Digital Commons Network^™

A Convolutional Neural Network (Cnn) For Defect Detection Of Additively Manufactured Parts, Musarrat Farzana Rahman

Masters Theses

“Additive manufacturing (AM) is a layer-by-layer deposition process to fabricate parts with complex geometries. The formation of defects within AM components is a major concern for critical structural and cyclic loading applications. Understanding the mechanisms of defect formation and identifying the defects play an important role in improving the product lifecycle. The convolutional neural network (CNN) has been demonstrated to be an effective deep learning tool for automated detection of defects for both conventional and AM processes. A network with optimized parameters including proper data processing and sampling can improve the performance of the architecture. In this study, for the …

Optimization And Modeling Of Esd Protection Devices, Li Shen

Masters Theses

“Transient voltage suppressors (TVS) are used to protect ICs (integrated circuits) against overvoltage, ESD (Electrostatic Discharge), inductive load switching, and even lightning strikes. In this research, a transient behavior model framework for ESD protection devices is used for modelling four different types of TVS (non-snapback, snapback, spark gap like device and varistor). The System-Efficient ESD Design (SEED) methodology is utilized to strengthen the trust in the model framework by efficient simulation of ESD interaction of the off-chip ESD protection devices with the IC ESD protection device and associated measurement data.

Improvements in the TVS transient response, accounting for conductivity modulation, …

Feasibility Of A Critical Experiment Utilizing Uranium Dioxide-Beryllium Oxide With Neutron Spectrum Shifting Capabilities, Ashley Rachel Raster

Masters Theses

“The goal of this project is to determine the feasibility of utilizing Annular Core Research Reactor (ACRR) fuel in core design with Sandia Pulse Reactor Facility’s (SPRF) Seven Percent Critical Experiment (7uPCX) fuel rods as driver fuel for a critical experiment facility to support future critical and benchmark experiments for the International Criticality Safety Benchmark Evaluation Project (ICSBEP) handbook. This is part of the Critical Experiment Design (CED) process for future criticality experiments. These criticality experiment designs have the main goal of being performed in the same facility at different neutron energy ranges. To test the feasibility of this experiment …

Man-In-The-Middle Attacks On Mqtt Based Iot Networks, Henry C. Wong

Masters Theses

“The use of Internet-of-Things (IoT) devices has increased a considerable amount in recent years due to decreasing cost and increasing availability of transistors, semiconductor, and other components. Examples can be found in daily life through smart cities, consumer security cameras, agriculture sensors, and more. However, Cyber Security in these IoT devices are often an afterthought making these devices susceptible to easy attacks. This can be due to multiple factors. An IoT device is often in a smaller form factor and must be affordable to buy in large quantities; as a result, IoT devices have less resources than a typical computer. …

Pressure Relief Wells: Analysis Of Subsurface Heterogeneity To Evaluate Relief Well Locations For Mississippi River Levees, Emma Marie Young

Masters Theses

“When designing pressure relief well systems, it is imperative to understand what major geomorphology and heterogenies features are present, such as buried oxbow lakes, especially when the feature is parallel to the source, such as the Mississippi River. When present, there is a notable greater increase in head pressures, especially on the landward tow of the levee. This can cause erosional features that originally thought of to have been protected from by installing pressure relief wells. When comparing the effective hydraulic conductivities of horizontal clay layers and vertical clay layers spanning the length of the model, little to no noticeable …

Controlling Microalloy Interactions On Precipitation, Hot Ductility, And Microstructure -- Mechanical Property Relationships, Madhuri Varadarajan

Masters Theses

“One of the main problems faced in the continuous casting of micro-alloy steels is the formation of transverse cracks. Transverse cracks are surface, or near-surface cracks formed perpendicular to the casting direction. The research focuses on using laboratory hot tensile tests methods to determine the low ductility ranges in high strength steel grades with different micro-alloy additions of titanium, niobium, and vanadium. The hot ductility of commercially produced as-cast slab and beam blank samples was evaluated using two experimental methods: tensile testing utilizing a servo-hydraulic load frame with a resistance furnace and thermomechanical testing using rapid Joule heating. The tests …

Validation Of Edna Metabarcoding : A Comparison To Traditional Survey Methods In Ozark Streams, Veronica Marian Lee

Masters Theses

Environmental DNA (eDNA) sampling provides a method for assessing fish communities that has potential as a supplement to traditional sampling methods due to its ability to save time as well as its non-invasive nature. This is a method in which from just one sample, eDNA from multiple individual species are able to be sequenced in tandem and the resulting reads identified to describe a community. In order to evaluate this technique and its efficacy for monitoring fish community diversity, we collected water samples alongside surveys performed by the Missouri Department of Conservation sampling program in summers 2020-21. DNA were extracted …

Juggling A Devil-Stick: Hybrid Orbit Stabilization Using The Impulse Controlled Poincaré Map, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The control design for juggling a devil-stick between two symmetric configurations is proposed. Impulsive forces are applied to the devil-stick at the two configurations; and impulse of the force and its point of application are modeled as the control inputs. The dynamics of the devil-stick is described by a single return Poincaré map, and it is shown that the control objective of juggling can be achieved by stabilizing a hybrid orbit. The impulse controlled Poincaré map (ICPM) approach, recently proposed for stabilization of continuous-time orbits of underactuated systems, is extended to achieve asymptotic stabilization of the hybrid orbit. The applicability …

Graphical Revamping Of A Crude Distillation Unit Under Two Variable Operational Scenarios - Naphtha Stabilizer And Reformer Operated, Amany G. Abo-Mousa, Dina A. Kamel, Hany A. Elazab, Mamdouh A. Gadalla, Mai K. Fouad

Chemical and Biochemical Engineering Faculty Research & Creative Works

Energy costs represent significant parts of the total operating costs of crude refining industries. Energy integration is a typical solution to reduce heating and cooling utilities in crude refining plants through maximizing the target temperature of crude oil streams before entering the furnace. Over the past few decades, a significant progress has been made in energy integration methods including Pinch technology and mathematical programming approaches. Example of these is a graphical technique which plots Thot versus Tcold for energy analysis and revamping studies. The current research employs the Thot - Tcold diagrams in an algorithm to retrofit an existing crude …

Effect Of Açai Berry Extract Application On The Bond Strength To The Bleached Enamel Using An Experimental Etch-And-Rinse Adhesive, Lamiaa M. Moharam, Haidy N. Salem, Shahinaz N. Hassan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Background: To evaluate the bleached enamel shear bond strength (SBS) after antioxidants application using an experimental adhesive. Material and Methods: Sixty sound human molars had their roots removed then cut into buccal and lingual halves and mounted in acrylic blocks. Enamel bleaching was done using an in-office chemical bleaching agent. Specimens were arbitrarily allocated into 12 groups (n=10) regarding the three experimental levels of the study: two antioxidant agents [10% açai berry extract, 10% sodium ascorbate prepared gels (applied for 15-min) and the control group (no antioxidant application)], two adhesive materials [commercial etch-and-rinse (ER) adhesive and an experimental ER adhesive] …

Monetization For Content Generation And User Engagement On Social Media Platforms: Evidence From Paid Q&A, Jonathan Hua Ye, Cecil Eng Huang Chua

Business and Information Technology Faculty Research & Creative Works

Social media platforms want to increase their valuation in terms of total content quantity and user engagement. Monetization is often used to induce user content generation. However, research documents that while monetization increases the quantity of specific kinds of content, it does not necessarily increase the total content quantity or user engagement (i.e., platform value). Furthermore, the impact of monetization may depend on the social status of content creators. This article investigates paid question and answer (paid Q&A). Based on expectancy theory and relevant research, this article hypothesizes the effects of introducing paid Q&A on both total content quantity and …

Information Systems Analysis And Design: Past Revolutions, Present Challenges, And Future Research Directions, Keng Siau, Carson Woo, Veda C. Storey, Roger H.L. Chiang, Cecil Eng Huang Chua, Jon W. Beard

Business and Information Technology Faculty Research & Creative Works

Systems Analysis and Design (SAND) is Undoubtedly a Pillar in the Field of Information Systems (IS). Some Researchers Have Even Claimed that SAND is the Field that Defines the Information Systems Discipline and is the Core of Information Systems. the Past Decades Have Seen the Development of Structured SAND Methodologies and Object-Oriented Methodologies. in the Early 1990s, Key Players in the Field Collaborated to Develop the Unified Modeling Language and the Unified Process. Agile Approaches Followed, as Did Other Dynamic Methods. These Approaches Remain Heavily Employed in the Development of Contemporary Information Systems. at the Same Time, New Approaches Such …

Novel Data-Driven Spatial-Spectral Correlated Scheme For Dimensionality Reduction Of Hyperspectral Images, Yanming Zhang, Ping Yuan, Lijun Jiang, Hong Tat Ewe

Electrical and Computer Engineering Faculty Research & Creative Works

Hyperspectral imaging technology has been popularly applied in remote sensing because it collects echoed signals from across the electromagnetic (EM) spectrum and thereby contributes fruitfully spatial-spectral information. However, the processing or storage of high-data-volume hyperspectral images (HSIs), also viewed as snapshots varying with the EM spectrum, burdens the hardware resources, especially for the high spectral resolution and spatial resolution cases. To address this challenge, a novel unsupervised dimensionality reduction method based on the dynamic mode decomposition (DMD) algorithm is proposed to analyze hyperspectral data. This method decomposes the spatial-spectral HSIs in terms of spatial dynamic modes and corresponding spectral patterns. …

A Novel Data-Driven Modeling Method For The Spatial-Temporal Correlated Complex Sea Clutter, Yanming Zhang, Lijun Jiang, Hong Tat Ewe

Electrical and Computer Engineering Faculty Research & Creative Works

The sea clutter, referred to as the time-varying radar backscatter from the ocean surface, plays a significant role in marine radar development. The ocean's complex hydrodynamics cause it to exhibit non-Gaussian and nonstationary characteristics, which brings challenges in the sea clutter modeling, especially for establishing its spatial-temporal correlated and coherent model. In this article, a data-driven method based on the Koopman mode decomposition (KMD) is proposed for modeling spatial-temporal correlated complex sea clutter. The method decomposes the coherent sea clutter dynamic behavior in terms of Koopman modes and corresponding temporal patterns. Then, these spatiotemporal patterns are used to construct the …

Single-Snapshot Localization For Near-Field Ris Model Using Atomic Norm Minimization, Omar Rinchi, Ahmed Elzanaty, Ahmad Alsharoa

Electrical and Computer Engineering Faculty Research & Creative Works

Reconfigurable intelligent surfaces (RISs) are expected to play a significant role in the next generation of wireless cellular technology. This paper proposes an uplink localization scheme using a single-snapshot solution for user equipment (UE) that is located in the near-field of the RIS. We propose utilizing the atomic norm minimization method to achieve super-resolution localization accuracy. We formulate an optimization problem to estimate the UE location parameters (i.e., angles and distances) by minimizing the atomic norm. Then, we propose to exploit strong duality to solve the atomic norm problem using the dual problem and semidefinite programming (SDP). The RIS is …

Robust Modifications To Model Reference Adaptive Control For Reference Voltage Tracking In A Dual Active Bridge Dc-Dc Converter, Kartikeya J.P. Veeramraju, Alvaro Cardoza, Jagannathan Sarangapani, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

Model Reference Adaptive Control (MRAC) is useful for achieving a desired dynamic response with no prior knowledge of system parameters. Traditional MRAC is sensitive to noise in the state variables, leading to adaptation parametric drift. The drift in parameters, if left unchecked, leads to loss of closed loop stability. In power electronic systems, the ripple in the output voltage serves as a bounded noise, which leads to MRAC instability. This drift phenomenon is observed through the simulation and hardware experimentation of a Dual Active Bridge (DAB) converter and mitigated using deadzone modification and σ modification approaches. These two methods are …

Chimeranet: U-Net For Hair Detection In Dermoscopic Skin Lesion Images, Norsang Lama, Reda Kasmi, Jason R. Hagerty, R. Joe Stanley, Reagan Harris Young, Jessica Miinch, Januka Nepal, Anand Nambisan, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

Hair and ruler mark structures in dermoscopic images are an obstacle preventing accurate image segmentation and detection of critical network features. Recognition and removal of hairs from images can be challenging, especially for hairs that are thin, overlapping, faded, or of similar color as skin or overlaid on a textured lesion. This paper proposes a novel deep learning (DL) technique to detect hair and ruler marks in skin lesion images. Our proposed ChimeraNet is an encoder-decoder architecture that employs pretrained EfficientNet in the encoder and squeeze-and-excitation residual (SERes) structures in the decoder. We applied this approach at multiple image sizes …

Dielectric Loss Tangent Extraction Using Two Single-Ended Striplines Of Different Width, Jiangshuai Li, Yuanzhuo Liu, Liang Liu, Shengxuan Xia, Scott Hinaga, Victor Khilkevich

Electrical and Computer Engineering Faculty Research & Creative Works

Frequency-dependent electrical properties of dielectric materials are one of the most important factors for high-speed signal integrity design. Recently a method of accurately measuring the dielectric loss tangent ($\tan \delta$) of differential lines was proposed. By taking into account the ratio between the differential and common mode per-unit-length resistances the surface roughness contribution to the total loss is eliminated and dielectric parameters can be determined. In this article a similar method is applied to a combination of two single-ended lines. To evaluate the accuracy of the extraction, the impact of the de-embedding errors was investigated, which allows to optimize the …

A Fast Cascading Method For Predicting The Coupling From External Plane Waves To Pcbs, Shengxuan Xia, James Hunter, Aaron Harmon, Mohamed Z.M. Hamdalla, Ahmed M. Hassan, Chulsoon Hwang, Victor Khilkevich, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

The radio frequency (RF) coupling to electronic devices impacts their EMC performance. The functionalities of a working electronic device may be disrupted when the electromagnetic (EM) coupling reaches a certain level. Studies of the EM coupling to printed circuit boards (PCBs) are therefore essential for RF susceptibility and EMC purposes. For decades, researchers focused on the analytical modeling of EM coupling to transmission lines. However, when it comes to more realistic PCBs the analysis usually still relies heavily on full-wave simulations because of the complexity of the structures and the lack of analytical solutions. Using a traditional full-wave modeling approach, …

Predicting Radiated Emissions From A Complex Transportation System Wiring Harness, Fuwei Ma, Ruijie He, Sameer Walunj, Tamar Makharashvili, Chulsoon Hwang, Daryl G. Beetner, Brian Booth, Kerry Martin

Electrical and Computer Engineering Faculty Research & Creative Works

Low frequency radiated emissions problems are often caused by common mode currents flowing on wiring harnesses. The ability to predict radiated emissions problems early in the design process can save both time and money and result in a better product. Methods have previously been reported for rapidly characterizing common-mode sources driving a harness and then using these equivalent sources to predict radiated emissions. These methods are extended in the following paper to predict radiated emissions from a complex 32-wire harness bundle connected to an engine control unit. Rapid experimental characterization of the common mode sources is enabled using an equivalent …

Practical Fss-Based Sensor Sensitivity, Mahboobeh Mahmoodi, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Frequency selective surfaces are a periodic array of unit cells that, when illuminated externally, have a specific frequency response that depends on element geometry, spacing, and substrate properties. Theoretically, FSS is assumed as an infinite array of unit cells with a plane wave excitation. However, in practice, an FSS is finite and hence, due to edge effects, the limited number of unit cells, and non-uniform illumination, the response will deviate from the theoretical. As it relates to FSS-based sensing in particular, a localized illumination is often used in order to improve the sensing resolution. However, due to the aforementioned factors, …

Modeling Of Rf Interference Caused By Solid-State Drive Noise, Junho Joo, Woncheol Song, Taelim Song, Sunkyu Kong, Jungcheol Lim, Inmyung Song, Jongjoo Lee, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, modeling of RFI problem caused by a solid-state drive (SSD) in a laptop is proposed. Two noise sources (one outside and one inside a cavity) in the SSD are reconstructed as dipole moments with magnitude-only near-field scanning data. The dipole moment inside a cavity is then replaced by a Huygens' box covering four side surfaces of the cavity using a numerical simulation. The noise voltage at an RF antenna port is calculated by combining the two reconstructed noise sources with measured transfer functions. The model is successfully validated through a comparison of the calculation with measurement results.

Insertion Loss Reduction Using Rounded Corners To Mitigate Surface Roughness Effect In Pcb Transmission Lines, Yuandong Guo, Donghyun Kim, Yuanzhuo Liu, Xiaoning Ye, Jimmy Hsu, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Signal integrity (SI) can be interpreted as a measure of the distortion of the incident pulse, which is attributed to various contributors, e.g., inter-symbol interference (ISI), crosstalk, jitter, etc. The channel insertion loss is generally the most critical concern in SI designs, since it determines the working bandwidth of a high-speed channel, and the bandlimited channels are known as the root cause of ISI. At the tens of Gigabit rates in use today, PCB transmission lines may have appreciable losses, which can be divided into frequency-dependent dielectric loss and conductor loss, and noticeable amount of losses can be generated at …

Fixture Design For Parasitic Capacitances Of Mosfets For Emi Applications, Anfeng Huang, Hanyu Zhang, Li Du, Cheung Wei Lam, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the fast-switching nature of modern power converters, up to hundreds of MHz of common-mode noise can easily be generated. The characterization of switching components, e.g., Si MOSFETs, is essential for noise reduction. However, limited by the bandwidth of instruments, the voltage-dependent capacitances of high voltage MOSFETs are typically characterized at approximately 1 MHz, which is insufficient for EMI applications. In this paper, the measurement method and the test fixtures are presented. The measurement bandwidth is pushed to 30 MHz and higher, and frequency-dependent capacitances of a MOSFET are observed through measurements.

Generation Expansion Planning Considering Discrete Storage Model And Renewable Energy Uncertainty: A Bi-Interval Optimization Approach, Siyuan Wang, Guangchao Geng, Qy Jiang, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

Both discrete storage model (DSM) and continuous storage model (CSM) have been used in the power system planning literature. In this work, we conduct a sizing-error analysis for the use of CSM in generation expansion planning (GEP), which shows more reasonable storage sizing decisions are offered by the DSM in comparison to the CSM. However, when the DSM is considered in the context of interval optimization, the discrete status variables in mutually exclusive constraints and the strong temporal coupling in state-of-charge (SOC) constraints create significant challenges. To tackle this, a tailored interval optimization approach is proposed to consider both DSM …

I2Mtc 2021 Special Issue In Ieee Transactions On Instrumentation And Measurement, Pawel Niewczas, Kristen M. Donnell, Melanie Ooi

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

An Energy-Efficient Internet Of Things Relaying System For Delay-Constrained Applications, Abdullah M. Almasoud, Ahmad Alsharoa, Daji Qiao, Ahmed E. Kamal

Electrical and Computer Engineering Faculty Research & Creative Works

The emerging Internet-of-things (IoT) systems contain a large number of small wireless devices with limited energy, communication, and computational capabilities. In such systems, a helping station located between the IoT devices and backhaul servers can be deployed to broadcast the IoT devices to the backhaul networks. This paper investigates a hybrid energy-efficient framework using multiple energy harvested relays with data buffering capabilities. The relays are powered by a hybrid energy supply consisting of a traditional electric grid and renewable energy grid. We propose an energy efficient novel approach aiming to support the wireless uplink transmission from IoT devices to backhaul …

Concurrent Learning-Based Neuro-Adaptive Robust Tracking Control Of Wheeled Mobile Robot: An Event-Triggered Design, Krishanu Nath, Manas Kumar Bera, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an event-based neuro-adaptive robust tracking controller for a perturbed and networked differential drive mobile robot (DMR) is designed with concurrent learning. A radial basis function neural network, which approximates an unknown perturbation, is used to design an adaptive sliding mode controller (SMC). The RBFNN weights and SMC parameters are estimated online using an adaptive tuning law to ensure performance with reduced chattering. To improve the convergence of RBFNN weight estimation error, a concurrent learning-based adaptive law is derived, which uses measured online and recorded data. Further, a suitable triggering condition is designed to achieve a reduced number …

An Interleaved High Step-Up Dc-Dc Converter With Built-In Transformer-Based Voltage Multiplier For Dc Microgrid Applications, Ramin Rahimi, Saeed Habibi, Mehdi Ferdowsi, Pourya Shamsi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a high step-up DC-DC converter with a built-in transformer (BIT)-based voltage multiplier (VM) that is suitable for integrating low-voltage renewable energy sources into a DC microgrid. A three-winding BIT is combined with the switched-capacitor (SC) cells to extend the voltage gain and reduce the voltage stress on the switches. The current-falling rates of the diodes are controlled by the leakage inductances of the BIT, alleviating the reverse-recovery problem of the diodes. The operating modes and steady-state analysis are presented. Additionally, the validity of the proposed converter is confirmed by the simulation and experimental results of a 400 …

Identification Of Volatile Organic Liquids By Combining An Array Of Fiber-Optic Sensors And Machine Learning, Wassana Naku, Anand K. Nambisan, Muhammad Roman, Chen Zhu, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

In This Paper, We Report an Array of Fiber-Optic Sensors based on the Fabry-Perot Interference Principle and Machine Learning-Based Analyses for Identifying Volatile Organic Liquids (VOLs). Three Optical Fiber Tip Sensors with Different Surfaces Were Included in the Array of Sensors to Improve the Accuracy for Identifying Liquids: An Intrinsic (Unmodified) Flat Cleaved End face, a Hydrophobic-Coated End face, and a Hydrophilic-Coated End face. the Time-Transient Responses of Evaporating Droplets from the Optical Fiber Tip Sensors Were Monitored and Collected Following the Controlled Immersion Tests of 11 Different Organic Liquids. a Continuous Wavelet Transform Was Used to Convert the Time-Transient …