Digital Commons Network^™

In Depth Analytics Of Vehicle-Vehicle And Vehicle-Pedestrian Conflicts Across Various Conditions, Qianqian Jin

Graduate Thesis and Dissertation post-2024

This study explores key traffic safety challenges by analyzing threshold discrepancies in rear-end conflicts under different weather conditions, conflict likelihood and severity at interconnected intersections, and interaction patterns between right-turning vehicles and pedestrians at signalized intersections. First, using CitySim trajectory data, the study examines the impact of weather conditions on surrogate safety measure (SSMs) thresholds for Modified Time to Collision (MTTC), Deceleration Rate to Avoid a Crash (DRAC), and Single-step Probabilistic Driving Risk Field (S-PDRF). Results indicate that MTTC and DRAC thresholds vary significantly under clear (2.3s v.s 3.0 m/s²) and rainy (4s v.s. 2.4 m/s²) conditions, whereas S-PDRF remains …

The Spray And Atomization Characteristics Of An Lrdre Injector, Samuel J. Schuetz

Graduate Thesis and Dissertation post-2024

The Ongoing effort to advance the Technology Readiness Level (TRL) of Rotating Detonation Engines (RDEs) has faced significant challenges with respect to the development of accurate analytical models for the performance of liquid fueled detonations. A key issue lies in the lack of comprehensive experimental data to validate and refine these models. To address this gap, the present study seeks to provide detailed characterization data on a specific Liquid Rotating Detonation Rocket Engine (LRDRE) injector, which can be leveraged to improve simulation accuracy and predictive capabilities. This investigation is divided into two primary phases. The first phase focuses on the …

Grid-Forming Inverters: Comprehensive Review, Design, And Implementation Of Advanced Control Methods, Yousef H. Abudyak

Graduate Thesis and Dissertation post-2024

The growing integration of renewable energy (RE) resources into power systems requires urgent measures by system operators to address stability challenges caused by the intermittency of such resources. GridForming (GFM) inverters have emerged as a promising solution to mitigate such grid instabilities. Their ability to establish and regulate voltage and frequency under various load and grid conditions makes them a potential alternative to Grid-Following (GFL) inverters, which are highly susceptible to loss of synchronism in grid conditions with low Short Circuit Ratios (SCRs). Numerous GFM control methods have been proposed in the literature, each addressing specific research gaps, however, several …

Application Of Industry 5.0 Attributes For Successful Implementation: Framework Of Manufacturing Excellence In Aerospace And Defense Industries, Rena Lewis

Graduate Thesis and Dissertation post-2024

As a novel concept, Industry 5.0 is making its rounds around the academic community and various industries. Despite its introduction over five years ago, definitions and perceptions are still under deliberation. Applications, methods of implementation and values are still in the conceptual phase. This study introduces a framework inclusive of human-centricity, sustainability and resilience, the pillars associated with Industry 5.0. It aims to differentiate the revolution from its predecessor, Industry 4.0, as it dives into the technologies associated with Industry 4.0 including but not limited to the Internet of Things (IoT), autonomous robots, and artificial intelligence. As those technologies evolve …

Patient Transfer Robot (Patro) For Mobility Independence Of Patients In Need Of Assistance, Eric W. Frankle

Graduate Thesis and Dissertation post-2024

This thesis is about the design, assembly, and testing of a prototype Patient Transfer Robot, or PATRO. The purpose of this device is to create and validate a mobile wheeled robot to motorize and automate the patient transfer process for use in home and hospital environments. This device aims to reduce the load and risk of injuries for caregivers during patient transfer process and to increase the autonomy and independence of the patient. While the idea of an automated patient transfer device is not a novel concept, PATRO aims to improve on existing designs by improving the safety, size factor, …

Quality 5.0 Management System Design: A Human-Centric And System Of Systems Approach, Johnson O. Olaitan Sr.

Graduate Thesis and Dissertation post-2024

This dissertation presents the Integrated Human-Techno Quality 5.0 System Management Framework (IHT-Q5.0MSF) as a solution to the fragmented and inflexible structures of Quality 4.0. The framework fosters synergy between human insight and technologies such as AI, IoT, and cloud-native systems, addressing adaptability, ethical governance, and sustainability within Industry 5.0. Using a mixed-methods approach, including the Delphi Method, system modeling, and empirical validation, the study identifies enablers, barriers, and strategic priorities for implementation. The results highlight the effectiveness of modular design, human-AI collaboration, and transparent deployment. IHT-Q5.0MSF offers a validated, scalable, and ethically guided system poised to advance quality management in …

Fundamental Breakup Mechanisms Of Micron-Scale Fuel Droplets Behind Hypersonic Shock Waves, Steven Schroeder

Graduate Thesis and Dissertation post-2024

The enhanced efficiency of pressure-gain combustion through detonation has fueled renewed research towards how liquid droplets atomize within a hypersonic shock-driven flow field. The heightened energy of post-hypersonic-shock flow compared to post-supersonic-shock flow leads to increased heating of the droplet, and faster phase change rate, which could potentially alter dominant breakup modes from mass loss via aerodynamic drag towards evaporation. As such, the displacement, deformation, and breakup timescales of various micron-scale liquid fuel droplets (RP-2, Jet A-1, and dodecane) behind hypersonic shocks were observed via high-speed 5 MHz shadowgraph imaging. The role of aerodynamic drag was quantified by modulating the …

Smart Work Zone Connectivity For Traffic Safety Applications, Mariam Nour

Graduate Thesis and Dissertation post-2024

Work zones play a vital role in the maintenance and upgrading of roads and highways; however, they also pose substantial risks to both drivers and workers. Utilizing technology, such as Smart Work Zones (SWZs), Connected Autonomous Vehicles (CAVs), and data dissemination algorithms, is crucial in improving safety in work zones by providing decision-makers with timely and accurate information. Ensuring safety in these environments is essential for reducing accidents and fatalities and enhancing drivers' sense of security, and protecting the well-being of workers operating in hazardous conditions. In this dissertation, we proposed a methodology based on three complementary approaches to enhance …

Emission Spectroscopy Measurements And Post-Processing Methods For Nitromethane And Aluminum In A Post Detonation Enviroment, Hamil Patel

Graduate Thesis and Dissertation post-2024

The doping of conventional liquid fuels has been a topic of interest in the research community due to the potential for increased energy density and improved performance in oxygen-deficient environments. One of these proposed fuels is nitromethane doped with micron-sized aluminum powder. This work is focused on early spectroscopic measurements of each of these constituent fuel parts in a post-detonation environment that aims to mimic the real-world temperatures and pressures seen in explosives that are not typically replicated in experimental facilities. Spectroscopy was chosen as the primary diagnostic technique for these experiments because it can non-invasively probe the relatively harsh …

Liquid Fuel Cloud Detonation Propagation And Dynamics, Taylor R. Brown

Graduate Thesis and Dissertation post-2024

Detonations are a form of combustion that produce significantly higher work per specific volume than traditional deflagration combustion, thus are an active area of interest for increased combustion efficiency and power generation. However, the highly unsteady nature of detonations complicates the ability to harness their energy in a fieldable technology, prompting the need for a more fundamental understanding of the detonation phenomena. Fundamental detonation research has overwhelmingly focused on gaseous reactants due to ease of experimentation, though liquid fuels are increasingly relevant as their high energy density makes them more suitable for real-world engine applications, and much of the research …

Laminar Burning Speed Of Dme-Hydrocarbon Mixtures, Ahmed F. Safdari

Graduate Thesis and Dissertation post-2024

Fossil fuels, when burned in the air, release large amounts of carbon dioxide (CO₂) and greenhouse gases (GHG) into the air, causing significant pollution. To reduce greenhouse gas emissions (CO₂, CO, and NOₓ), alternative fuels such as Dimethyl Ether (DME) are being explored for their potential to offer cleaner combustion solutions. This study investigates the laminar burning speed (LBS) DME blends with several alkanes and alkenes in air at atmospheric pressure (1 atm) across a wide range of equivalence ratios (Φ). LBS is essential for understanding combustion characteristics, including combustion efficiency, heat release rates, and chemical kinetics. Accurate …

3d Printing Of Ceramics With Masked Stereolithography (Msla) And Volumetric Printing Techniques, Nancy Zheng

Graduate Thesis and Dissertation post-2024

Ceramics have offered a variety of high temperature applications for extreme environments such as power generation, thermal protection systems, aero-prolusion, and space exploration. They possess high strength and modulus at high temperatures and inherent corrosion resistance. Recent advances in 3D printing allow manufacturing of ceramic structures with more intricate designs and multi-functionalities. In this study, the masked stereolithography (mSLA) technique was utilized to fabricate a thin, light weight, and compact counterflow ceramic heat exchanger. The slurry feedstock of alumina was selected for fabrication of the heat exchanger due to high heat resistance and tailorable thermal conductivity. Material characterization including SEM, …

Framework For A Successful Startup Using Lean Startup Methodology Within Ecosystem, Mohamed Elsalamy

Graduate Thesis and Dissertation post-2024

Entrepreneurs want to change the world by converting their business visions to reality. Their dreams are to provide and invent a solution for the society they created to fill a specific market gap that has an opportunity to profit, scale, and grow fast. Startup businesses are booming very progressive due to the boom in technology. However, what is the definition of a startup? What is this business, and what are its business and revenue models? What are the parameters for success and failure? Different thoughts and concepts for a startup are being designated by business professionals and through the media. …

Examination Of Users’ Privacy Issues In Live Streaming Information Disclosure, Yanlai Wu

Graduate Thesis and Dissertation post-2024

Live streaming has gained global popularity, raising significant privacy concerns due to its performance-driven, real-time, on-camera, and public nature. Increasing reports highlight privacy violations in live streaming, including streamers facing harassment from malicious viewers and bystanders being inadvertently exposed to audiences. Despite these challenges, research on privacy in live streaming remains limited. This dissertation addresses this gap by examining users' privacy concerns and strategies in information disclosure and exploring design solutions to enhance privacy management on live streaming platforms.

To achieve these objectives, I conducted three qualitative studies: two interview studies (Study 1: Chapter 4 and Study 2: Chapter 5) …

A Deep Learning Framework For Last-Mile Delivery Enhancement Using Social Media, Valeria Laynes Fiascunari

Graduate Thesis and Dissertation post-2024

Over the past decade, people have been spending more time online. Almost anything can be done from a laptop or cellphone. This is one of the reasons why e-commerce has been in a constant boom, as it is easier to buy something online and have it delivered to the front door than to go to the store. As more people engage in this activity, e-commerce platforms' challenges are more complicated and need to be addressed faster. However, these challenges escape the company's scope when external factors influence the objective of optimized deliveries, for example, traffic issues or bad weather during …

Multiscale Modeling And Experimental Evaluation Of Droplet Evaporation In High-Pressure Pulsed Spray Cooling For Thermal Management Applications, Fernando Soria Proano

Graduate Thesis and Dissertation post-2024

Droplet evaporation plays a vital role in spray cooling applications, helping to maintain safe operating temperatures for high-powered devices such as lasers and supercomputers. There exists an ongoing debate regarding the appropriateness of diffusion-limited versus kinetically limited models for describing this complex process. This work seeks to bridge the macro-scale evaporation, governed primarily by capillary forces, with the nano-scale interactions among the vapor, liquid, and solid phases through a comprehensive description of disjoining pressure.

By integrating principles from lubrication theory, heat conduction, diffusion, and statistical methods, a detailed model for evaporative mass flux is developed. This model incorporates various interactions, …

Algorithms And Benchmarking For Parallel Identity-By-Descent Segment Detection, Kecong Tang

Graduate Thesis and Dissertation post-2024

As genomic biobank initiatives continue to grow, the availability of large-scale genotype datasets, encompassing hundreds of thousands to millions of individuals, has transformed genetic research and biomedical discovery. However, the sheer volume of this data presents major computational barriers. Efficient and scalable methods are urgently needed to process and extract meaningful signals from biobank-scale data using modern multi-core architectures. One central task in this domain is the detection of identity-by-descent (IBD) segments, which underpins a range of applications including genealogical inference, disease mapping, phasing, and population structure analysis.

This dissertation addresses these challenges by presenting a sequence of contributions that …

Stress-Strain-Strength Behavior Of Florida Sands And Silty Sands, Sergio A. Marin Savatier

Graduate Thesis and Dissertation post-2024

Understanding the mechanical response of granular materials is fundamental to geotechnical engineering design. The presence of fines significantly influences the stress-strain-strength behavior, particularly when the material response is controlled by fines content. In this study, Florida sands were initially characterized by their grain distribution and particle morphology, while natural fines were evaluated according to their plasticity characteristics. Two materials were selected for detailed investigation: clean sands and a sand-fines mixture containing 20% fines, representing the threshold between coarse- and fine-dominated behavior. Constant rate of strain (CRS) consolidation tests were performed in both materials to study compressibility and effect of strain …

A Numerical Assessment Of Shock-Raindrop Interaction: An Investigation Of Cavitation Dynamics Driven By Internal Pressure Wave Focusing, Reed Forehand

Graduate Thesis and Dissertation post-2024

This dissertation investigates the formation and evolution of cavitation within liquid droplets subjected to shock wave interactions, with emphasis on internal pressure wave focusing as a fragmentation mechanism. A numerical framework is developed in which high-resolution Volume-of-Fluid (VoF) simulations resolve shock transmission into spherical, cylindrical, and cubic water droplets across a range of flow conditions. The resulting pressure histories at droplet centers are extracted and post-processed using the Rayleigh–Plesset equation to model the dynamics of spherical vapor bubbles.

The modeling framework is validated against established benchmarks, including canonical shock tube behavior, shock-droplet interaction studies, and experimental cavitation observations. A series …

Improving Vulnerable Road Users' Safety Through Computer Vision-Based Crossing Direction Prediction And Multimodal Large Language Model-Based Accident Scene Description, Younggun Kim

Graduate Thesis and Dissertation post-2024

Vulnerable Road Users (VRUs), such as pedestrians and cyclists, are among the most at-risk participants in traffic, making their safety a key priority for intelligent transportation systems (ITS). Accurate perception and understanding of VRU behavior are essential for proactive accident prevention and the design of human-centric mobility systems. Computer vision has become a core component of ITS, enhancing VRU safety. This thesis introduces a human behavior-aware transformer-based framework for VRU intention prediction and presents VRU-Accident, a large-scale benchmark enabling systematic assessment of multimodal large language models (MLLMs) in understanding accident scenarios involving VRUs.

First, the proposed framework leverages multi-modal cues, …

The Elliptical Instability In Turbulent Flows: A Mechanistic Framework, David M. Smerina

Graduate Thesis and Dissertation post-2024

The conveyance of energy through the formation, interaction, and destruction of eddies over a wide range of spatial scales, from the largest scale where energy is injected to the smallest scales where the energy is dissipated through viscosity remains one of the most fundamental unsolved problems in fluid mechanics. This dissertation provides a comprehensive investigation spanning multiple flow regimes consisting of high-speed reacting flows and transitional boundary layer turbulence to establish the necessary conditions for turbulent flows to sustain cascades of energy to arbitrarily small scales while demonstrating how the nonlinear development of the elliptical instability leads to the emergence …

Robust Actor-Critic Trajectory Optimization And Autonomous Harvesting Robot Integration, Luis R. Tituana

Graduate Thesis and Dissertation post-2024

This dissertation is organized into two parts. First, we develop a neural network–based constrained trajectory optimization algorithm with stability guarantees, along with a neural network–driven numerical error correction. The framework reformulates the structure of an optimal control problem as a neural network optimization problem, where the solution space lies on a subspace manifold generated by a bio-inspired motion rule that produces open-loop control commands. To address changing conditions, real-world disturbances, and numerical errors, we propose an Actor–Critic–like architecture. In this setup, the Actor network outputs the optimal open-loop control for the optimized trajectory, while the Critic network compensates for disturbances …

Detonation Morphology For Hypersonic Propulsion, Adam R. Kotler

Graduate Thesis and Dissertation post-2024

Standing detonations are uniquely stabilized in hypersonic flows. The portion of the detonation containing the stabilized shock front is remotely similar to non-reacting normal and oblique shocks and is uniquely differentiable from the latter by its coupling to a reaction front characterized by intense heat-release rates and fast chemical kinetics. The formation of an inert induction region characterized by slow-evolving chemical kinetics, subsequent development of a transition region within which these rates escalate, and terminal coalescence between shock wave and reaction front define the formation sequence of the standing detonation. Observations of this process are reported across multiple research groups. …

Removal Of Long- And Short-Chain Per- And Polyfluoroalkyl Substances From Surface Water Using Green Sorption Media–Nanofiltration Hybrid Processes, Md Touhidul Islam

Graduate Thesis and Dissertation post-2024

Per- and polyfluoroalkyl substances (PFAS) are a class of persistent environmental contaminants that pose significant risks to human health and aquatic ecosystems. This dissertation addresses the removal of both long- and short-chain PFAS from surface water through an integrated approach that combines green sorption media (GSM) with nanofiltration (NF). The research comprises laboratory-scale and field-scale studies designed to evaluate the effectiveness of novel recycled-material-based GSM formulations—namely, CPS and ZIPGEM—as pretreatment options to mitigate membrane fouling and enhance PFAS removal during NF. The study also investigates the adsorption mechanisms under varying water chemistry conditions, including pH, ammonia, and divalent cation concentrations. …

When Sediment Meets Strategy: Linking Shoaling Dynamics, Vessel Behavior, And Dredging Optimization, Matthew P. Davies

Graduate Thesis and Dissertation post-2024

Navigation channels are the economic arteries of U.S. maritime trade, yet their efficiency and safety are continually threatened by sedimentation and the escalating costs of dredging. Traditional tools used by the U.S. Army Corps of Engineers (USACE) to forecast shoaling and estimate dredging needs often fall short of capturing the complex interplay between channel condition, vessel behavior, and maintenance decisions. This dissertation develops and integrates three complementary innovations to address this challenge. First, a Parametric Linear Regression Methodology (PLRM) is introduced to improve shoaling predictions by blending long-term and short-term sedimentation rates with tunable weighting factors. This method achieves forecasting …

On Transient Dynamics And Persistent Organization Of Landscape Evolution, Aysan Hassanzadeh Bavojdan

Graduate Thesis and Dissertation post-2024

The evolution and organization of landscapes result from the competition between tectonic uplift, fluvial incision, and hillslope diffusion. Understanding how these processes interact under varying external conditions (i.e., extreme climatic events) is critical for predicting landscape dynamics and long-term geomorphic adjustment. Using a physically based landscape evolution model, we first investigate how variations in the fluvial incision coefficient (K) and soil diffusion coefficient (D) mimic different climatic conditions and control the transient and steady-state organization of landscapes. Results indicate that landscapes with the same non-dimensional index (defined as the ratio of the timescales of advective (fluvial) to diffusive (hillslope) processes) …

Study Of Injector Performance From An Accumulator-Based Plumbing System, Michael R. Benedict

Graduate Thesis and Dissertation post-2024

Accumulators are an alternative solution to pumps as they do not require energy in flight. This means power generated does not have to be diverted to an accumulator, boosting overall efficiency. Additionally, accumulators do not have pressure oscillations or cavitation risks typically associated with pump-driven systems. Further, they are lightweight systems with lower points of failure than traditional pumps. This makes them an interesting candidate for use in hypersonic flight. However, prior to flight data, accumulator-based systems should be tested statically on the ground to determine its feasibility. In this study, a piston accumulator is used in a plumbing system …

Thermal Characterization Of Cmc Materials Subjected To Deflagration And Detonation Process, Luis C. Longas

Graduate Thesis and Dissertation post-2024

Transition to greener fuels such as hydrogen is a process that requires developing several technologies. One of those is being able to develop materials that can withstand the higher temperatures of hydrogen combustion. One of the most promising materials are the ceramic matrix composites which could potentially replace the superalloys with thermal barrier coatings which are used in gas turbine engines. This project aims to characterize a ceramic matrix composite manufactured by Polymer Infiltration and Pyrolysis process. The characterization of the material would be done under deflagration and detonation operating conditions. This study would pave the way for the development …

A Predictive Model Of Adsorption Of Cryogenic Liquids In Aerogel-Based Materials, Julie E. Foroosh

Graduate Thesis and Dissertation post-2024

Commodities that are gaseous at standard temperature and pressure are generally stored in thick-walled pressure vessels, or as cryogenic liquids in vacuum-jacketed tanks. An advantage of cryogenic storage is that more mass can be stored per unit volume. However, cryogenic tanks are often bulky and cannot be made into conformal geometries. Adsorption storage in porous and flexible materials, such as aerogel blankets, is a promising method for storing these commodities. Previous studies have shown that when the commodity is adsorbed from the liquid cryogen, instead of from a gaseous state, the mass adsorbed per unit volume of aerogel blanket is …

Modeling And Predicting The Thermal Behavior Of Si/Cnt Nano Composites Using Pinns, Olamide Osigbemeh

Graduate Thesis and Dissertation post-2024

Silicon/Carbon Nanotube (Si/CNT) composites have shown great performance as Thermal Interface Materials (TIMs) for cooling in advanced electronics. The heat transfer in these materials is highly influenced by the interfacial thermal resistance (ITR) at the interfaces between the CNT filler and the silicon matrix. The ITR poses a critical challenge that hinders the design and performance of the TIM. This research designs a Physics Informed Neural Network (PINN) that predicts the thermal behavior of Si/CNT through a forward and inverse solver since they are known networks in solving complex partial and ordinary differential equations. However, despite the advantages of PINNs, …