Engineering Commons^™

Explainable And Reduced-Feature Machine Learning Models For Shape And Drag Prediction Of A Freely Moving Drop In The Sub-Critical Weber Number Regime, Md Amanullah Kabir Tonmoy

Theses and Dissertations

Accurately predicting the shape and drag of a moving drop is crucial in many spray applications. However, due to the complex interaction between the drag force and drop shape deformation, accurate prediction of drop shape and drag from Computational Fluid Dynamics (CFD) simulation requires large computational resources and time. A novel data-driven approach using NARXNN (Non-linear Auto Regressive eXogenous input Neural Network) is proposed in this study, which recurrently predicts the drop shape and drag for a given Weber number (We) and Reynolds number (Re), in the sub-critical We regime where there is no drop breakup. The average error in …

Frequency-Based Rapid Structural Damage Detection Using Embedded Edge Computing On Resource-Constrained Devices, Ryan Yount

Theses and Dissertations

Structural Health Monitoring (SHM) is essential for ensuring reliability and longevity of useful structures. Traditional SHM approaches rely on manual or remote data transmission and external processing, which introduce latency and can depend on stable communication links. This work aims to advance SHM by integrating edge-computing techniques for rapid damage detection to enable faster and more autonomous structural assessments in resource-constrained environments. The research spans three key contributions including 1) frequency-based damage detection of civil structures using a sensor package with the addition of an edge processor, 2) additions to the computational efficiency of the edge-computing sensor package in a …

Cross-Layer Design And Optimization Of Analog In-Memory Computing Systems, Md Hasibul Amin

Theses and Dissertations

There has been a rapid growth in the computational demands of machine learning (ML) workloads in recent days. Conventional von Neumann architectures are not capable of keeping up with the high cost of data movement between the processor and memory, well-known as memory wall problem. In-memory computing (IMC) has been focused as a solution by the researchers, where the computation is performed inside the memory devices such as SRAM, MRAM, RRAM etc. Most commonly, the memory devices are arranged in a crossbar setting where the matrixvector multiplication (MVM) operation is performed through intrinsic parallelism of analog computations. The conventional IMC …

Bilateral Gait Trainer For Transtibial Amputees, Desmond Greer, Odinachi Anene, Andrew Wallace, Noah Hill

Bioengineering Senior Theses

Lower limb amputation affects over 2.3 million individuals in the U.S., with peripheral vascular disease and diabetes as leading causes. Prosthetic rehabilitation is critical for restoring mobility, yet barriers like therapist shortages, cost, and inconsistent at-home training limit patient outcomes. This thesis presents the design, development, and testing of a bilateral gait training device that addresses these challenges by providing real-time haptic feedback and quantitative gait metrics for at-home rehabilitation. The device integrates force-sensitive resistors embedded in insoles to monitor plantar pressure distribution, haptic actuators (eccentric rotating mass motors) mounted on thigh straps to deliver corrective feedback, and an Arduino-based …

Effects Of High Temperature Compaction On 3d Printed Carbon Fiber Reinforced Polymer Composites, John D. Barber

Mechanical & Aerospace Engineering Theses & Dissertations

The aim of this dissertation was to study the effects of hot temperature compaction (HTC) upon the polymorphism and the mechanical behavior of an additively manufactured (AM), carbon fiber reinforced polyamide (PA6). Different pressure and temperature levels during HTC were tested to determine the overall effect upon the mechanical behavior and the material crystalline composition. Treated, carbon fiber reinforced PA6 samples were analyzed using differential scanning calorimetry, x-ray diffraction, thermogravimetric analysis, scanning electron microscopy, double cantilever beam testing and three-point bending testing. When considered with respect to as-printed samples, an HTC temperature of 190°C combined with 80 psi pressure resulted …

Distribution Comparisons Of Eac Cost Growth For Aircraft Work Breakdown Structure Elements, Kyle P. Marquis, Edward D. White, Brandon M. Lucas, Robert D. Fass, Jonathan D. Ritschel, Shawn M. Valentine

Faculty Publications

This article analyzes and investigates the distribution of cost growth of the Estimate at Completion (EAC) for the Work Breakdown Structure (WBS) elements of approximately 60 historical United States Acquisition Category I Research, Development, Test and Evaluation aircraft programs. Using the method of maximum likelihood in conjunction with the Akaike Information Criterion, the authors suggest that both the lognormal and Weibull distributions provide relatively good fit to EAC cost growth, with the lognormal slightly edging out the Weibull. As a summarized finding, the authors present their empirical results for the mean, coefficient of variation (CV), the 15th and 85th percentiles …

Amplification In Mems Rlc Circuits For Enhanced Sensitivity And Mems Applications, Mutaz Mohd Hamdi Al Fayad

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Micro-electro-mechanical systems (MEMS) have garnered significant attention due to their unique characteristics, including small size, high sensitivity, and cost-effective mass production. While electrostatic actuation offers low power consumption, it requires high voltage to move the MEMS structure, posing a challenge for applications such as RF switches and MEMS resonator-based sensors. Reducing the required input voltage for electrostatic MEMS remains a key research focus.

This thesis investigates voltage amplification in electrostatic MEMS through integration with resonant RLC circuits. By leveraging resonance, optimized configurations are designed to maximize voltage gain and enhance the signal-to-noise ratio. Through theoretical modeling and simulations using MATLAB …

Next-Generation Biomedical Implants And Stimuli Responsive Soft Optical Arrays Via Surface Functionalized Elastomeric Materials, John M. Kapitan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The demands of emerging technologies, such as soft robotics, stretchable electronics, and next generation biomedical implants, has led to the development of diverse polymeric and hybrid organic/inorganic materials specifically tuned to meet these challenges. These materials typically have low Young’s moduli and are inert with high chemical stability. However, this has led to materials that are static in nature, lacking any meaningful way of responding to changes in their environment and adapting to these changes. This has driven a shift towards the design, manufacturing, and characterization of various stimuli responsive surfaces, relying on precise control of surface chemical coatings and …

Enhancing Remote Sensing Imagery Temporal Resolution Using Starfm Data Fusion Approach For Improved Land Surface Monitoring, Ahmadreza Pourghodrat

School of Computing: Dissertations, Theses, and Student Research

High-resolution remote sensing imagery plays a critical role in various domains, such as farm-level agricultural operations, environmental monitoring, and natural resource management. However, data with high spatial resolution typically have low temporal resolution, and those with high temporal resolution often lack spatial detail. For example, Landsat 8 and 9 satellites deliver high spatial resolution images with a 30-meter pixel size but suffer from low temporal resolution, with a 16-day revisit cycle. In contrast, satellites like MODIS and VIIRS provide daily images but with a much coarser spatial resolution (375 meters or more), reducing spatial details. Additionally, there is a lack …

Analysis Of Responder-Involved Struck-By Crashes, Jacob Wilhelm

Doctoral Dissertations and Master's Theses

Emergency responders face significant risks of injury and death from struck-by crashes while operating on or near roadways. Annually, about 50 responders are killed, and hundreds more are injured, leading to operational disruptions and damage to life-saving equipment (ERSI, 2024). This study takes a data-driven approach to identify key risk factors and effective countermeasures for reducing the severity of struck-by crashes. Key findings indicate that struck-by crashes most frequently occur on weekends during late-night hours (2 AM–4 AM), often at crash scenes or disabled vehicle scenes on limited-access highways. Driver behavior – particularly “D” drivers (distracted, drugged, drowsy, disgruntled) – …

Dual Quaternions For Gravity Recovery Missions, Ryan Kinzie

Doctoral Dissertations and Master's Theses

A dual quaternion-based modeling, state estimation and control approach is introduced as a better alternative to the traditional methods which are currently utilized for gravity recovery missions. The proposed modeling and control approach was verified against and compared to the tangent bundle to Special Euclidean Group 3 through MATLAB simulations. The dual quaternion-based approach shows superior performance over traditional linearized and uncoupled methodologies, in both modeling accuracy of spacecraft translational position, and the ability to control the pose of a test mass relative to its host spacecraft. Utilizing data products from the Gravity Recovery and Climate Experiment Follow-On mission, a …

Exploring A Novel Adaptive Mesh Refinement Strategy For High-Speed Cfd, Arjun Jaishankar Vedam

Doctoral Dissertations and Master's Theses

Adaptive Mesh Refinement (AMR) techniques to efficiently and robustly achieve grid independent solutions on multi-element unstructured grids is a topic of practical interest within the CFD community.

The current effort focuses on the efficiency of a novel Adaptive Mesh Refinement (AMR) strategy that is developed and evaluated for transonic high-speed flows using Ansys Fluent. The algorithm for marking cells for adaptation is designed to systematically reduce local truncation errors based on the curvature of the primitive vector field. The algorithm for marking cells for adaptation is described in sufficient detail to be portable to other flow solvers that offer AMR. …

The Interaction Of A Transient Forward Axial Disturbance Flow With A Rotor, Zhuorui Li

Doctoral Dissertations and Master's Theses

This research presents an in-depth investigation of the aeroacoustic characteristics of a scaled-down Joby Aviation rotor, focusing on its performance under realistic conditions for urban air mobility (UAM). Utilizing a high-fidelity numerical simulation approach that combines Large-Eddy Simulation (LES) and Unsteady Reynolds-Averaged Navier-Stokes (URANS) models, the study effectively captures the complex aerodynamic and acoustic interactions inherent in rotor operations. Validation of the numerical framework was achieved through comprehensive comparisons with available experimental data, demonstrating a high level of accuracy in predicting both aerodynamic performance metrics, including thrust and torque, as well as acoustic emissions. The simulation revealed significant impacts resulting …

Aeroacoustics Applications To Jets And Rotors, Michael Marques G.

Doctoral Dissertations and Master's Theses

Aeroacoustics plays a critical role in the advancement of propulsion technologies for both conventional and emerging aerial systems. This dissertation investigates two key topics: noise suppression in supersonic rectangular jets and rotor noise characterization in hover and ground effect. Using high-fidelity numerical simulations and theoretical analyses, this research aims to develop effective noise mitigation strategies and improve predictive methodologies.

The first part of this study focuses on the reduction of noise in supersonic rectangular jets through active control techniques. A novel approach utilizing unsteady microjet actuation at the nozzle lip is explored to disrupt the formation of large-scale turbulent structures …

Experimental Investigation Of Heat Transfer To Tightly Packed Cylinder Arrays, Cameron M. Sexsmith

Doctoral Dissertations and Master's Theses

With the increased emphasis on the development of hybrid electric aircraft and other electric driven vehicles, the thermal demand on batteries is increasing. Unique to the aviation sector is the combined need of high battery thermal loads and a light-weight thermal management system. A proposed configuration is an array of batteries directly cooled with a dielectric coolant. The knowledge of heat transfer characteristics of battery cooling is becoming an ever pressing issue due to the need to optimize volume and mass in a safe manner. Tighter spacings between batteries provide higher pack densities, however, at the cost of increased cooling …

Modeling The Dynamics Of Flexible Aerospace Vehicles Using The Theory Of Functional Connections, Carlo Lombardi

Doctoral Dissertations and Master's Theses

Modeling and control of flexible vehicles is a topic of high interest in the aerospace field and a key challenge lies in finding accurate mathematical representations of the flexible dynamics of continuous elastic structures that allow simple integration into estimation and control algorithms. The answer was found in approximating the dynamics of these systems with sets of coupled Ordinary Differential Equations (ODE) for which a well-established estimation and control theory is available. Each of the techniques employed to achieve this goal is characterized by its own strengths and limitations. Hence, the main objective of this research is to develop the …

Machine Learning Methods For Hypervelocity Fragment Flyout Characterization, Katharine Larsen

Doctoral Dissertations and Master's Theses

Resulting from breakup events, such as collisions and explosions, hypervelocity fragments create potential hazards for both terrestrial and on-orbit environments, such as terrestrial weapons explosions and satellite breakup events, respectively. To avoid unnecessary damage, an accurate understanding or characterization of hypervelocity fragmentation events is vital. Currently, publicly available two-line elements collected from on-orbit breakup events are limited, excluding pre-detonation parent body conditions, such as orientation, and information of smaller fragments. The uncertainty of these datasets varies between each collected set. Therefore, the overall goal of this work is to employ machine learning to estimate distribution characteristics of a space debris …

On The Provenance Of Software Systems: Automating Software Traceability With Knowledge Graph And Large Language Model Synergy, Tyler Procko

Doctoral Dissertations and Master's Theses

The present dissertation delineates a system that enables those engaged in software development to automatically generate and maintain project life cycle provenance. All projects are implemented and made manifest with the development of artifacts, e.g., papers, code files, etc. Tools exist to accelerate artifact creation, but little focus is paid to the processes that produce them. In terms of Ontology, or, from Ancient Greek, the study of being, the two most basic entities in reality are Continuant and Occurrent, or, roughly, “Artifact” and “Process”. This dissertation posits that for any created artifact, its process of creation, i.e., its life …

Developing Fixed-Bias Langmuir Probes For Multi-Point Constellation Deployments, Henry Carter Valentine

Doctoral Dissertations and Master's Theses

Since their initial development in the early 20th century, electrostatic Langmuir probes have proved invaluable in terrestrial and interplanetary ionospheric sounding applications. When deployed aboard rocket and satellite platforms, these probes yield high-cadence, in-situ measurements of key plasma parameters such as electron density, ion density, and electron temperature. Furthermore, the efficacy of Langmuir probes in characterizing the three-dimensional structure and dynamics of ionospheric plasmas can be augmented by the technique of multi-payload deployments. In this work, we discuss the design, development, and analysis of fixed-bias Langmuir probes constructed for two multi-point science campaigns: the Mars-bound, dual-satellite Escape and Plasma Acceleration …

Analytical Dispatch Strategies For Pumped Storage Hydro: A Conditional Dynamic Programming Approach To Discontinuous Multi-Period Optimization Problems, Jian Liu, Jianwen Zhang, Zaiwu Gong, Donald C. Wunsch, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

The increasing integration of renewable energy sources like wind and solar poses significant challenges to secure and stable grid operation. Energy storage systems, particularly pumped storage hydro (PSH), play a crucial role in balancing power supply and demand. Traditional analytical studies of PSH economic dispatch problems often assume zero lower bounds for generating and pumping rates to simplify analysis and derive analytical solutions for multi-period optimization problems. However, the inherent mechanical design constraints of PSH require non-zero minimum flow rates for efficient operation. We analyze two scenarios, merchants having PSH only and merchants having both PSH and wind farms. In …

‘To Zero By Thirty-Five’ Geoexchange System Optimization, Andrew Moy , '25

Senior Theses, Projects, and Awards

Swarthmore College’s ’To Zero by Thirty Five’ project involves the construction of a geothermal exchange plant to provide heating and cooling to campus buildings. This report follows the implementation of the project and the impact of building envelopes on the effectiveness of the system. Groups of potential upgrades and their impacts on building performance were analyzed using integer linear programming and the PuLP python library. This analysis provides recommendations on which buildings to upgrade according to the priorities of Swarthmore College.

Silenttalk Final Report, Yihui Wu , '25

Senior Theses, Projects, and Awards

SilentTalk is a noninvasive communication system that uses ultrasound technology to detect and interpret silent speech by analyzing lip and facial movements. This E90 project presents the design, construction, and experimental evaluation of a speaker–microphone device capable of emitting and capturing ultrasonic waves in the 20–55 kHz range. Data wereadS collected under five distinct conditions, including various static mouth gestures, and analyzed using Root Mean Square (RMS) smoothing and Fast Fourier Transform (FFT) techniques. The results show that the distinct features in the time and frequency domains correspond to different mouth shapes, supporting the feasibility of silent gesture classification. A …

Using Software Defined Radio To Detect Human Life, John-William Cordero , '25

Senior Theses, Projects, and Awards

The goal of this project is to develop a device that uses software-defined radio to detect human biological activity through walls by detecting changes in the received signals depending on if a human is present or not. Such a device will help local survivors locate victims from being stuck under collapsed buildings and debris, as opposed to having to wait for search and rescue teams. By making a relatively low cost and easy to use device, a more practical application of human detection was developed. Results showed that while the device requires user interpretation to determine the presence of a …

Jigsaw Puzzle Solving Robot, Jeffrey Zhang , '25

Senior Theses, Projects, and Awards

Jigsaw puzzles are an exciting activity that people of all ages love to do. This project seeks to develop a robot capable of solving jigsaw puzzles. To do so, I took a preexisting CNC mill and assembled the mill except the spindle. The mill ran using G-code, a programming language I learned. From here I created a program that can move the arm of the mill to any point chosen, and can move up and down, as a proof of concept for the robot. On the puzzle solving side, I started by first taking high resolution scans of the backs …

Building A New System To Advance Vortex-Induced Vibration Energy Harvesting, Jacob Sherman , '25

Senior Theses, Projects, and Awards

When a cylindrical object is placed in a moving fluid of sufficiently high Reynolds number, vortices will form and be shed in the wake of the object. Vortex-Induced Vibrations (VIV) will occur on the cylinder when the frequency at which vortices are shed approached the natural frequency of the structure. Harvesting energy on a small scale from VIV is a promising new method of generating electricity from fluid motion, but more data is needed to investigate the parameter space for such a system [4]. The goal of this E90 project was to design and implement a robust system that could …

Analyzing The Resilience Of Infrastructure-Based Vs. Camera-Based Lane Detection In Autonomous Vehicles, Pritesh Yashaswi Patil

Masters Theses

Traditional autonomous vehicle perception subsystems that use on-board sensors have the drawbacks of high computational load and data duplication. Infrastructure-based sensors, which can provide high-quality information without the computational burden and data duplication, are an alternative to traditional autonomous vehicle perception subsystems. However, these technologies are still in the early stages of development and have not been extensively evaluated for lane detection system performance. Therefore, there is a lack of quantitative data on their performance relative to traditional perception methods, especially during hazardous scenarios, such as lane line occlusion, sensor failure, and environmental obstructions. This need is addressed by evaluating …

Co2 Utilization For Cementitious Materials - A Review, Seongho Han, Jae Hong Kim, Rohitashva Kumar Singh, Surendra P. Shah

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This review examines methods for utilizing CO₂ in construction materials to reduce the carbon footprint of cement and concrete production. Key approaches include direct carbonation of calcium silicates through CO₂ curing, use of industrial by-products as supplementary cementitious materials activated by carbonation, production of alternative binders and aggregates via CO₂ treatment of waste materials, injection of CO₂ into fresh concrete mixtures, and use of CO₂-dissolved mixing water. Both academic research and emerging commercial technologies are covered. While these methods show promise for enhancing material properties and sequestering CO₂, challenges remain in optimizing …

From Flames To Change: An Exploration Of Housing, Fire, And Inequity, Helen Underhill, Charles R. Jennings, Brian Meacham, Danielle Antonellis

Publications and Research

Housing and fire safety are deeply connected: inadequate and poorly maintained housing poses heightened fire risk for occupants. An individual or household’s housing situation (including limited or constrained choice) interacts with issues such as affordability, access, location, quality, safety, occupancy levels, tenure type, and resident or immigration status. These dynamics shape vulnerability, and inequity becomes most visible in the event of a fire. The extreme end of this spectrum includes the unhoused, who occupy structures entirely outside of regulatory systems with little or no fire protection.

On Generalization Across Environments In Multi-Objective Reinforcement Learning, Jayden Jing Xiang Teoh, Pradeep Varakantham, Peter Vamplew

Research Collection School Of Computing and Information Systems

No abstract provided.

Wind Tunnel Automation For Propeller Testing, David Ricardo Lara

Mechanical & Aerospace Engineering Theses & Dissertations

An automated propeller test capability for the ODU Low-Speed Wind Tunnel Facility is demonstrated; implementing automation improved both ease of testing and quality of results. An experiment was performed with and without automation to compare results. Prior to this effort, propeller RPM and airstream velocity were manually controlled, leading to time consuming experiments. The setpoint for RPM had to be adjusted at each run to compensate for changes in airstream velocity.

LabVIEW, a graphical programming software, was used to develop the controllers and automation algorithm. A Proportional Integral Derivative (PID) control approach was developed to simultaneously control airstream velocity and …