Engineering Commons^™

Energy-Efficient Neuromorphic Architectures For Nuclear Radiation Detection Applications, Jorge I. Canales-Verdial, Jamison R. Wagner, Landon A. Schmucker, Mark Wetzel, Nathan J. Withers, Philippe Erol Proctor, Christof Teuscher, Multiple Additional Authors

Electrical and Computer Engineering Faculty Publications and Presentations

A comprehensive analysis and simulation of two memristor-based neuromorphic architectures for nuclear radiation detection is presented. Both scalable architectures retrofit a locally competitive algorithm to solve overcomplete sparse approximation problems by harnessing memristor crossbar execution of vector–matrix multiplications. The proposed systems demonstrate excellent accuracy and throughput while consuming minimal energy for radionuclide detection. To ensure that the simulation results of our proposed hardware are realistic, the memristor parameters are chosen from our own fabricated memristor devices. Based on these results, we conclude that memristor-based computing is the preeminent technology for a radiation detection platform.

Are Vehicle Tires Major Contributors To Microplastic Emissions Into The China Seas? A Simple Model Perspective., Shuolin Xiao, Yuran Liang, Xiaowei Zhu, Simone Q. Kyes, Xiaofeng Cai

Mechanical and Materials Engineering Faculty Publications and Presentations

Microplastics pose a substantial threat to our environment. Given China's large population and rapid economic growth, it is urgent to estimate the annual emissions of microplastics into its marine environment. The microplastics show a significant variation in their source emissions as well as in their physical and chemical properties, leading to differences in their transport and fate in aquatic environments. To account for these variations, we developed a process-oriented model that considers microplastics from different sources and the inter-provincial variation in their retention rate to assess annual microplastic emissions into the China seas. On a national scale, of the microplastics …

Mmwave Rat Optimization: Mac Layer Initial Access Design And Transport Layer Integration, Suresh Srinivasan

Dissertations and Theses

MmWave Radio Access Technology (RAT) is a promising technology for wireless communication due its large bandwidth and is already being deployed in 5G cellular and emerging WiFi technologies. MmWave systems use highly directional beams with narrow beamwidths to overcome the high path loss associated with their frequency bands. A mmWave radio can be used either in a standalone mode (where all radios use the same technology) or simultaneously with other technologies such as LTE and low frequency WiFi in a communication mode commonly referred to as integrated mode. This thesis proposes two methods to optimize mmWave RAT performance in both …

Understanding Quadrature Modulation By Designing A 7mhz Iq Test Bench To Encode The Polybius Square, William Lee Bradley

Dissertations and Theses

This thesis outlines the design of an IQ Test Bench that allows for experimentation of quadrature modulation techniques. Quadrature modulation utilizes two signals I and Q, 90° out of phase from each other, to greatly increase communication data rates. Using Desmos, a thorough mathematical analysis of waveform mixing is presented, and constellation diagrams are plotted from the results. From this an ancient fire signaling technique known as the Polybius Square is encoded into the system. The IQ Test Bench is built from fundamental components that would be contained within an RFFE: a local oscillator and two frequency mixers. The LO …

A Time Synchronized Multi-Hop Mesh Network With Crystal-Free Nodes, Filip Maksimovic, Austin Patel, David C. Burnett, Thomas Watteyne, Kristofer S.J. Pister

Electrical and Computer Engineering Faculty Publications and Presentations

In this work we propose and demonstrate a protocol for a time synchronized channel hopping mesh network for wireless transceivers that use exclusively imprecise and inaccurate on-chip oscillators. This protocol is built on an IEEE 802.15.4 physical layer radio that enables interoperability with protocols such as 6TiSCH or Thread. A calibration-bootstrapped multi-hop mesh network is demonstrated with a single crystal-enabled node acting as the root. The protocol is designed to create a multi-hop mesh while compensating noisy and drifting oscillators and timers. With a 4 s synchronization period, an experimental implementation of the network maintains, in the worst case, 1.8 …

Droplet Jump From A Particle Bed, Karl Cardin, Facundo Cabrera-Booman, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Drop tower experiments have been performed to study droplet jump from a particle bed across a wide range of fluid viscosities. Here the droplet jumps from the particle bed in response to the apparent step reduction from terrestrial gravity to microgravity when the experiment is dropped and enters free fall. The presence of a particle layer has been found to affect contact line dissipation and the overall jumping behavior of droplets. Additionally, the study has identified the impact of the Ohnesorge number (Oh) on droplet morphology. The investigation has yielded results that not only validate a modified version of the …

Pcl And Dmso2 Composites As Biomaterials For Additive Manufacturing, Jae-Won Jang

Dissertations and Theses

Tissue engineering provides a viable solution to address the shortage of organ donors for allograft transplants. Its primary objective is the replacement or regeneration of damaged tissues which is developed by combining living cells, a scaffold, and a bioreactor. Among these components, the scaffold serves as an artificial extracellular matrix (ECM), which plays a pivotal role in supporting cell adhesion, proliferation, differentiation, and overall tissue development. Additive manufacturing (AM), commonly referred to as three-dimensional (3D) printing, emerges as a promising method for scaffold fabrication due to its capability to create complex and repeatable geometries.

Polycaprolactone (PCL) has been one of …

Implementation Profile: Egot Derms Server/Client System (Doe-Psu-0000922-2), Tylor Slay, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

This implementation profile (IP) provides the scope and requirements necessary to implement a distributed energy resource management system (DERMS), which networks large numbers of DER within an energy grid of things (EGoT). This document originated as part of a U.S. DOE-funded project to develop a DERMS based on a set of rules known as the Energy Services Interface (ESI). The ESI serves as an umbrella, ensuring the information exchange between an aggregator and DER owners conforms to expectations: protect privacy, provide security, develop trustworthiness, and ensure interoperability. DERMS developers use the ESI to ensure that information exchange meets these expectations. …

Product Specification: Distributed Trust Model System (Doe-Psu-0000922-4), Narmada Sonali Fernando, Abdullah Barghouti, Robert B. Bass, John M. Acken

Electrical and Computer Engineering Faculty Publications and Presentations

A Distributed Trust Model (DTM) System is a supervisory component within an energy grid of things. The role of a DTM System is to implement the trust aspects of an energy services interface. The DTM System augments existing security measures by monitoring the communication between the various EGoT System actors and quantifying metrics of trust of each actor.

Implementation Profile: Modeling Environment (Doe-Psu-0000922-3), Sean Keene, Midrar Adham, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

This implementation profile provides the scope, background, and requirements necessary to implement a Modeling Environment (ME) to test a Distributed Energy Resource (DER) Management System (DERMS). A DERMS is used by an aggregator to dispatch large numbers of DERs in order to provide grid services to a Grid Operator. The ME addresses scalability issues inherent to Hardware-in-the-Loop DERMS simulation; a large number of assets are needed in order to observe effects on the grid from deployment and dispatch of DERs.

Product Specification: Distributed Control Module (Doe-Psu-0000922-5), Nicole Henderson, Kai Zeng, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

This product specification describes the architecture, implementation, and hardware descriptions of a Distributed Control Module (DCM) prototype. A DCM is an enabling technology for distributed energy resources (DER). DERs are grid-enabled generation, storage, and load devices that are owned by utility customers. DCMs enable information exchange between a distributed energy resource management system (DERMS) and DERs for the purpose of networking large numbers of DERs. The DCM prototype described within this document enables DER participation in a service-oriented aggregation system. A DERMS server provides IEEE 2030.5 smart energy resource services to DCM clients using a request/response information exchange process. DCMs …

Energy Services Interface (Doe-Psu-0000922-1), Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

This document defines a set of rules known as the Energy Services Interface (ESI), which “establish a bi-directional, service-oriented, logical interface to support secure, trustworthy information exchange between an aggregator and distributed energy resources (DERs). These exchanges facilitate energy interactions between the DERs and the aggregator, thereby allowing the aggregator to provide grid services through dispatch of the DERs.” The ESI serves as an umbrella, ensuring the information exchange between an aggregator and DER owners conforms to expectations: protect privacy, provide security, develop trustworthiness, and ensure interoperability. DERMS developers use the ESI to ensure that information exchange meets these expectations.

Psu Derms Operating Manual And Egot System Reference (Doe-Psu-0000922-7), Tylor Slay, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

This document guides the user of the Portland State University Distributed Energy Resource Management System in configuration and normal operation. For direct access to the underlying code and its usage see the accompanying PSU EGoT System Reference. The system reference outlines all classes and methods used through the Energy Grid of Things system including applications, models, interfaces and the entity component system.

Data From: Active Transportation Counts From Existing On-Street Signal And Detection Infrastructure, Sirisha Kothuri, Patrick Allen Singleton, Mahyar Vahedi Saheli, Elizabeth Yates, Joseph P. Broach

Civil and Environmental Engineering Faculty Datasets

This study’s objective was to use data from existing traffic signal infrastructure to estimate pedestrian volumes. Pedestrian push-button actuations were collected from signal controller logs at 49 intersections in western Oregon and an additional 16 intersections in eastern Oregon. These actuations were then compared to observed pedestrian counts, totaling over 34,000 people, obtained from video recordings. After exploring various options, a simple quadratic relationship was modeled using a single measure of pedestrian signal activity: the number of push-button presses (filtered to remove multiple presses within 15 seconds). The model’s predictions showed a correlation of 0.86 with observed pedestrian volumes and …

Experimental And Modeled Assessment Of Interventions To Reduce Pm2.5 In A Residence During Awildfire Event, Chrissi Argyro Antonopoulos, H. E. Dillon, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Increasingly large and frequent wildfires affect air quality even indoors by emitting and dispersing fine/ultrafine particulate matter known to pose health risks to residents. With this health threat, we are working to help the building science community develop simplified tools that may be used to estimate impacts to large numbers of homes based on high-level housing characteristics. In addition to reviewing literature sources, we performed an experiment to evaluate interventions to mitigate degraded indoor air quality. We instrumented one residence for one week during an extreme wildfire event in the Pacific Northwest. Outdoor ambient concentrations of PM_2.5 reached historic …

Training Practitioners For Real-Time Product Development Using Generative Artificial Intelligence, Antoine J. Jetter, Ameeta Agrawal, Dahm Mongkol Hongchai, Charles Weber, Yufei Tao

Engineering and Technology Management Faculty Publications and Presentations

A workshop to train practitioners in real-time new product development (NPD) using generative artificial intelligence (AI) was conducted. Three teams of graduate students in Engineering and Technology Management (many with work experience as managers and engineers) were given minimalist instructions to develop a product concept and a preliminary marketing plan for a product of their choosing within six hours using ChatGPT, search engines, and other Internet-based tools. The product was to be novel, and the plan was to include customer identification, market analysis, generating personas, and a 15-minute presentation at the end of the workshop. The goal was to 'inspire …

Developing An Assessment Model For Entrepreneurship Ecosystems Using Hierarchical Decision Model, Mustafa Almuzel, Tugrul U. Daim, Birol Yesilada, Marina Dabic, Gulin Idil Bolatan

Engineering and Technology Management Faculty Publications and Presentations

Entrepreneurship is a crucial driver of economic growth, necessitating the development of effective entrepreneurial ecosystems. However, there are significant gaps in the literature regarding the structured assessment of these ecosystems. This study addresses three main research gaps: the lack of structured evaluation methods, the need for a comprehensive analysis of ecosystem challenges from various perspectives, and the identification of critical factors essential for ecosystem growth. To bridge these gaps, the research introduces the Hierarchical Decision Model (HDM) as a universal assessment framework that can be adapted to different cities for creating effective entrepreneurial environments. The research methodology involved formulating perspectives …

Path Instabilities And Drag In The Settling Of Single Spheres, Facundo Cabrera-Booman, Nicolas Plihon, Mickael Bourgoin

Mechanical and Materials Engineering Faculty Publications and Presentations

The settling behavior of individual spheres in a quiescent fluid was studied experimentally. The dynamics of the spheres was analyzed in the parameter space of particle-to-fluid density ratio (Γ) and Galileo number (Ga), with Γ ∈ (1.1,7.9) and Ga ∈ (100,340). The experimental results showed for the first time that the mean trajectory angle with the vertical exhibits a complex behavior as Ga and Γ are varied. Numerically predicted regimes such as Vertical Periodic for low Γ values, and Planar Rotating for high Γ values were validated. In particular, for the denser spheres, a clear transition from planar to non-planar …

Barriers And Variable Spacing Enhance Convective Cooling And Increase Power Output In Solar Pv Plants, Brooke Stanislawski, Todd Harman, Raul Bayoan Cal, Marc Calaf

Mechanical and Materials Engineering Faculty Publications and Presentations

When the temperature of solar photovoltaic (PV) modules rises, efficiency drops and module degradation accelerates. Thus, it is beneficial to reduce module operating temperatures. Previous studies of solar power plants have illustrated that incoming flow characteristics, turbulent mixing, and array geometry can strongly impact convective cooling, as measured by the convective heat transfer coefficient h. In the fields of heat transfer and plant canopy flow, previous work has shown that system-scale arrangement modifications—e.g., variable spacing, barriers, or windbreaks—can passively alter the flow, enhance turbulent mixing, and influence convection. However, researchers have not yet explored how variable spacing or barriers …

Automation Of Productive Machinery. Bases For An Innovative Business Model, Carlos Guillermo Hernández-Cenzano, Angel Contreras-Cruz, Eduardo Humada-Tello

Engineering and Technology Management Faculty Publications and Presentations

Nowadays, some laboratories perform elastic properties tests for concrete or rock cores using equipment manufactured 50 years ago. The original data collection procedure uses analog and manual recordings, which can cause inaccuracies in the measurements taken during these trials The process is tedious and updated since each trial's measurement data is recorded manually. In this context, this study systematizes the process and proposes an automated data acquisition and recording system for this type of equipment, followed by a case study presenting a rock compression test.

Moisture-Controlled Triboelectrification During Coffee Grinding, Joshua Méndez Harper, Yong-Hyun Kim, Robin E. Bumbaugh, Connor S. Mcdonald, Christopher H. Hendon, Elana J. Cope, Leif E. Lindberg, Justin Pham, Multiple Additional Authors

Electrical and Computer Engineering Faculty Publications and Presentations

Triboelectrification is the physical process where materials acquire surface charge from frictional interactions at their interfaces.The magnitude of charge depends on the interfacial material composition and can be harnessed in emergent technologies for energy generation.

The mechanism of electrostatic accumulation is complex and is further obscured in granular materials where collisions are sufficiently energetic to cause fracturing. In this “fractoelectric” regime, crack initiation and propagation are thought to charge particles through transfer of electrons and/or ions at the hot crack interface.

Whether a material’s charging is dominated by tribo- or fractoelectrification, fracture-generated granular flows often comprise particles whose surface charge …

Psu Esi Review (Doe-Psu-0000922-6), Tylor Slay, Jaime Kolln, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

A guide to developing an Energy Service Interface (ESI) was created as part of the Grid Modernization Laboratory Consortium 2.5.2 ESI project. The approach applies device-agnostic and service-oriented ESI principles and leverages documents such as the Interoperability Maturity Model and Common Grid Service Definitions to provide a methodology to review, develop, and update standards and profiles to engage distributed energy resources to provide grid services. This document evaluates the ESI developed by Portland State University’s Power Engineering Group under the Electric Grid of Things project funded by the U.S. Department of Energy. The evaluation explores the compliance of this specific …

Analyzing Frequency Event Detection Algorithm Performance Using Different Denoising Methods, Hussain A. Alghamdi, Midrar Adham, Robert Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Maintaining grid frequency at its nominal value is crucial for power system stability and supply-demand balance. Swift and accurate detection of frequency events is vital for providing primary frequency response support. Frequency event detection algorithms often rely on Phasor Measurement Unit data, which may contain noise. Implementing a denoising preprocessing step enhances detection precision and accuracy. In previous works, a frequency event detection algorithm based on wavelet transform was developed, which uses discrete wavelet transform (DWT) for denoising purposes. In this paper, several denoising techniques are considered as potential replacements for the current DWT method. This research investigates and compares …

Trust Model Utilization For Energy Grid Communication, N. Sonali Fernando, John M. Acken, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

The internet information that is used by the Energy Grid of Things requires both preventative security measures as well as surveillance measures. The preventative security measures include certificates, encryption, and all of the basic security protocols as defined by published standards. The surveillance measures include monitoring information flow activities and evaluating these messages for indications of potential security attacks. We describe in this paper the utilization of a Distributed Trust Model that was developed specifically for monitoring communication within an Energy Grid of Things. The goal for the Distributed Trust Models is to provide a level of aggregate trust that …

Field Demonstration Of Residential Der Service-Oriented Load Participation, Zhongkai Zeng, Dana Paresa, Midrar Adham, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Amidst a concerning surge in power consumption during peak hours, coupled with heightened power grid instability, and driven by a growing demand for electricity, aggregations of Distributed Energy Resource are becoming a viable means for providing essential reliability services. Electric utility companies have proactively implemented Demand Response programs for decades. These programs employ Direct Load Control methods to enhance power grid stability, achieved by controlling customers’ Distributed Energy Resource during peak hours to reduce power consumption. However, a notable drawback of Direct Load Control has been high unenrollment rates of DR program participants due to customer discomfort. Therefore, the underlying …

A Magnetic Constant Torque Mechanism, Gozde Sivka, Dawei Che, Bert Dechant, Colton Bruce, Jonathan Z. Bird

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents the design of a new type of magnetic constant torque mechanism. The constant torque is shown to be created over a prescribed ±65° stroke length and is shown to be highly uniform. The value of the constant torque is adjustable through the relative axial motion of the rotors. The constant torque is created using a simple magnet arrangement which makes use of the axial transverse-flux path of one rotor's magnetic field relative to the azimuthal field flow of the fixed secondary rotor. It is shown that the use of segmented magnets introduces torque ripple.

Mud Acoustics, Charles W. Holland, Stan E. Dosso, Jason D. Chaytor

Electrical and Computer Engineering Faculty Publications and Presentations

Imaging the ocean requires an understanding of how different seafloor sediments interact with sound waves.

A Transverse-Flux Constant Force Mechanism, Gozde Sivka, Bertrand Dechant, Colton Bruce, Jonathan Z. Bird

Electrical and Computer Engineering Faculty Publications and Presentations

A new type of constant force magnet mechanism is presented that relies on the interaction of magnets alone to create a constant force over a prescribed stroke length. It is demonstrated that by using a transverse field path a very uniform radial field along the travel length is created. This can then be used to create a constant force over a long stroke length. The constat force value is shown to be adjustable through the rotation of the stator relative to the translator. The operating principle of the presented transverse-flux constant force mechanism is validated by using 3-D finite element …

Uncertainty Quantification Of Live Load Effect In Buried Rc Box Culverts, Mohd Firoj

Dissertations and Theses

Although buried and mostly invisible to the traveling public, bridge-sized culverts (i.e., culverts with span around or longer than 20 ft) account for a large proportion of state-managed bridges. As per Oregon Department of Transportation inventory, there are approximately 35,000 culverts in the state highway system. Among them, 10,862 are in poor conditions and need to be analyzed for load rating purposes. The prediction and understanding of live load effects in culverts are crucial to the design, evaluation, and life-cycle maintenance of culverts. These live load effects include maximum bending moments and shear forces at different critical cross sections.

This …

Polycyclic Aromatic Hydrocarbons (Pahs) In Wildfire Smoke Accumulate On Indoor Materials And Create Post-Smoke Event Exposure Pathways, Aurélie Laguerre, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Wildfire smoke contains PAHs that, after infiltrating indoors, accumulate on indoor materials through particle deposition and partitioning from air. We report the magnitude and persistence of select surface associated PAHs on three common indoor materials: glass, cotton, and mechanical air filter media. Materials were loaded with PAHs through both spiking with standards and exposure to a wildfire smoke proxy. Loaded materials were aged indoors over ~4 months to determine PAH persistence. For materials spiked with standards, total PAH decay rates were 0.010±0.002, 0.025±0.005, and 0.051±0.009 d -1 , for mechanical air filter media, glass, and cotton, respectively. PAH decay on …