Digital Commons Network^™

Electrocardiogram Signal Analysis For R-Peak Detection And Denoising With Hybrid Linearization And Principal Component Analysis, Harjeet Kaur, Rajni Rajni

Turkish Journal of Electrical Engineering and Computer Sciences

In the areas of biomedical and healthcare, electrocardiogram (ECG) signal analysis is one of the major aspects of research. The accuracy in the detection of subtle characteristic features in ECG is of great significance. This paper deals with an algorithm based on hybrid linearization and principal component analysis for ECG signal denoising and R-peak detection. The ECG data have been taken from the MIT-BIH Arrhythmia Database for performance evaluation. The signal is denoised by applying the hybrid linearization method, which is an arrangement of the extended Kalman filter along with discrete wavelet transform, and then principal component analysis is employed …

Offset-Free Adaptive Nonlinear Model Predictive Control With Disturbance Observer For Dc-Dc Buck Converters, Bahareh Vatankhah, Mohammad Farrokhi

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this paper is to design a nonlinear model predictive control for DC-DC buck converters to track constant reference signals with zero steady-state error. The online trained neural network (NN) model is employed as the predictor and the steady-state error, which is called the offset, is studied in the presence of the changes in system parameters and the external disturbances. The stability of the closed-loop system is investigated using the Lyapunov direct theory. The proposed method can provide offset-free behavior in the presence of constant disturbances. For rejecting nonconstant disturbances, a nonlinear disturbance observer based on the NN …

Modified Control Of The Matrix Converter-Based Drive For Voltage Sag Impact Reduction, Gytis Petrauskas, Gytis Svinkunas

Turkish Journal of Electrical Engineering and Computer Sciences

Faults in transmission and distribution networks often cause voltage sags. Direct matrix converter (DMC)-based drives are a new generation of electrical drives. Unlike the conventional two-stage diode supply-side inverter drive, the DMC drive has no direct current (DC) link capacitor and no capacitor charging-time delay before operation. The absence of a DC link makes the DMC-based drive more sensitive to voltage sags. The above-mentioned faults in transmission and distribution networks could degrade the DMC drive's performance and reliability. This paper investigates possible kinds and levels of voltage sags, dependency on network configuration, and the behavior of the DMC-based drive under …

Study Of Thermal History In Hollow Cylinder Under Laser-Assisted Machining Process Using Fem, Mujahid Mohiuddin Mohammed

Graduate Research Theses & Dissertations

Ceramics are brittle material and possess lower toughness when compared to metals. This brittle nature results in the formation of cracks and cutting tool fracture when tried to machine conventionally. Thus, diamond grinding was the only method of processing ceramics until the development of Laser Assisted Machining (LAM). In LAM, a laser is used to rise the temperature of the surface of the component which is later machined conventionally. LAM yields in higher material removal rate and superior surface finish while reducing the total machining cost. At elevated temperatures ceramics act as a ductile material thereby enabling plastic deformation and …

Study Of Wear On Square-Shaped Die During Deep Drawing Of An Anisotropic Sheet, Syed Zakrea

Graduate Research Theses & Dissertations

Deep drawing is a manufacturing operation widely used in manufacturing industries for producing diversified products in large numbers and for continuous production. The automobile is one among those using deep drawing for manufacturing components like automobile outer body parts and seals. Die is one of the expensive components in this operation and the quality of the die has an impact on the quality of the finished product. Die is subjected to severe mechanical and tribological conditions due to sliding of sheet over the die and high contact pressure between the die and sheet. These harsh tribological conditions result in wear …

Stereotype Threat : A Qualitative Study Of The Challenges Facing Female Undergraduate Engineering Students, J. R. Entsminger Ii

Graduate Research Theses & Dissertations

From a sociocultural point of view, this qualitative case study explored how upper-level, female undergraduate engineering students perceived the possibility of or experience with stereotype threat as shaping their experiences. The study also investigated how these students explained their reasons for choosing their engineering major, the challenges they encountered in the major, and their reasons for persevering in spite of those challenges. Using Steele and Aronson's (1995) stereotype threat theory as a framework, and considering the documented underrepresentation of females in engineering, the study sought to examine how stereotype threat shaped the experiences of these students and if stereotype threat …

Dbhgt : The Fungal Horizontal Gene Transfer Database, Marcus Nguyen

Graduate Research Theses & Dissertations

Horizontal gene transfer (HGT) is a growing area of research in bioinformatics. It has been studied heavily in bacteria due to the abundance of genome data available as well as its various links to pathogenicity and antimicrobial resistance. With the growing number of fungi being sequenced, fungal research in HGT has also began to grow. It has also been linked to pathogenicity as well. Many tools exists to predict HGT candidates; many of these are targeted for bacteria. Due to the growing research in fungi, tools that have been tested on fungi are in high demand. Having precomputed, public results …

Density-Based Spatial Clustering Of Applications With Noises For Dna Methylation Data, Mohammed Atef Alghzzy

Graduate Research Theses & Dissertations

Density-based spatial clustering of applications with noise (DBSCAN) is one of the most popular clustering methods to classify nonlinearly grouped data. In particular, DNA methylations are considered to be differently skewed by CpG sites and to be nonlinearly grouped by cancer statuses. Under this circumstance, DBSCAN is expected to have a desirable clustering feature. This thesis reviews the DBSCAN algorithm and compares its performance to the other traditional clustering algorithm, K-means method. Simulation studies show the misclassification ratios of DBSCAN with the comparison of K-means method to evaluate their performance, and the classification of DNA methylations from patients with lung …

Design And Mechanical Stability Analysis Of The Interaction Region For The Inverse Compton Scattering Gamma-Ray Source Using Finite Element Method, Andrei Khizhanok

Graduate Research Theses & Dissertations

Development of a compact source of high-spectral brilliance and high impulse frequency gamma rays has been in scope of Fermi National Accelerator Laboratory for quite some time. Main goal of the project is to develop a setup to support gamma rays detection test and gamma ray spectroscopy. Potential applications include but not limited to nuclear astrophysics, nuclear medicine, oncology ('gamma knife'). Present work covers multiple interconnected stages of development of the interaction region to ensure high levels of structural strength and vibrational resistance. Inverse Compton scattering is a complex phenomenon, in which charged particle transfers a part of its energy …

Non-Newtonian Rheological Characteristics Of Oil-Based Metal Oxide Nanofluids, Syed Mahmood Hasan

Graduate Research Theses & Dissertations

A nanofluid is a generally considered to be base fluid that contains nanoparticle suspensions, where the nanoparticles could either be metals, metal oxides, or non-metals. Rheological properties of nanofluids play an important role in determining heat transfer capacity and pumping power of a fluid as they have the potential to improve heat transfer capacity and pumping power over a base fluid. This research can give us a clear understanding of how particle concentration and type of nanoparticle affect the viscosity of a nanofluid, which is the main parameter that influences the rheological properties of a fluid based on range of …

Principal Motivation In The Era Of Accountability, Matthew Vosberg

Graduate Research Theses & Dissertations

The state of Illinois has raised the expectations for principal performance with the 2010 passage of the Performance Evaluation Reform Act (PERA), which requires 30% of a principal's evaluation to be linked to student achievement data. This reform effort is the latest iteration of school accountability measures that have been implemented in schools across the country. There have been increased efforts at the state and federal level to increase accountability for school performance as measured by standardized test results. The linkage of standardized test scores to individual evaluations marks the strongest efforts to bring accountability to principals for the academic …

Helping Users Learn About Social Processes While Learning From Users : Developing A Positive Feedback In Social Computing, Venkata Sai Sriram Pillutla

Graduate Research Theses & Dissertations

Social computing is concerned with the interaction of social behavior and computational systems. From its early days, social computing has had two foci. One was the development of technology and interfaces to support online communities. The other was to use computational techniques to study society and assess the expected impact of policies. This thesis seeks to develop systems for social computing, both in the context of online communities and the study of societal processes, that allow users to learn while in turn learning from users. Communities are approached through the problem of Massive Open Online Courses (MOOCs), via a complementary …

High School Science Teachers' Interpretations And Perceptions Of Reform And Literacy In The Discipline Of Science, Rachel A. Lesinski-Roscoe

Graduate Research Theses & Dissertations

This qualitative study sought to gain an understanding of science teachers' perceptions of reform and their role in implementing reform and science-based literacy practices in the classroom, as well as gain an understanding of science teachers' knowledge of disciplinary literacy as the implied framework of reform (i.e., the Next Generation Science Standards). Four focal participants from a suburban, middle-class high school district comprised of two high schools participated in semi-structured interviews, observations, and a stimulated recall task and interview. Data analysis revealed some of the Discourse memberships in which participants claimed membership and the tensions that resulted from those memberships. …

Review Symposium: Four Perspectives On Karl Rahner's Theological Aesthetics, By Peter Joseph Fritz, Judith Wolfe, Gesa Thiessen, Robert Masson, Mark F. Fischer

Theology Faculty Research and Publications

No abstract provided.

Energetic Effects Of Hole Transporting Materials On The Performance Of Organometal Halide Perovskite Photovoltaic Cells, So Min Park

Theses and Dissertations--Chemistry

Efficient, inexpensive, lightweight and flexible solar cells are desired to help meet the world’s growing energy needs. Organometal halide perovskite (OMHP) photovoltaic (PV) cells have shown dramatic increases in solar cell efficiencies increase over the last 5 years. OMHP PV cells have attracted significant attention due to their broad absorption spectra, high electron and hole mobility, and low production cost. The interface between hole transporting layer (HTL) and perovskite thin films have a significant influence on charge transfer and overall solar cell performance. 2,2’,7,7’-tetrakis(N,N-di-p-methoxyphenylamine)9,9’-spirobifluorene (Spiro-OMeTAD) is a small molecule largely used as HTL in perovskite solar cells. However, this material …

Biomimetic Devices To Drive A Thermodynamically Uphill Reaction Using Light And To Degrade Industrial Waste Stream Components, Madison Joanne Sloan

Theses and Dissertations--Chemistry

Given the amount of industrial waste produced each year, as well as the accruing amount of greenhouse gases in our atmosphere produced by the burning of fossil fuels, it is imperative that humanity develop environmentally-sustainable sources of energy and methods of remediation. Nature achieves both of these by use of enzymes as catalysts, inspiring interest in designing biomimetic systems capable of harnessing clean energy and remediating industrial waste. This study examined the ability of enzymes in electrochemical and convective flow systems to achieve these tasks. The first portion studied the incorporation of enzymes into an electrochemical system to drive the …

Oxidative Stress And Proteomic Studies Of Mammalian Models Of Age-Related Metabolic Dysfunction In Neurodegenerative Disorders, Aaron M. Swomley

Theses and Dissertations--Chemistry

Expression proteomics is the field of science wherein proteins that make up the cellular proteome are identified both by name and by fold-change. Depending on the application of proteomics, this change in level could be due to internal cellular stressors or introduction of xenobiotics. Global oxidative stress measures use immunohistochemistry to determine the relative level of oxidative stress of macromolecules within the cell. In this dissertation, both global oxidative stress measures and expression proteomics were used in a variety of mammalian models in order to determine the effects of protein upregulation, intranasal insulin administration, and resveratrol supplementation on the cellular …

Mechanisms Of Heterogeneous Oxidations At Model Aerosol Interfaces By Ozone And Hydroxyl Radicals, Elizabeth A. Pillar-Little

Theses and Dissertations--Chemistry

Atmospheric aerosols play an important role in climate by scattering and absorbing radiation and by serving as cloud condensation nuclei. An aerosol’s optical or nucleation properties are driven by its chemical composition. Chemical aging of aerosols by atmospheric oxidants, such as ozone, alters the physiochemical properties of aerosol to become more hygroscopic, light absorbing, and viscous during transport. However the mechanism of these transformations is poorly understood. While ozone is a protective and beneficial atmospheric gas in the stratosphere, it is a potent greenhouse gas in the troposphere that traps heat near the Earth’s surface. It also impacts human heath …

Heterogeneous Base Metal Catalyzed Oxidative Depolymerization Of Lignin And Lignin Model Compounds, John Adam Jennings

Theses and Dissertations--Chemistry

With the dwindling availability of petroleum, focus has shifted to renewable energy sources such as lignocellulosic biomass. Lignocellulosic biomass is composed of three main constituents, lignin, cellulose and hemicellulose. Due to the low value of cellulosic ethanol, utilization of the lignin component is necessary for the realization of an economically sustainable biorefinery model. Once depolymerized, lignin has the potential to replace petroleum-derived molecules used as bulk and specialty aromatic chemicals. Numerous lignin depolymerization strategies focus on cleavage of β-aryl ether linkages, usually at high temperatures and under reductive conditions.

Alternatively, selective benzylic oxidation strategies have recently been explored for …

Semiconductor Photocatalysis: Mechanisms, Photocatalytic Performances And Lifetime Of Redox Carriers, Ruixin Zhou

Theses and Dissertations--Chemistry

Photocatalytic reactions mediated by semiconductors such as ZnS, TiO₂, ZnO, etc. can harvest solar energy into chemical bonds, a process with important prebiotic and environmental chemistry applications. The recycling of CO₂ into organic molecules (e.g., formate, methane, and methanol) facilitated by irradiated semiconductors such as colloidal ZnS nanoparticles has been demonstrated. ZnS can also drive prebiotic reactions from the reductive tricarboxylic acid (rTCA) cycle such as the reduction of fumarate to succinate. However, the mechanism of photoreduction by ZnS of the previous reaction has not been understood. Thus, this thesis reports the mechanisms for heterogeneous photocatalytic reductions …

Characterization And Application Of Hybrid Nanostructures For Enhanced Biological Imaging Using Fluorescence Microscopy Techniques, William E. Martin

Theses and Dissertations--Chemistry

Fluorescence microscopy is a powerful tool for interpreting the structure and function of biomolecules, and their interactions with one another. Understanding fundamental biological mechanisms is important to the development of improved treatments for a variety of diseases. Fluorescent tags are used to track the motion and longevity of such events, with the ability to monitor several biomolecules at once. Currently, many of these studies are conducted using bulk measurements, or several biological events at the same time, because the added light from several emitters can more easily overcome the high fluorescence background inherent to biological systems. Although important in their …

Interactions Of Compounds Containing Group 12 And 16 Elements, Daniel Burriss

Theses and Dissertations--Chemistry

The focus of this dissertation is on the interactions of compounds containing group 12 and 16 elements. This work is presented in three major parts. First, the interaction of the synthetic dithiol N,N’-bis(2-mercaptoethyl)isophthalamide), abbreviated BDTH₂, with selenite. Second, the interaction of cysteine with Cd(II) and the biologically relevant Cd-Cysteine crystal structure. Third, the green synthesis of CdSe quantum dots (QDs).

The interaction of BDTH₂ with selenite is different from the interactions with other metals and metalloids previously studied. Under ambient conditions, BDTH₂ is oxidized to the disulfide, BDT(S-S), while selenite is reduced to elemental selenium. However, …

Epigenetic Modifications To Cytosine And Alzheimer’S Disease: A Quantitative Analysis Of Post-Mortem Tissue, Elizabeth M. Ellison

Theses and Dissertations--Chemistry

Alzheimer’s disease (AD) is the most common form of dementia and the sixth leading cause of death in the United States, with no therapeutic option to slow or halt disease progression. Development of two characteristic pathologic lesions, amyloid beta plaques and neurofibrillary tangles, in the brain are associated with synaptic dysfunction and neuron loss leading to memory impairment and cognitive decline. Although mutations in genes involved in amyloid beta processing are linked to increased plaque formation in the inherited familial form of AD, the more common idiopathic form, termed sporadic AD, develops in the absence of gene mutations. In contrast, …

Thermal Analysis Of Selective Laser Melting (Slm) Process For Metallic Additive Manufacturing, Shiva Ratakonda

Graduate Research Theses & Dissertations

Additive manufacturing widely known as 3D printing is receiving groundbreaking level of attention from industry and research laboratories. The research and development effort has gained tremendous momentum from simple 3D printers to advanced quick manufacturing systems that create functional parts without the need for tooling. While majority of the current 3D printers available in the market build parts using polymeric materials, recent research and development effort is also concentrated on building parts using metals, ceramics, and composites. Electron Beam Melting (EBM), Selective Laser Sintering (SLS), and Selective Laser Melting (SLM) are attractive processes for metallic parts. It is one of …

A Utility-Value Intervention : Will It Help Hispanic Parents To Motivate Their Adolescents In Mathematics?, Margaret Molenda-Lesniak

Graduate Research Theses & Dissertations

Academic motivation declines during middle- and high-school years and its diminishing effects are especially evident in science, technology, engineering, and mathematics (STEM) subjects. The goal of this study was to examine a possible cause-effect relationship between a utility-value intervention and mathematics motivation of middle-school Hispanic students. Through experimental manipulation, the researcher assisted parents in conveying the importance of mathematics to their adolescents to influence students' mathematics motivation. The four-month long intervention consisted of a brochure that was mailed to parents, a website, and biweekly Facebook posts, all emphasizing the usefulness and importance of mathematics courses. Data were collected using pre- …

Ability Group Configuration For The High School Physics Classroom, Scott Zitnik

Graduate Research Theses & Dissertations

This research project looks to investigate the effectiveness of different ability grouping arrangements for the high school physics classroom. Students were first organized based on their academic aptitude in physics into three general groups of high, medium, and low achieving students. They were then divided into both groups of four and dyads that were constructed in one of four arrangements, namely: random, homogeneous, heterogeneous, or student choice. Data was collected based on their academic performance as well as survey responses regarding the group and dyad performance. Students worked in a rotation of these groups and dyads for a unit to …

Acceptance Of Integration Of Mobile Technology In The Higher Education Environment : Instructors' Perception, Shawnice L. Avilez

Graduate Research Theses & Dissertations

The purpose of this survey research was to determine factors that influenced college instructors' behavioral intentions to use mobile technology. The study extended the Technology Acceptance Model (TAM) framework, with subjective norm and facilitating conditions acting as potential predictors of instructors' behavioral intention and self-reported intention to use mobile technology (iPads/laptops). A survey instrument was adapted by the author from published guidelines and prior research surveys. The survey was delivered using Qualtrics, a web-based survey tool. The survey instrument included items based on the constructs of the TAM model. The researcher analyzed the data using multiple regression analyses. Utilization of …

Competition And Community Interactions Of Two Generalist Herbivores, Elizabeth Ellen Barnes

Electronic Theses and Dissertations

Competition can have far-reaching consequences for the fitness and distribution of many organisms. In herbivorous insects, competition mediated by a third organism is more common than direct competition and has a strong effect on insect communities; yet most research on indirect competition among herbivores focuses on dietary specialists, and those studies that do include generalists tend to rear them on agricultural crops. My project examines species interactions at three levels: intraspecific competition (within species), interspecific competition (between species), and ecosystem engineering effects at the community level. I studied competition and community interactions of two temporally-separated species of herbivorous insects, western …

Mathematics Teachers' Beliefs And Mathematical Knowledge For Teaching: How Teachers' Mkt Shifts In Planning And Impacts Their Beliefs And Instructional Practice, Paul Conley

Electronic Theses and Dissertations

In an effort to understand how a teacher developed Mathematical Knowledge for Teaching and how that knowledge can shift teacher's beliefs and instructional practice, I worked with a teacher to deeply plan and implement six mathematical lessons.

The research suggests that planning can be a vehicle to develop a teacher's Mathematical Knowledge for Teaching. In addition, as a teacher's Mathematical Knowledge for Teaching started to develop through lesson planning, the teacher's beliefs about her own knowledge of mathematics started to increase which started to shift the teacher's instructional practice.

This combination of a stronger Mathematical Knowledge for Teaching, self confidence …

Formulation And Characterization Of Poly(Β-Amino Ester) Networks For Controlled Delivery Of Antioxidants In Pharmaceutical Applications, Vinod Shivaji Patil

Theses and Dissertations--Chemical and Materials Engineering

Oxidative stress, which reflects an imbalance between oxidants and endogenous antioxidants, is known to be a cause as well as an effect of health conditions such as cancer, diabetes, Alzheimer’s disease, Parkinson’s disease and ischemia-reperfusion injury. Antioxidants have shown promising results in vitro in controlling oxidative stress. However, years of in vitro studies have failed to translate into effective clinical interventions for controlling oxidative stress in the disease conditions. This has been due to low bioavailability and lower stability of antioxidants. Poly(antioxidant β-amino esters) (PABAE) are a recently-developed class of biodegradable polymeric hydrogels that have shown promise in their ability …