Electrical and Computer Engineering Commons^™

Assessment Of Risk In Preterm Infants Using Point Process And Machine Learning Approaches, Venkata Naga Sai Apurupa Amperayani

Electrical Engineering Theses

Preemies, infants who are born too soon, have a higher incidence of Life-Threatening Events (LTE’s) such as apnea (cessation of breathing), bradycardia (slowing of heart rate) and hypoxemia (oxygen desaturation) also termed as ABD (Apnea, Bradycardia, and Desaturation) events. Clinicians at Neonatal Intensive Care Units (NICU) are facing the demanding task of assessing the risk of infants based on their physiological signals. The aim of this thesis is to develop a risk stratification algorithm using a machine-learning framework with the features related to pathological fluctuations derived from point process model that will be embedded into the current physiological recording system …

Digital Enhancement Of Analog Measurement Systems For Temperature Compensation Of Strain Gages, Islombek Karimov

Electrical Engineering Theses

Generally known temperature compensation techniques for strain gages (like the use of a dummy gage or the implementation of half- and full-bridge configurations) are not applicable to all strain-measurement situations and cannot fully compensate for all sources of error. Digital Enhancement of Analog Measurement Systems presents a universal method of corrections for these effects in which temperature is measured independently of other variables and ex post facto corrections are computed and applied to digitized readings of the analog measurement system.

A single, linear-pattern strain gage, self-temperature-compensated for steel 1018, has been utilized in a quarter-bridge to measure tensile strain in …

Electrical & Computer Engineering News, Georgia Southern University

Electrical & Computer Engineering: News & Publications (2014-2023)

• Control of High-Frequency Power Electronic Systems

The Power Of Coefficients And Methods Of Coding In Delimiting Species Using Phenetic Approach: The Case Of African Solanum Section Solanum Sensu Edmonds, Mkabwa Lk Manoko

Tanzania Journal of Science

Phenetics is one of approaches used to delimit species in plant classification. Conclusion in phenetics is based on overall similarity often of morphological data. The approach uses coded data that are analyzed using coefficients to create similarity matrices that are analyzed using clustering analysis to create the classification. Exists different similarity coefficients and coding methods though in practice are used intuitively sometimes giving results that have been challenged. Though similarity coefficients and coding methods have some times been blamed, studies to analyze their influences are limited. The trend however is to avoid morphological data in favor of DNA markers. The …

Total Electron Content Derived From Global Positioning System During Solar Maximum Of 2012-2013 Over The Eastern Part Of The African Sector, Emmanuel D Sulungu, Christian Bs Uiso, Patrick Sibanda

Tanzania Journal of Science

This work presents results of diurnal, seasonal and latitudinal variations of vertical Total Electron Content (TECv) derived from GPS receivers at four locations, [Dodoma (6.19oS, 35.75oE), Mzuzu (11.43oS, 34.01oE), Zomba (15.38oS, 35.33oE) and Tete (16.15oS, 33.58oE)] during the solar maximum period of 2012 – 2013. The receivers are located directly below the EIA and at approximately the same longitude, ~ (33 – 3 oE) within the eastern part of the African sector. Diurnal and latitudinal variations of TECv are presented for an average of the five (5) quietest days of each of the four seasons: March equinox, June solstice, September …

Tolerance Sensitivity Analysis And Robust Optimal Design Method Of A Surface-Mounted Permanent Magnet Motor By Using A Hybrid Response Surface Method Considering Manufacturing Tolerances, Cha-Seung Jun, Byung-Il Kwon, Ohbong Kwon

Publications and Research

This paper presents a robust optimal design method using a hybrid response surface method (H-RSM) which directly finds an optimal point satisfying a target Z-value or a probability of failure. Through three steps, this paper achieves the goal that is to increase the open-circuit airgap flux (OCAF) in a surface-mounted permanent magnet motor and decrease its variation caused by variations of the airgap lengths including an additional one between permanent magnets and rotor back yoke. First, the OCAF equation is derived from the magnetic equivalent circuit (MEC) considering the additional airgap. Then, the equation is validated by comparing its results …

Thermal Comparison Of Polycrystalline Diamond And Aln In Power Semiconductor Device Packages, Brandon M. Guenther

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The desire for improved thermal management in power semiconductor device packaging is becoming increasingly important due to the progression towards implementing wide-bandgap semiconductor (WBG) materials, such as silicon carbide (SiC) and gallium nitride (GaN). These semiconductor materials have the capability of operating at much higher voltages, temperatures, and frequencies compared to standard silicon-based devices. However, utilizing this enhanced operating region will induce larger thermomechanical stress within the package structure as a consequence of operating at higher junction temperatures around 250-300 °C. To handle the higher and improved operating characteristics from the WBG semiconductors, the current package technology is modified by …

Nmr Studies Of Loaded Microspheres, Ming Huang, Sisi Chen, Rex E. Gerald Ii, Jie Huang, Klaus Woelk

Electrical and Computer Engineering Faculty Research & Creative Works

Porous-wall hollow glass microspheres (PWHGMs) are a novel form of glass materials that consist of 1-μm-thick porous silica shells, 20-100 μm in diameter, with a hollow cavity in the center. Utilizing the central cavity for material storage and the porous walls for controlled release is a unique combination that renders PWHGMs a superior vehicle for targeted drug delivery. In this study, NMR spectroscopy was used to characterize PWHGMs for the first time. A vacuum-based loading system was developed to load PWHGMs with various compounds followed by a washing procedure that uses solvents immiscible with the target material. Immiscible binary model …

Radiation Source Localization By Using Backpropagation Neural Network, Jian Meng, Christof Teuscher, Walt Woods

Student Research Symposium

The most difficult part of the radiation localization is that we cannot use the traditional acoustic localization method to determine where the radiation source is. It’s mainly because the electromagnetic waves are totally different with the sound wave. From the expression of the radioactive intensity, we can tell that the intensity of radiation not only depend on the distance from the radiation but also related to the type of the nuclide. In general, the relationship between the intensity and the distance satisfy the inverse-square law, which is a non-linear relationship. In other words, if we can use the measurement and …

Biochemical Reservoir Computing, Hoang Nguyen, Christof Teuscher

Student Research Symposium

Reservoir computing is an emerging machine learning paradigm. Compared to traditional feedforward neural networks, the reservoir can be unstructured and recurrent and only the output layer is trained. Reservoirs can be built with various types of physical components, yet, biochemical building blocks have not been widely used. This project focuses on designing and testing a reservoir computer (RC) based on chemical reaction network (CRN). We simulated high-level CRNs in MATLAB and their complex chemical dynamics were observed over time. A CRN constructed by a network of coupled deoxyribozyme oscillators was chosen for the final RC model. The inputs of the …

Using Reservoir Computing To Build A Robust Interface With Dna Circuits In Determining Genetic Similarities Between Pathogens, Christopher Neighbor, Christof Teuscher

Student Research Symposium

As computational power increases, the field of neural networks has advanced exponentially. In particular recurrent neural networks (RNNs) are being utilized to simulate dynamic systems and to learn to predict time series data. Reservoir computing is an architecture which has the potential to increase training speed while reducing computational costs. Reservoir computing consists of a RNN with a fixed connections “reservoir” while only the output layer is trained. The purpose of this research is to explore the effective use of reservoir computing networks with the eventual application towards use in a DNA based molecular computing reservoir for use in pathogen …

Wideband Absorber Characterization Using Coaxial Airline And Electromagnetic Simulation, Ha Tran, Thanh Le, Branimir Pejcinovic

Student Research Symposium

With the increase in popularity of electronic devices especially the wireless devices, microwave absorber becomes more essential to reduce electromagnetic interference. A deep understanding of electromagnetic properties namely electric permittivity and magnetic permeability is required in order to fabricate, test and use microwave absorber. In this study, we focused on developing a procedure to parameterize material electromagnetic properties. We first extract material properties by placing samples inside an airline and taking measurements of scattering parameters matrix with a vector network analyzer. Air-line is the preferred transmission line medium since the traveling wave inside the airline is both TEM and confined. …

Experimental Validation Of External Load Effects For Micro-Contacts Under Low Frequency, Low Amplitude Alternating Current (Ac) Test Conditions, Protap Mahanta, Ronald A. Coutu Jr., Dushyant Tomer

Electrical and Computer Engineering Faculty Research and Publications

The use of micro-contacts has been demonstrated in various radio frequency (RF) applications. However, the premature failure of such devices under alternating current (AC) operations is still a hurdle to further development. In this work, modified gray scale lithography is performed to fabricate two types of gold–gold (Au–Au) micro-contacts: hemispherical-planar and hemispherical-2D pyramid. The performance of these devices was investigated under low frequency, low amplitude AC conditions with external circuit loads. A custom-made experimental setup which uses various load configurations, controls the frequency of the applied voltage and modifies the cycle rate of switch operation to obtain the contact resistance …

Harmonic Detection And Selectively Focusing Electromagnetic Waves Onto Nonlinear Targets Using Time-Reversal, Joseph Michael Faia

Graduate Theses - Electrical and Computer Engineering

Ultra-wide band radar is a growing interest for the enhanced capability of ranging, imaging, and multipath propagation. An ultra-wide band pulse imposed on a system provides a near impulse like response and is, therefore, more descriptive than a conventional monotonic pulse. Combining pulse inversion with ultra-wide band DORT (a French acronym for the decomposition of the time reversal operator) is a technique which could be used to for greater visibility of nonlinear targets via harmonic detection in the presence of larger linear scatterers. Energy can be selectively focused onto nonlinear scatterers in complex, inhomogeneous environments. This thesis1, will expand upon …

Long-Range Indoor Emitter Localization From 433mhz And 2.4ghz Wlan Received Signal Strengths, Hang Du

Graduate Theses - Electrical and Computer Engineering

An improved search method for localizing a radio emitter in a building from its signal strength is proposed and implemented. It starts from floor level determination, which samples the signal strength on each floor and determines the floor level of the emitter. Then the search is conducted iteratively on a specific floor. For each round of search, one-dimensional (1-D) or two-dimensional (2-D) signal strength is collected according to the actual structure of the floor. The signal strength data are processed to fit a 1-D curve or a 2-D surface with regression models to establish an indicator or trend, which can …

Differential Launch Structures And Common Mode Filters For Planar Transmission Lines, Zachary Thomas Bergstedt

Graduate Theses - Electrical and Computer Engineering

Increases in signal speeds and decreases in dimensions pose increasing threats to signal integrity (SI) and electromagnetic compatibility (EMC) in differential interconnects due to the enhanced risk of common mode (CM) conversion. This thesis examines CM filtering solutions for multiple transmission topologies that mitigate CM noise, reducing the threat to SI and EMC. These topologies include microstrip and stripline, which are the most commonly used transmission line architecture in printed circuit boards (PCB), and broadside coupled coplanar waveguides (BC-CPW). Stripline and BC-CPW transmission lines have lower dispersion and attenuation than the commonly used microstrip but have added complexity in introducing …

A Folded Cascode Operational Amplifier With Wide-Swing Current Mirrors And High Icmr, Designed With A 1.2-Micron Silicon-Carbide Process, Austin Gattis

Electrical Engineering Undergraduate Honors Theses

This thesis describes in detail the process of designing, simulating, and creating the layout for a modified folded cascode op-amp, fabricated with silicon carbide MOSFETS. The modifications consist of using a wide-swing current mirror to help deal with output voltage issues stemming from high threshold voltages in the silicon carbide process, as well as using a modification that allows for an increased input common mode range. The folded cascode op-amp uses silicon carbide transistors, as it is intended to be used for high temperature applications, ideally in the 25 C - 300 C range. It is designed to have 25 …

Command Validation For Cybersecure Power Router, Isaac M. Kroger

Electrical Engineering Undergraduate Honors Theses

For grid-connected homes equipped with solar panels, power electronics are necessary to manage and convert power between the solar panels, battery storage, grid, and residential load. A power router can be used to manage these power electronics and govern power generation, storage, and distribution within the household. This level of control makes power routers that do not employ cybersecurity a target for external attacks. The use of command validation is an effective way to prevent unauthorized commands from maliciously altering the state of a home’s power router. The purpose of this thesis is to describe the development of the command …

Comparison Of Data Transfer Alternatives In Asynchronous Circuits, Mark Howard

Computer Science and Computer Engineering Undergraduate Honors Theses

Digital integrated circuits (ICs) have become progressively complex in their functionality. This has sped up the demand for asynchronous architectures, which operate without any clocking scheme, considering new challenges in the timing of synchronous systems. Asynchronous ICs have less stringent environmental constraints and are capable of maintaining reliable operation in extreme environments, while also enjoying potential benefits such as low power consumption, high modularity, and improved performance. However, when the traditional bus architecture of synchronous systems is applied to asynchronous designs, handshaking protocols required for asynchronous circuit operation result in significantly increased power consumption, offsetting the low power benefit of …

Automatic Testing In The United States Air Force, Pearson Wade

Computer Science and Computer Engineering Undergraduate Honors Theses

The need for standardized Automatic Testing Equipment in the United States Department of Defense has brought about new policies and procedures within entities like the United States Air Force. The diversity and lifespan of systems such as jets, missiles, drones, and other electronics have brought on the need for a new system known as the Versatile Depot Automatic Test Station, or VDATS. The VDATS handles the automatic testing of replaceable digital circuits from different systems. I was introduced to this system firsthand during my time as an intern at Tinker AFB, Oklahoma. This new standardized approach to testing a diverse …

Scada And Plc Systems Configuration For The Ncrept Test Facility, Arman Ahmed

Electrical Engineering Undergraduate Honors Theses

This thesis details the project to update the control and interface system of the National Center for Reliable Electric Power Transmission (NCREPT) testing facility. The need for this project arose from the 2017-2018 expansion of the facility, which included some modifications in the layout of electrical equipment used for testing purposes. These modifications necessitated the update of the control and interface system. Additionally, the old system was implemented a decade ago and is nearing obsolescence, so the facility’s expansion served as an opportune time for an upgrade.

There were two main parts to the scope of this project, which were …

A Human Powered Micro-Generator For Charging Electronic Devices, John Adam

Senior Theses

A hand-pulled generator has been designed and tested. A preliminary result has been obtained and discussed. This device was created to provide outlet-free charging. Electronic devices are useful when going out into the wilderness. A portable power supply is necessary to keep an electronic device alive. This project created a device that converts human energy into electricity to charge electronic devices. This thesis overviews the device’s design, build, and tests. Two different tests were run to determine that the device is capable of charging the storage battery. The device presented can provide 14 minutes of charging time with one hour …

Increasing The Longevity Of Tungsten Filaments In A Zone Refiner, Byron D. Greenlee

Senior Theses

Zone refining is used for its ability to purify material and grow single crystals. To produce these single crystals, a suspended molten zone, generated by electron bombardment, passes along the polycrystalline stock. During a zone refining run, the filaments that produce the electron bombardment can fail. In this project, the longevity of tungsten filaments in a zone refiner was investigated. A new bombardment geometry was constructed to attempt to increase the longevity of the filaments. The new geometry had a shield machined into it to prevent line-of-sight impurities originating in the molten zone from striking the filaments. It was found …

Measuring The Double Layer Capacitance Of Electrolyte Solutions Using A Graphene Field Effect Transistor, Agatha Ulibarri

Senior Theses

When operating graphene field effect transistors (GFETs) in fluid, a double layer capacitance (C_dl) is formed at the surface. In the literature, the C_dl is estimated using values obtained using metal electrode experiments. Due to the distinctive electronic and surface properties of graphene, there is reason to believe these estimates are inadequate. This work seeks to directly characterize the double layer capacitance of a GFET. A unique method for determining the C_dl has been implemented, and data has been obtained for three electrolytes and one ionic fluid. The results yield dramatically lower C_dl values than …

Measuring The Double Layer Capacitance Of Electrolytes With Varied Concentrations, Geoffrey Rath

Senior Theses

When electric potentials are applied from an electrolytic fluid to a metal, a double layer capacitor, C_dl, develops at the interface. The layer directly at the interface is called the Stern layer and has a thickness equal to roughly the size of the ions in the fluid. The next layer, the diffuse layer, arises from the gathering of like charges in the Stern layer. This layer is the distance needed for ionic charges to return to equilibrium. This distance, called the Debye length, λ, depends on the square root of the electrolyte concentration. To study the properties of …

High Temperature Wide Bandgap Light Emitting Diodes For Harsh Environment Applications, Stephanie Sandoval

Electrical Engineering Undergraduate Honors Theses

The need for high temperature, high power density power modules for applications such as electric vehicles and space exploration has driven the research into wide bandgap LEDs due to their potential operation at elevated temperatures. Wide bandgap LEDs offer an attractive solution due to properties such as high temperature tolerance, strong radiation hardness and good thermal conductivity. In this thesis, the electrical properties of GaN-on-SiC heterojunctions are studied as a precursor to an LED study, and the optical characterization of an InGaN/GaN MQW is reported. The GaN-on-SiC study revealed that these wide bandgap LEDs have linear sensitivity at high temperatures. …

Efficient Control Message Dissemination In Dense Wireless Lighting Networks, Conrad Dandelski

PhDs

Modern lighting systems using LED light sources lead to dense lighting installations. The control of such systems using wireless Machine-to-Machine (M2M) where standard LED light sources are replaced by wirelessly controllable LED light sources create new problems which are investigated in this thesis. Current approaches for control message transmission is such networks are based on broadcasting messages among luminaires. However, adequate communication performance - in particular, sufficiently low latency and synchronicity - is difficult to ensure in such networks, in particular, if the network is part of a wireless building management system and carries not only low-latency broadcast messages but …

Thermoelectrics And Thermoelectric Devices, Benjamin T. Erck

Senior Theses

The field of thermoelectrics has many applications, and more are found in everyday systems. From its current studies, it is apparent that improving the figure of merit zT (which defines a good thermoelectric material) is important in the effectiveness of power generation. Another important part of thermoelectrics is the duality of these devices. They can both move heat and generate power, depending on their role in the system. In this thesis research, a process was made to test these thermoelectric relationships for a few Peltier devices in order to understand their efficiencies and what systems they can be applied to.

Wireless Powered Flexible Gastrostimulator, Souvik Dubey

Electrical Engineering Dissertations - Archive

Gastric electrical stimulation (GES) is an effective alternative to long-term dietary and medicinal treatment for gastroparesis. This work presents the design and development of two miniature implantable battery-less gastrostimulators, operated by wireless radio-frequency power. The devices deliver controlled electrical pulses to the stomach tissues to help regain normal motility. The first prototype was designed with the goal to optimize the wireless power transfer efficiency, various antenna configurations were investigated. The attenuation due to human tissue barrier was examined with an equivalent model. To enable reconfiguring the device to meet the patients' needs after implantation, a novel method of changing the …

Devices To Study Cancer Cell Behavior, Mohammad G. Abdallah

Electrical Engineering Dissertations - Archive

Cancer is a major health concern that effects millions of people worldwide. The main contributing factor to the deadliness of the disease is cancer metastasis, where the cancer cells break away from the primary tumor site, transmigrate through the endothelium, and form secondary tumors in distant areas. Many studies have identified links between the mechanical properties of the cellular microenvironment and the behavior of cancer cells. Also, nanobiotechnology and bioMEMS have had a tremendous impact on biosensing in the areas of cancer cell detection and therapeutics, disease diagnostics, and DNA analysis. Most current technologies enable observation of only the population-level …