Engineering Commons^™

Metric Learning Via Linear Embeddings For Human Motion Recognition, Byoungdoo Kong

Masters Theses

We consider the application of Few-Shot Learning (FSL) and dimensionality reduction to the problem of human motion recognition (HMR). The structure of human motion has unique characteristics such as its dynamic and high-dimensional nature. Recent research on human motion recognition uses deep neural networks with multiple layers. Most importantly, large datasets will need to be collected to use such networks to analyze human motion. This process is both time-consuming and expensive since a large motion capture database must be collected and labeled. Despite significant progress having been made in human motion recognition, state-of-the-art algorithms still misclassify actions because of characteristics …

Camera-Based Remote Photoplethysmography For Estimation Of Heart Rate Using Single Board Computers, Benjamin Sweely

Masters Theses

The objective of this project was to develop a wireless, noncontact monitoring system that measures multiple physiological parameters in human faces from a distance using a camera. Compared to traditional sensors, this monitoring system does not use wires or adhesives, providing a safer, more user-friendly application. The goal of the monitoring systems was to estimate heart rate (HR). The current practices of measuring HR involve collecting electrocardiogram (ECG) signals from adhesive electrodes placed on various parts of the body and using a pulse oximeter (PO) typically placed on the ear lobe or finger. We were able to successfully create 2 …

Design Of Power Receiving Units For 6.78mhz Wireless Power Transfer Systems, Hoang Phuc Tran Pham

Masters Theses

In the last decade, the wireless power transfer (WPT) technology has been a popular topic in power electronics research and increasingly adopted by consumers. The AirFuel WPT standard utilizes resonant coils to transfer energy at 6.78 MHz, introducing many benefits such as longer charging distance, multi-device charging, and high tolerance of the coil misalignment. However, variations in coil coupling due to the change in receiving coil positions alter the equivalent load reactance, degrading efficiency.

In recent studies, active full-bridge rectifiers are employed on WPT receivers because of their superior efficiency, controllability, and ability to compensate for detuned WPT networks. In …

Perception System: Object And Landmark Detection For Visually Impaired Users, Chenguang Zhang

Masters Theses

This paper introduces a system which enables visually impaired users to detect objects and landmarks within the line of sight. The system works in two modes: landmark mode, which detects predefined landmarks, and object mode, which detects objects for everyday use. Users can get audio announcement for the name of the detected object or landmark as well as its estimated distances. Landmark detection helps visually impaired users explore an unfamiliar environment and build a mental map.

The proposed system utilizes a deep learning system for detection, which is deployed on the mobile phone and optimized to run in real-time. Unlike …

Thermal Transport Modeling Of Semiconductor Materials From First Principles, Aliya Qureshi

Masters Theses

Over the past few years, the size of semiconductor devices has been shrinking whereas the density of transistors has exponentially increased. Thus, thermal management has become a serious concern as device performance and reliability is greatly affected by heat. An understanding of thermal transport properties at device level along with predictive modelling can lead us to design of new systems and materials tailored according to the thermal conductivity. In our work we first review different models used to calculate thermal conductivity and examine their accuracy using the experimentally measured thermal conductivity for Si. Our results suggest that empirically calculated rates …

A Framework To Support Automatic Certification For Self-Adaptive Systems, Ioannis Nearchou

Masters Theses

Presently, cyber-physical systems are increasingly being integrated into societies, from the economic sector to the nuclear energy sector. Cyber-physical systems are systems that combine physical, digital, human, and other components, which operate through physical means and software. When system errors occur, the consequences of malfunction could negatively impact human life. Academic studies have relied on the MAPE-K feedback loop model to develop various system components to satisfy the self-adaptive features, such that violation of the safety requirements can be minimized. Assurance of system requirement satisfaction is argued through an industrial standard form, called an assurance case, which is usually applied …

Numerical Simulation Of Thermoelectric Transport In Bulk And Nanostructured Sisn Alloys, Venkatakrishna Dusetty

Masters Theses

The current high demand for sustainable and renewable energy sources to solve world energy crisis has enormously increased interest in looking at alternative sources of energy. All the machines used in manufacturing process, electricity generation, residential applications, transportation etc., rejects energy in the form of heat into environment. Thermoelectric materials can convert thermal-to-electrical and electrical-to-thermal energy and can be utilized in waste-heat harvesting, more efficient cooling to reduce energy usage and CO₂ emissions. Significant research efforts have been devoted over the past decade to thermoelectric materials, with particular emphasis being placed on combining materials selection with nanostructuring. The overarching …

Compound Effects Of Clock And Voltage Based Power Side-Channel Countermeasures, Jacqueline Lagasse

Masters Theses

The power side-channel attack, which allows an attacker to derive secret information from power traces, continues to be a major vulnerability in many critical systems. Numerous countermeasures have been proposed since its discovery as a serious vulnerability, including both hardware and software implementations. Each countermeasure has its own drawback, with some of the highly effective countermeasures incurring large overhead in area and power. In addition, many countermeasures are quite invasive to the design process, requiring modification of the design and therefore additional validation and testing to ensure its accuracy. Less invasive countermeasures that do not require directly modifying the system …

Flexible Capacitive Pressure Sensors And Triboelectric Energy Harvesters Using Laser-Assisted Patterning Process For Flexible Hybrid Electronic Applications, Valliammai Palaniappan

Masters Theses

This work focuses on the design, fabrication and characterization of novel flexible capacitive pressure sensors and triboelectric energy harvesters using laser-assisted patterning process for flexible hybrid electronic applications. Initially, the capacitive pressure sensor was developed by fabricating a set of polydimethylsiloxanes (PDMS) dielectric films with pyramid shaped micro-structures using a laser-assisted patterning process. The pressure sensor consists of two electrodes (top and bottom) that were fabricated by depositing silver (Ag) on flexible polyethylene terephthalate (PET) using additive screen-printing process. Finally, the pressure sensor was assembled by attaching the top and bottom Ag electrodes to the smooth side of pyramid shaped …

Optimized System For On-Route Charging Of Battery Electric Buses And High-Fidelity Modelling And Simulation Of In-Motion Wireless Power Transfer, Yogesh Bappasaheb Jagdale

Masters Theses

Electrifying cars, buses and trucks is an attractive means to reduce energy use and emissions, because it involves minimal restructuring of the transportation network. Transit buses drive fixed routes, minimizing driver range anxiety by properly sizing energy storage system but the major challenge to fully electrifying transit buses, is the amount of energy they consume in a day of driving. To enable a full day of operation, batteries need to be large, which is expensive and heavy. This work utilizes real-world transit bus data fed to a battery electric drive-train model to co-optimize charger locations, charger power levels, and vehicle …

Passive And Active Battery Balancing Methods Implemented On Second Use Lithium-Ion Batteries, Walter Bartek

Masters Theses

As the number of electric vehicles (EVs) increases, the number of used battery packs that require disposal increases; however, many of these packs still have useful capacity and can be repurposed. When using repurposed large lithium-ion battery packs, deviations between cells within a pack become problematic. These deviations result in a pack that is unbalanced, affecting performance and proving potentially hazardous when charging. Consequently, a battery management system (BMS) is needed. To provide safety, the BMS in this paper monitors and controls the operation of the battery pack. In addition, it controls the redistribution of charge between the cells within …

Accelerating Rsa Public Key Cryptography Via Hardware Acceleration, Pavithra Ramesh

Masters Theses

A large number and a variety of sensors and actuators, also known as edge devices of the Internet of Things, belonging to various industries - health care monitoring, home automation, industrial automation, have become prevalent in today's world. These edge devices need to communicate data collected to the central system occasionally and often in burst mode which is then used for monitoring and control purposes. To ensure secure connections, Asymmetric or Public Key Cryptography (PKC) schemes are used in combination with Symmetric Cryptography schemes. RSA (Rivest - Shamir- Adleman) is one of the most prevalent public key cryptosystems, and has …

Crosstalk Based Side Channel Attacks In Fpgas, Chethan Ramesh

Masters Theses

As FPGA use becomes more diverse, the shared use of these devices becomes a security concern. Multi-tenant FPGAs that contain circuits from multiple independent sources or users will soon be prevalent in cloud and embedded computing environments. The recent discovery of a new attack vector using neighboring long wires in Xilinx SRAM FPGAs presents the possibility of covert information leakage from an unsuspecting user's circuit. The work makes two contributions that extend this finding. First, we rigorously evaluate several Intel SRAM FPGAs and confirm that long wire information leakage is also prevalent in these devices. Second, we present the first …

Compressive Parameter Estimation Via Approximate Message Passing, Shermin Hamzehei

Masters Theses

The literature on compressive parameter estimation has been mostly focused on the use of sparsity dictionaries that encode a discretized sampling of the parameter space; these dictionaries, however, suffer from coherence issues that must be controlled for successful estimation. To bypass such issues with discretization, we propose the use of statistical parameter estimation methods within the Approximate Message Passing (AMP) algorithm for signal recovery. Our method leverages the recently proposed use of custom denoisers in place of the usual thresholding steps (which act as denoisers for sparse signals) in AMP. We introduce the design of analog denoisers that are based …

Vehicle Velocity Prediction Using Artificial Neural Networks And Effect Of Real-World Signals On Prediction Window, Tushar Dnyaneshwar Gaikwad

Masters Theses

Prediction of vehicle velocity is essential since it can realize improvements in the fuel economy/energy efficiency, drivability, and safety. Many publications address velocity prediction problems, yet there is a need for the understanding effect of different signals for the prediction. There are numerous new sensor and signal technologies like vehicle-to-vehicle and vehicle-to-infrastructure communication that can be used to obtain comprehensive datasets. Several references considered deterministic and stochastic approaches that use the datasets as input to determine future operation predictions. These approaches include different traffic models and artificial neural networks such as Markov chain, nonlinear autoregressive model, Gaussian function, and recurrent …

Modeling And Control Of Cascaded Bridgeless Multilevel Rectifier Under Unbalanced Load Conditions, Sai Hemanth Kankanala

Masters Theses

“The goal of this project is to model and control a novel unidirectional cascaded multilevel bridgeless rectifier as an active front end in medium and high voltage applications. This topology has many advantages over a conventional cascaded H-bridge rectifier, such as lower implementation cost, higher reliability, and greater flexibility with similar power quality. The complete design process of the proposed converter is developed step by step in order to meet all the desired objectives. The steady-state mathematical model is used to develop a method for the voltage balancing of dc cells. Power factor analysis is discussed to mathematically derive requirements …

Design And Development Of Power Processing Units For Applications In Electrically-Propelled Satellite Systems, Kartikeya Jayadurga Prasad Veeramraju

Masters Theses

"Electrospray technology provides a way to ionize specialized liquids by applying high voltages across a sharp porous tip and a metallic mesh. This technology is widely used in the field of mass spectroscopy for generating ions for testing purposes. The dawn of nano-satellites posed new challenges in the miniaturization of many conventional satellite sub-systems. One significant challenge faced in such a process was the miniaturization of the propulsion system. Electrosprays have started to find their application in the field of Aerospace Engineering and now are formally known as Electrospray Thrusters. These thrusters provide high specific impulse and are attractive substitutes …

Serdes Channel Crosstalk Mitigation Methodology With Industrial Implementation Guidance, Junda Wang

Masters Theses

"With the increasing data rate of digital circuits, the differential crosstalk degrades the signal integrity performance in PCBs drastically. Usually, in the trace area, crosstalk can be isolated by stitching vias and adding shielding ground vias can also shield coupling in the ball gate array (BGA) and pin field area. The traditional way to mitigation crosstalk in the BGA and pin field area through adding more ground vias between signal pairs or increasing the spacing in between, it demonstrated us the efficiency on crosstalk cancellation efficiency but it also increases the size of products and it would be contradictory to …

Design And Comparison Of Unoptimized And Optimized Gray Code Multi-Level Systems, Shirly Adams Gamliel

Masters Theses

“As the conventional binary MOS-based VLSI technology is reaching limitations in chip area, speed, and power, new technologies are being researched. Some such technologies relate to multi-level logic design. This thesis explores the process and benefits of applying and optimizing multi-level design techniques to an existing Gray code binary system. Specifically, the multi-level system is designed using CoreMem technology and is optimized using Indira Dugganapally’s optimization techniques.

The first step is generating the n-bit binary and quaternary truth tables for an encoder’s Gray code output and additional desired data. Then, the data for each n-bit system is arranged in multi-level …