivers has a broad range of commercial and security applications. This thesis presents detection, identification, and localization methods for multiple RC electronic devices in a realistic environment. First, a Hurst parameter based detection method for super-regenerative receivers (SRR) has been used for detection. Hurst parameter based detection method exploits a self-similarity property of the SRR receiver emissions to distinguish it from background noise. Second paper presents a novel detection and localization scheme of multiple RC electronic devices called Edge-Synthetic Aperture Radar (Edge-SAR). It employs cost-effective, mobile antenna-array detectors. Two types …

Detection And Removal Of Emerging Environmental Contaminants, Ruipu Mu

Doctoral Dissertations

"Water is a very crucial natural resource for human. The increasing number of contaminants detected in water bodies has drawn considerable increasing attention over the last decade. There are numerous emerging environmental contaminants which may cause serious health issues. The recent occurrence studies of these contaminants show both industrial and household activity introduction of chemicals into water resources. These various sources result in a large variety of chemicals such as explosives, pharmaceutical and personal care products (PPCPs) and disinfection byproducts detected in water worldwide. Due to the relatively low contaminant concentrations, development of new and improved detection methods along with …

Occurrence, Monitoring And Removal Of Drinking Water Contaminants By Advanced Technologies, Danielle Marie West

Doctoral Dissertations

"In order to maintain drinking water primary standards compliance under the USEPA Stage 2 Disinfectant Disinfection Byproducts Rule, drinking water treatment plants (DWTPs) are switching from free chlorine (FC) to chloramines (MCA). Concerns are raised as MCA disinfection has been linked N-nitrosamine formation. N-nitrosamines are a group of nitrogenous DBPs (N-DBPs) which are highly carcinogenic in comparison to regulated DBPs (THMs and HAAs, generated by FC disinfection). Also in the forefront of drinking water concerns are other emerging drinking water contaminants such as perchlorate. Perchlorate is a contaminant which can enter drinking water from natural deposits or through introduction by …

On Testing Common Indices For Several Multi-Index Models: A Link-Free Approach, Xuejing Liu

Doctoral Dissertations

"To avoid the curse of dimensionality, and to help us better understand the structure of the high dimensional data, methods for dimension reduction are clearly called for. The common linear dimension reduction techniques for single population include principal component analysis (PCA) which is unsupervised in regression and supervised Partial Least Squares (PLS). Modern sufficient dimension reduction techniques, like the ones we consider, constitute a form of supervised linear dimension reduction which outperform PCA and PLS without the underlying model assumptions.

In practice, we often deal with situations where the same variables are being measured on objects from different groups, and …

Privacy-Preserving Power Usage Control In Smart Grids, Huchun

Doctoral Dissertations

"The smart grid (SG) has been emerging as the next-generation intelligent power grid system because of its ability to efficiently monitor, predicate, and control energy generation, transmission, and consumption by analyzing users' real-time electricity information. Consider a situation in which the utility company would like to smartly protect against a power outage. To do so, the company can determine a threshold for a neighborhood. Whenever the total power usage from the neighborhood exceeds the threshold, some or all of the households need to reduce their energy consumption to avoid the possibility of a power outage. This problem is referred to …

Nano-Structured Materials For Energy Storage Applications, Dongxue Zhao

Doctoral Dissertations

"Hydrogen is a non-polluting and efficient energy carrier. One barrier to utilizing hydrogen is a reliable storage method. NaAlH₄ is the prototypical example of a complex metal hydride with high hydrogen storage capacities (~ 5.5 wt.%) and acceptable reaction temperatures of around 100⁰ when using catalyst. On decomposition of these complex hydrides, such as NaAlH₄, one is left with monohydride NaH. The kinetics of diffusion in the monohydrides is important because reversibility hinges on mass transport and the formation of [AlH₄]^- anions that must structurally coordinate with the alkali metal cation on hydrogen absorption. …

Flow Mechanisms And Numerical Simulation Of Gas Production From Shale Reservoirs, Chaohua Guo

Doctoral Dissertations

"Shale gas is one kind of the unconventional resources which is becoming an ever increasing component to secure the natural gas supply in U.S. Different from conventional hydrocarbon formations, shale gas reservoirs (SGRs) present numerous challenges to modeling and understanding due to complex pore structure, ultra-low permeability, and multiple transport mechanisms.

In this study, the deviation against conventional gas flow have been detected in the lab experiments for gas flow through nano membranes. Based on the experimental results, a new apparent permeability expression is proposed with considering viscous flow, Knudsen diffusion, and slip flow. The gas flow mechanisms of gas …

Discrete And Dynamic Population Models With Logistic Growth Rate, Sabrina Heike Streipert

Doctoral Dissertations

"The Beverton-Holt difference equation defines a discrete relation describing a population model. Considering periodic carrying capacity and periodic inherent growth rate, a population with seasonal changing life cycle and environment is reflected. The so-called periodically forced Beverton-Holt equation is investigated and its unique periodic solution is derived. This provides the first Cushing-Henson conjecture, while a counterexample proves that the classical second Cushing-Henson conjecture is not satisfied. Modifications of the conjecture are formulated. To extend the studies, the Beverton-Holt equation is investigated in the quantum calculus time setting. The existence of the globally attracting periodic solution of the Beverton-Holt q-difference …

Discrete Analogues Of Some Classical Special Functions, Thomas Joseph Cuchta

Doctoral Dissertations

"Analogues of special functions on time scales are studied with special focus on the time scale 𝕋 = hℤ. Functions investigated in particular include complex monomials, new trigonometric functions, Gaussian bell, Hermite and Laguerre polynomials, Bessel functions, and hypergeometric series"--Abstract, page iii.

Small Sample Saddlepoint Confidence Intervals In Epidemiology, Pasan Manuranga Edirisinghe

Doctoral Dissertations

"In section 1, we develop a novel method of confidence interval construction for directly standardized rates. These intervals involve saddlepoint approximations to the intractable distribution of a weighted sum of Poisson random variables and the determination of hypothetical Poisson mean values for each of the age groups. Simulation studies show that, in terms of coverage probability and length, the saddlepoint confidence interval (SP) outperforms four competing confidence intervals obtained from the moment matching (M8), gamma-based (G1,G4) and ABC bootstrap (ABC) methods.

In section 2, we first consider Brillinger's classical model for a vital rate estimate with a random denominator. We …

Small Sample Umpu Equivalence Testing Based On Saddlepoint Approximations, Renren Zhao

Doctoral Dissertations

"In the first section, we consider small sample equivalence tests for exponentiality. Statistical inference in this setting is particularly challenging since equivalence testing procedures typically require a much larger sample size, in comparison to classical "difference tests", to perform well. We make use of Butler's marginal likelihood for the shape parameter of a gamma distribution in our development of equivalence tests for exponentiality. We consider two procedures using the principle of confidence interval inclusion, four Bayesian methods, and the uniformly most powerful unbiased (UMPU) test where a saddlepoint approximation to the intractable distribution of a canonical sufficient statistic is used. …

Quantum Inspired Algorithms For Learning And Control Of Stochastic Systems, Karthikeyan Rajagopal

Doctoral Dissertations

"Motivated by the limitations of the current reinforcement learning and optimal control techniques, this dissertation proposes quantum theory inspired algorithms for learning and control of both single-agent and multi-agent stochastic systems.

A common problem encountered in traditional reinforcement learning techniques is the exploration-exploitation trade-off. To address the above issue an action selection procedure inspired by a quantum search algorithm called Grover's iteration is developed. This procedure does not require an explicit design parameter to specify the relative frequency of explorative/exploitative actions.

The second part of this dissertation extends the powerful adaptive critic design methodology to solve finite horizon stochastic optimal …

Active - Passive Spent Fuel Interrogation Using Neutrons And Photons, Tayfun Akyurek

Doctoral Dissertations

“This dissertation consists of three main parts. The first part is devoted to the comprehensive dead-time calculations with different detectors and conditions using different dead-time models as well as computer simulations. The minimum time that must separate two detectable events is called the counting system’s dead-time. If events take place during the system’s dead-time, they will not be recorded and will be lost. Such lost information is very important in many applications including high-intensity spectroscopy and nuclear spent fuel interrogations. The second part, a multitude of fission products identified as candidates have been scrutinized for their suitability of burnup analysis …

Cormem Digital Reasoning Architecture Using Cmos Technology, Indira Priyadarshini Dugganapally

Doctoral Dissertations

”This dissertation describes the application of a multi-level, memory-based approach for building digital circuits. To reflect the alternative approach, the basic science is termed digital reasoning and the specific CorMem technology is based on recent patents. CMOS transistors are used in a non-traditional way for multi-level operations and memory manipulation. The combination of multi-level architectures and matrix algebra principles can create flexible, modular systems using standard fabrication methods and can avoid many of the limitations of other multi-valued logic approaches.

Quaternary, memory-based systems are developed to implement logic-gate-type functions, digital adder circuits, a complete arithmetic and logic unit (ALU), quaternary-to-binary …

Mechanistic Modeling Of Cutting Forces In Wavy-Edge Bull-Nose Helical End-Milling Of Inconel 718 Under Different Cooling-Lubrication Strategies, Abdulhakim Ali Sultan

Doctoral Dissertations

“This research presents the results of the development of a mechanistic cutting force prediction model for the wavy-edge bull-nose helical endmill (WEBNHE). The mechanistic model was developed to predict cutting force components and the resultant cutting force in high-speed end-milling of Inconel 718 under two cooling strategies: emulsion and Minimum Quantity Lubrication (MQL). The effects of the cooling strategies are incorporated into the mechanistic model through six cutting force coefficients (K_tc, K_rc, K_ac), and edge force coefficients (K_te, K_re, K_ae), which have been experimentally identified in a separate …

Efficient Cryptographic Primitives: Secure Comparison, Binary Decomposition And Proxy Re-Encryption, Feng Li

Doctoral Dissertations

”Data outsourcing becomes an essential paradigm for an organization to reduce operation costs on supporting and managing its IT infrastructure. When sensitive data are outsourced to a remote server, the data generally need to be encrypted before outsourcing. To preserve the confidentiality of the data, any computations performed by the server should only be on the encrypted data. In other words, the encrypted data should not be decrypted during any stage of the computation. This kind of task is commonly termed as query processing over encrypted data (QPED).

One natural solution to solve the QPED problem is to utilize fully …

Microstructure And Geotechnical Properties Of St. Peter Sandstone In Clayton, Iowa, Amir Hossein Bagherieh

Doctoral Dissertations

"The St. Peter Sandstone is significantly different from the minerals and rocks which have been studied extensively in mining. It is brittle and characterized by an unusually high friction angle. On the other hand it is friable, and it is nearly cohesionless. The scarcity of the ground control techniques for this particular mining environment has created many difficulties for mine operators. This research aims to establish a fundamental understanding of the basic mechanical and strength properties of the St. Peter Sandstone for engineering design and scientific research. The specific objectives are 1) characterizing the strength of the St. Peter Sandstone, …

Distributed State Verification In The Smart Grid Using Physical Attestation, Thomas Patrick Roth

Doctoral Dissertations

"A cyber process in a distributed system can fabricate its internal state in its communications with its peers. These state fabrications can cause other processes in the distributed system to make incorrect control decisions. Cyber-physical systems have a unique advantage in the detection of falsified states because processes typically have observable effects on a shared physical infrastructure. This physical infrastructure acts as a high-integrity message channel that broadcasts changes in individual process states. The objective of this research is to demonstrate that there are cases where physical feedback from the shared infrastructure can be used to detect state fabrications. To …

Detection And Recognition Of R/F Devices Based On Their Unintended Electromagnetic Emissions Using Stochastic And Computational Intelligence Methods, Shikhar Prasad Acharya

Doctoral Dissertations

"Radio Frequency (RF) devices produce some amount of Unintended Electromagnetic Emissions (UEEs). UEEs are generally unique to a device and can be thought of as a signature of the device. This property of uniqueness of UEEs can be used to detect and identify the device producing the emission. The problem with UEEs is that they are very low in power and are often buried deep inside the noise band which makes them difficult to detect. There are two types of UEE detection methods. The first one is called stimulated detection method where the UEEs of a device are enhanced using …

Mineral And Geochemical Attributes Of The Midcontinent Rift Sequence; An Application For Deep Carbon Dioxide Sequestration, Alsedik Mohamed Ali Abousif

Doctoral Dissertations

"The potential for using the Oronto Group of the Midcontinent Rift (MCR) Sequence for CO₂ sequestration has been disparaged because of low porosity-permeability characteristics, which are largely a result of extensive calcite cementation. This study investigated the potential for using the MCR as a target for CO₂ sequestration by examining reactions involving detrital host-rock minerals at high pressure-temperature conditions that could provide dissolved Ca²⁺, Mg²⁺, and Fe²⁺, and then precipitating these cations as carbonate minerals. The effect of carbonic acid on cement dissolution was also evaluated with respect to enhancing porosity and …

Dynamic Behavior Of Operational Wind Turbines Considering Aerodynamic And Seismic Load Interaction, Mohammad-Amin Asareh

Doctoral Dissertations

"With the advancements in the wind energy production industry, the demand for a cost effective and safe design of wind turbine structures is growing rapidly. The wide deployment of wind turbines in locations with high seismic hazard has lead engineers to take into account a more comprehensive seismic design of such structures. In response to the need for a computational tool that can perform coupled simulations of wind and seismic loads, a seismic module has been developed for the publicly available National Renewable Energy Laboratory (NREL) code, FAST, at the first step of this research. This achievement allows engineers working …

How Women’S College Student Involvement Contributes To Their Career Aspirations And Navigation For Success In Technology Startup Organizations, Heather Doshay

Doctoral Dissertations

The purpose of the study was to explore the relationship between women’s (co)curricular student involvement in college and their career outcomes in technology startups. This study focused on the ways in which past student involvement shaped women’s future career aspirations and helped them navigate their present career situations to achieve success. The study extended Astin’s Student Involvement Theory by considering how student involvement impacted career outcomes.

The qualitative methodology incorporated nine semi-structured interviews with recent college graduates turned professional women in startups working in the San Francisco Bay Area. The interviews were transcribed and coded for themes and analyzed using …

Using Computer Simulations As A Pre-Training Activity In A Hands-On Lab To Help Community College Students Improve Their Understanding Of Physics, Blanca Pineda

Doctoral Dissertations

The purpose of this study was to investigate the effectiveness of using computer simulations as a pre-training activity to a hands-on lab to improve students’ understanding of induction topics in physics. The computer simulation activity was compared to an overview presentation. Conceptual understanding and spatial ability were measured. A two-group descriptive repeated measures design was implemented with a convenience sample of 35 community college physics students in the Bay Area. Participants were randomly assigned to a simulation group (n = 17) or a presentation group (n = 18). A 30-item spatial ability assessment was given to all participants one week …

Documenting The Experiences Of Gay Latinos In Higher Education Through The Use Of Testimonio, Lorenzo Fabian Garcia

Doctoral Dissertations

This qualitative study focuses on the stories of six self-Identified Gay Latinos in a higher education. The participant’s stories are documented using Testimonio. The six men were uniquely situated to give their testimonios about their campus experiences of seeking support in that they were the narrators of the experiences. Key findings indicated a pipeline of support which began with supportive families. Multidimensional identity was well defined by the participants as understanding of being both Latino and Gay. The participants, while exploring campus spaces for support, found themselves navigating through one identity or the other resulting in a process of selective …

Application Of Colloidal Unimolecular Polymer (Cup) Particles In Coatings, Sagar Vijay Gade

Doctoral Dissertations

"Colloidal unimolecular polymer (CUP) particles were prepared by the process of water reduction on copolymers containing hydrophobic and hydrophilic monomers at definite ratio using free radical polymerization. The CUPs are formed by the effect of hydrophilic /hydrophobic interactions of the polymer with a change in the solvent environment around them. Once formed these colloidal particles are thermodynamically stable with collapsed hydrophobic groups forming a spheroidal core and hydrophilic charges on the surface stabilizing the particle by the charge repulsion. CUPs contain only the charged CUP particles, water and counterions with all the functionality on the surface for further chemistry. CUP …

Modeling, Fabrication, And Characterization Of Memristors, Anas Mazady

Doctoral Dissertations

The term “memristor” was coined by L. Chua from its two distinct functional characteristics, memory and resistor. From the symmetry argument of the circuit element and circuit variable matrix, memristor is deemed as the fourth fundamental circuit element, after resistor, capacitor, and inductor. Memristor switching and observed I-V characteristics are explained utilizing the underlying physics of the device in terms of the formation and rupture of filaments. Three different conduction mechanisms, namely - filament assisted tunneling current, bulk tunneling current and currents flowing through low and high conductivity filaments give rise to the total current in memristive systems. DC and …

Utilizing Computer Programming To Analyze Post-Tonal Music: A Segmentation And Contour Analysis Of Twentieth-Century Music For Solo Flute, Kate Sekula

Doctoral Dissertations

Two concepts will be synthesized in this dissertation: 1) the creation of accessible computer applications for melodic segmentation and contour reduction and 2) the application of segmentation and contour reduction to analyze twentieth-century post-tonal works for unaccompanied flute. Two analytical methodologies have been chosen: James Tenney and Larry Polanski's Gestalt segmentation theory and Robert Schultz's refinement of Robert Morris's contour reduction algorithm. The investigation also utilizes Robert Schultz's concept of diachronic-transformational analysis in conjunction with contour reduction. While both segmentation and contour reduction are invaluable analytical tools, they are meticulous and time-consuming processes. Computer implementation of these algorithmic procedures produces …

Promoting Academic Talent Development In Adolescents: Protective Factors And Linkages To Summer Program Participation, Kelly L. Kearney

Doctoral Dissertations

Special summer programs are considered a popular service-delivery approach to bolster the talent development of all students. This study seeks to explore protective factors that influence high-ability students’ talent development. Factors influencing the talent development of high-ability students are understudied, often in favor of researching underachievement and resilience.

Because very little research seeks the perceptions of these students in their own words, this study used a grounded theory approach to explore 54 students’ perceptions of their own talent development within the context of a residential, inquiry-based summer program for high-ability adolescents. Responses across all parts of the study revealed three …

Project Technologia: A Game-Based Approach To Understanding Situated Intentionality, Stephen Thomas Slota

Doctoral Dissertations

Since the early 2000s, educators, administrators, politicians, and researchers have given increased attention to the potential affordances of video games for educating K-12 and university learners. This has led to the instantiation of numerous game-based learning (GBL) journals, investigations of efficacy, achievement, and motivation using multimillion dollar tools, and a federally-funded competition for science, technology, engineering, and mathematics game development. Yet, little is known about the way particular game mechanics, narrative structures, and community-driven tools (e.g., forums, cheat guides, mods) influence the skills needed to be a successful 21^st century learner. Few studies have catalogued the particular actions and …

Implementing Professional Learning Communities In A High-Performing School District To Address Stagnating Student Performance, Alan Addley

Doctoral Dissertations

Abstract

This study explored the implementation of professional learning community (PLC) teams as a primary strategy for school improvement in the immediate schools (grades 3-6) and middle school (grades 7 & 8) of a high performing school district. The study used program theory as an evaluation approach (Chen and Rossi, 1992; Rogers, Petrosino, Huebner & Hacsi, 2000; Weiss, 1996). Through the use of a logic model, program theory was used to retrospectively investigate the PLC implementation steps taken by principals that were intended to change teachers’ practices and lead to higher levels of student achievement. The evaluation of the PLC …