Digital Commons Network^™

Development Of A Comprehensive Multi-Factored Methodology For Identification Of Landslides In The Buffalo National River Of Arkansas, Abdurraouf Okok

Doctoral Dissertations

"In northern Arkansas's Springfield and Boston Mountain Plateaus, distinctive geomorphological landslide features have shown historical continuity. USGS topographic maps (1:24,000, 7.5-minute series) serve as valuable resources for studying terrain characteristics and hydrological patterns.

This study uses a manual mapping approach with high-resolution LiDAR data and geological maps in a GIS environment. The method identifies historic landslide features by analyzing anomalous topographic contour patterns overlaid on LiDAR-derived hillshade maps, revealing various mass movements along the Buffalo National River. Data from the Office of State Geologist and fieldwork reconnaissance were utilized to map older landslide features with high confidence. Some previously unrecognized …

Deep Reinforcement Learning Based Strategies For Inverter Dominated Microgrids, Oroghene Oboreh-Snapps

Doctoral Dissertations

The integration of inverter-based distributed generators (IBDGs) in modern power systems has ushered in a new era of renewable energy utilization, prompting the rise of Microgrid (MG) architectures. Nevertheless, as IBDG penetration increases, a host of challenges surface. Foremost among these challenges are issues related to frequency stability stemming from the inherent lack of inertia in IBDGs, and inaccurate sharing of reactive and active power, particularly evident in parallel IBDG networks with mismatched feeder impedance. This research presents novel solutions to these challenges by adopting deep reinforcement learning (DRL), specifically, the twin delayed deep deterministic policy gradient (TD3) algorithm, to …

Highly Dipole-Parallel Aligned Nonlinear Optical Organic Molecular Crystalline Materials: Rational Design, Experimental And Theoretical Studies Of Supramolecular Structures And Non-Covalent Interactions, Harmeet Singh Bhoday

Doctoral Dissertations

Highly dipole-parallel aligned donor-acceptor substituted organic molecules are attractive for a wide array of applications, including nonlinear optics. However, only a limited number of crystals are known to adopt polar non-centrosymmetric space groups. The concepts guiding the fabrication of these polar materials have been described. The study focused on unsymmetrical donor-acceptor substituted azines and butadiene's. An improved design over (MeO, Y)-azines led to the realization of three crystals perfectly aligned in dipole parallel orientation for (PhO, Y)-azines with Y = Cl, Br, I, and one nearly perfectly aligned crystal for Y = F (Paper I). The unique bonding properties associated …

Modelling Weave Effect In Pcbs Using 2d Cross-Sectional Analysis, Victor Khilkevich, Scott Hinaga

Electrical and Computer Engineering Faculty Research & Creative Works

Printed circuit board dielectric substrates are composite materials produced by embedding fiber glass fabrics into epoxy resin. Because of this the medium in the PCB transmission lines is inhomogeneous which often leads to degradation of the signal integrity performance of the lines, particularly due to the differential skew. The detrimental effect of the fiber weave can be modeled relatively accurately using full-wave analysis, but at a high computational cost. Alternative modelling techniques are less demanding but often lack accuracy. This article investigates a possibility of using the 2D cross-sectional analysis for the fiber weave effect modeling, which considerably decreases 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. …

Evaluation Of Transfer Learning Models On Traumatic Brain Injury Severity Classification, Ngoc Do, Daniel B. Hier, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

After traumatic brain injury (TBI), clinicians use the Glasgow Coma Scale (GCS) to classify patients by severity and radiologists use the Rotterdam score and the Marshall score to classify CT scans by severity. This work investigates a viable efficient low-cost transfer learning model to use MRI images to predict GCS, Rotterdam, and Marshall severity class after TBI. The enhanced transfer learning model architecture integrates multiple fine-tuning steps in which a few layers of the pre-trained model is unfrozen in each iteration so that the neural network is able to learn layer by layer further aspects of the image for better …

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 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 …

Low Noise Wireless Sensing In Termite Detection, Wei Zhang, Xiangshu Qi, Yunlong Luo, Alex Qi, Yihong Qi, Gang Feng

Electrical and Computer Engineering Faculty Research & Creative Works

Termites cause enormous financial damages all around the world every year. The majority of research on wireless sensing is always concerned with the various human-centric applications, however, the vast potential of wireless sensing for termite detection is often disregarded. In this article, a Wireless Intelligent Sensing (WISe) millimeter-wave (mmWave) radar system for termite detection is proposed. Here, we design a three-layer architecture with some intelligent resources to monitor the movement signs of the termites. In addition, we present a low noise sensing architecture that minimizes the noise in hardware and digital signal processing, which can reduce the impact of environment …

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

Electrical and Computer Engineering Faculty Research & Creative Works

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

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

Electrical and Computer Engineering Faculty Research & Creative Works

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

Design Of Waveguide Probe For Emi Characterization Of Ddr5 Sodimm, Xiangrui Su, Junho Joo, Minsu Lee, Jeongho Ju, Hyunsik Kim, Taeil Bae, Haekang Jung, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

In the latest portable electronic devices, 5th generation double data rate small outline dual in-line memory modules (DDR5 SODIMMs) are more and more used and have been identified as one of the critical electromagnetic interferences (EMI) noise sources that could cause RF desensitization. In this paper, the radiation mechanism of DDR5 SODIMM deployed in a laptop is identified and investigated based on near-field scanning. It was found that a cavity formed by the SODIMM and the main board can generate strong radiation around 2.4 GHz due to their dimensions, which overlap with the Wi-Fi band. To quantify the radiation from …

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 …

Relative Altitude Estimation Of Infrared Thermal Uav Images Using Sift Features, Shirin Nasr Esfahani, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Unmanned Aerial Vehicles (UAVs) have become indispensable in various applications, including surveillance, urban scene analysis, and agricultural monitoring. Accurate altitude estimation is critical for UAV operations, especially in environments where traditional sensors like GPS, pressure altimeters, and radar may fail. This paper explores the use of infrared and thermal imaging for relative altitude estimation of UAVs, highlighting their significant advantages over traditional RGB images. Infrared and thermal imaging offer superior performance in low-light and adverse weather conditions, providing clearer visibility and more reliable feature detection. By leveraging the Scale-Invariant Feature Transform (SIFT) features, this approach utilizes the inherent benefits of …

In-Plane And Out-Of-Plane 2-D Microdisplacement Sensor Based On A Single Microwave Resonator With Machine Learning, Shiyu Li, Osamah Alsalman, Jie Huang, Chen Zhu

Electrical and Computer Engineering Faculty Research & Creative Works

Microwave displacement sensors have garnered significant research interest in recent years and have found successful applications in industrial automation and aerospace engineering. However, most microwave sensors are limited to measuring in-plane displacement, with the assumption that out-of-plane displacement remains constant during operation. In this work, we propose and experimentally demonstrate a novel concept for 2-D micro displacement sensing that simultaneously measures both in-plane and out-of-plane displacement. We developed a proof-of-concept sensor system based on a custom-made coaxial cable resonator (CCR) serving as the stator and a rubber-metal heterogeneous plate as the movable part. The in-plane and out-of-plane micromovements of the …

Characterization Of The Kansas River Alluvial Aquifer Using Towed Transient Electromagnetic Geophysical Method, Jonathon Daniel Voss

Masters Theses

"Forecasted urban development areas west of Kansas City, Kansas in the coming decades has caused an increase of research into water resources (Butler et al. 2022). A location of investigation has been the Kansas River Alluvial Aquifer (KRAA) for shallow ground water resources. To investigate the KRAA structure and grain texture, the towed transient electromagnetic system (tTEM) in conjunction with direct push electrical conductivity logs and lithology wells were used to investigate four locations between Lawrence and Manhattan, Kansas. In total, 110 line-kilometers of tTEM data was collected. The tTEM data collected were high quality and through inversions of the …

Ontogenetically Driven Changes In The Endocranial Anatomy Of Maiasaura Peeblesorum And Its Implications For Sensory Functions, Emma Puetz

Masters Theses

"Hadrosaurids exhibited extreme morphological diversity and behavioral characteristics that can be compared with other, closely related members of Dinosauria – particularly through the study of neuroanatomy. X-ray CT generated endocrania of the Late Cretaceous saurolophine hadrosaur Maiasaura peeblesorum, known as the “good mother” dinosaur, offers a unique opportunity to compare complex ecological behaviors between non-avian dinosaurs and their modern archosaur relatives. The 3D reconstruction software ORS Dragonfly provided linear and volumetric measurements taken from the digital cranial endocast and endosseous labyrinths of three ontogenetically varied M. peeblesorum specimens from the Two Medicine Formation in Montana that were used to …

Learn From The Past: Using Peer Data To Improve Course Recommendations In Personalized Education, Colton Walker

Masters Theses

"This work describes a recommendation approach designed to enhance student success by identifying semester schedules and graduation paths. The primary objective is to provide personalized graduation path recommendations rooted in individual student performance and draw insights from the academic journeys of similar students who successfully graduated. The original research contribution of this work lies in the development of a graduation path recommender system that leverages a combination of Markov Decision Process, Q-Learning, and collaborative filtering techniques to pinpoint graduation paths with a higher likelihood of leading students to success based on their academic progress thus far. The effectiveness of the …

Computational Fluid Dynamics Analysis Of Thermal-Hydraulic Phenomena In Nuclear Reactor Systems, Mehedi Hasan Tusar

Masters Theses

"A computational analysis of thermal-hydraulic processes in nuclear reactor systems is performed, leveraging Computational Fluid Dynamics (CFD) to advance the design and ensure the safety of nuclear reactors. Divided into two primary sections, the initial part examines thermal-hydraulic behavior in the Replacement Research Reactor (RRR) operating at 20 megawatts and evaluates potential enhancements for the Missouri University of Science and Technology Reactor (MSTR) to operate at an increased capacity of 2 megawatts from the existing 0.2 megawatts. Detailed simulations reveal insights into flow characteristics, temperature distributions, and pressure drops, highlighting the effective use of realistic and porous media modeling techniques …

Addressing The Negative Externalities Of Trade: Flanking Policies And The Role Of Package Treaties, Gregory Shaffer

Georgetown Law Faculty Publications and Other Works

This article examines the rationales for addressing sustainability and social inclusion in trade policy and the tradeoffs among imperfect institutional choices in doing so through “flanking policies.” It examines three types of negative spillovers or externalities implicated by trade: material, moral, and social/political. Part I defines terms and sets forth the argument. Part II typologizes the three categories of negative externalities and then highlights the challenges posed for flanking measures given the reciprocal nature of externalities. It respectively addresses environmental harms and labor and social inclusion concerns. Part III assesses different institutional choices for addressing negative externalities, dividing them between …

Blinded By The Light: Resolving The Conflict Between Satellite Megaconstellations And Astronomy, David A. Koplow

Georgetown Law Faculty Publications and Other Works

The sudden emergence of large constellations of small satellites in low altitude orbits represents one of the most dramatic contemporary innovations in outer space. Promising low-cost, low-latency global communications and spectacular capacities for remote sensing of the Earth, these satellites will soon number in the tens of thousands, sponsored by diverse corporations and countries around the world. But this proliferation of spacecraft comes at a steep cost in unavoidable interference with ground-based astronomy: as the satellites overfly the observatories, they block the views of remote objects and phenomena, leaving obliterating white streaks on the collected imagery, and obscuring access to …

Loper Bright In A Larger Interpretive Perspective: Is This Justice Scalia’S Court Anymore?, Victoria Frances Nourse

Georgetown Law Faculty Publications and Other Works

Loper Bright Enterprises v. Raimondo has left administrative lawyers agog: Could the Supreme Court really reverse the “goliath” known as Chevron deference? For those who study the Court’s interpretive landscape more broadly, however, Chevron reversal may not be as unexpected as administrative lawyers believe. This Article will look at Loper Bright by linking three notable interpretive developments: the major questions doctrine, Chevron skepticism, and strict constructions of statutory text. These developments share the same risk: the Court is imposing a new “clarity tax” on both Congress and administrative agencies. Having said this, others’ grave worries about changes in Chevron are …

Shades Of Service: Navigating Racial Diversity, Mental Health, And Occupational Stress Among Black Police Officers, Manina Jeudy

Theses and Dissertations

This study was conducted to learn about the unique challenges Black police officers face by exploring their lived experiences. This study looked at how these current and retired Black police officers navigate racial diversity, handle occupational stress and how their mental health is affected. The research was prompted by the lack of existing literature that focuses specifically on the lived experiences of Black police officers, as most studies of policing do not address this population in depth. Through Zoom interviews with a small group of officers, this study revealed their struggles at work and in their personal lives. By sharing …

A Descriptive Study Of The Perception Of Emerging Adults Aged 18-25 Years Toward Police Efficacy And Image In The United States, Jude Louis

Theses and Dissertations

The purpose of this study was to investigate the perceptions of emerging adults toward police efficacy and image. The study was descriptive, used quantitative methodology, and utilized a non-experimental design. Close-ended questions were used in an online format to survey emerging adults aged 18-25 years in the United States. The data was collected using the SurveyMonkey Audience, which was relatively cost-effective, able to gather information from the target audience within a short period of time, and efficient with any sample size. The study occurred over two months in 2024. Emerging adults in the United States aged 18-25 years irrespective of …

Spouse Violence In Case Of Police Officers In Puerto Rico: Violence In Police Families, Jorge Ismael Suarez

Theses and Dissertations

This applied dissertation was designed to explore the relationship between factors related to police work and whether these factors help predict domestic violence in a sample of officers of the Puerto Rico Police. The following factors were explored in this study: external burnout, alcohol abuse, department withdrawal, and authoritarian spillover. This study was based on a previous study by Johnson et al. (2005), which revealed that violence exposure and domestic violence among police officers are linked according to four mediation chains. The mediation chain was a model implemented by the authors to determine the influence of burnout, authoritarian spillover, alcohol …

Administrators’ Perceptions Of The Impact Of Restorative Practices On Discipline Referrals And Suspension Rates In A Rural Elementary School, Gregory W. Brown

Theses and Dissertations

The problem addressed in the study involved excessive out-of-school suspensions, which have been a major concern for public school educators for decades. The purpose of the study explored the perceptions of participants regarding the effects of implementing restorative practices on suspension rates at a rural elementary school.The qualitative phenomenology study used a purposive sample of 10 educators who interacted with students suspended for violating the school's code of conduct. Six kindergarten through Grade 5 teachers, two Grades 3–5 grade-level chairpersons, the Positive Behavioral Interventions and Support coordinator, and one administrator participated in the study. Utilizing case study approaches, this qualitative …

A Phenomenological Study On University Students’ Perceptions And Attitudes Of The Effectiveness Of Mobile Apps On Communicative Competence, Leveth Jackson

Theses and Dissertations

This phenomenological study is focused on understanding how university students who are learning English as a foreign language (EFL) perceive and experience using mobile application on their speaking abilities. The primary goal was to examine the perception and attitudes of EFL learners towards using mobile apps for independent English-speaking practice and creating a customized learning experience outside of the classroom.

The researcher also investigated the participants’ views on the challenges and advantages of incorporating mobile apps into university speaking courses. The findings of this investigation may inform language educators at universities on the potential benefits of using mobile apps in …

Engagement Strategies In A Virtual Classroom, Kelly Clarke

Theses and Dissertations

This applied dissertation was designed to determine if cooperative learning strategies increased student engagement in a virtual elementary classroom. The purposes of this study were (a) to determine whether the implementation of cooperative learning strategies increased student engagement and (b) to explore student perceptions of engagement.

In this mixed methods research, the writer utilized a sequential explanatory design. The pre-test and post-test survey used in this study was based on the Elementary Student Engagement: Student Response created by the American Institutes for Research (2023). Convenience sampling was used to select 12 students to complete both surveys. A total of 4 …

African American Parents And School-Based Parental Involvement At The Secondary Level, Mark A. Dykes

Theses and Dissertations

Parental involvement is a multifaceted construct that includes school-based, home-based, and academic socialization. School-based parental involvement in education has been positively associated with academic achievement for all students. However, educational leaders are challenged to get parents involved in school-based activities, such as the School Site Council, Parent Council, and Open Houses.

The purpose of this qualitative descriptive study is to examine the reasons why African American parents are not fully involved in the policymaking and organizational activities at the target secondary school. This study is guided by the combined conceptual frameworks of Critical Race Theory, the Hoover-Dempsey and Sandler framework, …

A Study On Reducing Motor Stereotypy With Response Interruption And Redirection Using Functionally Matched And Unmatched Stimuli, Alana Fallucca

Theses and Dissertations

This applied dissertation was designed to expand the scope of existing literature on the use of response interruption and redirection intervention with functionally matched and unmatched stimuli to reduce motor stereotypy in children with autism. While response interruption and redirection is an effective, evidence-based strategy for the reduction of vocal and motor stereotypy, it requires interruption of each instance of stereotypic behavior and implementation of an alternative behavior. This process can be laborious, implementation of which depends upon the frequency of stereotypy. To mitigate the intervention difficulties with response interruption and redirection implementation, a single-step functionally matched stimulus that is …