Engineering Commons^™

Numerical Modelling Of Carrier Transport In Organic Field Effect Transistors, Sameh O. Abdellatif, Salma Ahmed

Electrical Engineering

No abstract provided.

Enhancing Resilience In Complex Energy Systems Through Real-Time Anomaly Detection: A Systematic Literature Review, Ali Aghazadeh Ardebili, Oussama Hasidi, Ahmed Bendaouia, Adem Khalil, Sabri Khalil, Dalila Luceri, El Hassan Abdelwahed, Sara Qassimi, Antonio Ficarella

Manufacturing & Industrial Engineering Faculty Publications

As real-time data sources expand, the need for detecting anomalies in streaming data becomes increasingly critical for cutting edge data-driven applications. Real-time anomaly detection faces various challenges, requiring automated systems that adapt continuously to evolving data patterns due to the impracticality of human intervention. This study focuses on energy systems (ES), critical infrastructures vulnerable to disruptions from natural disasters, cyber attacks, equipment failures, or human errors, leading to power outages, financial losses, and risks to other sectors. Early anomaly detection ensures energy supply continuity, minimizing disruption impacts, an enhancing system resilience against cyber threats. A systematic literature review (SLR) is …

Analysis And Design Of Synchronous Machines With Reluctance Rotor And Pm Stator Combined Excitation, Oluwaseun A. Badewa, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper studies motors that are part of a general class of synchronous machines with stator-only excitation including those that may be referred to in recent literature as of the flux switching, variable flux reluctance, or hybrid excitation type. In the studied example machine, the active stator has circumferentially magnetized spoke-type PMs and concentrated toroidal coils for improved slot fill and shortened end turns. A systematic analysis of the mmf produced by the toroidal coils in the stator and open-circuit airgap flux is developed to define feasible polarities of this synchronous motor and to establish that the dominant pole pair …

Remote Operated Amateur Radio Using Raspberry Pi And Limesdr, Esteban I. Perez

College of Engineering Summer Undergraduate Research Program

This project presents the design and implementation of a portable, remotely programmable amateur radio system operating on the 2-meter and 70-cm bands. The system utilizes Raspberry Pi 5 and LimeSDR hardware to facilitate communication between aerial and ground units, allowing for efficient transmission and reception of synchronization and calibration waveforms. A custom communication protocol incorporating BPSK modulation and a two-tone signaling mechanism enables time-of-flight measurements for calculating distances between nodes. This low-cost solution has potential applications in civilian sectors, such as search and rescue operations, where accurate direction finding and target localization are critical. Full-duplex operation enhances the system's capability …

New Loads And Service Factors For Distribution Transformers Following The Transition To High-Efficiency Heat Pumps, Solar Pv, And Ev Charging, Steven B. Poore, Rosemary E. Alden, Timothy Rooney, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Replacement of conventional high-power appliances including heating ventilation and air-conditioning (HVAC) and resistive electric water heaters (EWHs) with heat pumps is expected to be implemented long-term to increase energy efficiency. Even with efficiency upgrades, future residential power demand may rise due to increasing electric vehicle (EV) penetration. Extensive experimental data from field demonstrators and regional utilities as well as thousands of synthetically generated loads are utilized to investigate the effect of heat pumps, EV charging, and distributed solar PV on residential power demand and distribution transformers. Values are established for typical rating distribution and connection to multiple houses to study …

Solar Pv And Ev Controls For Reactive Power Support On Large Distribution Systems Modeled With Experimental And Synthetic Loads, Rosemary E. Alden, Malcolm Mcculloch, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Changes to electric power distribution equipment may be needed to adapt to distributed energy resources (DERs) such as solar photovoltaic (PV) generation and electric vehicle (EV) batteries. Within this paper, an optimization methodology for reactive power support (RPS) controls managed by utilities for EV bi-directional charger power factor and improve substation power quality and voltage across the system is proposed. An IEEE benchmark distribution system, the 123 node test feeder, is modified to include 1,765 experimental residential profiles at typical, high resolution of 15min from smart meters, solar PV generation calculated from weather data, and EV modules based on driver …

Optimal Design And Comparison Of Synchronous Machines With Inner And Outer Reluctance Rotors And Pm Or Dc Stator Combined Excitation, Oluwaseun A. Badewa, Ali Mohammadi, Donovin D. Lewis, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents an optimal design and comparative analysis for a toroidally wound reluctance rotor synchronous machine with either PM or DC excitation in the stator. The prototype of the PM version is experimentally evaluated, and its results are used to validate the model of the DC version as they share the same topology. The stator DC-excited synchronous (SDCES) motor is optimized at different outer diameters using large-scale multi-objective differential evolution (DE) and comparatively analyzed at power ratings typical for electric traction and propulsion applications. Its performance at reduced temperatures shows increased efficiency and goodness due to reduced losses, and …

Two-Level Design Optimization Of Ac Machines With Dc Stator Excitation And Minimal Torque Ripple Using Reluctance Rotor Profile Shaping, Ali Mohammadi, Oluwaseun A. Badewa, Yaser Chulaee, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Torque ripple mitigation in electric machines is important for a smooth and stable operation, minimize mechanical vibrations, and enhance the overall performance. In this paper, a novel two-level optimization method is proposed for the design of synchronous flux-switching and hybrid excitation machines with an innovative multi-point spline shaping method to minimize the torque ripple. This study uses models that are validated by experimental tests from a prototype with similar topology, and exemplifies the aforementioned optimization process on a 28 pole machine. The analysis results indicate that the torque ripple can be substantially reduced with improved electromagnetic torque of the electric …

Design Of High-Power Polyphase Pcb Coil Systems For Wireless Power Transfer, Donovin D. Lewis, Lucas Gastineau, Omer Onar, Malcolm Mcculloch, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Printed circuit board (PCB) coils have been pro- posed prior for implementation as inductive wireless charging coils to minimize size and cost. Utilization of PCBs can allow for a reduced cost, improved manufacturability, and a wide range of geometric customization options. To circumvent material limitations on insulation and thermal performance, parallel paths can be implemented to divide the current per path accordingly. Within this paper, an unconventional high power PCB coil is designed employing all possible techniques for wiring with axial and radial parallel paths with equivalent transposition to minimize circulating currents. Design studies are simulated in 3D finite element …

Analytical And Fe Modeling For The Design Of Coreless Axial Flux Machines With Halbach Array And Surface Pm Rotors, Matin Vatani, Yaser Chulaee, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper introduces a rapid analytical modeling approach for coreless axial flux permanent magnet (AFPM) machines featuring surface-mounted and Halbach PM array rotors. The methodology employs a 2D model at an arbitrary diameter of the machine and converts AFPM machines into an equivalent linear machine. Initially, equations for PM flux density, accounting for harmonic content, are developed for both rotor types. Subsequently, a force equation is derived for the 2D equivalent machine based on the Lorentz force equation and the stator winding factor. In the final step, a torque equation at an arbitrary diameter—specifically, the average diameter in this paper—is …

Multi-Disk Coreless Axial Flux Permanent Magnet Synchronous Motors With Surface Pm And Halbach Array Rotors For Electric Aircraft Propulsion, Matin Vatani, John F. Eastham, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents multiple single- and multi-disk coreless axial flux permanent magnet (AFPM) motors, focusing on specific power density and reliability for electric aircraft propulsion. Several 3D finite element analysis (FEA) parametric studies were conducted to assess the geometric impacts on a single-disk coreless AFPM motor featuring two separate stators and a double-sided Halbach array rotor configuration. These studies form the foundation for the design of both single and multi-disk machines. Single-disk coreless AFPM motors with rotor back iron embedded between the stators, offering magnetically decoupled stators, are subsequently introduced. The paper concludes by presenting four multi-disk coreless AFPM motor …

Multi-Wound Axial Flux Generators With Halbach Array Rotors, Matin Vatani, Yaser Chulaee, John F. Eastham, Xiaoze Pei, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper presents three coreless axial flux permanent magnet (AFPM) generator topologies that feature magnetically and electrically decoupled outputs using a single prime mover. The proposed topologies include: (1) two separate generators mounted on the same shaft, (2) a nested configuration with a smaller generator inside a larger one, and (3) a multi-wound generator with two sets of windings and different pole numbers for each rotor side. The multi-wound generator is selected for further investigation due to its superior power-to-volume ratio and the advantage of utilizing a single structure for stator cooling. The airgap magnetic flux density equation is derived …

This Is An Automated Software Platform For Grid Interconnection Of Renewable Energy Resources., Cathy Chen, Lani Nguyen

College of Engineering Summer Undergraduate Research Program

To help curb climate change, the United States is rapidly electrifying many sectors of the energy economy, such as transportation (electric vehicles) and home heating (electric heat pumps). Thus, recent years have witnessed an explosion of businesses that want to connect and operate energy resources on the electric grid. However, getting an energy resource connected to the grid is an arduous process that takes years or more, requires specialized technical knowledge, and requires navigating complex and varying regulatory procedures. This project will develop a software platform that leverages AI and high-performance computing to automate and accelerate grid interconnection and energy …

Measurement Automation & Measurement System Research Endowment, Brian Bivinetto, Beneda Loya, Shiron Bendrihem

College of Engineering Summer Undergraduate Research Program

Road travel safety is always the most important issue in transportation systems. In general, several factors cause road accidents, such as human error, vehicle mechanical failure, roadway limitations (e.g. pavement, lane geometry, etc.), and inclement weather conditions. The major focus of today’s transportation developments is related to making highway transportation safer, smarter, and greener to enhance livability. Many accidents are caused when drivers lack a better understanding of the surrounding traffic conditions because the driver not only needs to control his/her vehicle but also needs to be aware of the movements of the vehicles around him/her. A driver cannot be …

Sal-E: Responsive Space Pathfinder Mission, Liam Duckworth, Berfredd Quezon

College of Engineering Summer Undergraduate Research Program

The main objective of the SAL-E mission is to grow the Cal Poly CubeSat Lab’s (PolySat) capabilities in rapid spacecraft design, as well as to provide the current generation of students with the opportunity to design, test, integrate, and communicate with a satellite. This summer we will be focusing on a few aspects of the spacecraft design and preparing our test facilities for Fall. Specifically, we will be ordering electronics boards that were designed in Spring, testing the boards as they arrive, developing software to interface with the payloads, begin integrated testing, updating the control system in our thermal vacuum …

Machine Learning-Based Stress Detection Using Smartphones And Wearable Sensors, Robert Burns, Kassandra Martinez-Mejia

College of Engineering Summer Undergraduate Research Program

Stress and mental health have been considered increasing global concerns in modern society, including some of the illnesses responsible for a large proportion of comorbidities and deaths worldwide, such as depression and cardiovascular disease. Recently, smartphones, smartwatches, and smart wristbands have become an integral part of our lives and have reached widespread usage [1]. This raised the question of whether we can detect and prevent stress with smartphones and wearable sensors wirelessly. The challenge of such an approach is that the weak ECG signal is prone to errors, and the battery life of the smart devices is limited. In this …

Drive To Succeed: Empowering Underserved Communities Through Autonomous Driving Education, Amanda I. Chan

College of Engineering Summer Undergraduate Research Program

Autonomous vehicle (AV) technology represents the leading edge of innovation in transportation and holds immense potential to transform industries across the globe, with California at the forefront. However, access to education and technical training in this field has often been out of reach for students in underserved communities. The “Drive to Succeed” project endeavors to bridge this gap by introducing autonomous driving technology to high school students in communities where access has traditionally been limited. We propose an outreach program specifically designed to address the underrepresentation of marginalized groups in technology sectors and cultivate the next generation of engineers from …

Distributed Multi-Robot Localization And Coordination Framework For Mobile Robots, Dmitri Dobrynin, Indigo T. Garcia

College of Engineering Summer Undergraduate Research Program

This project aims to develop an experimental framework for multiple mobile robots, both in simulation and real-world hardware, using ROS 2 as the primary operating system. Utilizing TurtleBot 3 platforms, the team will establish a robust setup that enables tasks such as distributed localization, autonomous navigation, path planning, and formation control for mobile robots. Leveraging simulation environments like Gazebo, the project will replicate real-world setups in a simulated environment for testing and development. All tasks, communication, and sensor integration will be implemented using ROS 2, ensuring seamless coordination and interoperability among the robots. The project involves integrating various sensors and …

Assessing The Impact Of Femur Morphological Variations On Pediatric Hip Joint Biomechanics Using Statistical Shape Modeling, Tamara Chambers

Doctoral Dissertations and Master's Theses

This dissertation aimed to (1) quantify morphological variations in the pediatric hip joint and (2) evaluate the sensitivity of an infant musculoskeletal model (MSM) to these variations, considering hip joint center estimation errors. A shape statistical model (SSM) of decedent infant femurs from the Ortolani collection was created using ShapeWorks, capturing key morphological features, such as variations in the femoral neck-shaft and anteversion angles. Seven synthetic femurs were generated from the SSM to create SSM-informed MSMs, which were systematically evaluated through kinematics and kinetics analyses in OpenSim. Incorporating the SSM led to slight changes in the pediatric MSMs’ kinematics but …

Gratings In Optical Waveguides And Lasers, Weida Zhang

Electrical Engineering Theses and Dissertations

Gratings play a crucial role in Distributed Bragg reflector (DBR) lasers, influencing their performance and characteristics. The focus of this work is aimed at the design of DBR lasers that significantly impact the laser's spectral and temporal behavior, making it a key component in optimizing DBR laser functionality.

The SMU developed grating software, compared with commercially available photonics software, has improved accuracy and much smaller computation times. The improved accuracy and reduced computation times compared with commercial photonics software occur because commercial software is typically based on numerical methods such as finite-difference time-domain (FDTD), eigenmode expansion and beam propagation methods …

A Review On Photoacoustic Spectroscopy Techniques For Gas Sensing, Dakshith Ruvin Wijesinghe, Md Abu Zobair, Mina Esmaeelpour

Electrical and Computer Engineering Faculty Research & Creative Works

The rapid growth of industry and the global drive for modernization have led to an increase in gas emissions, which present significant environmental and health risks. As a result, there is a growing need for precise and sensitive gas-monitoring technologies. This review delves into the progress made regarding photoacoustic gas sensors, with a specific focus on the vital components of acoustic cells and acoustic detectors. This review highlights photoacoustic spectroscopy (PAS) as an optical detection technique, lauding its high sensitivity, selectivity, and capability to detect a wide range of gaseous species. The principles of photoacoustic gas sensors are outlined, emphasizing …

Production Box Cost Estimating Relationships For Dod Avionics, Carla J. Cisneros, Edward D. White, Brandon M. Lucas, Jonathan D. Ritschel, Robert D. Fass, Shawn M. Valentine

Faculty Publications

The authors use historical information obtained from the Cost Assessment Data Enterprise to estimate recurring production unit cost for DoD avionics via cost estimating relationships (CERs). The specific modeled responses include mean unit cost, median unit cost, and the 100th production unit cost (T100) utilizing learning curve theory. For T100, the authors adopt both a multiplicative and an additive error for CER comparison. Recommended CERs consist of the mean unit cost and the T100 utilizing a multiplicative error. Moreover, results reveal that weight has a significant effect on cost as well as a potential underaccounting of real price change or …

Real-Time Synthesis Of A Nonuniformly Correlated, Partially Coherent Beam Using An Optical Coordinate Tansformation, Milo W. Hyde Iv

Faculty Publications

We design, build, and validate an optical system for generating light beams with complex spatial coherence properties in real time. Beams of this type self-focus and are resistant to turbulence degradation, making them potentially useful in applications such as optical communications. We begin with a general theoretical analysis of our proposed design. Our approach starts by generating a Schell-model (uniformly correlated or shift-invariant) source by spatially filtering incoherent light. We then pass this light through an optical coordinate transformer, which converts the Schell-model source into a nonuniformly correlated field. After the general analysis, we discuss system engineering, including trade-offs among …

Thermal Management For Optimal Performance Of Unitized Regenerative Fuel Cells, Mythy T. Tran

Mechanical & Aerospace Engineering Theses & Dissertations

As the race to net zero energy intensifies around the world, hydrogen production and fuel cell technologies are attracting more attention, and the technologies are growing rapidly. Together, hydrogen production and fuel cell technologies hold potential for a reliable, green, and sustainable energy system. Hydrogen is an excellent energy carrier and can be produced from various sources, especially green and renewable sources. Fuel cells generate electricity and water from hydrogen and oxygen. In reverse mode, fuel cells operate as electrolyzers to produce hydrogen and oxygen from electricity and water. However, the major drawback that keeps hydrogen and fuel cells from …

Optical Investigation Of A Low-Pressure Plasma In A Superconducting Radio-Frequency Cavity, Zachary A. Caudell

Electrical & Computer Engineering Theses & Dissertations

The state-of-the-art cryomodules for particle accelerators use superconducting radio-frequency (SRF) cavities. It is known that accumulation of hydrocarbon impurities reduces the cavity surface work function, decreasing cryomodule performance metrics such as field emission, thermal stability, and accelerating gradients. An in-situ method of plasma processing has recently been developed to clean the cavities and restore cryomodule performance [1]. This study is to understand the properties of the low-pressure plasmas generated in a C100 SRF cavity and ultimately to improve the performance of plasma surface cleaning using optical emission spectroscopy. Using a 500 mm focal length Czerny-Turner monochromator coupled with a photomultiplier …

Bht-Qaoa: The Generalization Of Quantum Approximate Optimization Algorithm To Solve Arbitrary Boolean Problems As Hamiltonians, Ali Al-Bayaty, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

A new methodology is introduced to solve classical Boolean problems as Hamiltonians, using the quantum approximate optimization algorithm (QAOA). This methodology is termed the “Boolean-Hamiltonians Transform for QAOA” (BHT-QAOA). Because a great deal of research and studies are mainly focused on solving combinatorial optimization problems using QAOA, the BHTQAOA adds an additional capability to QAOA to find all optimized approximated solutions for Boolean problems, by transforming such problems from Boolean oracles (in different structures) into Phase oracles, and then into the Hamiltonians of QAOA. From such a transformation, we noticed that the total utilized numbers of qubits and quantum gates …

Characterization Of A Carbon Fiber Based Broadband Microwave Absorber, Ha Tran, Branimir Pejcinovic, Robert Doneker, Kent Thompson, Adithya Ramachandran

Electrical and Computer Engineering Faculty Publications and Presentations

This paper reports the development and characterization of a novel ultra-wideband microwave absorber material (MAM) based on vertically aligned carbon fibers and ferrite beads. This specific material combination and manufacturing process allows MAM design that is thin, lightweight, and broadband. The material is prepared using a flocking process in which its components are electrostatically deposited on top of an adhesive substrate. Distinct material properties of the substrate and materials layers require characterization done with two separated layers. The microwave absorption characteristics are studied first by rectangular waveguide measurements at X and Ku bands that yield complex electric permittivity and magnetic …

Sex Differences In Active Avoidance And Neural Circuit Mechanisms In Contextual Fear Generalization, Carly Vincent

Theses and Dissertations

The current studies were aimed to investigate two behavioral hallmarks of anxiety and stress-related disorders, avoidance responses and the over-generalization of fear. In the first set of studies, active avoidance and extinction learning, that parallels exposure therapy in preclinical rodent models, were used. It is known that stress can influence aversive learning and extinction training, which can result in poor extinction retention. However, it is not well understood how the stress response is facilitating extinction resistance in active avoidance learning across sexes. Therefore, the first set of studies aimed to investigate the role of biological sex and glucocorticoid receptor (GR) …

Development Of Avalanche Photo Detector For Uv-C Using Gallium Oxide Material System, Md Ghulam Ghulam Zakir

Theses and Dissertations

This work describes the metal-organic chemical vapor deposition (MOCVD) optimization process for epitaxially grown gallium oxide (Ga2O3) layers, electrical field distribution, and the design for Avalanche Photo Detector (APD). MOCVD is a well-accepted process in the semiconductor industry, as it is well-known for its precise deposition of ultra-thin, high-quality semiconductor layers with extraordinary control over composition and thickness. The choice of Ga2O3 is due to r its distinctive properties of ultra-wide bandgap and low turn-on resistance. Thus, Ga₂O₃-based materials can withstand high voltage and current with the least energy loss, making them an attractive choice for …

Thermal Management Of Power Electronic Devices Using Single Crystal Aln Heat Spreaders, Md Abdullah-Al Mamun

Theses and Dissertations

Due to high critical electric field and saturation velocity, wide bandgap (WBG) III-Nitride semiconductor materials (AlxGa1-xN) and their heterostructures have gone through extensive research in academia and industry for applications requiring high-voltage, high-current, high-frequency, and high-temperature transistor operation. AlGaN/GaN high electron mobility transistor (HEMT) has been commercialized for 650-V power converters, smartphones, PCs, USB wall power outlets, on-board and off-board EV chargers, and numerous other applications. However, AlGaN/GaN HEMTs grown on low-cost sapphire or Si substrates face significant self-heating issues due to the poor thermal conductivity of the substrate. The high thermal resistance (RTH) and heat capacity of the substrates …