Digital Commons Network^™

Thermal Diffusivity Materials Characterization Via Active Microwave Thermography, Logan M. Wilcox, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Active microwave thermography (AMT) is a relatively new nondestructive evaluation method which is proposed in this work for thermal materials characterization. Specifically, AMT is investigated as a single-sided measurement option for out-of-plane thermal diffusivity (a parameter traditionally measured using a two-sided technique). Simulation and measurement results support the use of AMT for such a characterization for materials backed by an electromagnetically absorptive material. Both lossless and lossy materials may be measured, with better accuracy for lossless materials. The effect of heating time was also considered. The results indicate that for the 50 W system used here, 100 seconds of electromagnetic …

Dipole-Moment-Based Reciprocity For Practical Desensitization Identification And Mitigation, Shengxuan Xia, Hanfeng Wang, Yansheng Wang, Zhonghua Wu, Chulsoon Hwang, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Radio frequency interference can degrade the receiving sensitivity of antennas. The interference is usually caused by certain coupling structures, such as layouts without adequate grounding for the radio frequency signal return path. Those structures can be modeled as a set of equivalent dipole moments when they are electrically small. Herein, the dipole moment model-based coupling framework is applied to a practical cellphone design case to devise an engineering solution. The coupling framework incorporates dipole moments as radiation sources and a coupling model based on the reciprocity theorem. Unfortunately, near-field scan probes often lack access to all locations, owing to the …

Esd Events To Wearable Medical Devices In Healthcare Environments—Part 1: Current Measurements, Mehdi Kohani, Javad Meiguni, David J. Pommerenke, Michael G. Pecht

Electrical and Computer Engineering Faculty Research & Creative Works

Wearable medical devices are widely used for monitoring and treatment of patients. Electrostatic discharge can render these devices unreliable and cause a temporary or permanent disturbance in their operation. In a healthcare environment, severe electrostatic discharge (ESD) can occur while a patient, lying down or sitting on a hospital bed with a wearable device, discharges the device via a grounded bedframe. To protect the devices from ESD damage, the worst-case discharge conditions in the usage environment need to be identified. Previous studies by authors revealed that such events could be more severe than the conventional human metal model (HMM). However, …

Rafid: A Lightweight Approach To Radio Frequency Interference Detection In Time Domain Using Lstm And Statistical Analysis, Luke A. Smith, Vishesh Kumar Tanwar, Maciej Jan Zawodniok, Sanjay Kumar Madria

Electrical and Computer Engineering Faculty Research & Creative Works

Recently, the utilization of Radio Frequency (RF) devices has increased exponentially over numerous vertical platforms. This rise has led to an abundance of Radio Frequency Interference (RFI) continues to plague RF systems today. The continued crowding of the RF spectrum makes RFI efficient and lightweight mitigation critical. Detecting and localizing the interfering signals is the foremost step for mitigating RFI concerns. Addressing these challenges, we propose a novel and lightweight approach, namely RaFID, to detect and locate the RFI by incorporating deep neural networks (DNNs) and statistical analysis via batch-wise mean aggregation and standard deviation (SD) calculations. RaFID investigates the …

Challenges And Solutions For Automotive Ota Testing, Jiyu Wu, Yihong Qi, Penghui Shen, Wei Yu, Lie Liu, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

OTA (Over-The-Air) Testing is Essential for Developing Assisted and Autonomous Driving Systems in Vehicles, as It Plays a Crucial Role in the Localization, Perception, and Intelligent Driving Capabilities of ICVs (Intelligent Connected Vehicles). Automotive Antennas, Typically Much Smaller in Size Than the Vehicle itself and Can Be Located in Various Positions, Require Spherical Near-Field Measurement for OTA Testing. While There Are Established Standards for OTA Testing Methods and Uncertainties for Mobile Devices, Base Stations, and Satellite Components, There Are Still Many Challenges in the OTA Testing of Automotive Systems. These Challenges, specifically in SISO (Single Input Single Output) and MIMO …

On The Permittivity Of Xt-Cf20, Aaron Harmon, Wei Zhang, Victor Khilkevich

Electrical and Computer Engineering Faculty Research & Creative Works

In This Work, the Permittivity of a 3D-Printed Carbon Fiber-Loaded Anisotropic Material, XT-CF20, is Examined Further. the Microstructure of XT-CF20 is First Examined Via Optical Imaging and is Shown to Be Composed of Inclusions that Are Aligned with the Print Direction of the Sample. the Permittivity Tensor for the Aligned Microstructure is Then Measured using a Capacitive Measurement Technique and Simulations Are Provided to Demonstrate the Validity of This Measurement Method. the Simulated Permittivity Values for XT-CF20 Samples with Varying Infill Structures Are Then Presented and Compared to the Measured Permittivity Values of Said Samples. an Error of Less Than …

Roughness Losses Computation Through The Partial Elements Equivalent Circuit Method, Fabrizio Loreto, Daniele Romano, Giulio Antonini, Albert E. Ruehli, Mauro Lai

Electrical and Computer Engineering Faculty Research & Creative Works

Conductor Loss Caused by Conductor Surface Roughness is a Critical Aspect in the Design of High-Speed Electronic Systems Since It Significantly Affects their Performances. Well-Established Roughness Models Have Been Proposed over the Years but They Have Been Applied Only to the Transmission Line Models of Interconnects. Typically, the Roughness Models Are Used to Modify the Per-Unit-Length Impedance of the Transmission Line Which is Extracted by 2D Model Methods. The Aim of This Work is to overcome This Limitation Thus Making It Possible to Model Roughness Conductors in the Framework of 3D Full-Wave Methods. More Precisely, it is Presented How to …

Extraction For Multilayer Ceramic Capacitor Vibration Induced Force, Yifan Ding, Jianmin Zhang, Mingfeng Xue, Xin Hua, Benjamin Leung, Eric A. Macintosh, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the Piezoelectric Characteristic of the MLCC Dielectric BaTiO3, the Multilayer Ceramic Capacitor (MLCC) Can Vibrate When the Supply Voltage Has AC Components. the Vibration of the MLCC Will Generate a Force on the Printed Circuit Board (PCB) It is Connected To, Causing the PCB to Vibrate as Well. the MLCC Vibration-Generated Force is Extracted using a Measurement-Simulation-Based Methodology in This Paper. the Force of an MLCC is First Extracted at the PCB Resonance Frequencies. Then, a Broadband Force Profile is Obtained by using the Interpolating Method. the Extraction Methodology Can Be Used in Different Boundary Conditions, on Different …

Coupling Path Analysis For Smart Speaker Intentional Electromagnetic Interference Attacks, Tanner Fokkens, Shengxuan Xia, Aaron Harmon, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Shows an Improved Understanding of the Coupling Path for Intentional Electromagnetic Interference (IEMI) Attacks on Smart Speaker Devices. This Includes a Method for Finding the Ideal Attack Angle and Locating the Region Sensitive to the Coupled EMI. in Previous Works, It Was Shown to Be Possible to Send RF Commands to a Smart Speaker and Have These Commands Be Interpreted as Voice Commands by the Microphone. However, the Attack Still Had Some Limited Understanding in Terms of the Coupling Path Location and Long-Distance Attack Potential. using the Improved Understanding of the Attack, a Longer Attack Distance is Achieved …

On Finding An Equivalent Force To Mimic The Multilayer Ceramic Capacitor Vibration, Yifan Ding, Jianmin Zhang, Mingfeng Xue, Shengyin Ding, Benjamin Leung, Eric A. Macintosh, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

The Multilayer Ceramic Capacitor (MLCC) Can Vibrate Due to the Piezoelectric Effect When There is AC Noise on the Power Rail. the Vibration of the Capacitor Will Generate a Force on the PCB and Thus Cause the PCB Vibration and Audible Problems May Occur. the Work in This Paper Finds an Equivalent Force with Similar Behavior to the MLCC-Generated Force. the Force is Controllable and Knowable and Thus Can Mimic the Capacitor Vibration on the PCB.

Decomposition Measurement For Antenna Gain And Radio Sensitivity Of Wireless Receiving System, Chaoqiang Zang, Lidong Chi, Fuhai Li, James L. Drewniak, Gang Feng, Yihong Qi

Electrical and Computer Engineering Faculty Research & Creative Works

A General Procedure for Decomposition Measurements for Receiver Antenna Gain and Radio Sensitivity based on Received Signal Strength Indicator (RSSI) Reporting is Proposed in This Paper. This Procedure Standardizes the Measurement Steps for Eliminating Nonlinear Error in RSSI Reporting. after Path Loss Calibration and RSSI Uncertainty Calibration, the Real Performance of the Antenna and the Radio Working in the Actual Environment of Wireless Receiving System Can Be Measured. the Antenna Gain is Obtained from the Difference between RSSI Reporting and Transmit Power, and the Radio Sensitivity is Obtained from the Transmit Power. This Method Helps to Improve the Development Efficiency …

Equivalent Force Extraction Methodology For Electrical Component Induced Pcb Vibration, Yifan Ding, Jianmin Zhang, Ming Feng Xue, Xin Hua, Benjamin Leung, Eric A. Macintosh, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

On-board electrical components can cause printed circuit board (PCB) vibration, thus generating audio noise if the electrical noise is in the audible frequency range. The electrical component-induced vibration can be equated to an external force applied to the PCB. This article presents a novel methodology to extract the equivalent force of electrical components on a PCB to study board vibration and potential acoustic noise problems. The method is based on a combination of measurement and simulation, wherein PCB vibration is used as the medium in the extraction process. The methodology is validated by the correlation of PCB vibration pattern, frequency, …

A Statistical Shmoo For A Decision Feedback Equalizer (Dfe), Junyong Park, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

This article proposes a statistical shmoo for a Decision Feedback Equalizer (DFE). A statistical shmoo shows a Bit-Error Rate (BER) distribution of a system depending on conditions such as a threshold voltage and sampling time. The previous statistical eye diagram can be converted to a statistical shmoo except for the case of a DFE. In the shmoo, rows and columns represent different threshold voltages and sampling times, respectively. Thus, the DFE operation also depends on each row and column. Furthermore, a DFE may have error propagations because of substantial noise. Therefore, this article proposes a statistical shmoo for an ideal …

Cascaded Sapphire Fiber Bragg Gratings Inscribed By Femtosecond Laser For Molten Steel Studies, Dinesh Reddy Alla, Deva Prasad Neelakandan, Farhan Mumtaz, Rex E. Gerald, Laura Bartlett, Ronald J. O'Malley, Jeffrey D. Smith, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This research reports a distributed fiber optic high-temperature sensing system tailored for applications in the steel industry and various other sectors. Recent advancements in optical sensor technology have led to the exploration of sapphire crystal fibers as a solution for sensing in harsh environments. Utilizing a femtosecond (fs) laser, cascaded fiber Bragg gratings (FBGs) were meticulously fabricated within a multimode sapphire optical fiber. These FBGs endowed the system with distributed sensing capabilities and underwent rigorous testing under extreme temperatures, reaching up to 1,800 °C. The study delves into the investigation of the FBG reflection spectrum, facilitated by the development of …

Towards Robust Consensus For Intelligent Decision-Making In Iot Blockchain Networks, Charles Rawlins, S. (Sarangapani) Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Distributed consensus is the core aspect of blockchain protocol security design. Recent protocols like IOTA have improved concurrency and scalability over Proof-of-work (PoW) with Bitcoin but have core design decisions that are inefficient for limited devices and do not take advantage of previous network experience to reduce calculations. This work proposes the first blockchain consensus protocol based on active machine-learning decisions, called Proof-of-history (PoH). PoH is setup as a distributed reinforcement-learning task for monitoring classification and training of blockchain transactions with an inner deep classifier. Early theoretical analysis and simulations show that PoH is robust to uncoordinated byzantine attacks through …

Deep-Learning-Based Accurate Beamforming Prediction Using Lidar-Assisted Network, Omar Rinchi, Ahmad Alsharoa, Ibrahem Shatnawi

Electrical and Computer Engineering Faculty Research & Creative Works

Beamforming optimization can enhance the next-generation wireless networks. However, finding the optimal beamforming in real-time is hard due to the need for large beam training overhead. The problem can be more challenging in dynamic environments with small coherence channel time. In this paper, we propose an accurate beam prediction solution using light detection and ranging (LiDAR)-assisted radio frequency (RF) system. More specifically, we propose a deep-learning model based on long-sort term memory (LSTM) to predict future beam indices from a set of pre-defined beam steering codebook. In addition to solving the beamforming overhead problem, the proposed deep learning approach is …

Accelerated Statistical Eye Diagram Estimation Method For Efficient Signal Integrity Analysis, Junyong Park, Youngwoo Kim, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

This article proposes an accelerated statistical eye diagram estimation method for efficient signal integrity (SI) analysis. An eye diagram is a critical metric in the SI analysis, however obtaining an eye diagram is time-consuming in simulation. The required time might be a few weeks depending on the complexity. Because the eye diagram is obtained by superposition of the received waveforms. Statistical eye diagram estimation methods were proposed to make the eye diagram acquisition efficient, however, it still has a limited improvement due to a large number of convolution operations. To address this limitation, the proposed method includes two approaches: (i) …

Nmr Study Of Co2 Capture By Butylamine And Oligopeptide Kdde In Aqueous Solution: Capture Efficiency And Gibbs Free Energy Of The Capture Reaction As A Function Of Ph**, Kaidi Yang, Joseph Schell, Fabio Gallazzi, Wei Wycoff, Rainer Glaser

Chemistry Faculty Research & Creative Works

We Have Been Interested in the Development of Rubisco-Based Biomimetic Systems for Reversible CO₂ Capture from Air. Our Design of the Chemical CO₂ Capture and Release (CCR) System is Informed by the Understanding of the Binding of the Activator CO₂ (^ACO₂) in Rubisco (Ribulose-1,5-Bisphosphate Carboxylase/oxygenase). the Active Site Consists of the Tetrapeptide Sequence Lys-Asp-Asp-Glu (Or KDDE) and the Lys Sidechain Amine is Responsible for the CO₂ Capture Reaction. We Are Studying the Structural Chemistry and the Thermodynamics of CO₂ Capture based on the Tetrapeptide CH₃CO−KDDE−NH₂ ("KDDE") in Aqueous …

Nanostructured Ternary Nickel-Based Mixed Anionic (Telluro)-Selenide As A Superior Catalyst For Oxygen Evolution Reaction, Ibrahim Munkaila Abdullahi, Siby Thomas, Alessio Gagliardi, Mohsen Asle Zaeem, Manashi Nath

Chemistry Faculty Research & Creative Works

Developing Protocols for Designing High-Efficiency, Durable, Cost-Effective Electrocatalysts for Oxygen Evolution Reaction (OER) Necessitates Deeper Understanding of Structure–property Correlation as a Function of Composition. Herein, It Has Been Demonstrated that Incorporating Tellurium into Binary Nickel Chalcogenide (NiSe) and Creating a Mixed Anionic Phase Perturbs its Electronic Structure and Significantly Enhances the OER Activity. a Series of Nanostructured Nickel Chalcogenides Comprising a Layer-By-Layer Morphology Along with Mixed Anionic Ternary Phase Are Grown in Situ on Nickel Foam with Varying Morphological Textures using Simple Hydrothermal Synthesis Route. Comprehensive X-Ray Diffraction, X-Ray Photoelectron Spectroscopy, and in Situ Raman Spectroscopy Analysis Confirms the Formation …

Natural Product Co-Metabolism And The Microbiota–Gut–Brain Axis In Age-Related Diseases, Mark Obrenovich, Sandeep Kumar Singh, Yi Li, George Perry, Bushra Siddiqui, Waqas Haq, V. Prakash Reddy

Chemistry Faculty Research & Creative Works

Complementary alternative medicine approaches are growing treatments of diseases to standard medicine practice. Many of these concepts are being adopted into standard practice and orthomolecular medicine. Age-related diseases, in particular neurodegenerative disorders, are particularly difficult to treat and a cure is likely a distant expectation for many of them. Shifting attention from pharmaceuticals to phytoceuticals and "bugs as drugs" represents a paradigm shift and novel approaches to intervention and management of age-related diseases and downstream effects of aging. Although they have their own unique pathologies, a growing body of evidence suggests Alzheimer's disease (AD) and vascular dementia (VaD) share common …

Effects Of Downwash When Measuring Gas Concentration With Uav-Mounted Gas Sensors, Jacob Lane Brinkman

Doctoral Dissertations

"This research concludes that the downwash region of a rotary-wing unmanned aerial vehicle (UAV) does not produce pressure variations substantial enough to cause significant changes in density-based gas concentration measurements. US regulations evaluate gas concentration as a function of gas density, and accurate concentration measurements are critical for protecting health and safety, which means evaluation of actual downwash effects on measured gas concentration is essential.

During experimentation, the UAV was fixed to a stand in a sealed chamber filled with NOx (NO and NO₂) of constant concentration. The UAV rotors ran at hovering speeds, and gas concentrations were …

Fiber Optic Sensors For Liquid Identifications, Wassana Naku

Doctoral Dissertations

"The fiber optic Fabry-Perot interferometer (FPI) is a widely utilized sensing configuration, offering numerous advantages over conventional electronic sensors, including high accuracy, distributed sensing capabilities, immunity to electromagnetic interference, and compact size. In this study, we propose a remarkably simple fiber optic-tip sensor system combined with machine learning techniques for the identification of pure and volatile organic liquids (VOLs).

A liquid droplet forms an extrinsic FPI (EFPI), with its effective reflectance being a function of the droplet's length. As the droplet evaporates, its length decreases. We conducted immersion tests using optical fiber tip sensors and monitored the time-transient responses of …

Investigation Of Recrosslinkable Preformed Particle Gels For Natural Gas Conformance Control, Ali Abdulmohsen Al Brahim

Doctoral Dissertations

"Recross linkable Preformed Particle Gel (RPPG) is a novel type of preformed particle gel in which particles can bond together to form a strong bulk gel system after being placed in the target formation. In this research, I systematically evaluated the feasibility of using this product to improve gas flooding conformance for mature reservoirs with conduits or fractures. Two RPPG systems were used for the experiment: a CO₂- resistant RPPG (CR-RPPG) synthesized using acrylamide (AM) and 2-acrylamide-2- methylpropane sulfonate acid (AMPS), designed for CO2 flooding; and an acrylamide-co-acrylic acid-based RPPG (LT-RPPG), designed for water flooding. Different experimental apparatuses …

Sustainable Development: A Data Analysis Investigation For A New Conceptual Model, Case Study Comparison And Validation Techniques, Tiffanie Marie Toles

Doctoral Dissertations

"The three pillars model for sustainability, often represented with three intersecting circles described as economic, environmental, and social factors with sustainability being at the center is a complex and philosophically open model [1]. As society promotes efforts to reduce carbon impacts, there becomes a need to critically review the models employed for understanding. This research presents a validated methodology, an updated conceptual configuration of sustainability for overall use, as well as a sustainable development performance measurement system. Using the 2020 Sustainable Development Goals Index Data, 232 indicators from 193 countries were used to evaluate the efficacy of using more than …

Efficient High Order Ensemble For Fluid Flow, John Carter

Doctoral Dissertations

"This thesis proposes efficient ensemble-based algorithms for solving the full and reduced Magnetohydrodynamics (MHD) equations. The proposed ensemble methods require solving only one linear system with multiple right-hand sides for different realizations, reducing computational cost and simulation time. Four algorithms utilize a Generalized Positive Auxiliary Variable (GPAV) approach and are demonstrated to be second-order accurate and unconditionally stable with respect to the system energy through comprehensive stability analyses and error tests. Two algorithms make use of Artificial Compressibility (AC) to update pressure and a solenoidal constraint for the magnetic field. Numerical simulations are provided to illustrate theoretical results and demonstrate …

Identification, Mapping, Analysis, And Dating Of Composite Mega Landslides In The Colorado Plateau, Conor Maris Watkins

Doctoral Dissertations

"This research consists of three articles focusing on landslide complexes within the Grand Canyon region of the Colorado Plateau. This is a vast and remote region of rugged topography. The landslide complexes in this study are greater than 10 million cubic meters in volume. The slides are located within different areas of the region and consist of differing geology but share multiple commonalities. Stratigraphic and structural controls tend to dictate where the slides occur. All of the landslides occur where carbonates and/or sandstones overlie over consolidated shales. The shales are susceptible to creep and strain softening where lateral confinement has …

Advances In Differentially Methylated Region Detection And Cure Survival Models, Daniel Ahmed Alhassan

Doctoral Dissertations

"This dissertation focuses on two areas of statistics: DNA methylation and survival analysis. The first part of the dissertation pertains to the detection of differentially methylated regions in the human genome. The varying distribution of gaps between succeeding genomic locations, which are represented on the microarray used to quantify methylation, makes it challenging to identify regions that have differential methylation. This emphasizes the need to properly account for the correlation in methylation shared by nearby locations within a specific genomic distance. In this work, a normalized kernel-weighted statistic is proposed to obtain an optimal amount of "information" from neighboring locations …

Development Of A Mission Design Tool For Computing Libration Point Formations Using Differential Corrections Initialized With A Genetic Algorithm, Donna Jennings

Doctoral Dissertations

"The growing interest in deep space spacecraft missions and distributed spacecraft formations has established the need for state-of-the-art advancements in the areas of relative dynamics and mission design. The focus of this research is to develop methods for identifying natural (i.e. ballistic) relative formation trajectories in the vicinity of the collinear libration points. A natural formation decreases the station keeping costs, lowering the consumption of spacecraft resources and extending mission lifetime. This research adapts both numerical and machine learning approaches to the problem of mission design. A genetic algorithm was first used to identify a multi-agent spacecraft formation in the …

Recurrent Event Data Analysis With Mismeasured Covariates, Ravinath Alahakoon Mudiyanselage

Doctoral Dissertations

"Consider a study with n units wherein every unit is monitored for the occurrence of an event that can recur with random end of monitoring. At each recurrence, p concomitant variables associated to the event recurrence are recorded with q (q ≤ p) collected with errors. Of interest in this dissertation is the estimation of the regression parameters of event time regression models accounting for the covariates. To circumvent the problem of bias and consistency associated with model's parameter estimation in the presence of measurement errors, we propose inference for corrected estimating functions with well-behaved roots under additive measurement errors …

Applied Geochemistry, Geochronology And Biostratigraphy: Case Studies From The 38th Parallel Structures In Missouri And Orange Basin, Offshore Western South Africa, Marissa Kay Spencer

Doctoral Dissertations

"The unique alignment of the Decaturville, Crooked Creek, and Weaubleau geological structures in central Missouri, three of nine known such structures along the 38th parallel in Illinois, Missouri, and Kansas, has puzzled geoscientists for decades. Research using palynology (palynomorphs and particulate organic matter) and radiometric dating of impact spherules were used to constrain age and a relationship between these enigmatic structures and infer their paleoenvironmental conditions. Novel melting damages, unique to impact, were documented in the palynomorphs in all the three structures. Early Ordovician acritarchs with melted processes correlate with ⁴⁰Ar-³⁹Ar stepwise heating age of impact spherules …