Engineering Commons^™

Highly Sensitive Liquid-Level Sensing Based On Microwave Frequency Domain Reflectometry And Interferometry, Chen Zhu, Osamah Alsalman, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Frequency domain reflectometry (FDR) and interferometry are two widely used investigative techniques that have been instrumented using optical and microwave devices for a diverse array of sensing applications. In this paper, we present a highly sensitive liquid-level sensor using a custom hollow coaxial cable transmission line. Measurements of liquid levels with high sensitivity and resolution can be achieved by both FDR and interferometry-based measurements using the same sensor device. We show that FDR-based measurements are more straightforward for liquid-level sensing and are suitable for both small and large variations of liquid level, while interferometry-based measurements provide slightly higher measurement resolution …

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 …

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 …

Evaluating Electromagnetic Interference Effects On Gnss Receivers, Giorgi Tsintsadze, Haran Manoharan, Arushi Sahai, Daryl G. Beetner, Brian Booth

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic interference can be highly disruptive to global navigation satellite system (GNSS) receivers. Interference can be intentional but can also occur from electronics modules placed within the same system, where these modules may create sufficient unintended radiated emissions to disrupt GNSS operation. In this paper, GNSS receiver performance is evaluated in the presence of multi-tone interference. An expression for the GNSS correlator output in the presence of continuous wave interference (CWI) is derived and is extended to predict the carrier to noise density ratio, C/N0, of the receiver in the presence of multi-tone interference. C/N0 is widely used for characterizing …

Design Of Experiment Analysis On Multiple Pim Sources In An Rf Antenna System, Shengxuan Xia, Yuchu He, Haicheng Zhou, Hanfeng Wang, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

Passive intermodulation (PIM) has been identified as one of the common root causes for receiving sensitivity degradation (desense) on radiofrequency (RF) antennas working in frequency-division duplex mode. The component-level PIM characterization and simulation have been well-established over the years. However, the study has been using an ideal 50 Ω transmission line system while antenna modules are more complicated than a simple transmission line structure. Moreover, the metallic contacts can exist in multiple locations with different connection topologies in real applications. This paper provides a method to simulate the PIM performance caused by the metallic contacts in a practical environment. In …

Radiated Emission Modeling Of A Wireless Power Transfer System, Hanyu Zhang, Guanghua Li, Viswa Pilla, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

A radiated emission (RE) model of a wireless power transfer (WPT) system is proposed in this paper to help designers predict, analyze, and mitigate the RE issues during the design process. The proposed model employs both full-wave simulation and circuit simulation to derive a transfer function. Subsequently, it predicts the emission level by combining the transfer function with the measured transmitter waveform through a straightforward calculation. The predicted emissions match the measured RE peaks well up to 300 MHz, with the error within 3 dB. The impact of functional parameters, such as load and coil gap distance, is analyzed based …

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 …

Virtual Inertia Scheduling (Vis) For Microgrids With Static And Dynamic Security Constraints, Buxin She, Fangxing Li, Jinning Wang, Hantao Cui, Xiaofei Wang, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

Microgrids feature a high penetration of inverter-interfaced distributed energy resources (DERs). The low inertia characteristic and fast dynamics of DERs pose challenges to conventional decoupled static economic operation and dynamic control design within microgrids. Hence, this paper proposed virtual inertia scheduling (VIS) for microgrids, aiming to ensure both economy and security. First, a unified framework for device-level control and grid-level operation is introduced, with VIS serving as a key application to address low inertia issues. VIS actively harnesses the controllability and flexibility of DERs to effectively manage microgrid inertia. It updates the conventional economic operation framework by incorporating the virtual …

Design Of The Tm010 Mode Cylindrical Cavity Resonator For Pcb Dielectric Characterization, Reza Asadi, Chaofeng Li, Seyedmehdi Mousavi, Seyed Moastafa Mousavi, Reza Vahdani, Xiaoning Ye, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the study of the TM₀₁₀ mode cylindrical resonator, which can be used for printed circuit board (PCB) material properties extraction, e.g., the dielectric constant (Dk) and the loss tangent (Df) extraction. The theoretical formulas of the resonance frequency and Q-factor of the resonator are presented. In real measurement, the TM₀₁₀ mode cylindrical cavity resonator needs to be excited by the probe. The study emphasizes the impact of probe orientation, location, and field distribution on the accuracy of material property extraction. The relationship between cavity dimensions and resonance frequency is explored, highlighting the influence of cavity …

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, …

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. …

Behavior Model Of A Multiphase Voltage Regulator Module With Rapid Voltage Drop Protection, Junho Joo, Hanyu Zhang, Hanfeng Wang, Wei Shen, Zhigang Liang, Lihui Cao, Seungtaek Jeong, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a modeling method of voltage regulator module (VRM) with rapid voltage drop protection is introduced. The proposed VRM model captures a pulse-width modulation scheme developed to counteract substantial load currents with high di/dt, resulting in a large voltage drop across the power delivery network (PDN). The equations to describe the non-linear behavior associated with the multiphase VRM behavior are proposed and successfully validated for both light and heavy loads, the latter being particularly crucial to trigger the voltage drop protection measures.

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 …

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.

Impact Of Non-Functional Pads Location On Eye Diagram Performance, Mehdi Mousavi, Kevin Cai, Junyong Park, Chaofeng Li, Manish K. Mathew, Reza Asadi, Shameem Ahmed, Donghyun Kim, Bidyut Sen

Electrical and Computer Engineering Faculty Research & Creative Works

This study shows that placing four NFPs in selective PCB layers significantly improves signal integrity, reducing minimum jitter from 18.28 ps to 12.81 ps and maximum jitter from 27.66 ps to 22.03 ps.

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 …

Suppression Of Power Distribution Network Pcb-Package Resonance For Low Target Impedance, Francesco De Paulis, Faye Squires, Yifan Ding, Matteo Cocchini, Matthew Doyle, Samuel Connor, Albert E. Ruehli, Chulsoon Hwang, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The suppression of the large resonance peak that may appear due to the equivalent parallel circuit between the package capacitance and PCB inductance is discussed. Such resonance may be amplified if the decoupling capacitors are not appropriately selected. The relevant parameters involved in the PDN design, and a feasible solution strategy are presented based on the identification of a simplified equivalent circuit that is able to replicate the resonant behavior. The optimization of the relevant parameters of such circuit are able to suggest the best strategy for identifying the decoupling capacitors with appropriate values of parasitic inductance and resistance.

Ai Trustworthy: Ethical Challenges And Strategies, Jian Liu, Iwan Sandjaja, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This paper explores the pivotal role of trust in the widespread application of Artificial Intelligence (AI) across various domains. We review AI applications in sectors like energy, healthcare, and autonomous vehicles and discuss the crisis of human trust they face. This paper introduces a novel framework that delineates the relationship between AI transparency and user trust, highlighting specific industry applications. Through a systematic review of recent literature, we first delve into factors such as emotional response, acceptance, transparency, accuracy, and interpretability that shape human trust in AI. We then underscore the necessity of ethical AI practices and highlight the importance …

Understanding Student Perceptions Of Project Impact In The Epics In Ieee Service-Learning Program, Stephanie Gillespie, Steve Eugene Watkins, Ashley F. Moran

Electrical and Computer Engineering Faculty Research & Creative Works

This innovative practice full paper addresses the assessment component of student service-learning projects. Through IEEE, the Engineering Projects in Community Service in IEEE committee (EPICS in IEEE) sponsors service-learning projects for student groups in project areas spanning human services, environmental, access and abilities, and education and outreach. Service learning and community-engaged learning can provide positive outcomes for both the students and the community organization or community members. The intent of assessment in a service-learning project or program is that both the student-learning outcomes and the humanitarian/community impact of the implementation or engagement are gauged. Often, the latter aspect of assessment …

Void Fraction And Quality Correlation Analysis Using The Separated Flow Model For Pulsed-Power Heat Loads, Zachary Joseph Carner

Browse all Theses and Dissertations

Aircraft platforms are continually upgraded with increasingly high quantities of high-powered electronics. As such, efficient thermal management systems are crucially important to overcome system instabilities and support pulsed power profiles. To create effective thermal control systems, it is imperative to thoroughly examine and account for a variety of potential system behaviors caused by transient changes in the flow regime. If left unconstrained, these changes will create thermal instabilities, which can severely damage electronics and hurt the overall reliability of the aircraft. These instabilities can be described by both void fraction and quality. Electrical Capacitance Tomography (ECT) allows for the collection …

Mechanical Reliability Of Aerosol Jet Printed Sensors And Interconnects, Lemuel A. Duncan

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Heterogeneous integration (HI) is currently being investigated to maintain the pace of technological progress in the electronics industry. With the recent acceleration witnessed in additive manufacturing (AM) technology, interest has been expressed in introducing aerosol jet (AJ) printing to the fabrication process for sensors and electronic packages. Integrating AM technology in these areas promises design flexibility and minimal material waste. Three AJ printed applications investigated in this work include strain sensors, electrical interconnects, and metal embedded chip assemblies. Before moving forward with the use of AJ printing in these applications, it is necessary to evaluate their performance under standard mechanical …

Integrating Knowledge Graphs With Large Language Models For Natural Language Querying, Rakesh Kandula

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This research explores the integration of knowledge graphs with large language models that have already been trained on a vast pool of unstructured text data. Large language models trained on this type of data have a tendency to hallucinate and produce factually inaccurate results. This behavior is primarily due to the data being trained is unstructured and huge text corpus, and large language model uses predictive text analysis methods to obtain a response. These issues can be addressed by applying Retrieval Augmented Generation and Fine-tuning to large language models, employing an underlying domainspecific knowledge graph. Integrating knowledge graph and large …

Prediction Interpretations Of Ensemble Models In Chronic Kidney Disease Using Explainable Ai, K M Tawsik Jawad

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Chronic Kidney Disease (CKD) poses significant health and financial threat to millions of patients all around the world. The irreversible nature of this disease not just leads to comorbid diseases like Diabetes Mellitus, Hypertension, Anemia, Bone Disease, Neurological Implants etc. It can permanently damage the kidney by progressing to Acute Kidney Injury (AKI) or End Stage Renal Diseases (ESRD). The risk factors of CKD become more dangerous as patients suffering from it have little to no idea about the presence of CKD in their body until it takes the shape of AKI or ESRD. There are severe economic burdens for …

Biomechanical Simulation Of Cardiovascular Implantable Electronic Device Leads With Residual Properties, Anmar Mahdi Salih

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Implantable leads used in pacemakers, defibrillators, and cardiac resynchronization therapy are designed for in-vivo applications, yet their longevity is inevitably shaped by the conditions within the human body. The mechanical behavior of these leads can be affected over time, necessitating the evaluation of their residual properties. Two main insulators, silicone, and polyurethane are commonly used for the outer insulation of cardiac leads. Understanding the long-term performance of these insulators is crucial for ensuring the reliability and safety of cardiac implantable devices. The research aims to assess the long-term mechanical properties and performance of implantable leads utilized in cardiovascular implantable electronic …

Managing Inventory With A Database, David Bartlett

Williams Honors College, Honors Research Projects

Large commercial companies often use warehouses to store and organize their product inventory. However, manually keeping track of inventory through physical means can be a tedious process and is at risk for a variety of potential issues. It is very easy for records to be inaccurate or duplicated, especially if large reorganizations are undertaken, as this can cause issues such as duplicate product ID numbers. Therefore, it was decided that an inventory management system utilizing a SQL database should be created. The system needed to have capabilities including allowing the entry of product information, the ability to search database records …

Optimized Pi Compound Mixing Strategy, Cecilia Mainzer

Williams Honors College, Honors Research Projects

The project focuses on developing an optimal mixing strategy for a polyisoprene (PI) compound at the Goodyear Tire & Rubber Company. The aim is to optimize performance objectives of the compound. The project involved research, design iterations, mixing analyses, and performance evaluations, while adhering to engineering codes and standards.

The design process includes analyzing differences between two mixing technologies, intermesh and tangential rotors; altering mixing conditions; and exploring additional polymer systems and coupling technology of the compound.

Validation data confirms that the mixing technology and compound recipe meets all success metrics, including stiffness, hysteresis, adhesion, cure rate, and tear performance …

Materials Testing For Large Format 3d Printing, William Jenkins

Williams Honors College, Honors Research Projects

An ABS Carbon Fiber blend was printed into single walled hexagons at a variety of settings on a Cincinnati BAAM large format 3D printer. These hexagons were then cut down into sheets and had tensile and flexural test samples cut out of them, in order for materials testing to be performed. Tensile strength, tensile strain, young’s modulus, flexural strength, deflection and elastic modulus were all determined. A desktop CNC machine and a planer were purchased for the manufacturing of these samples, and an efficient cutting procedure was designed and optimized. After all data collection concluded, this data was thoroughly analyzed, …

Space Force - Inspection, Romualdo Cipro

Williams Honors College, Honors Research Projects

Our project deals with a common problem that is encountered with satellites in earth orbit or beyond. It is very common in space for there to be small collisions between satellites and foreign space debris, and it takes a lot of time and money to send a person out to repair the damage caused by the collision. Our goal is to develop a way to perform these repairs autonomously. We plan to develop a way to scan a satellite or spacecraft hull for damage using a robot and then repair the damage while still maintaining the material specifications required for …

Stanley Black And Decker Slag Removal Design Project, Colt Hemphill, Kyle Stober, Andrew Raymond, Robert Artrip

Williams Honors College, Honors Research Projects

My group given the task of designing a system to remove the slag of large metal plates. Removing this slag is an important step in creating the final assembly of a model. Currently we the operators are flipping the plates using a large magnet and crane. The issue that we see with the current method is the risk of injury while having the plate suspended in the air. These plates can reach upwards of 600lbs and poses a serious threat to the operators if the magnet is not secured correctly. Our new system for removing the slag is designed to …