Engineering Commons^™

Leveraging Code Embeddings To Identify And Address Blind Spots In Benchmark Creation, Charles Moloney

School of Computing: Dissertations, Theses, and Student Research

Formal software verification remains critical for early vulnerability detection, yet benchmarking these tools is costly and often reliant on centralized datasets such as SV-COMP. While such repositories enable standardized evaluation, they introduce risks of overfitting and bias, particularly due to first-party benchmark contributions. To address these limitations, we extend ARG-V, our tool for generating SV-COMP-compatible benchmarks from real-world Java code, with a novel approach of using code embedding techniques to selectively sample from mined code. By leveraging Nomic Embed Code and a cosine-based Minimum Hyperspherical Energy (MHE) objective, we systematically select and transform benchmarks from scraped GitHub code that …

Design And Development Of A Passive Dust Protection System For Lunar Docking Operations, Simon Thengvall

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Lunar docking systems face a unique set of environmental conditions that can create significant challenges for mechanical design. Among these, the abrasive nature of lunar regolith can impair the kinematic function of traditional terrestrial mechanisms as well as contaminate critical spacecraft components such as environmental seals, causing them to fail. For crew-rated docking systems, failure of these systems not only threatens mission success, but also crew safety, so dust protection is crucial for docking components. To address the concerns of regolith intrusion, the Simple External Attachment for Lunar Openings (SEALO) is developed as a key architecture for mechanism evaluation when …

Dynamic Load Assessment Of Pem Fuel Cell Systems Under Pid-Based Control Strategies For Sustainable Operation, Tarek Abedin, Paw, Normy Norfiza Abdul Razak, Chen Chai Phing, Yaw Chong Tak, Monowar Mahmud, Manzoore Elahi M. Soudagar, T. M. Yunus Khan, Mohammad Tariqul Islam, Mohammad Nur-E-Alam

Research outputs 2022 to 2026

Proton exchange membrane fuel cell (PEMFC) systems’ reliable operation under variable load conditions is a significant challenge because of voltage fluctuations, transient variations, and the high computational requirements of sophisticated control techniques like intelligent and model predictive controllers. Even while these state-of-the-art methods provide great precision, complexity and cost often limit their real-time applicability, underscoring the need for a simpler but efficient control solution. To achieve effective voltage regulation in PEMFC systems, this study suggests a DC–DC buck converter in conjunction with a comparator-based proportional–integral–derivative (PID) control technique. In order to provide stable operation under both constant and changing load …

Thermo-Hydro-Chemical Coupled Numerical Modeling Of Hydrogen-Thermal Co-Development In Hydraulically Fractured Peridotite, Jiacheng Dai, Zhonglin Ma, Yunzhi Yue, Yujie Yuan, Shouceng Tian

Research outputs 2022 to 2026

Hydrogen generation through serpentinization reactions in peridotite formations under high temperature conditions represents a promising avenue for subsurface hydrogen production. However, the thermal energy in the formation environment have not been sufficiently considered. To integrate hydrogen production with thermal energy development, this study develops a thermo-hydro-chemical coupled numerical model, which is used to investigate hydrogen-thermal co-development in hydraulically fractured peridotite. Given that the hydrogen-thermal co-development process involves fluid flow, heat transfer and serpentinization reactions, the governing equations are formulated based on Darcy flow and energy conservation equations, with serpentinization kinetics incorporated through the reactive source terms. To evaluate hydrogen production …

3d-Printed Cf-Pla Bone Plates With Metamaterial Structures: Design, Fabrication, And Mechanical Evaluation, Ani Daniel, Hamed Bakhtiari, Alireza Nouri, Barun K. Das, Muhammad Aamir, Majid Tolouei-Rad

Research outputs 2022 to 2026

This study presents the design, fabrication, and mechanical performance of carbon fiber-reinforced polylactic acid (CF-PLA) bone plates incorporating auxetic and non-auxetic metamaterial architectures. Four lattice-structured bone plates (re-entrant, rotating square, tetrachiral, and hexagonal) were evaluated for their flexural, tensile, and compressive properties. The specimens were fabricated using Fused Deposition Modelling (FDM). The tetrachiral structure demonstrated superior bending capacity, achieving a flexural stress of 17 MPa and a modulus of 1214 MPa. Under both tension and compression, it exhibited the highest strength (24.5 MPa and 40 MPa, respectively) and stiffness (1441 MPa in tension and 2352 MPa in compression), while the …

Board-Level Operating System Infrastructure In Rust, Lydia Klaus

McKelvey School of Engineering Graduate Student Theses & Dissertations

Memory and multi-threading problems are the cause of many exploits and security vulnerabilities, and errors of this nature are easy to cause in programming languages such as C and C++. Despite this, these languages are still heavily used for systems programming and underpin the majority of operating system kernels. This is partially due to a lack of suitable replacements; however, Rust is becoming more prominent as an option for systems programming. This language features a much more stringent approach to memory and multi-threading safety. It also aims to support a wide range of hardware targets, including microcontrollers, which have long …

Side-To-Side Differences In Three-Dimensional Femoral Head Coverage Associated With Initial Symptom Development In Patients With Bilateral Developmental Dysplasia Of The Hip, Jiayi Sun

McKelvey School of Engineering Graduate Student Theses & Dissertations

Developmental dysplasia of the hip (DDH) is characterized by insufficient acetabular coverage of the femoral head and is a recognized cause of hip pain, instability, and early osteoarthritis. Although bilateral deformity is common, symptoms often first develop in only one hip. The purposes of this study were: (1) to determine whether, in patients with bilateral DDH, side-to-side differences in three-dimensional (3D) femoral head coverage vary according to radiographic symmetry defined by the lateral center-edge angle (LCEA); and (2) to determine whether hips that appear radiographically symmetric still demonstrate focal 3D asymmetry.

This retrospective imaging-based study included patients with bilateral DDH …

Analysis Of Oscillating Flow Over A 2-D Airfoil With Flow Reversal, Colter Couillard-Rodak

McKelvey School of Engineering Graduate Student Theses & Dissertations

Finite-state models are useful tools in modeling the aerodynamics of rotorcraft in flight simulators. 2-D and 3-D finite-state models have been developed and compared to closed form solutions, however these models are currently unable to handle situations where the freestream changes directions and the rotor re-enters its own wake. A 2-D finite state model was previously developed that includes a parameter that accounts for the change in free stream. This model, however, contains an inherent stability issue at the instant that the velocity changes direction.

The effects of this instability can be mitigated in certain flow conditions. A purely oscillatory …

Establishing Caenorhabditis Elegans As A Platform For Bioaccumulation And Selectivity Screening Of Anthelmintic Compounds, Jiarui Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

To address the cuticular barrier in anthelmintic discovery, this study establishes a bifurcated framework in Caenorhabditis elegans. First, HPLC-based quantification of 14 PIM inhibitors revealed that cuticular penetrance is primarily dictated by phylogenetic lineage (Clade V) rather than ecological niche. Specifically, C. elegans demonstrated a significant pharmacokinetic correlation with the hookworm Ancylostoma ceylanicum (Clade V) but not the whipworm Trichuris muris (Clade I), validating it as a superior surrogate model for hookworm bioaccumulation. Within this small molecule inhibitor library, SGI-12was identified as a lead candidate with superior potency against C. elegans and bioaccumulation. Second, target validation using a C. …

Multiscale Architecture Governs Stability In Suction-Actuated Variable Stiffness Catheters, Sheridan Lee

McKelvey School of Engineering Graduate Student Theses & Dissertations

Endovascular procedures require devices with widely varying mechanical properties: flexibility for navigating tortuous vessels and rigidity for stable therapeutic delivery. Suction-actuated variable stiffness sheaths address this challenge by incorporating axial wire string arrays that mechanically couple under suction to increase flexural rigidity. However, prototype devices achieve stiffening ratios below theoretical predictions, suggesting that interlayer mechanics and string positioning play a critical role. This study investigates whether interweaving polytetrafluoroethylene (PTFE) tape within the string array enhances flexural rigidity modulation and curvature stability. Prototype devices with varying wrap configurations were fabricated and evaluated using flexural testing, curvature stability testing, and mathematical modeling. …

Conditioning Hierarchical Diffusion Transformers On Rf Circuit Parameters, Ethan Morton

McKelvey School of Engineering Graduate Student Theses & Dissertations

As modern ML techniques have become increasingly advanced, they have begun to be integrated into wireless RF systems for classification, identification, and spectrum management. Deep Neural Networks (DNNs) enable RF system operators and designers to design more flexible systems with greater robustness to errors and attacks. However, neural networks require significant amounts of properly annotated data to train. Current data labeling methods lack the ability to obtain reliable true labels for circuit properties such as carrier frequency offset (CFO), power amplifier (PA) non-linearity, and in-phase/quadrature (IQ) imbalance. This thesis investigates the efficacy of a novel architecture, RF-Diffusion, for generating high-quality …

Data-Driven Multimodal Mri Representation Learning For Subtype Discovery And Disease Progression Modeling In Parkinson’S Disease, Zihan Zhou

McKelvey School of Engineering Graduate Student Theses & Dissertations

Parkinson’s disease (PD) exhibits substantial clinical and neuroanatomical heterogeneity, limiting robust patient stratification and clinically meaningful progression modeling from MRI. We propose a unified multimodal 3D generative representation-learning framework that learns an interpretable latent space from co-registered baseline T1/T2 MRI with an edge-aware channel. Confound-corrected latent embeddings support unsupervised subtype discovery, while disease duration provides weak supervision to orient a continuous progression axis. On an independent external cohort (PPMI, N=171), the discovery-trained subtype structure shows significant partial replication (ARI=0.35; permutation test p=0.001) and enables longitudinal clinical stratification: mixed-effects modeling reveals subtype-dependent MDS-UPDRS III progression, with the strongest effect in subtype …

Computational Fluid Dynamics (Cfd)-Based Performance Prediction Of Transcatheter Microvascular Plugs In Single-Ventricle Patients, Zhuhuan Zou

McKelvey School of Engineering Graduate Student Theses & Dissertations

Transcatheter palliation using fenestrated Modified Micro Vascular Plugs (MVP) has emerged as a promising, minimally invasive alternative to surgical pulmonary artery banding (PAB) for high-risk neonates with single-ventricle physiology. However, clinical applications are currently limited by the difficulty in predicting the resulting pulmonary-to-systemic flow ratio () and the lack of a standardized approach for selecting the optimal fenestration size. This study utilizes patient-specific computational fluid dynamics (CFD) to quantitatively evaluate the impact of varying fenestration diameters on circulatory balance. Patient-specific 3D models of the pulmonary artery (PA) were reconstructed from imaging data for two clinical cases using SimVascular. Transient CFD …

Role Of Directional Conditional Filtering On Droplet Velocity And Size Distribution, Farzad Hossain, Matthew J. Cleary, Yasir M. Al-Abdeli, Mehdi Khiadani

Research outputs 2022 to 2026

This study investigates the role of directional filtering in the analysis of spray behaviour using two full cone nozzles (65° and 75°) emitting aqueous sprays under atmospheric conditions. A hybrid computational–experimental framework was applied, using Large Eddy Simulation (LES) with Discrete Phase Model (DPM) and Rosin-Rammler distribution in ANSYS Fluent, validated against Shadowgraph and Particle Image Velocimetry (PIV) measurements. The sensitivity of directional filtering to the effects of spray angle and flow rate (1.75 and 3.5 L/min), were also done. Upward-filtered droplets consistently exhibited greater breakup than both raw and downward-filtered data due to gravitational opposition and longer air exposure. …

Engineered Uio-66-Nh2 Hybrid Nanocomposites For Antifouling Ultrafiltration Membranes With Dual Resistance To Microplastics And Protein Fouling, Mitra Golgoli, Mohadeseh Najafi, Javad Farahbakhsh, Masoumeh Zargar

Research outputs 2022 to 2026

The growing presence of microplastics (MPs) in water and their impact on ultrafiltration (UF) membranes during the early stages of wastewater treatment highlight the need for effective mitigation strategies. This study explores the innovative modification of UF membranes by incorporating various hybrid metal-organic frameworks (MOFs) nanoparticles, including UiO-66-NH2 hybrids with multi-walled carbon nanotubes (MWCNTs) (UiOM), chitosan (UiOC), and sulfobetaine zwitterions (UiOZ). These nanoparticles were synthesized and integrated into innovative UF membranes to compare their performance on MPs fouling effect in particular. The integration enhanced membrane hydrophilicity and altered surface roughness, creating a hydrophilic functional network that improved water permeability. Water …

Range Extension Of Electric Propulsion General Aviation Aircraft Using Solar Technology, Mary Kathryn Shultz

Theses and Dissertations

Alternative propulsion technologies in aviation have been a long-time topic of interest as operators aim to bypass growing fuel prices and meet environmental sustainability requirements set globally. Research regarding alternative propulsion technologies is primarily centered around marginally improving efficiency of combustion systems or large-scale implementation of novel technologies. This research evaluates the feasibility of implementing solar-integrated propulsion for general aviation aircraft to extend range through a comparison of full-electric, hybrid solar, and internal combustion engine propulsion systems. This evaluation of existing technology by range analysis indicates that hybrid solar‑electric propulsion is viable primarily for short‑range training and recreational aircraft, rather …

Reconfigurable Antennas Using Varactors On A Planar Parasitic Layer And Pin Diodes On A Dome Parasitic Layer, Andrew J. Hendricks

All Graduate Theses and Dissertations, Fall 2023 to Present

This research explores two types of reconfigurable, steerable antennas. These antennas change their beam direction based on electric input signals. The antennas have a layer that overlays the main antenna circuit board. The layer has small copper rectangles (pixels) that may be connected using either varactor diodes (which behave as voltage-controlled capacitors) or PIN diodes (electronic switches). The first antenna can steer in the xz-plane in any direction within about 23° from boresight (straight up from the antenna) and in the yz-plane to about 29° from boresight. The antenna uses varactor diodes on a planar layer. The second …

Freshwater Mussel Reintroduction And Recolonization Habitat Modeling Using Hydraulic, Sediment And Geomorphic Parameters, Megan Elizabeth Dinicola

All Graduate Theses and Dissertations, Fall 2023 to Present

Freshwater mussels are an important group of aquatic animals that live within the riverbed, but their populations have been drastically reduced by habitat alteration and other anthropogenic activities. In an effort to bolster populations, river managers and biologists are using mussel reintroductions as part of their restoration efforts but there are gaps in our understanding of where to reintroduce mussels within a river to see them create self-sustaining populations. This research helps shrink this gap by better understanding the physical habitat needs and population expansion potential of subadult freshwater mussels, or the size of mussel that hatcheries grow for reintroduction, …

Designing A Steel Bridge: A Structural Overview, Andrew Orr

Honors Theses

The American Society of Civil Engineers (ASCE) and American Institute of Steel Construction (AISC) host the Student Steel Bridge Competition (SSBC), a nation-wide competition where students design, fabricate, and construct a model bridge based on a provided rule set. A group of Arkansas State University civil engineering students participated in that competition in Spring 2026.

Extracting Wildfire Influence From Natural Streamflow Variability To Inform Post-Fire Peak Flow Predictions, Haley Anne Canham

All Graduate Theses and Dissertations, Fall 2023 to Present

Wildfire is a natural process, however, wildfire occurrence, severity, and size is increasing globally along with large storms. Despite the expectation that floods will be larger after wildfire, a large range in post-fire flood size has been observed. This creates challenges for emergency managers to prepare for flooding in areas where wildfire might occur. Aside from wildfire, many other factors influence the size of floods, making it difficult to isolate the influence of wildfire. This work finds that factors including wetter versus drier years and seasons can alter the size of a flood, effectively hiding the influence of wildfire. Additionally, …

Low-Cost Rf Exposure Monitoring With Tinyml Prediction, Sanad Sahawneh

Nanoscale Science & Engineering (discontinued with class year 2014)

The proliferation of wireless technologies has produced a dense, increasingly heterogeneous radio-frequency (RF) environment that surrounds modern life. While regulatory bodies such as the Federal Communications Commission (FCC) and the World Health Organization (WHO) maintain exposure guidelines, the tools that ordinary people, educators, and small institutions can use to actually observe RF exposure in their own spaces remain expensive, specialized, and largely confined to professional laboratories. Spectrum analyzers and calibrated field probes routinely cost between five hundred and one hundred thousand dollars per unit, placing continuous local monitoring out of reach for most environments where exposure questions are most natural …

An Experimental Study Of The Morphology Of Dna-Carbon Nanotube Hybrid Structures In Direct Dna Sequencing, Avery P. Davis

Biomedical Engineering Undergraduate Honors Theses

Hybrid structures formed between single-stranded DNA (ssDNA) and single-walled carbon nanotubes (SWCNT) have emerged as promising components in future direct DNA sequencing technologies due to their unique morphological and electronic properties. The nanoscale configuration of these hybrids, including the DNA wrapping angle, pitch, and contour behavior, directly influences their potential for stable electronic readout. This thesis presents an experimental study of DNA-SWCNT hybrid morphology using a fixed, reproducible wrapping protocol designed to minimize environmental variability and isolate the influence of DNA nucleotide sequence on hybrid structure. As described in prior work, this protocol produces well-dispersed hybrids suitable for high-resolution imaging. …

Porous Hydrophobic Adsorbent Coatings For Carbon Dioxide Capture, Samuel Babatunde Olushola

Theses and Dissertations

This work presents the development of a porous, hydrophobic zeolite 13X coating for the separation of carbon dioxide (CO₂) from flue gas or natural gas. Zeolite 13X was combined with yeast, glucose, and sodium alginate as pore-forming agents, and with polytetrafluoroethylene (PTFE) and Polydimethylsiloxane (PDMS) as hydrophobicity-inducing agents to enhance water resistance while maintaining CO₂ access to the adsorbent. The study explored PTFE/13X mass ratios ranging from 0 to 2.33 to investigate the interplay between hydrophobicity and CO₂ uptake. The wettability of the coating was characterized by using a temporal water contact angle (WCA) measurement. Increasing …

An Experimental Study On Turbine-Based Energy Harvesters For Thermal Underwater Gliders, Stephen Edward Coster

Theses and Dissertations

Buoyancy-driven underwater gliders have been optimized for long-duration missions primarily for continual monitoring of the ocean’s water column. However, longer missions and higher-powered sensors have increased the energy requirements of gliders. While current solutions aim to increase battery capacity, the development of energy-harvesting systems (EHMs) could greatly improve mission capabilities in both ability and duration. This thesis discusses the experimental testing of an underwater glider with an EHM as detailed in the theoretical study, “Development of a Turbine-Based Ocean Thermal Energy Harvesting Mechanism Applied to the Underwater Glider” by Hongbo Hou, PhD. The rear-mounted turbine captures energy using the kinetic …

A New Approach To Generate Combinatorial Patterns In Logical Analysis Of Data And Its Application To Predict College Retention, Salihah Ahmed E. Jaafari

Theses and Dissertations

Student retention and degree completion remain central challenges for higher-education institutions, with significant implications for student success, institutional effectiveness, and public accountability. While advances in predictive analytics have enabled earlier identification of students at risk of withdrawal, many commonly used machine learning approaches suffer from limited interpretability, constraining their practical usefulness for advising, intervention, and policy decision making. This dissertation addresses the problem of predicting student persistence by developing and evaluating optimization based, interpretable classification models within the Logical Analysis of Data (LAD) framework. Building on existing LAD formulations, this research introduces two novel pattern generation models, the Best Term …

Manned Exploration Of Satellites Of The Outer Planets: An Analysis Of Current Technologies And A Discussion Of Advancements Required, Joshua Carson Meador

Theses and Dissertations

The Solar System’s outer planets have many satellites, some of which are known to be the most likely places to find extraterrestrial life in our celestial backyard. Multiple scientific missions have been sent to glean information from these satellites, yet the possibility of a manned expedition has long been exclusive to science fiction stories. This paper intends to collect and analyze the current state of space travel technology to explore the feasibility of such a mission with modern technology and to discuss which future advancements should be the focal point for making such missions a reality. To begin, data on …

Aircraft Fault Detection Via Weight And Bias Analysis Of A Custom First Neural Network Layer, George Harrison Chen

Theses and Dissertations

Fault detection in aircraft is traditionally handled through redundant hardware and comparison algorithms to detect failures. Alternatives like model-based residual generation and data-driven approaches such as supervised fault classification and unsupervised anomaly detection have been explored, but they suffer from practical limitations; model-based methods require accurate system models, and data-driven methods have large constraints on the data limiting scalability and adaptability. This work presents a purely data-driven neural network architecture featuring a custom first layer designed for real-time fault detection where the weights and biases of this layer are used to detect faults. The network requires zero supervision and complements …

Hdra-Fusion: Hybrid Detection With Routed Architecture For Manipulation-Aware Ai Face Forgery Detection, Omar Ebeid

Theses and Dissertations

With the rapid advancements in artificial intelligence-based image generation and manipulation tools, it is extremely difficult to detect if an image is genuine or artificially crafted. Despite extensive research in this area, existing image detection systems suffer from three major problems: suboptimal cross-dataset generalization due to shortcut learning of dataset-specific patterns, unreliable probability estimates due to domain shift, particularly in cross-manipulation evaluation settings, and an inability to detect images manipulated by multiple types of manipulations within a single detection framework. To address these limitations, we propose HDRA-Fusion (Hybrid Detection with Routed Architecture), a framework built on the conclusion that different …

Design And Simulation Of Anti-Resonant Hollow-Core Fiber For Sensing Applications, Pravallika Kante

Theses and Dissertations

This thesis presents the design and simulation of an 8-tube single-ring anti-resonant hollow-core fiber for sensing applications, with particular emphasis on methane gas detection at the fundamental absorption wavelength of 3.3 µm. Conventional solid-core silica optical fibers exhibit strong multi-phonon material absorption beyond 2.5 µm, rendering them fundamentally unsuitable for efficient light guidance and direct gas sensing at mid-infrared wavelengths. Anti-resonant hollow-core fibers overcome this limitation by guiding light predominantly through an air-filled hollow core via the anti-resonant reflecting optical waveguide mechanism, in which the thin silica glass walls of the cladding tubes act as Fabry-Pérot etalons that confine the …

Moodify: A Mood-Based Music Recommendation System, Meghana Kagitha

Theses and Dissertations

Music has long been recognised as a powerful tool for emotional regulation, yet existing music streaming platforms often fail to align song recommendations with a user's current emotional state. Moodify is a mood-based music recommendation system designed to bridge this gap by delivering personalised playlists that reflect how a user feels in real time.

This project presents the design, development, and evaluation of Moodify, a mobile application that leverages the Circumplex Model of Emotion to capture user mood through an intuitive two-dimensional valence-arousal interface. Rather than relying on text input or manual search, users plot their emotional state directly onto …