Digital Commons Network^™

Prompt, Accurate, And Noncontact Material Identification Using A Single Microwave Sensor With Machine Learning Analysis, Chen Zhu, Osamah Alsalman, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

In This Article, a Novel Approach to Microwave Sensors is Proposed and Demonstrated that Allows for Prompt, Accurate, and Noncontact Material Identification Even with Arbitrary Lift-Off Distances between the Sensor and the Material under Test (MUT). a Multilayer Perceptron (MLP) is Trained to Directly Learn the Relation of the Measured Reflection Spectra of a Homemade Open-Ended Coaxial Cable Resonator Probe with Respect to Different MUTs and Then Achieve One-To-One Mapping between a Measured Spectrum and the MUT. as a Proof-Of-Concept Demonstration, the Performance of the MLP Model is Tested using Easily Accessible Materials, Including Wood, Glass, Water, and Metal. Reflection …

Electromagnetic-Circuital-Thermal-Mechanical Multiphysics Numerical Simulation Method For Microwave Circuits, Huan Huan Zhang, Zheng Lang Jia, Peng Fei Zhang, Ying Liu, Li Jun Jiang, Da Zhi Ding

Electrical and Computer Engineering Faculty Research & Creative Works

An electromagnetic-circuital-thermal-mechanical Multiphysics numerical method is proposed for the simulation of microwave circuits. The discontinuous Galerkin time-domain (DGTD) method is adopted for electromagnetic simulation. The time-domain finite element method (FEM) is utilized for thermal simulation. The circuit equation is applied for circuit simulation. The mechanical simulation is also carried out by FEM method. A flexible and unified Multiphysics field coupling mechanism is constructed to cover various electromagnetic, circuital, thermal and mechanical Multiphysics coupling scenarios. Finally, three numerical examples emulating outer space environment, intense electromagnetic pulse (EMP) injection and high-power microwave (HPM) illumination are utilized to demonstrate the accuracy, efficiency, and …

Modeling Wideband Radiated Emissions From Pcbs In Shielding Enclosures Based On Single-Plane Phaseless Near-Field Scanning, Zhifei Xiao, Zi An Wang, Li Jun Jiang, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents a wideband phase less source reconstruction method (SRM) for the evaluation of the radiated emissions from printed circuit boards (PCBs) in shielding enclosures. The PCBs are modeled with equivalent dipoles, and the numerical Green's function (NGF) is deployed to establish the relationship between the equivalent source and the input near-field (NF) data, thus the electromagnetic influences of the surrounding environments comprehensively accounted. This method only requires magnitude-only NF scanning over a single plane, thus significantly decreasing the NF measurement difficulty. To remedy the lack of phase information of the NF data, the input NF data are equally …

Adaptive Critic Optimal Control Of An Uncertain Robot Manipulator With Applications, Ravi Prakash, Laxmidhar Behera, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Realistic manipulation tasks involve a prolonged sequence of motor skills in varying control environments consisting of uncertain robot dynamic models and end-effector payloads. To address these challenges, this article proposes an adaptive critic (AC)-based basis function neural network (BFNN) optimal controller. Using a single neural network (NN) with a basis function, the proposed optimal controller simultaneously learns task-related optimal cost function, robot internal dynamics, and optimal control law. This is achieved through the development of a novel BFNN tuning law using closed-loop system stability. Therefore, the proposed optimal controller provides real-time, implementable, cost-effective control solutions for practical robotic tasks. The …

Influence Of Variations In Imbalanced Lisn Termination Impedances On Radiated Emissions, Hossein Rezaei, Morten Sørensen, Kim Jensen, David Pommerenke, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

Radiated emissions measurements are often performed using a line impedance stabilization network (LISN) with a balanced termination, but in the real-world the common-mode characteristic of the termination may be highly variable. An asymmetric LISN allows testing under more realistic asymmetric termination conditions. The common-mode termination impedance of these LISNs must fall within set tolerances, but the impact of these tolerances is unknown. An analysis of the radiated emissions from a device under test (DUT) for a wide variety of power cable termination impedances is performed in the following paper to estimate the impact of allowed variations in imbalanced LISN termination …

A Method For Measuring The Transfer Function Inside A Compact Metallic Enclosure Using A Slot Antenna, Xiangrui Su, Wenchang Huang, Junghee Cho, Joonki Paek, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

Radio frequency desensitization issues comprise two components: noise radiation sources and the transfer function from noise sources to the victim antenna. For modern electronic products, noise sources are often located inside a compact metal enclosure, making it difficult to measure the transfer function using conventional methods. Moreover, opening the metallic enclosure would dramatically change the transfer function, and inserting a near-field probe into the enclosure is challenging and may not even be possible because of the limited space inside. In this article, a novel practical method for measuring the transfer function inside a compact metallic enclosure is proposed and experimentally …

Vertical Interconnect Technology In Silicon, Package, And Printed Circuit Board (Pcb) With Coaxial Structure, Junyong Park, Chaofeng Li, Eddie Mok, Joe Dickson, Joan Tourne, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces vertical interconnect technology in silicon, package, and printed circuit board (PCB) levels with a coaxial structure, respectively. The coaxial structure has been known to be advantageous in terms of signal integrity (SI) compared to the non-coaxial structure. The coaxial structure is easy to control the characteristic impedance Z0 and robust to crosstalk. The silicon-level interconnect includes the wire bonding (WB) and through-silicon via (TSV) technology, the package-level interconnect includes an elastomer package test socket. The PCB-level interconnect includes the vias, and vertical conductive structure (VeCS). For each level, the non-coaxial and coaxial interconnects are compared with the …

Mechanisms For Unwanted Magnetic Field Coupling To A Shielded Magnetic Near-Field Probe, Xin Yan, Wei Zhang, Sajjad Sadeghi, Mehdi Gholizadeh, David J. Pommerenke, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

Unwanted field coupling is a major concern when using magnetic near-field probes for high-frequency scanning. The unwanted coupling of the tangential electric field to a tangential magnetic field probe has been studied extensively. This article shows a second unwanted coupling mechanism: coupling from a vertical magnetic field. The standing wave of a shorted pure TEM microstrip in air is utilized to separate the magnetic and electric field coupling. Simulations show that the eddy currents induced within the probe by the vertical magnetic field couple inductively to the pickup loop if the layer stack up is not symmetric. The unwanted magnetic …

Coupling-Informed Data-Driven Scheme For Joint Angle And Frequency Estimation In Uniform Linear Array With Mutual Coupling Present, Yanming Zhang, Wenchao Xu, A. Long Jin, Min Li, Peifeng Ma, Lijun Jiang, Steven Gao

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a novel coupling-informed data-driven algorithm tailored for the concurrent estimation of frequency and angle within a uniform linear array (ULA), while addressing the complicating influence of mutual coupling. Leveraging the hybrid dynamic mode decomposition (DMD) methodology, termed as averaged DMD, we incorporate moving average techniques to achieve effective denoising. The averaged DMD further decomposes the received signal into eigenvalues and corresponding eigenvectors. The frequency information is derived from the eigenvalues and the corresponding eigenvectors represent the steering vectors of sources. Subsequently, mutual coupling is informed into the calibration of the steering vector for each source. Specifically, the …

A Tensor-Based Data-Driven Approach For Multidimensional Harmonic Retrieval And Its Application For Mimo Channel Sounding., Yanming Zhang, Wenchao Xu, A. Long Jin, Min Li, Ping Yuan, Lijun Jiang, Steven Gao

Electrical and Computer Engineering Faculty Research & Creative Works

In wireless channel sounding, accurately estimating multiple parameters within a multipath signal, such as azimuth, elevation, Doppler shift, and delay, necessitates addressing the challenges posed by the multidimensional harmonic retrieval (MHR) problem. To overcome these complexities, we propose a framework based on high-order dynamic mode decomposition (HODMD) that designed for robustly estimating frequencies of interest from high-dimensional sinusoidal signals, particularly in additive white Gaussian noise conditions. The HODMD approach, a hybrid algorithm amalgamating high-order singular value decomposition (HOSVD) and dynamic mode decomposition (DMD), operates by initially decomposing observed tensorial data into a core tensor and R mode matrices through HOSVD. …

Cascading Of 2d And 3d Simulations Of Asic Substrate Interconnect Up To 100 Ghz, Zhekun Peng, Junyong Park, Sathvika Bandi, Santosh Pappu, Srinivas Venkataraman, Xu Wang, Granthana Ranzaswamy, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

A method of cascading 3D models and 2D models to model the full channel of ASIC package substrate interconnects is proposed, showing good match to full-wave results in S-parameter and TDR up to 100 GHz.

Saint Benedict’S Woods, Lodge And Lake Sarah, Peggy L. Roske

Archives History Lessons

Learn some of the history of the Sisters’ woods, their Lodge, the turkey industry there, Lake Sarah, and other historical information about the southwest corner of the CSB campus.

“I’M Especially Sorry To Those Impacted”: Conventional Visions Of Leadership In The 2022/2023 Tech Layoffs, Jared J. Watkins

Student Theses and Dissertations

In 2022 and 2023, over 400,000 employees in the technology sector were laid off. This study conducted a thematic analysis using coding on memos announcing layoffs sent by leaders at Meta, Google, and Microsoft in late 2022 and early 2023. This study also conducted an analysis of layoff memos sent by leaders of Google and Microsoft in 2009 for comparison. Key findings include that writing to multiple stakeholders in the 2022/2023 memos produced novel contradictions and paradoxes that may impede employee sensemaking, that 2022/2023 memos used more passive and distancing language that disconnected the leader from the layoff decision and …

Profitability Analysis Of Time-Restricted Double-Spending Attack On Pow-Based Large Scale Blockchains With The Aid Of Multiple Attacks, Yiming Jiang, Jiangfan Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

We consider the time-restricted double-spending attack (TR-DSA) on the Proof-of-Work-based blockchain, where an adversary conducts a DSA within a finite timeframe and simultaneously launches multiple types of attacks on the blockchain. To be specific, the adversary can conduct attacks to isolate some honest miners and cause block propagation delays among miners to enhance the success probability of the TR-DSA. We first develop the closed-form expression for the success probability of a TR-DSA with the aid of multiple types of attacks, which is leveraged to develop the closed-form expression for the expected profit of a TR-DSA. The numerical analysis reveals that …

Frequency Division Multiplexing And Random Phasing For Improved Uniformity In Microwave Heating Applications, Logan M. Wilcox, Ali Mirala, Mohammad Tayeb Al Qaseer, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Microwave heating has been recently used as an active thermal excitation method in thermography. Within the nondestructive testing and evaluation (NDT&E) realm, this method is referred to as active microwave thermography, or AMT. In AMT, unlike other thermal excitation methods utilized in thermography, microwave heating inherently provides a nonuniform heating pattern. This is a direct result of the radiating antenna used to deliver the energy. This nonuniform pattern may result in defect detection errors (i.e., false positives and/or negatives). To reduce this potential for detection error and improve the overall robustness of the technique, a new electromagnetic system, consisting of …

High-Sensitivity Fabry-Perot Interferometric Sensor Based On Microwave Photonics With Phase Demodulation, Ruimin Jie, Hongkun Zheng, Osamah Alsalman, Jie Huang, Chen Zhu

Electrical and Computer Engineering Faculty Research & Creative Works

Optical fiber sensors have emerged as vital tools in various applications. Among them, Fabry-Perot interferometers (FPIs), have gained prominence due to their compactness and versatility in sensor design. Microwave photonics (MWP) techniques offer enhanced performance and flexibility for developing optical sensor interrogation methods. This paper proposes and experimentally demonstrates a novel MWP interrogation technique based on phase measurement for short-cavity FPI sensors. The technique utilizes the phase response of the FPI sensor within an MWP-assisted single radio frequency bandpass filter, providing improved sensitivity and dynamic sensing capabilities compared to traditional methods. Simulation and experimental results validate the effectiveness of the …

Lidar From The Sky: Uav Integration And Fusion Techniques For Advanced Traffic Monitoring, Baya Cherif, Hakim Ghazzai, Ahmad Alsharoa

Electrical and Computer Engineering Faculty Research & Creative Works

Light detection and ranging (LiDAR) technology's expansion within the autonomous vehicles industry has rapidly motivated its application in numerous growing areas, such as smart cities, agriculture, and renewable energy. In this article, we propose an innovative approach for enhancing aerial traffic monitoring solutions through the application of LiDAR technology. The objective is to achieve precise and real-time object detection and tracking from aerial perspectives by integrating unmanned aerial vehicles with LiDAR sensors, thereby creating a potent Aerial LiDAR (A-LiD) solution for traffic monitoring. First, we develop a novel deep learning algorithm based on pointvoxel-region-based convolutional neural network (RCNN) to conduct …

Effect Of Signal Modulation On Active Microwave Thermography, Logan M. Wilcox, Mathias Bonmarin, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Active microwave thermography (AMT) is a coupled electromagnetic and thermographic nondestructive testing and evaluation (NDT&E) technique. AMT utilizes an active electromagnetic source to induce heat on or within a specimen under test (SUT) with subsequential infrared measurements via an infrared camera. AMT has been successfully employed in multiple fields, including aerospace, space, and infrastructure, among others. Generally, for AMT, the excitation (electromagnetic source) is applied over a specified period of time (referred to as the heating time). If inspection continues for additional time after the excitation is removed (turned off), this period is referred to as the cooling time. This …

Rurality, Resilience, & Identity: A Soft Systems Methodology Approach To Understanding Self-Reported Issues In Rural America, Kayla M. Gabehart, Allegra H. Fullerton, Kristin Olofsson

Michigan Tech Publications

This study investigates how rural communities In Oklahoma conceive of their socioeconomic position in larger systems, as well as their resiliency and ability to withstand challenges. Utilizing systems thinking and polycentricity literature, we analyze interviews to construct an understanding of how rural communities perceive themselves, and how this impacts interactions with other communities and governments. Rural communities and their associated challenges are complex and impacted by a range of factors. We find that rural residents also feel this complexity, and understand their issues as products of overlapping systems and structures, and both internal and external factors. Additionally, we observe little …

Recent Progress In Microrna Detection Using Integrated Electric Fields And Optical Detection Methods, Logeeshan Velmanickam, Dharmakeerthi Nawarathna

Electrical & Computer Engineering Faculty Publications

Low-cost, highly-sensitivity, and minimally invasive tests for the detection and monitoring of life-threatening diseases and disorders can reduce the worldwide disease burden. Despite a number of interdisciplinary research efforts, there are still challenges remaining to be addressed, so clinically significant amounts of relevant biomarkers in body fluids can be detected with low assay cost, high sensitivity, and speed at point-of-care settings. Although the conventional proteomic technologies have shown promise, their ability to detect all levels of disease progression from early to advanced stages is limited to a limited number of diseases. One potential avenue for early diagnosis is microRNA (miRNA). …

Comparing Alternative Developmental Modes: Structure And Gene Expression In The Olfactory System Of Plethodontid Salamanders, Giuseppina S. Lanzilli

Cal Poly Humboldt theses and projects

The olfactory system of extant amphibians changes as the animal transitions from a fully aquatic to a terrestrial lifestyle at metamorphosis. Cellular morphology of the nose and expression patterns of olfactory genes in the nasal cavity have been examined for a variety of frogs and salamanders, but among plethodontid salamanders, molecular data are available only for Plethodon shermani. Using standard histology and micro-CT reconstruction, I investigated the structure of the olfactory organs of larvae, juveniles, and adults of six plethodontid species, with terrestrial, streamside, semiaquatic, and aquatic adults. The overall structure of the olfactory cavity was generally similar across …

"They Are Expecting Us To Stay Strong": How Ambulance Personnel Navigate And Manage Their Emotions In A Rural Region Of Northern California, Tina M. Orton-Owens

Cal Poly Humboldt theses and projects

This research examines how emergency medical service (EMS) workers navigate and manage their calls in Humboldt County, a rural region of Northern California. The primary theoretical framework is drawn from Arlie Hochschild’s theory of Emotional Labor. This paper examines how emotional labor impacts EMS workers within a rural environment and with limited resources. I also look at how COVID-19 complicated EMS workers’ experiences. This paper is based on qualitative research where I conducted 13 mostly face-to-face interviews with EMS workers throughout the County between 2020 and 2022. Interviews consisted of 30 questions and interviews ranged in length from 1 to …

Agitprop: A Deep Dive Into Leftist Affinity Spaces, Brittany M. Fuher

Cal Poly Humboldt theses and projects

This project is designed to explore what methods and theories of how we learn can tell us about what is occurring in leftist digital affinity spaces. My focus is the HasanAbi community, an online collective built around Twitch streamer Hasan Piker. I will examine the way YouTubers create memetic systems using an understanding of semiotics and translingualism. Based on my own experiences with digital community, and inspired by Linda Adler-Kassner, and Elizabeth Wardle’s discussion of Threshold Concepts in Naming What We Know, I’ve created five of my own Threshold Concepts for Leftist Community and crafted a video for each. …

Incorporating Equity Into Sea-Level Rise Planning: Perspectives From Practitioners Across California, Nayré Herrera

Cal Poly Humboldt theses and projects

Scholars along with national and state governments have increasingly made calls to incorporate an equity lens into climate adaptation processes and into sea-level rise planning specifically. However, the language used in these high-level policies remains vague. There remains a need to learn from practitioners on the ground about the challenges and opportunities for effectively incorporating an equity lens into sea-level rise adaptation and planning efforts. I conducted interviews with 17 individuals who are working within their agencies or organizations to advance equity across the California coast along with a review of 17 California coastal policy documents to gain insights into …

Effects Of Exergaming On Health And Fitness Outcomes For Students With Disabilities: A Meta-Analysis, Jordan Mauch

Cal Poly Humboldt theses and projects

While research on VR gaming and Exergaming is in its infancy, both are interventions that have demonstrated positive results such as promoting physical activity participation and positive attitudes towards physical activity in children and adolescents. Exergaming has also been shown to be effective in increasing physical activity in children, and children with disabilities may find exergaming to be an enjoyable alternative to traditional physical activity due to increased accessibility and the focus on both gross and fine motor skills. In studies of VR and/or exergaming with participants with cerebral palsy and autism spectrum disorder, researchers reported increases in motor function …

The Larval Preference Of An Invasive Bryozoan (Watersipora 'New Species') For Copper-Based Antifouling Paints, Alexander K. Strawhand

Cal Poly Humboldt theses and projects

The bryozoan Watersipora subtorquata and its cryptic congener Watersipora ‘new species’ are now globally invasive species. Previous studies have found this species complex to have a high tolerance to copper-based antifouling paints, which represent a large portion of the mitigation effort toward preventing hull fouling by invasive invertebrates. Tolerance alone, however, is unlikely to explain the full extent of Watersipora’s massive and rapid worldwide invasion success. The aim of this research was to move beyond tolerance, and test whether larvae of Watersipora ‘new species’ exhibit a preference for copper-coated settlement surfaces in both laboratory and field settings. For the laboratory …

Effectiveness Of An Inclusive, Small-Group Adapted Aquatics Program On Increasing Vo2max In Children With Autism Spectrum Disorder, Peggy Manuelita Scarborough

Cal Poly Humboldt theses and projects

There is a need to examine the effectiveness of interventions, such as swimming, that are aimed at increasing physical health and developing psychomotor skills in an inclusive setting for children with ASD. The purpose of this study was to examine the effectiveness of an inclusive, small-group adapted aquatics program on increasing VO₂max in children with ASD. Participants included two 11-year-old children diagnosed with ASD. The study took place over eight weeks and included a six-week Small-Group Adapted Aquatics (SGAA) program. Participants were assessed for VO₂max using the 20m PACER test during week one and week eight …

Countering Dominant Narratives In Community: The Many Voices In Spoken Word Poetry, Natalie Raquel Acuña

Cal Poly Humboldt theses and projects

In this project I research the counternarratives within spoken word poetry by authors of color (i.e., Rafeef Ziadah, José Olivarez, and Denise Frohman) and how they resist the dominant narratives that are broadcast towards a larger audience. I analyze categories of counterstory through the following paired themes: immigration/citizenship, and joy/trauma. I delve into the heavy importance of community within my project in the realm of spoken word poetry. A lot of poetry is going against dominant narratives, community within this discourse gives a sense of belonging and relatability to the experience of the spoken word performers.

Is Cognitive Fatigue Pushing Peripheral Group Members Towards Extreme Attitudes?, James E. Robinson

Cal Poly Humboldt theses and projects

Both cognitive fatigue and group membership impact how individuals respond to persuasive messaging. Cognitively demanding tasks cause mental fatigue, lessening the ability to effortfully consider persuasive messaging and increasing the likelihood of making automatic decisions based on heuristics (Schmeichel et al., 2003). Additionally, self-perception of prototypicality (i.e., level of group membership) impacts motivation to identify with and engage in group normative behavior (Hohman et al., 2017). This research project aimed to further the understanding of how prototypicality and cognitive fatigue interact and come to impact attitude and the effortful elaboration of persuasive messaging.

A Resilient Decarbonization Package For The Hoopa Shopping Center, Esther Obikoya

Cal Poly Humboldt theses and projects

The Hoopa Shopping Center, located within the Hoopa Valley Tribe Reservation, faces significant energy cost fluctuations and reliability issues. Given the susceptibility of remote communities to power disruptions, the Tribe's move toward achieving a sustainable and resilient power infrastructure is essential. This study investigates the technical and economic decarbonization strategies for the Hoopa Shopping Center, focusing on reducing energy bills, energy consumption, and greenhouse gas emissions through electrification and energy efficiency improvements, as well as the integration of renewable energy sources.

This decarbonization could be done in a way consistent with the development of a microgrid to energize the community …