Digital Commons Network^™

Statistical Analysis Of Electromagnetic Coupling To Printed Circuit Boards, Shengxuan Xia, Victor Khilkevich, Daryl Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

Determining electromagnetic (EM) coupling to printed circuit boards (PCBs) is essential to finding potential EM susceptibilities early in the design process. For realistic PCB structures, analysis usually relies heavily on time-consuming full-wave simulations because of the complexity of the geometries and the lack of analytical solutions. In this paper, we adopt a segmentation approach based on far-field reciprocity which allows for rapid estimation of the voltage induced at trace terminations over frequency, and which is then used to estimate statistical characteristic of coupling across trace geometries. Frequency-domain results can then be used to estimate time-domain responses with appropriate transformations. Super-position …

Uncertainty Quantification For Peec Based On Wasserstein Generative Adversarial Network, Yuan Ping, Yanming Zhang, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This article proposes a modified generative adversarial network (GAN)-based approach, namely Wasserstein GAN (WGAN), for the uncertainty quantification (UQ) in partial equivalent element circuit (PEEC) models. Initially, the stochastic PEEC is constructed to obtain the sample data of the quantities of interest (QoI). This sample data, along with the fake data from the generator, serves as input for the discriminator in WGAN. The loss function of the generator in WGAN is constructed using the Wasserstein distance to provide a more usable gradient than that in the traditional GAN. By estimating the distribution of sample data using the fake data in …

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 …

Towards Explainability Of Dimension Reduction Plots Of Unsupervised Learning Model Outcomes, Tony E.Astuhuaman Davila, Daniel B. Hier, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

Dimension reduction methods are used to visualize the output of unsupervised learning models when applied to complex data. These techniques improve interpretability by transforming a high-dimension space to a lower-dimension space (usually 2D or 3D). The results are typically viewed as 2D scatter plots, and class centroids may be added to increase interpretability. Although useful, the relationship of these class centroids to the underlying feature space remains opaque. The innovative aspect of this work is to create a strong link between the dimension-reduced space and the underlying high-dimension feature space by adding selected feature centroids to the 2D scatter plots. …

On The Feasibility Of A Direct Injection Probe With A Capacitively Coupled Return And Integrated Voltage Monitor, Aaron Harmon, Daniel Szanto, Victor Khilkevich, Daryl Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

Characterizing the susceptibility of an IC while it is integrated within a system can be challenging. Characterization is even harder if one wants to know the waveform at the target IC pin when injecting a signal on the pin. In this work, the feasibility of a direct injection probe with a capacitively coupled return and integrated voltage monitor is proposed. This probe is advantageous because it does not need to be soldered to the test device and its ability to provide a measurement of the waveform on the target IC pin during the injection. Methods for reconstructing the pin waveform …

A Model For Corona Streamer Propagation On Glass During An Air Discharge, Zhekun Peng, Jianchi Zhou, Darryl Kostka, David Pommerenke, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

Corona discharge to a glass surface is challenging to model due to a poorly understood air and surface ionization process. A modeling methodology based on the transmission line modeling (TLM) approach is proposed to simulate the streamer propagation process. The time-changing corona streamer resistance is estimated using the Rompe and Weizel spark model. The streamer is represented using small segments consisting of the arc resistance, per unit length (PUL) capacitance of the streamer, PUL inductance, a switch representing streamer formation, and a surface discharge gap voltage representing the voltage drop caused by ions within the streamer length. The propagation of …

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 …

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 …

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 …

Novel Formulation For Generalization Of Mixed-Mode S-Parameters For Coupled Differential High-Speed Digital Channels, Manish K. Mathew, Kevin Cai, Chaofeng Li, Mehdi Mousavi, Shameem Ahmed, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

As the demand for higher data rates intensifies, achieving accurate S-parameter calculation becomes increasingly critical. The conventional single-ended to mixed-mode S-parameter conversion formulation assumes uncoupled structures, which may not be true for high-speed digital channels. This work introduces a novel, generalized formulation for mixed-mode S-parameters and their corresponding transformation matrices [M1] and [M2], enabling comprehensive analysis of multi-pair coupled differential traces. An intra-pair crosstalk analysis of a tightly coupled strip line and microstrip line verifies and highlights the difference between the proposed and old formulations. A loosely coupled case is analyzed as an additional validation of the proposed formulation. Finally, …

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 …

Analytical Modeling Of Partially-Filled Tm010-Mode Dielectric Resonator For Accurate Dk And Df Extraction, Mehdi Mousavi, Chaofeng Li, Reza Asadi, Seyedmostafa Mousavi, Reza Vahdani, Xiaoning Ye, Mina Esmaeelpour, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

In high-speed printed circuit board (PCB) modeling, the accurate determination of the dielectric constant (DK) and dissipation factor (DF) is crucial for signal integrity analysis at design stage. This paper introduces an analytical approach using a partially filled TM010-mode dielectric resonator, an effective tool for DK and DF extraction of PCB material. We begin by discussing the theoretical underpinnings of TM₀₁₀-mode dielectric resonators and their applicability in measuring the DK and DF of the material under test. A mathematical model is then presented, linking the resonant characteristics directly to the DK and DF of the dielectric material. The …

Modeling Of Power Distrubition Network (Pdn) Noise Coupling Induced Clock Phase Noise, Zhekun Peng, Junyong Park, Chaofeng Li, Joey Stecher, Srinivas Venkataraman, Xu Wang, Granthana Rangaswamy, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Phase noise analysis is important to clock design. Noise sources of spurs shown on the phase noise result are challenging to find out due to the unknown source locations and coupling mechanisms. Noise from power distribution network (PDN) is one of the most troublesome sources. A behavioral modeling methodology is proposed to simulate the clock phase noise induced by PDN noise coupling for two different mechanisms: PDN-to-clock additive coupling and PDN-to-PDN up-conversion modulation. The thermal noise and 1/f flicker noise are simplified to provide a straightforward view of spur level. The model can be applied to both single-ended clock and …

Dk And Df Characterization Of Low-Loss Dielectric Liquid By Cylindrical Cavity Resonator, Chaofeng Li, Seyedmehdi Mousavi, Reza Asadi, Seyedmostafa Mousavi, Reza Vahdani, Xiaoning Ye, Kai Wang, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

A novel cylindrical cavity resonator-based measurement method was developed to characterize the dielectric property of the low-loss dielectric liquid in the paper. The proposed method can be used to accurately measure the dielectric constant (Dk) and the loss tangent (Df) of the low-loss coolant for signal integrity analysis. The cylindrical cavity resonator works at tangential magnetic (TM010) mode is used in the paper to demonstrate the proposed method. A cylindrical cavity resonator apparatus was designed and investigated using full-wave simulations at first. The relative error of Dk and Df extractions based on the designed apparatus are less than 1% and …

Graph Convolutional Neural Network Assisted Genetic Algorithm For Pdn Decap Optimization, Haran Manoharan, Jack Juang, Ling Zhang, Hanfeng Wang, Jingnan Pan, Kelvin Qiu, Xu Gao, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a hybrid algorithm combining reinforcement learning (RL) and a genetic algorithm (GA) for PDN decap optimization. The trained RL agent uses a graph convolutional neural network as a policy network and predicts the decap solution for a given PDN impedance and target impedance, which is seeded as an initial population to the GA. The trained RL agent is scalable regarding the number of decap ports. The main goal is to save computation time and find the near global minimum or global minimum. Generalization of the algorithm to different decap libraries is achieved through transfer learning, eventually reducing …

Lifelong Safe Optimal Adaptive Tracking Control Of Nonlinear Strict-Feedback Discrete-Time Systems, Behzad Farzanegan, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a comprehensive approach for achieving multi-task safe optimal adaptive tracking (MSOAT) for a class of nonlinear discrete-time systems, particularly those in strict-feedback form, utilizing a multi-layer neural network (MNN)-based framework. To begin, a cost function with a novel Barrier function (BF) term is introduced for each subsystem to address the weak safely reachable problem, serving as a crucial tool for guiding the system's trajectory toward the safe set while avoiding unwanted sets. To deal with the tracking problem, the Hamilton-Jacobi-Bellman (HJB) framework is used through the actor-critic MNN-based backstepping technique to estimate the solution of the value …

Lifelong Direct Error-Driven Learning For Uav Altitude Estimation In Different Weather Conditions, Shirin Nasr-Esfahani, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

While deep neural networks achieve remarkable visual perception capabilities for UAV position and orientation estimation, their resilience to different weather conditions still needs improvement. These models often suffer from catastrophic forgetting when adapted to new environments, losing previously acquired knowledge. Lifelong learning methods aim to balance learning flexibility and memory stability. In this paper, we present an image-based approach to estimate the relative altitude of a UAV using 2D images under varying weather conditions, including sunny, sunset, and foggy scenarios. Our experiments demonstrate significant performance degradation when the model is trained sequentially on different weather datasets, especially when new images …

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.

Hoodies In The Halls Of Power: A Rhetorical Materialist Critique Of Professional Decorum In The United States Senate, Ryan Cheek, Samuel T. Allen

English and Technical Communication Faculty Research & Creative Works

This brief paper explores the controversy surrounding Senator John Fetterman's sartorial choices of casual attire in the hyper-professionalized space of the United States Senate. Fetterman's clothing choices transcend mere fashion; they embody a statement of class identity and challenge the established power dynamics within the Senate. His attire reflects Pittsburgh's industrial and labor-oriented history, in contrast to the conventional, affluent image most associated with politicians. Although controversial, Fetterman's white male privilege minimized the consequences of his indecorous behavior. The reactions to Fetterman's attire highlight the debate over what constitutes appropriate professional decorum, unveiling the underlying biases and demonstrating how something …

Expanding Australia's Defence Capabilities For Technological Asymmetric Advantage In Information, Cyber And Space In The Context Of Accelerating Regional Military Modernisation: A Systemic Design Approach, Pi-Shen Seet, Anton Klarin, Janice Jones, Michael N. Johnstone, Violetta Wilk, Stephanie Meek, Summer O'Brien

Research outputs 2022 to 2026

Introduction. The aim of the project was to conduct a systemic design study to evaluate Australia'sopportunities and barriers for achieving a technological advantage in light of regional military technological advancement. It focussed on the three domains of (1) cybersecurity technology, (2) information technology, and (3) space technology.

Research process. Employing a systemic design approach, the study first leveraged scientometric analysis, utilising informetric mapping software (VOSviewer) to evaluate emerging trends and their implications on defence capabilities. This approach facilitated a broader understanding of the interdisciplinary nature of defence technologies, identifying key areas for further exploration. The subsequent survey study, engaging 828 …

Characteristics Of Proliferating Cryptocurrencies: A Comparative Study Between Stable And Non-Stable Cryptocurrencies, Cheuk Hang Au, Gerrard Li, Wen Shou Hsu, Po Hsu Shieh, Kris M.Y. Law

Research outputs 2022 to 2026

The emergence of cryptocurrencies has caught the attention worldwide. Some parties have considered issuing cryptocurrencies an excellent opportunity to raise capital and other businesses. However, the factors that foster the proliferation of cryptocurrency are not fully explored. This paper documented a comparative case study of USDT (a successful stablecoin) and EOS (a successful non-stable cryptocurrency). Based on our findings and previous literature, we suggested a Technology-Institution-Market (TIM) framework for cryptocurrency proliferation. We also elaborated on previous FinTech product development and adoption theories and provided some practical implications for cryptocurrency investors, issuers and regulators.

Enhancing Writing Quality And Self-Efficacy Beliefs Through Process-Oriented Task-Based Instruction And Multiple Feedback Forms, Samira Moussaoui

Journal of Educational and Psychological Studies

Abstract:This article presents the research findings of a quasi-experimental study seeking to enhance the writing quality and self-efficacy beliefs of Algerian undergraduate learners. The study employed task-based writing instruction within the process approach framework, and various forms of formative feedback (self-, peer-, and teacher feedback). The sample comprised 24 English as a foreign language (EFL) undergraduate learners with an intermediate level in academic writing. Data were collected through pre- and post-intervention writing tests to assess the participants’ writing quality, as well as pre- and post-intervention surveys, along with post-hoc interviews, to measure their writing self-efficacy levels. The analysis of the …