Electrical and Electronics Commons^™

High Voltage Dc-Dc Converter Design For Submarine Application, Oscar Ambriz

Master's Theses

In this work a proof of concept for a step-down DC-DC converter used in a high voltage submarine application is presented. The purpose of the converter is to step down a 5000V-6000V input to a 24V output which can serve as an input to a submarine sensor. The completed system consists of two stages where the first stage is an unregulated switched capacitor converter to step down the initial input to a voltage range more appropriate for the selected second stage. The second stage is a regulated flyback converter topology which regulates the final output to the desired 24V. Performance …

Non-Invasive In-Vitro Glucose Monitoring Using Optical Sensor And Machine Learning Techniques For Diabetes Applications, Maryamsadat Shokrekhodaei

Open Access Theses & Dissertations

Diabetes is a major public health challenge affecting more than 451 million people. Physiological and experimental factors influence the accuracy of non-invasive glucose monitoring, and these need to be addressed before replacing the finger prick method with a non-invasive glucose measurement technique. Also, the suitable employment of machine learning techniques on experimental data can significantly improve the accuracy of glucose predictions.

This work includes the design, development, testing and data analysis of an optical based sensor for glucose measurements. The feasibility of non-invasive measurement of glucose within aqueous solutions that assimilate the composition of human blood plasma is investigated. The …

Fast Magnetic Resonance Image Reconstruction With Deep Learning Using An Efficientnet Encoder, Tahsin Rahman

Open Access Theses & Dissertations

This thesis aims to develop an efficient, deep network based method for Magnetic Resonance Imaging (MRI) acceleration through undersampled MR image reconstruction. Deep Neural Networks, particularly Deep Convolutional Networks, have been demonstrated to be highly effective in a wide variety of computer vision tasks, including MRI reconstruction. However, modern highly efficient encoder structures, such as the EfficientNet can potentially reduce reconstruction times further while improving reconstruction quality. To that end, we have developed a multi-channel U-Net MRI reconstruction network which uses an EfficientNet encoder and a custom asymmetric. The network was trained and tested using 5x undersampled multi-channel brain MR …

Embracing Low-Power Systems With Improvement In Security And Energy-Efficiency, Pramesh Pandey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As the economies around the world are aligning more towards usage of computing systems, the global energy demand for computing is increasing rapidly. Additionally, the boom in AI based applications and services has already invited the pervasion of specialized computing hardware architectures for AI (accelerators). A big chunk of research in the industry and academia is being focused on providing energy efficiency to all kinds of power hungry computing architectures. This dissertation adds to these efforts.

Aggressive voltage underscaling of chips is one the effective low power paradigms of providing energy efficiency. This dissertation identifies and deals with the reliability …

Analysis And Design Of 3-Phase Unfolding Based Ac-Dc Battery Chargers, Rees R. Hatch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents the analysis and design of high-efficiency battery chargers for heavy duty EV applications. The rise in popularity of the electric vehicles (EVs) due to their increased efficiency over conventional internal combustion engines, has driven the need for more battery charging infrastructure. Furthermore, heavy duty vehicles are also being converted to electric to fill needs such as public transportation via bus fleets as well as cargo delivery via semi-trucks. Such heavy duty vehicles require more energy than personal transportation vehicles and thus require larger battery packs. To charge heavy duty battery packs in the same amount of time …

Assessment Of The Impacts Of Climate Variability On Hydropower Generation: A Case Study Of The New Pangani Falls, Tanzania, Dativa Byarufu

Tanzania Journal of Engineering and Technology (TJET)

Climate change poses potential impacts on hydropower generation either positively by increasing or negatively by decreasing river flow. This study assessed the impacts of climate variability on hydropower with a focus on the New Pangani Falls in Tanzania. Rainfall and temperature time series data from 1980-2014 were analyzed in relation to river discharge and associated impacts to hydropower generation. The Man-Kendall test was used to detect trend in both annual and seasonal time series. The results showed a negative trend in annual rainfall with Z= -2.41 at α = 0.05 and the slope Q = -0.964. Seasonal trend analysis showed …

Performance Of Calcium Chloride- Ammonia Adsorption Refrigeration System, Michael John

Tanzania Journal of Engineering and Technology (TJET)

An experimental study on the performance of calcium chloride-ammonia adsorption system is described. A single bed water cooled condenser adsorption refrigerator prototype, which utilises calcium chloride-ammonia pair has been developed and tested in the laboratory. Experiments have been conducted for desorption temperatures of 100 °C with desorption time varying from 1 to 4 hours. An electric tape heater and a timer were used to perform the experiments. The adsorption temperature profile, adsorption rate and prototype performance have been analysed and discussed. The tested heating and desorption temperature of 100 °C and heating and desorption time of 1 to 4 hours …

Socio-Technical Perspective For Electronic Tax Information System In Tanzania, Lucas Ngowi, Ellen Kalinga

Tanzania Journal of Engineering and Technology (TJET)

Socio-technical systems theory has rarely been used by system architects in setting up computing systems. However, the role of socio-technical concepts in computing, which is becoming social in nature, has made the concepts more relevant and commercial. Tax information systems are examples of such systems because they are influenced by external variables such as the political environment, technological trends, and social environment, introducing complexity in their deployment and determining the type of e-services and their delivery to a diverse group of people. It was observed that in Tanzania there is resistance, reluctance and minimal use of electronic tax system because …

Load Flow Solution Of Distribution Systems - A Bibliometric Survey, K. V. S. Ramachandra Murthy, Vijay Kumar D, Lakshmi Kambhampati, Rayudu Srinivas, Rayudu Srinivas

Library Philosophy and Practice (e-journal)

In this paper, Bibliometric Survey has been carried out on ‘Load Flow Solution of Distribution Systems’ from 2012 to 2021. Scopus database has been used for the analysis. There were total 1711 documents found on this topic. The statistical analysis is carried out source wise, year wise, area wise, Country wise, University wise, author wise, and based on funding agency. Network analysis is also carried out based on Co-authorship, Co-occurrence. Results are presented. During 2020 and 2018, there were 263 documents published which is the highest. ‘IEEE Transactions on Power Systems’ has published 90 documents during the period of study …

Efficient, Dual-Particle Directional Detection System Using A Rotating Scatter Mask, Robert Olesen, Bryan V. Egner, Darren E. Holland, Valerie Martin, James E. Bevins, Larry W. Burggraf, Buckley E. O'Day Iii

AFIT Patents

A directional radiation detection system and an omnidirectional radiation detector. The omnidirectional radiation detector detects radiation comprising at least one of: (i) gamma rays; and (ii) neutron particles. A radiation scatter mask (RSM) of the radiation detection system includes a rotating sleeve received over the omnidirectional radiation detector and rotating about a longitudinal axis. The RSM further includes: (i) a fin extending longitudinally from one side of the rotating sleeve; and (ii) a wall extending from the rotating sleeve and spaced apart from the fin having an upper end distally positioned on the rotating sleeve spaced apart or next to …

Grammatical Evolution For Detecting Cyberattacks In Internet Of Things Environments, Hasanen Alyasiri, John Clark, Ali Malik, Ruairí De Fréin

Conference papers

The Internet of Things (IoT) is revolutionising nearly every aspect of modern life, playing an ever greater role in both industrial and domestic sectors. The increasing frequency of cyber-incidents is a consequence of the pervasiveness of IoT. Threats are becoming more sophisticated, with attackers using new attacks or modifying existing ones. Security teams must deal with a diverse and complex threat landscape that is constantly evolving. Traditional security solutions cannot protect such sys- tems adequately and so researchers have begun to use Machine Learning algorithms to discover effective defence systems. In this paper, we investigate how one approach from the …

Experimental And Analysis Of Electromagnetic Characterization Of Biological And Non-Biological Materials In Microwave, Millimeter-Wave, And Terahertz Frequency Bands, Nagma Vohra

Graduate Theses and Dissertations

The goal of this research is to characterize the electromagnetic properties of biological and non-biological materials at terahertz (THz), millimeter-wave, and microwave frequency bands. The biological specimens are measured using the THz imaging and spectroscopy system, whereas the non-biological materials are measured using the microwave and millimeter-wave free-space system. These facilities are located in the Engineering Research Center at the University of Arkansas. The THz imaging system (TPS 3000) uses a Ti-Sapphire laser directed on the photoconductive antennas to generate a THz time domain pulse. Upon using the Fourier Transform, the spectrum of the pulsed THz signal includes frequencies from …

Efficiently Estimating Survival Signature And Two-Terminal Reliability Of Heterogeneous Networks Through Multi-Objective Optimization, Daniel Bruno Lopes Da Silva

Graduate Theses and Dissertations

The two-terminal reliability problem is a classical reliability problem with applications in wired and wireless communication networks, electronic circuit design, computer networks, and electrical power distribution, among other systems. However, the two-terminal reliability problem is among the hardest combinatorial problems and is intractable for large, complex networks. Several exact methods to solve the two-terminal reliability problem have been proposed since the 1960s, but they have exponential time complexity in general. Hence, practical studies involving large network-type systems resort to approximation methods to estimate the system's reliability. One attractive approach for quantifying the reliability of complex systems is to use signatures, …

Design And Validation Of A High-Power, High Density All Silicon Carbide Three-Level Inverter, Zhongjing Wang

Graduate Theses and Dissertations

Transportation electrification is clearly the road toward the future. Compared to internal combustion engine, the electrified vehicle has less carbon-dioxide emission, less maintenance costs and less operation costs. It also offers higher efficiency and safety margin. More importantly, it relieves human’s dependence on conventional fossil energy. In the electrification progress, the revolution of electric traction drive systems is one of the most important milestone. The traction system should keep high efficiency to avoid performance reduction. Moreover, the motor drive should be designed within limited space without sacrificing output power rating. Based on the road map from US Drive Electrical and …

Reference Design Of An Online Emulation And Hot-Patching Approach For Power Electronic Controller Validation, Estefano Soria Pearson

Graduate Theses and Dissertations

This thesis aims to develop a reference design of an online security system approach embedded in a power electronic controller for cybersecurity purposes. Cybersecurity in power electronics focuses on reducing vulnerabilities in the system, where most reside in the communication with the hardware devices. Although methods to secure communications lessen the probability and effects of cyber-attacks, discovering vulnerabilities is inevitable. This thesis attempts to provide a fail-safe approach to securing the system by targeting the safety of the power-electronic controller. This approach applies an additional security layer in case of a malicious or accidental controller firmware malfunction.

The online security …

Monte-Carlo-Based Analysis Of Traffic Flow For Urban Air Mobility Vehicles, Sara Ghayouraneh

Graduate Theses and Dissertations

The research conducted in this dissertation is focused on developing a simulation tool that can predict the traffic flow patterns of the Urban Air Mobility vehicles to alleviate some of the challenges related to their traffic management. First, an introduction to the concept of Urban Air Mobility is given, the usage of Automatic Dependent Surveillance-Broadcast systems for Urban Air Mobility vehicles is suggested and dynamic addressing concept is introduced as an answer to a part of air traffic management and address scarcity challenge for Urban air Mobility vehicles. Next, in order to simulate the traffic flow patterns of the Urban …

Distributed Modeling Approach For Electrical And Thermal Analysis Of High-Frequency Transistors, Amirreza Ghadimi Avval

Graduate Theses and Dissertations

The research conducted in this dissertation is focused on developing modeling approaches for analyzing high-frequency transistors and present solutions for optimizing the device output power and gain. First, a literature review of different transistor types utilized in high-frequency regions is conducted and gallium nitride high electron mobility transistor is identified as the promising device for these bands. Different structural configurations and operating modes of these transistors are explained, and their applications are discussed. Equivalent circuit models and physics-based models are also introduced and their limitations for analyzing the small-signal and large-signal behavior of these devices are explained. Next, a model …

Computational Modeling Of Black Phosphorus Terahertz Photoconductive Antennas Using Comsol Multiphysics With Experimental Comparison Against A Commercial Lt-Gaas Emitter, Jose Isaac Santos Batista

Graduate Theses and Dissertations

This thesis presents computational models of terahertz (THz) photoconductive antenna (PCA) emitter using COMSOL Multiphysics commercial package. A comparison of the computer simulated radiated THz signal against that of an experimentally measured signal of commercial reference LT-GaAs emitter is presented. The two-dimensional model (2D) aimed at calculating the photoconductivity of a black phosphorus (BP) PCA at two laser wavelengths of 780 nm and 1560 nm. The 2D model was applied to the BP PCA emitter and the LT-GaAs devices to compare their simulated performance in terms of the photocurrent and radiated THz signal pulse. The results showed better performance of …

Flying Free: A Research Overview Of Deep Learning In Drone Navigation Autonomy, Thomas Lee, Susan Mckeever, Jane Courtney

Articles

With the rise of Deep Learning approaches in computer vision applications, significant strides have been made towards vehicular autonomy. Research activity in autonomous drone navigation has increased rapidly in the past five years, and drones are moving fast towards the ultimate goal of near-complete autonomy. However, while much work in the area focuses on specific tasks in drone navigation, the contribution to the overall goal of autonomy is often not assessed, and a comprehensive overview is needed. In this work, a taxonomy of drone navigation autonomy is established by mapping the definitions of vehicular autonomy levels, as defined by the …

On-Chip Nanoscale Plasmonic Optical Modulators, Abdalrahman Mohamed Nader Abdelhamid

Theses and Dissertations

In this thesis work, techniques for downsizing Optical modulators to nanoscale for the purpose of utilization in on chip communication and sensing applications are explored. Nanoscale optical interconnects can solve the electronics speed limiting transmission lines, in addition to decrease the electronic chips heat dissipation. A major obstacle in the path of achieving this goal is to build optical modulators, which transforms data from the electrical form to the optical form, in a size comparable to the size of the electronics components, while also having low insertion loss, high extinction ratio and bandwidth. Also, lap-on-chip applications used for fast diagnostics, …

A Brief Bibliometric Survey On Night Vision Bot Using Dynamic Ir And Object Detection, Devesh Abhyankar Mr., Gurumoorty Suresh Mr., Hrithik Sambhaji Karjule Mr., Parth Bhardwaj Mr., Harish Muleva Mr., Anurag Mahajan Dr.

Library Philosophy and Practice (e-journal)

This study aims to analyse the work done in the field of Night Vision Robots using IR and Object Detection from 2011 to 2021, using the bibliometric methods. This paper presents a Scopus database review on "Night Vision Bot using Dynamic IR and Object Detection". The necessity for doing this bibliometric survey is that to know how the technology in the field of mobile robotics and night vision, as well as to object detection, has evolved over the years. This paper shows the importance of Night Vision Robot from the year 2011 and continued up to 2021 April. The database …

Autonomous Navigation Of The Surface Autonomous Vehicle For Emergency Rescue (Saver), Andrew Skow

ENGS 88 Honors Thesis (AB Students)

Once dropped into the ocean, SAVER will autonomously navigate towards the Advanced Next-Generation Emergency Locator beacon, worn by every NASA astronaut, that emits a 121.5 MHz distress signal. Using a rotating directional loop antenna SAVER is able to detect and identify the direction of the distress beacon and navigate itself towards the signal source. The autonomous navigation system is dependent on several electrical, and mechanical systems to function properly and presents a novel systems engineering problem. Given testing limitations, NASA requires that SAVER is designed to operate indoors and with an umbilical power supply. The radio direction finding (RDF) system …

Detection Of Subsurface, Nanometer-Scale Crystallographic Defects By Nonlinear Light Scattering And Localization, Farbod Shafiei, Tommaso Orzali, Alexey Vert, Mohammad-Ali Miri, Pui Yee Hung, Man Hoi Wong, Andrea Alù, Gennadi Bersuker, Michael C. Downer

Advanced Science Research Center

Heteroepitaxial crystalline films underlie many electronic and optical technologies but are prone to forming defects at their heterointerfaces. Atomic-scale defects such as threading dislocations that propagate into a film impede the flow of charge carriers and light degrading electrical/optical performance of devices. Diagnosis of subsurface defects traditionally requires time-consuming invasive techniques such as cross-sectional transmission electron microscopy. Using III–V films grown on Si, noninvasive, bench-top diagnosis of subsurface defects have been demonstrated by optical second-harmonic scanning probe microscope. A high-contrast pattern is observed of subwavelength “hot spots” caused by scattering and localization of fundamental light by defect scattering sites. Size …

Pilltank, Lucas Chang, Hayden Tam, Aaron Teh, Krista Round

Electrical Engineering

Imagine an elderly family member, going through their daily routine of taking their pills. They find their pill box; however, they are having trouble identifying all the pills in there. Is there a name on the tablet? Can they read what it says? Do they just trust that the medication in their box is correct? How can they properly take care of themselves if they can not even confirm that what they are taking is the right medication? To combat this issue that many face, we present PillTank.

To decrease the risk of consuming the wrong medication, PillTank identifies the …

Development Of A Low-Cost Hybrid Music Synthesizer, Spencer Rollins Drewry

Electrical Engineering

Until recently, affordable music equipment has always been seen as “budget”, providing a poor user experience. Inexpensive equipment was plagued with audible noise, signal integrity issues, and convoluted user interfaces. Companies like Teenage Engineering have proven that this does not have to be the case, in 2019 introducing their "Pocket Operator” series for $89. Due to the modern availability of low cost, high quality, consumer off the shelf [COTS] analog and digital components as well as creative engineering, the quality of inexpensive audio equipment has increased significantly. Despite these industry advances, the market is relatively small and shows a great …

Dc-Dc Buck Boost Converter Using The Lt8390 Controller And Gan High Electron Mobility Transistors, Juan Manuel Urbano Jr, Brian Thongchai Keokot

Electrical Engineering

California Polytechnic State University, San Luis Obispo’s ongoing Energy Harvesting from Exercise Machines (EHFEM) project creates a sustainable energy source by converting physical exercise from exercise machines into renewable electricity. Implementing energy harvesting technology into the Recreation Center’s exercise machines helps Cal Poly make progress on its goal of carbon neutrality by 2050 [1]. An improvement to the system with new technology increases Cal Poly Recreation Center’s ability to save money and improve sustainability.

The focus of this project improves the design of Nicholas Serres, who used the LT8390 controller in his buck boost DC-DC converter [2]. This project improves …

Wildfire Early Detection System (Weds), Mason Mciver, Vincent Liang, Jeanreno Racines

Electrical Engineering

With climate change causing an increase in temperature over the past several decades, wildfires have been burning hotter and moving quicker leaving a trail of destruction in their path. Detecting a wildfire early allows firefighters to respond efficiently and effectively to ensure containment. With the rise of advanced computer vision and algorithms, autonomous systems can be used to monitor and report any fire activity. Having multiple devices spread out across a large area will allow first responders to map out the fire location and track the fire. By utilizing smart technologies, property damage can be minimized and residents living in …

Miniaturized Ultraviolet Imager High Voltage Power Supply, Nicholas Palmer, Jason Thomas Heil

Electrical Engineering

Sending satellites into orbit becomes exponentially more expensive with weight and size, so designing high-voltage DC-DC converters that can achieve kilovolt level outputs in a small form factor is crucial to reducing costs. The Miniaturized Ultraviolet Imager (MUVI) aims to monitor Earth’s ionosphere and report weather patterns to climate scientists within a 2U cube satellite footprint. The imaging equipment consists of a microchannel plate and phosphor screen that require 2.5kV and 5.5kV respectively at microamp level currents. This report explains the implementation of a high voltage boost cascaded flyback converter to meet all of the MUVI satellite output voltage requirements. …

First Order Self-Oscillating Class-D Circuit With Triangular Wave Injection, Matthew J. Carroll

Master's Theses

An investigation into performance improvements to the modulator stage of a class-D amplifier is conducted in this thesis. Two of the standard topologies, namely class-D open-loop pulse-width modulation (PWM), and the improved self-oscillating feedback system are benchmarked against a topology which includes both a hysteretic comparator in a feedback loop and triangle wave injection. Circuit performance is analyzed by comparing how the triangle injection circuit handles known issues with open-loop and self-oscillating circuits. Using this analysis, it is shown that the triangle injection topology offers an improved power supply rejection ratio relative to open-loop PWM and reduces distortion generated by …

Design And Modeling Of A Distributed Network For The Dc House Project, Lauren N. Rotsios

Master's Theses

This thesis covers the design and simulation of a model for a distributed network of DC Houses in MATLAB Simulink. The model will allow for sharing of power between houses within the network. The developed model consists of five separate DC House branches with local power generation. Each branch consists of a PV MPPT charge controller subsystem, a resistive load, and a bidirectional buck-boost converter subsystem. The high voltage side of every bidirectional buck-boost converter is connected together through the transmission line at a single high voltage DC bus. The performance of the individual components of the model is verified …