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Full-Text Articles in Engineering

The Distributed Trust Model Applied To The Energy Grid Of Things, Narmada Sonali Fernando Dec 2021

The Distributed Trust Model Applied To The Energy Grid Of Things, Narmada Sonali Fernando

Dissertations and Theses

Electric power system operators can manage distribution system utilization and usage by coordinating end customer usage of distributed energy resources. The end customers in this regard are Service Provisioning Customers, who provide their energy resources to a Grid Service Provider, which in turn dispatches large aggregations of distributed energy resources to provide reliable service to the power system. The security of this system relies upon information protection mechanisms, as described in IEEE 2030.5. However, in addition to preventive security measures, a monitoring function is required to ensure trustworthiness.

Trust models are a method to detect and respond to both expected …


Dual Multivector Model Predictive Control For The Power Converters Of A Floating Owc Wec, Marcos Blanco, Dionisio Ramirez, Mohammad Ebrahim Zarei, Mahima Gupta Dec 2021

Dual Multivector Model Predictive Control For The Power Converters Of A Floating Owc Wec, Marcos Blanco, Dionisio Ramirez, Mohammad Ebrahim Zarei, Mahima Gupta

Electrical and Computer Engineering Faculty Publications and Presentations

Oscillating Water Column (OWC) is one of the most well-known wave energy converter (WEC). Typically, OWCs are installed in rocky shores or in custom-built breakwaters. However, since the wave profile is more favorable in an open sea, it can also be installed in a point absorber in order to increase the energy extraction.

This paper presents the development of a new dual Multivector Model Predictive Control (MMPC) for the power converters of a floating OWC WEC. The fast dynamic response featured by the proposed MMPC has proven to be very suitable to deal with the highly variable torque and velocity …


Novel Quantum Algorithms To Minimize Switching Functions Based On Graph Partitions, Peng Gao, Marek A. Perkowski, Yiwei Li, Xiaoyu Song Nov 2021

Novel Quantum Algorithms To Minimize Switching Functions Based On Graph Partitions, Peng Gao, Marek A. Perkowski, Yiwei Li, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

After Google reported its realization of quantum supremacy, Solving the classical problems with quantum computing is becoming a valuable research topic. Switching function minimization is an important problem in Electronic Design Automation (EDA) and logic synthesis, most of the solutions are based on heuristic algorithms with a classical computer, it is a good practice to solve this problem with a quantum processer. In this paper, we introduce a new hybrid classic quantum algorithm using Grover’s algorithm and symmetric functions to minimize small Disjoint Sum of Product (DSOP) and Sum of Product (SOP) for Boolean switching functions. Our method is based …


Effectiveness Assessment Of The Search-Based Statistical Structural Testing, Yang Shi, Xiaoyu Song, Marek A. Perkowski, Fu Li Nov 2021

Effectiveness Assessment Of The Search-Based Statistical Structural Testing, Yang Shi, Xiaoyu Song, Marek A. Perkowski, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

Search-based statistical structural testing (SBSST) is a promising technique that uses automated search to construct input distributions for statistical structural testing. It has been proved that a simple search algorithm, for example, the hill-climber is able to optimize an input distribution. However, due to the noisy fitness estimation of the minimum triggering probability among all cover elements (Tri-Low-Bound), the existing approach does not show a satisfactory efficiency. Constructing input distributions to satisfy the Tri-Low-Bound criterion requires an extensive computation time. Tri-Low-Bound is considered a strong criterion, and it is demonstrated to sustain a high fault-detecting ability. This article tries to …


An Adjustable Stiffness Torsional Magnetic Spring With A Linear Stroke Length, Dawei Che, Jonathan Z. Bird, Alex Hagmüller, Md Emrad Hossain Nov 2021

An Adjustable Stiffness Torsional Magnetic Spring With A Linear Stroke Length, Dawei Che, Jonathan Z. Bird, Alex Hagmüller, Md Emrad Hossain

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents the analysis, mechanical design, and proof-of-principle experimental testing of a new type of adjustable stiffness torsional magnetic spring for an ocean generator application. Unlike prior published designs the rotary magnetic spring is shown to have a highly linear adjustable stroke length. The presented torsional spring is experimentally shown to be able to create a ± 45° angular stroke range with a peak torque of ± 39.1 N·m. The stiffness is adjusted by using a stepper motor to axially adjust the axial magnet offset. The stepper motor contains a brake so that power is not expended when maintaining …


Fourth-Order Nonlinear Distortion To The Power Spectrum Of Rf Amplifiers, Xianzhen Yang, Shiyu Li, Fu Li Oct 2021

Fourth-Order Nonlinear Distortion To The Power Spectrum Of Rf Amplifiers, Xianzhen Yang, Shiyu Li, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

Even-order intermodulation distortions are often considered easy to filter in narrowband radio frequency (RF) wireless systems because they are usually located far away from the desired passband and adjacent bands. However, even-order intermodulation distortions have recently attracted more interest with the increasing popularity of wideband RF appli- cations. The authors’ previous work was devoted to establishing the power spectrum model of second-order intermodulation distortion. Motivated by the latest efforts on RF power amplifier linearization with second-order and fourth-order intermodulation, our focus now is to establish a power spectrum model of fourth-order intermodulation distortion which can be used to discuss the …


Deep Learning Approach For Screening Autism Spectrum Disorder In Children With Facial Images And Analysis Of Ethnoracial Factors In Model Development And Application, Angelina Lu, Marek Perkowski Oct 2021

Deep Learning Approach For Screening Autism Spectrum Disorder In Children With Facial Images And Analysis Of Ethnoracial Factors In Model Development And Application, Angelina Lu, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Autism spectrum disorder (ASD) is a developmental disability that can cause significant social, communication, and behavioral challenges. Early intervention for children with ASD can help to improve their intellectual ability and reduces autistic symptoms. Multiple clinical researches have suggested that facial phenotypic differences exist between ASD children and typically developing (TD) children. In this research, we propose a practical ASD screening solution using facial images through applying VGG16 transfer learning-based deep learning to a unique ASD dataset of clinically diagnosed children that we collected. Our model produced a 95% classification accuracy and 0.95 F1-score. The only other reported study using …


Expanding Temperature Sensing For The Orion Bms 2, Samuel J. Parker Oct 2021

Expanding Temperature Sensing For The Orion Bms 2, Samuel J. Parker

University Honors Theses

Formula SAE (FSAE) is an annual collegiate design competition that takes place across the globe. Portland State University’s team, Viking Motorsports, was committed to designing an Electric Vehicle (EV) for the 2021 FSAE competition. The team designed a completely custom lithium-ion cell battery that is managed by an Orion BMS 2 battery management system. The FSAE rulebook requires a robust temperature monitoring system for any EV power supply. The Orion BMS 2 can only directly collect data from eight temperature sensors, which is not enough to meet FSAE regulation. However, the BMS can be configured to monitor many more sensors …


Proximal Policy Optimization For Radiation Source Search, Philippe Erol Proctor, Christof Teuscher, Adam A. Hecht, Marek Osiński Sep 2021

Proximal Policy Optimization For Radiation Source Search, Philippe Erol Proctor, Christof Teuscher, Adam A. Hecht, Marek Osiński

Electrical and Computer Engineering Faculty Publications and Presentations

Rapid search and localization for nuclear sources can be an important aspect in preventing human harm from illicit material in dirty bombs or from contamination. In the case of a single mobile radiation detector, there are numerous challenges to overcome such as weak source intensity, multiple sources, background radiation, and the presence of obstructions, i.e., a non-convex environment. In this work, we investigate the sequential decision making capability of deep reinforcement learning in the nuclear source search context. A novel neural network architecture (RAD-A2C) based on the advantage actor critic (A2C) framework and a particle filter gated recurrent unit for …


Head-Wave Correlations In Layered Seabed: Theory And Modeling, Jie Li, Martin Siderius, Peter Gerstoft, Jun Fan, Lanfranco Muzi Sep 2021

Head-Wave Correlations In Layered Seabed: Theory And Modeling, Jie Li, Martin Siderius, Peter Gerstoft, Jun Fan, Lanfranco Muzi

Electrical and Computer Engineering Faculty Publications and Presentations

This paper derives travel times and arrival angles of head-wave correlations from ocean ambient noise in shallow water over a layered seabed. The upcoming and surface reflected head-wave noise signal received at two receivers from the same interface are correlated, and their travel time differences give the travel times of the head-wave correlations. The arrival angle of head-wave correlations from an interface depends on sound speeds in the layers above and just below. The predictions of head-wave correlations from a seabed with two layers and the corresponding inversion results are verified with simulations.


A 3d Crossbar Architecture For Both Pipeline And Parallel Computations, John M. Acken, Muayad J. Aljafar Sep 2021

A 3d Crossbar Architecture For Both Pipeline And Parallel Computations, John M. Acken, Muayad J. Aljafar

Electrical and Computer Engineering Faculty Publications and Presentations

A 3D architecture made up of a CMOS layer combined with a 3D stack of bipolar memristor crossbar arrays provides an innovative approach to hardware support for utilizing the strength of CMOS combined with the strength of memristors. Memristors have been evaluated for implementing a broad spectrum of applications such as memory, computations, hardware-based security primitives, cryptography, etc., and numerous studies have shown that memristors are desirable candidates for such applications. This paper proposes a novel 3D memristive crossbar architecture (i.e., a stack of memristive crossbar arrays built on top of CMOS substrate) with a specific focus on the way …


What’S Left Before Participatory Modeling Can Fully Support Real-World Environmental Planning Processes: A Case Study Review, Beatrice Hedelin, S. Gray, S. Woehlke, Todd K. Bendor, Alison Singer, R. Jordan, Moira Zellner, Philippe J. Giabbanelli, Pierre D. Glynn, Antoine J. Jetter, Multiple Additional Authors Sep 2021

What’S Left Before Participatory Modeling Can Fully Support Real-World Environmental Planning Processes: A Case Study Review, Beatrice Hedelin, S. Gray, S. Woehlke, Todd K. Bendor, Alison Singer, R. Jordan, Moira Zellner, Philippe J. Giabbanelli, Pierre D. Glynn, Antoine J. Jetter, Multiple Additional Authors

Engineering and Technology Management Faculty Publications and Presentations

In environmental participatory modeling (PM), both computer and non-computer-based modeling techniques are used to aid participatory problem description, solution, and decision-making actions in environmental contexts. Although many PM case studies have been published, few efforts have sought to systematically describe and understand dominant PM processes or establish best practices for PM. As a first step, we have reviewed a random sample of environmental PM case study articles (n = 60) using a novel PM process evaluation instrument. We found that significant work likely remains for PM to fully support participatory and integrated planning processes. While PM reports systematically address knowledge …


Modeling Renal Function During Pregnancy, Christina A. Valtierra Aug 2021

Modeling Renal Function During Pregnancy, Christina A. Valtierra

REU Final Reports

The main goal of this research project is to build a computational model that illustrates the main processes in renal function during pregnancy. The analysis of how pregnancy affects all the factors that take place within the kidney will allow for a better understanding of how pathologies like proteinuria, hypertension, and glomerular endotheliosis develop. This model is a small part of a more complex model that showcases the complete pathophysiology of preeclampsia.


Modeling The Effect Of The Covid-19 Pandemic On Azithromycin Prescription In General Practices Across The Uk, Oluwasegun Isaac Daramola Aug 2021

Modeling The Effect Of The Covid-19 Pandemic On Azithromycin Prescription In General Practices Across The Uk, Oluwasegun Isaac Daramola

altREU Projects

In the early months of the COVID-19 pandemic, it was reported that some antibiotics were prescribed as a remedy for viral treatment and prophylaxis based on non-randomized, uncontrolled short clinical trials. A major antibiotic consulted being Azithromycin; a broad-spectrum macrolide selected based on its immunomodulatory effects in chronic inflammatory lung diseases, with a seasonal prescription increase of 21.5% in March 2020 compared to March 2019.

To analyze the effect and possible antimicrobial resistance impact of the pandemic on Azithromycin prescription across general practices in the United Kingdom (UK), this study uses a time series decomposition modeling method to compare a …


Developing A Strategy For Creating Affordable Student Housing Solutions, Juan D. Campolargo Aug 2021

Developing A Strategy For Creating Affordable Student Housing Solutions, Juan D. Campolargo

altREU Projects

College is becoming more and more expensive, and students are graduating with more and more debt. In 2021, we have almost 1.6 trillion dollars of student loan debt. While students are in college, they need a place to live, and this project will be about how to develop a strategy for creating affordable student housing solutions.

Housing should not be another cause of concern to students or really anyone.

The way it’s done is that people get more loans to pay for housing, or they work as much as they can when they’re not studying to pay for rent. Affordable …


Agent-Based Activity Generation Of Runners For City Infrastructure Planning, Quang Le Aug 2021

Agent-Based Activity Generation Of Runners For City Infrastructure Planning, Quang Le

REU Final Reports

Since the pandemic started, many gyms and indoor classes have been shut down to mitigate the spread of Coronavirus. Many people have been forced to get onto pavement streets to get some fresh air while running around and coping with the new reality. There are over 60 million runners in the U.S., and that number is growing rapidly during this time without any sign of stopping once life gets back to normal. In this project, an agent-based model has been developed to generate a set of routes that runners would take in their daily run in a neighborhood of Portland …


Finding Lonely Routes For Runners And Bikers, Ethan T. Spicher Aug 2021

Finding Lonely Routes For Runners And Bikers, Ethan T. Spicher

REU Final Reports

With COVID-19 raging around the world, personal health is even more important to a lot of people. One way to maintain good physical and mental health is to exercise according to Deslandes [2]. When exercising it may be important to make sure that you are running/biking on trails that are less populated than others, as well as taking into account the distance. This can be solved by creating an algorithm that allows the user to choose the starting and end point, and the algorithm will then find the optimal path between the two points with the distance and popularity of …


Assessing The Impact Of Changing Drought Conditions On Wildfire Emissions In Washington And Oregon, Maggie Liu Aug 2021

Assessing The Impact Of Changing Drought Conditions On Wildfire Emissions In Washington And Oregon, Maggie Liu

altREU Projects

Wildfires impact public health, and threaten life, livelihood, and property across the United States, particularly on the West Coast. This project seeks to find correlations between drought and wildfire emissions by comparing the Modified Palmer Drought Index (PMDI) with smoke particulate (PM2.5) emissions from fires in Oregon and Washington. PM2.5 emissions were taken from 2002 – 2020 from the National Center for Atmospheric Research’s FINN model, which uses satellite observations of active fires to assign burned area, and compares against observed vegetation to model emissions. This project found the strongest positive correlation between fire activity for a summer season (July …


The Effect Of A Ferrite-Core Relay Vs. An Air-Core Relay On The Output Power Characteristics Of A Three-Coil Wireless Power Transfer System, Jakob L. White Aug 2021

The Effect Of A Ferrite-Core Relay Vs. An Air-Core Relay On The Output Power Characteristics Of A Three-Coil Wireless Power Transfer System, Jakob L. White

University Honors Theses

The purpose of this thesis is to determine the effect of using a ferrite-core relay on the output power characteristics of a three-coil, parallel-tuned, domino-resonator wireless power transfer (WPT) system in comparison to the effect of using an air-core relay in such a system. First, a general mathematical model is presented to describe both the ferrite-core-relay system and the air-core-relay system and to calculate their output power characteristics for seven different resistive loads at each of five different distance configurations between the coils. Next, experimental results are analyzed and compared to the mathematical results to confirm model accuracy. Finally, the …


Quantum Grover's Oracles With Symmetry Boolean Functions, Peng Gao Aug 2021

Quantum Grover's Oracles With Symmetry Boolean Functions, Peng Gao

Dissertations and Theses

Quantum computing has become an important research field of computer science and engineering. Among many quantum algorithms, Grover's algorithm is one of the most famous ones. Designing an effective quantum oracle poses a challenging conundrum in circuit and system-level design for practical application realization of Grover's algorithm.

In this dissertation, we present a new method to build quantum oracles for Grover's algorithm to solve graph theory problems. We explore generalized Boolean symmetric functions with lattice diagrams to develop a low quantum cost and area efficient quantum oracle. We study two graph theory problems: cycle detection of undirected graphs and generalized …


Universal Biological Motions For Educational Robot Theatre And Games, Rajesh Venkatachalapathy, Martin Zwick, Adam Slowik, Kai Brooks, Mikhail Mayers, Roman Minko, Tyler Hull, Bliss Brass, Marek Perkowski Jun 2021

Universal Biological Motions For Educational Robot Theatre And Games, Rajesh Venkatachalapathy, Martin Zwick, Adam Slowik, Kai Brooks, Mikhail Mayers, Roman Minko, Tyler Hull, Bliss Brass, Marek Perkowski

Systems Science Faculty Publications and Presentations

Paper presents a concept that is new to robotics education and social robotics. It is based on theatrical games, in motions for social robots and animatronic robots. Presented here motion model is based on Drift Differential Model from biology and Fokker-Planck equations. This model is used in various areas of science to describe many types of motion. The model was successfully verified on various simulated mobile robots and a motion game of three robots called "Mouse and Cheese."


Seabed Observations At The New England Mud Patch: Reflection And Scattering Measurements And Direct Geoacoustic Information, Charles W. Holland, Chad M. Smith, Zackary Lowe, Jim Dorminy Jun 2021

Seabed Observations At The New England Mud Patch: Reflection And Scattering Measurements And Direct Geoacoustic Information, Charles W. Holland, Chad M. Smith, Zackary Lowe, Jim Dorminy

Electrical and Computer Engineering Faculty Publications and Presentations

Seabed reflection and scattering measurements were conducted at the New England Mud Patch to better understand the acoustic properties of fine-grained (muddy) sediments. The measurement philosophy and the measurements themselves are summarized. In addition, geoacoustic information accessed directly from the data in the time and frequency domains is presented. The main result is the existence of an angle of intromission. This observation proves that the mud sound speed is less than that of the water and yields a sediment sound speed ratio 0.9865 with outer bounds {0.985 0.989}. Another result is the observation of strong scattered arrivals from within the …


Sound Speed Gradients In Mud, Charles W. Holland Jun 2021

Sound Speed Gradients In Mud, Charles W. Holland

Electrical and Computer Engineering Faculty Publications and Presentations

Various methods have been used to estimate sound speed profiles in mud at the New England Mud Patch. Some of these methods show large sound speed gradients of order 10 s−1. New measurements of the seabed reflection coefficient exhibit an angle of intromission over three octaves in frequency; these data constrain the range of possible sound speed gradient values. The data indicate that sound speed gradients must be quite weak, i.e., much smaller than |10 s−1|. This conclusion is supported by core data which indicate nearly constant porosity in most of the mud layer.


Method Of Modeling The Swing Equation Using Time Synchronized Measurements, Robert Matthew Ferraro May 2021

Method Of Modeling The Swing Equation Using Time Synchronized Measurements, Robert Matthew Ferraro

Dissertations and Theses

In three phase, high-voltage transmission systems, synchronous generators accelerate or decelerate to adapt to changing power transfer requirements that occur during system disturbances. In network electrical power systems, frequency changes constantly based on system dynamics. Modeling network dynamics from oscillations and transients using time-synchronized measurements can provide real-time information, including angular displacements, voltage and current phasors, frequency changes, and rate of signal system decay from positive-sequence components.

Power system voltage and current waveforms are not steady-state sinusoids, especially during system disturbances. These waveforms contain sustained harmonic and non-harmonic components. Additionally, because of faults and other switching electromagnetic transients, there may …


Spectrum Modeling Of Rf Amplifiers Based On Intercept Points With Measurement Improvements, Siyuan Yan May 2021

Spectrum Modeling Of Rf Amplifiers Based On Intercept Points With Measurement Improvements, Siyuan Yan

Dissertations and Theses

Orthogonal frequency-division multiplexing has been developed into a popular modulation scheme for wireless communication systems, used in applications such as LTE and 5G. In wireless communication system, spectrum regrowth caused by RF amplifiers will generate distortions to both passband in use and adjacent channels such that the transmission quality will be degraded. The study of this dissertation aims to predict the spectrum regrowth for OFDM based signals at the output of a RF amplifier due to the nonlinearity. Based on Taylor polynomial coefficients, a power spectrum expression for amplified OFDM signals in terms of intercept points up to nth-order is …


On Compressional Wave Attenuation In Muddy Marine Sediments, Charles W. Holland, Stan E. Dosso May 2021

On Compressional Wave Attenuation In Muddy Marine Sediments, Charles W. Holland, Stan E. Dosso

Electrical and Computer Engineering Faculty Publications and Presentations

A method for measuring in situ compressional wave attenuation exploiting the spectral decay of reflection coefficient Bragg resonances is applied to fine-grained sediments in the New England Mud Patch. Measurements of layer-averaged attenuation in a 10.3 m mud layer yield 0.04 {0.03, 0.055} dB/m/kHz (braces indicate outer bounds); the attenuation is twice as large at a site with 3.2 m mud thickness. It is shown that both results are heavily influenced by a ∼1 m sand-mud transition interval created by geological and biological processes that mix sand (at the base of the mud) into the mud. Informed by the observations, …


Modeling Tools For Analyzing Electrical Power Distribution Systems Impacted By Electric Vehicle Load Growth, Jacob Sheeran Apr 2021

Modeling Tools For Analyzing Electrical Power Distribution Systems Impacted By Electric Vehicle Load Growth, Jacob Sheeran

Dissertations and Theses

Growing Electric Vehicle penetration presents unwanted problems to grid reliability. For nearly every EV there is corresponding household charging. High penetration of Electric Vehicle Service Equipment can lead to over loading of assets and under voltage conditions. In order to understand the effects EV have on a distribution system, studies have to be done for EVSE to understand how the distribution system is affected. Using advanced Power Engineering Simulation Software is often the best way to model systems due to the credibility of their software modules. For this thesis, I developed a suite of distribution system analysis tools using CYME …


On Ip2 Impact To Nonlinear Distortion Of Rf Amplifiers, Xianzhen Yang, Shiyu Li, Siyuan Yan, Fu Li Mar 2021

On Ip2 Impact To Nonlinear Distortion Of Rf Amplifiers, Xianzhen Yang, Shiyu Li, Siyuan Yan, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

The second-order distortion, often using second-order intercept point (IP2) as an indicator, has been considered easy to be filtered in narrowband radio frequency (RF) communications because it is located far away from the passband of transmitted signals. However, with rapidly increased applications in wideband RF communications, the secondorder intermodulation (IM) might become important, partially evidenced by the increased appearances of IP2 in the amplifier datasheets in recent years. In this article, a power spectrum model of the second-order IM is derived to quantify the second-order distortion using the IP2. This model could be used to determine under what conditions, in …


Memristor Crossbar Array Testing Using Sneak Paths, Rasika Dhananjay Joshi Mar 2021

Memristor Crossbar Array Testing Using Sneak Paths, Rasika Dhananjay Joshi

Dissertations and Theses

Moore's law decline has paved the way to shift to new technologies at architectural and device levels. CMOS based technologies are facing many challenges with the growing demand for miniaturization. The growing heat dissipation is the major limitation for performance, energy efficiency and reliability with the increasing transistor count in integrated circuits. Manufacturing costs and process/memory performance gap have also grown steadily over the last several decades with the scaling down of the CMOS feature size. Memristor, a nanoscale device, has the potential to address the CMOS limitations because of its non-volatility, high density, low power operation, low cost per …


Power Distribution System Tools For Analyzing Impacts Of Projected Electric Vehicle Load Growth Using Gridlab-D, Shahad Alomani Feb 2021

Power Distribution System Tools For Analyzing Impacts Of Projected Electric Vehicle Load Growth Using Gridlab-D, Shahad Alomani

Dissertations and Theses

The increased penetration of Electric Vehicle (EV) will provide substantial benefits to the environment. However, each EV will present a significant additional load to electric power distribution infrastructure, especially to radial distribution feeders. The additional load may cause transformers to operate beyond their thermal limits, unacceptable voltage drops along distribution lines, and primary conductor overloads. It is now, more than ever, vital to understand the limitations of existing infrastructure in light of an accelerating push for greener alternatives with insight that stems from modeling, simulation, and proper analysis as the backbone to a well-informed response.

The objective of this work …