Electrical and Computer Engineering Commons^™

Long-Term Human Participation Detection Using A Dynamic Scene Analysis Model, Wenjing Shi

Electrical and Computer Engineering ETDs

The dissertation develops new methods for assessing student participation in long (>1 hour) classroom videos. First, the dissertation introduces the use of multiple image representations based on raw RGB images and AM-FM components to detect specific student groups. Second, a dynamic scene analysis model is developed for tracking under occlusion and variable camera angles. Third, a motion vector projection system identifies instances of students talking.

The proposed methods are validated using digital videos from the Advancing Out-of-school Learning in Mathematics and Engineering (AOLME) project. The proposed methods are shown to provide better group detection, and better talking detection at …

Evaluation Of The Dynamic Vision Sensor’S Photoreceptor Circuit For Infrared Event-Based Sensing, Zinah M. Alsaad

Electrical and Computer Engineering ETDs

For space surveillance applications, neuromorphic imaging is being studied as it may perform sensing and tracking tasks with less power and downstream datalink demand. The read-out of the event-based camera is made to only be sensitive to changes in the signals it receives from the photodetector, which results in a datastream of events indicating where and when changes in illumination occur. This is in contrast to the conventional framing camera, which produces images by essentially counting the electrons produced by light incident on each pixel’s photodetector. These cameras are commercially available with siliconbased detectors for applications involving visible wavelengths. However, …

Network Economics-Based Crowdsourcing In Online Social Networks, Natasha S. Kubiak

Electrical and Computer Engineering ETDs

This thesis addresses the challenge of user recruitment by various competing marketing agencies (MAs) in Online Social Networks. A labor economics approach, following the principles of contract theory, is devised to enable MAs to reveal the potential of each participating user to contribute a personalized level of quality and quantity of information to the crowdsourcing process. The MAs objective is to maximize their personal benefit, i.e., total utility obtained, given its budget. The latter optimization problem is formulated as a Generalized Colonel Blotto (GCB) game among the MAs, where each MA aims at incentivizing each user to report its information. …

Improved Experimental Validation Of An Electromagnetic Subcell Model For Narrow Slots With Depth, Michael Anthony Illescas

Electrical and Computer Engineering ETDs

The coupling of electromagnetic (EM) energy into a system can disrupt operation of essential electronics present within it. Metal enclosures are used to shield these systems from potentially harmful electromagnetic interference (EMI). Seams and gaps in such metal enclosures are minimized but unavoidable for reasons such as maintenance and repair. These seams and gaps create an entry point for EM energy to couple into the system. Entry points are often modeled by EM analysts as narrow slots defined by their length, width, and depth. The depth of these slots can become significant compared to the wavelength, introducing resonances associated with …

Effective Utilization Of Battery-Supercapacitor Hybrid Energy Storage Systems In Dc Nano-Grids, Seyyed Ali Ghorashi Khalil Abadi

Electrical and Computer Engineering ETDs

This PhD dissertation proposes novel control strategies to improve the flexibility and reliability of DC nanogrids by utilizing battery-supercapacitor hybrid energy storage systems (HESSs). The dissertation is divided into five sections, each addressing a specific challenge in DC nanogrids and proposing unique control strategies to overcome them. The proposed strategies include an adaptive control system for multiple nanogrids, a distributed power management strategy for a grid-connected DC nano-grid, a model predictive control strategy to improve voltage quality and stability in islanded DC nanogrids, a cloud HESS technology to improve voltage stability in clustered DC nanogrids, and a method of electric …

Measuring Energy Deposition From A Laser Induced Plasma In Air Which Generates Broadband Microwave Radiation, Anna M. Janicek

Electrical and Computer Engineering ETDs

The absorbed energy from a short pulse laser produced plasma is proportional to the magnitude of the acoustic wave the plasma launches; however, methods to resolve absolute energy from the acoustic signal are still being developed. This is the first report of quantitatively estimating the energy deposited by a femtosecond laser-induced plasma using a shock wave approximation from acoustic measurements. To further understand energy deposition mechanisms, two diagnostics, a single microphone which measures the acoustic signal propagation and an array of microphones which measure the changing acoustic signal longitudinally along the plasma were developed and implemented to measure the energy …

On Refinements To Qmfd Based Chirp Parameter Estimation, Balu Santhanam, Thalanayar Santhanam

Electrical & Computer Engineering Technical Reports

Commuting matrix methods furnish a full basis of orthog- onal eigenvectors for the discrete Fourier transform or its centered version needed for computing the discrete fractional Fourier transform and multicomponent chirp signal analysis. However, these approaches suffer from ill-conditioning issues at higher matrix sizes, and require a computationally expensive eigenvalue decomposition.

In this paper, ill-conditioning issues associated with the QMFD approach developed previously by the authors are addressed via diagonal modification. Further symmetries of the eigenvectors are used to reduce the size of the underlying eigenvalue problem. These modifications are then incorporated into the real-arithmetic implementation of the QMFD approach …

Perceptual Anthropomorphic Walking Robot Platform For Navigation In Unstructured And Undifferentiated Environments, Luige Vladareanu, Mihai Rădulescu, Marius Pandelea, Hongbo Wang, Florentin Smarandache, Yongfei Feng, Ionel-Alexandru Gal, Alexandra C. Ciocîrlan

Branch Mathematics and Statistics Faculty and Staff Publications

This scientific presentation studies the VIPRO Platform for control of Anthropomorphic Walking Robots (AWR), the architecture control system of the SiMeLA MP robot motion, and shows several experimental results.

Autonomous Decision-Making In Interdependent Computing Systems Based On Artificial Intelligence, Georgios Fragkos

Electrical and Computer Engineering ETDs

With the advent of Artificial Intelligence (AI), the notion of autonomy, in terms of acting and thinking based on personal experience and judgment, has paved the way towards an autonomous decision-making future. This future can address the complex domain of the interdependent computing systems, whose main challenge is that they interact with each other with unpredictable and often unstable outcomes. It is crucial to envision and design this AI-driven autonomy for the reciprocal computing systems which cover a variety of use-cases ranging from the Internet of Things (IoT) to cybersecurity. This can be achieved by cloning the human decision-making process, …

Towards Robust Channel Dynamics: Photoionization In Nitrogen And Air, Justin K. Smith

Electrical and Computer Engineering ETDs

In present photoionization models used in computational studies, there is a lack of experimental data and several assumptions pertaining to photo-electron production in the gas. It is widely accepted that wavelengths between 98 nm and 102.5 nm are the primary contributors to photoionization of oxygen in an air plasma. In air, the collisional kinetics of nitrogen provide the photons, which results in the ionization of oxygen. Photoionization rate measurements from a low current corona discharge in synthetic air mixtures are reported to provide new empirical data. In addition, this provides a method to estimate the scaling parameter w/a. Concurrently, vacuum …

A Horn Microstrip Transmission Line For The Characterization And Investigation Of Multipactor At Various Pressure And Power, Shaho Hamadamin

Electrical and Computer Engineering ETDs

The University of New Mexico is designing, building, and testing a multipactor testbed based on a horn-microstrip transmission line to characterize and investigate the multipactor effect for a range of vacuum pressures and power. A horn-shaped, 50 Ω Al microstrip line is positioned inside a six-way cross stainless-steel chamber that is vacuumed down to low ~10−7 torr. A 100 𝑀𝑀𝑀𝑀𝑀𝑀 sine signal is fed to a rf amplifier with a bandwidth of 250 − 105 𝑀𝑀𝑀𝑀𝑀𝑀, that can reach 120𝑊𝑊 average (CW) power. Two multipacting detection methods, i.e., global, and local methods, are implemented for accurate multipaction detection. The former …

Protection And Control Of Electric Power Grid Under High Penetration Of Ders, Binod Prasad Poudel

Electrical and Computer Engineering ETDs

Modernizing power grids with communication-based technologies has introduced new challenges to the operation of the grid, especially when the communication network experiences failure or data is corrupted during the transfer. This issue is studied in this dissertation from the control and protection perspective. First, the cyber attack detection and mitigation of distributed control of microgrids is addressed when the distributed energy resources (DER) are exposed to false data injection attacks. A cyber-threat detection technique is proposed based on Kullback-Liebler divergence-based criterion. This criterion with a threshold can detect the misbehavior of a compromised DER control unit and, consequently, calculates the …

Void-Semiconductor Gaas Photonic Crystal Surface-Emitting Lasers By Epitaxial Regrowth And Single-Epitaxy Methods, Kevin James Reilly

Nanoscience and Microsystems ETDs

Monolithic semiconductor lasers including edge-emitting lasers (EELs) and vertical-cavity surface-emitting lasers (VCSELs) fail to realize simultaneous achievement of both high-power high-quality beams due to intrinsic limitations of their resonant cavity. Photonic crystal surface emitting lasers (PCSELs) address these structural limitations through employment of a two-dimensional photonic crystal (PC) cavity that creates feedback at a single wavelength for laterally scalable devices. This function of the PC allows PCSELs to power scale with area while maintaining single-mode emission required for diffraction-limited beams. In this way, PCSELs fulfill an industry demand for high-power high-quality lasing from a single chip.

Early PCSELs were fabricated …

Cyber-Secure Distributed Control Of Microgrids With Improved Communication And Control Protocols, Jee Won Choi

Mechanical Engineering ETDs

This dissertation proposes a cyber-secure distributed control of microgrids with improved communication and control protocols. The finite-time event-triggered control protocol for islanded AC and DC secondary control is introduced. For AC microgrids, the proposed strategy can effectively perform frequency restoration and voltage regulations while sharing the active and reactive power among the distributed generators (DGs) based on their power ratings. For DC microgrids, the proposed control protocol can provide accurate current sharing and critical bus voltage regulation. The finite-time control enables a system to reach a consensus in a finite period of time enhanced from asymptotic convergence. The event-triggered communication …

Reinforcement Learning-Based Demand Response Management In Smart Grid Systems With Prosumers, Jenilee Jao

Electrical and Computer Engineering ETDs

In this thesis, we introduce a reinforcement learning-based price-driven Demand Response Management (DRM) mechanism in smart grid systems consisting of prosumers. Our proposed approach accounts for the prosumers behavioral characteristics and models the emerging interactions among all the involved actors in the smart grid system, i.e., prosumers, Energy Management System (EMS) and utility companies. In particular, an off-policy reinforcement learning is introduced enabling the EMS to determine the optimal price that should be announced to the prosumers on an hourly-basis towards minimizing the overall systems cost. In this process, the utility companies hourly-based wholesale price and the prosumers energy generation …

Material Characterization And Comparison Of Sol-Gel Deposited And Rf Magnetron Deposited Lead Zirconate Titanate Thin Films, Katherine Lynne Miles

Mechanical Engineering ETDs

Lead zirconate titanate (PZT) has been a material of interest for sensor, actuator, and transducer applications in microelectromechanical systems (MEMS). This is due to their favorable piezoelectric, pyroelectric and ferroelectric properties. While various methods are available to deposit PZT thin films, radio frequency (RF) magnetron sputtering was selected to provide high quality PZT films with the added capability of batch processing. These sputter deposited PZT films were characterized to determine their internal film stress, Young’s modulus, composition, and structure. After characterization, the sputtered PZT samples were poled using corona poling and direct poling methods. As a means of comparison, commercially …

Exploratory Analysis Of Machine Learning For Images: Methods And Applications, Meenu Ajith

Electrical and Computer Engineering ETDs

This research focuses on implementing four different applications of machine learning on images. The various categories of digital images considered for these applications are grayscale, RGB, and infra-red images. The first framework uses an unsupervised learning strategy for detecting fire and smoke from an infra-red image dataset. This problem was solved using a classical machine learning algorithm since the dataset was small and unlabeled. Next, a semi-supervised deep learning model was used for facial expression recognition. Here we detect emotions from a moderately large dataset containing labeled and unlabeled grayscale images. The third application focused on single image superresolution, which …

Gp-K: A Probabilistic Method For Hourly Day-Ahead Power Load Forecasting, Miguel A. Hombrados-Herrera

Electrical and Computer Engineering ETDs

The elevated costs that incur power grid stakeholders due to forecasting errors in power load demand have created the need for forecasting methods that provide accurate predictions and allow for assessing the reliability of their predictions. This thesis proposes a probabilistic forecasting method for multi-step ahead forecasting.

In particular, it presents a probabilistic method to perform a 24-hours-ahead power load forecasting that arises as the combination of Gaussian Process regressors with NMF (nonnegative matrix factorization) and integrates the advantages of both methods. Instead of training 24 independent processes for each hour of the predicted day, this work proposes to factorize …

Combinatorial Cnn Meta-Structures In Deep Learning Applications, Aswathy Rajendra Kurup

Electrical and Computer Engineering ETDs

The study aims in applying combinatorial structures motivated from the basic CNN in various applications. Convolutional neural networks (CNNs) have grown to be very popular in the field of deep learning. The ability of such networks to learn both Spatial and temporal characteristics in the data have helped in deploying them in various fields. Through this research we explore different kinds of CNN-derived architectures and how these structures can be trained and setup in combinatorial environment to solve problems in deep learning applications. First, we introduce the basic idea of a deep learning meta-structures which is used in the application …

Stochastic Optimal Shared Control With Non-Gaussian Processes, Paul Onor

Electrical and Computer Engineering ETDs

In this paper, we propose an approach for shared control of a planar quadrotor that allows for non-Gaussian disturbance in the model and non-Gaussian variation in the pilot's control actions. We do this by constructing empirical characteristic functions for the state, inputs, and disturbance using demonstrations by a human expert. These are then used to make predictions of future states and of the system disturbance, using the first and second moments of the empirical characteristic function to estimate the mean and variance of these processes. With this method, we can extend assumptions from additive white Gaussian noise to any real-valued …

A Study On Electromagnetic Topology Optimization Using Binary Particle Swarm Algorithm, Mohammad Sazzad Hossain

Electrical and Computer Engineering ETDs

Topology optimization is a state-of-the-art tool for detecting the best material layout in a physical space to obtain certain goals. Initially developed as a structural engineering tool, it has been recently used in electromagnetics and has shown immense potential. The aim of this work is to build a framework for applying the topology optimization method in electromagnetics using a modified binary particle swarm optimization (BPSO) algorithm. In this thesis, a very classic problem of coax to waveguide transition has been considered, and a novel solution has been given using topology optimization. The steps to implementing topology optimization using BPSO have …

The Corona-To-Spark Transition And Its Dependence On Electric Field Non-Uniformity, David O. Smith

Electrical and Computer Engineering ETDs

The corona to spark transition is an important part of understanding gaseous breakdown in non-uniform fields. The degree of uniformity in the geometry determines both the onset of corona as well as the eventual spark transition. In a highly non-uniform geometry, the onset of corona precedes the development of a spark. However, in weakly non-uniform fields, corona is unable to form before it transitions into a spark. The degree of non-uniformity at which this transition occurs is known as the corona point.

An experimental setup using the point electrodes allows precise changes in field uniformity, characterizing the corona point in …

Gamma And Neutron Irradiation Effect On Ga-Polar And N-Polar Gan Based Diodes, Farnood Mirkhosravi

Optical Science and Engineering ETDs

III-nitride material (GaN) shows a lot of potential for next-generation power electronics. This material is advantageous due to its wide bandgap, high electron mobility, high thermal and mechanical stability, small form factor, and higher radiation tolerance. The higher radiation tolerance makes the GaN-based devices more attractive for harsh-environment applications, like aerospace, nuclear reactor, and fusion facilities, particle accelerators, and post-detonation environments applications.

GaN due to its unique crystal structure can be grown in different orientations and can provide specific advantages in electronic and optoelectronic devices. While the Ga-polar orientation of GaN has been widely investigated for its proprieties, there are …

Application Of Machine Learning For Predicting Iemi Upset In Multi-Architecture Microcontrollers, Daniel S. Guillette

Electrical and Computer Engineering ETDs

Four microcontrollers were programmed to execute a simple counting program. Pulsed RF signals – also known as Intentional ElectroMagnetic Interference (IEMI) – were injected into the clock input of the microcontrollers. At the same time, the output lines were monitored to determine whether the IEMI signal altered the output of the counting program – referred to as an upset. A state-of-the-art automated testing apparatus was used to collect and process 120,960 samples of IEMI upset data. The data was used to perform a traditional upset trends study and train a series of machine learning (ML) techniques – k-Nearest Neighbors, Support …

Decentralized Intelligent Decision Making In Cyber Physical Social Systems, Nathan Patrizi

Electrical and Computer Engineering ETDs

The accelerated evolution towards jointly considering the physical, cyber, and social space is expected to dramatically increase the interest of the research and industrial community to build efficient, resilient, and secure Cyber Physical Social Systems. In this dissertation, we focus our research activities on devising decentralized intelligent decision making models, frameworks, and algorithms to support the smooth operation of Cyber Physical Social Systems. The proposed decentralized intelligent decision making models are jointly exploiting theories from the field of Economics, such as Game Theory and Contract Theory, and from the field of Computer Science, such as Reinforcement Learning concepts. Reinforcement learning …

Speaker Diarization And Identification From Single-Channel Classroom Audio Recording Using Virtual Microphones, Antonio Gomez

Electrical and Computer Engineering ETDs

Speaker identification in noisy audio recordings, specifically those from collaborative learning environments, can be extremely challenging. There is a need to identify individual students talking in small groups from other students talking at the same time. To solve the problem, we assume the use of a single microphone per student group without any access to previous large datasets for training.

This dissertation proposes a method of speaker identification using cross-correlation patterns associated to an array of virtual microphones, centered around the physical microphone. The virtual microphones are simulated by using approximate speaker geometry observed from a video recording. The patterns …

Multicarrier Modulation Using Discrete Fractional Fourier Transform, Amir Raeisi Nafchi

Electrical and Computer Engineering ETDs

The focus of the research was to investigate the application of the discrete fractional Fourier transform (DFRFT) in communication systems. We investigated the compactness of the Gauss-Hermite like eigenvectors of the DFRFT and showed how a multi-carrier modulation system could benefit from it. This led to identifying an affine DFRFT. We proved the circular convolution property for the proposed DFRFT. Using this affine transform, we were able to design an orthogonal frequency division multiplexer (OFDM) communication system. In the process of implementing the OFDM, we developed a method for fast computation of the DFRFT using the chirp-z transform. Using the …

Dc Microgrid Fault Detection Using Multiresolution Analysis Of Traveling Waves, Rudy Montoya

Mechanical Engineering ETDs

Fast detection and isolation of faults in a DC microgrid is of particular importance. Fast tripping protection (i) increases the lifetime of power electronics (PE) switches by avoiding high fault current magnitudes and (ii) enhances the controllability of PE converters. This thesis proposes a traveling wave (TW) based scheme for fast tripping protection of DC microgrids. The proposed scheme utilizes a discrete wavelet transform (DWT) to calculate the high-frequency components of DC fault currents. Multiresolution analysis (MRA) using DWT is utilized to detect TW components for different frequency ranges. The Parseval energy calculated from the MRA coefficients are then used …

Analyzing Student Credits, Don R. Hush, Elias S. Lopez, Wisam Al-Doroubi, Tushar Ojha, Brianne Santos, Kevin Warne

Electrical & Computer Engineering Technical Reports

This report describes methods for decomposing student credits into three categories: applied, unusable, and excess where applied credits count towards the student's degree requirements, unusable credits do not count towards any degree requirement, and excess credits exceed one or more degree requirement specifications. These methods enable multiple types of analysis including student progress assessment, student planning (i.e. helping the student determine the best path forward), credit efficiency analysis (i.e. quantifying the number of applied versus unusable and excess credits), transfer credit analysis (i.e. determining the utility and efficiency of transfer credits), and requirement analysis (i.e. determining the types of requirements …

Relativistic Magnetron Powered By Electrons In A High-Energy State, Dmitrii Andreev

Electrical and Computer Engineering ETDs

A traditional relativistic magnetron is an efficient, high-power source of cm-wave radiation. Typically, a cathode sits inside the interaction region and produces a quickly expanding cathode plasma. However, rapid radial expansion leads to unwanted frequency drift and pulse shortening. Recently, researchers at Technion, in collaboration with the University of New Mexico, proposed to use a split cathode to form a low-energy “squeezed” state by injecting electrons externally into a potential well and squeezing them with a sufficiently strong magnetic field. Technion’s long-pulse experiments achieved a low-energy state, at the output power and efficiency comparable to a physical cathode inside the …