Engineering Commons^™

Denoising Diffusion Probabilistic Models Based Accelerated Mri, Alexander Francis Bugielski

Theses and Dissertations

Magnetic Resonance Imaging (MRI) is a cornerstone in obtaining intricate visualizations of anatomy and physiological processes within the human body. However, its extensive scan duration not only causes patient discomfort but also increases the likelihood of motion-induced artifacts in the images. To address such a challenge, this study investigates deep neural network models for reconstructing high-resolution MRI images from noisy and significantly undersampled data in a supervised learning manner. Specifically, it compares three models: a conventional U-Net, a self-attentive U-Net, and an innovative probabilistic diffusion model that builds upon the self-attentive U-Net architecture. These models are evaluated on their ability …

Investigating Factors Influencing Blockchain Adoption In Saudi Healthcare Data Management, Noura Mohammad Alkhalifah

Theses and Dissertations

Blockchain technology can potentially address security and privacy issues concerning the collection, storage, and sharing of healthcare data. However, its adoption within the healthcare sector is nascent in Saudi Arabia. This underutilization prompted our investigation into the determinants influencing blockchain adoption, intending to fully empower the Saudi healthcare sector to leverage blockchain capabilities. To achieve this, an extensive literature review was conducted to identify the pivotal factors encompassing technology, organization, and environment (TOE) that affect the successful implementation of blockchain technologies in managing healthcare data within the Saudi context. Utilizing the TOE framework, this study formulated three hypotheses concerning the …

Deep Learning System Identification, Linearization And Control Of Dynamical Systems Utilizing Koopman Theory With Applications In Orbital Systems, George Mario Nehma

Theses and Dissertations

The computational and complexity burden of current linearization techniques is one that is a hinderance in the application of real world guidance, navigation and control systems. With the advancements in Deep Neural Networks, large data handling and Koopman Theory, the possibility of global linearizations of nonlinear systems is more prominent. This work demonstrates the capability of a Deep Neural Network learned Koopman operator to transform a nonlinear system into a Linear Time-Invariant system. The method presented is applied to both two purely dynamical systems and one controlled system to emphasize the ability for the technique to be applied in all …

The Advancement Of Experimental And Computation Tools For The Study Of Molten Salt Chemistry To Facilitate The Extraction Of Strategic Elements In Nuclear Applications, Michael Stoddard

Theses and Dissertations

Nuclear energy presents environmental benefits, yet the challenge of radioactive waste management persists. Advanced solutions, such as Molten Salt Reactors (MSRs), require a more profound understanding of molten salt chemistry. This research aims to develop tools, including a depletion simulator, molten salt electrochemical simulator, and a fluoride-based thermodynamic reference electrode for electrochemical purification. The computationally inexpensive depletion simulator allows for exploration into extraction and processing strategies for molten salt reactors. An illustrative case study on Mo-99 production from MSRs demonstrates the practical application of the theoretical framework, emphasizing the need for optimization in extraction effectiveness and separation difficulty. The electrochemical …

Development Of Deployable Arrays For Satellites Through Origami-Pattern Design, Modeling, And Optimization, Nathan Mckellar Coleman

Theses and Dissertations

This research presents methods for modeling and optimizing an origami design using compliant mechanisms, improving origami design processes, modeling and analyzing rolling behavior of compliant designs, and an antenna design for SmallSats. A framework for the optimization of the origami Flasher pattern to mitigate issues with rigid-foldability is shown, and several optimization solutions are presented to overcome these issues. An alternative design method is presented which allows designers to more accurately predict the characteristics of a design in the deployed state, and configurations are shown for an example use case. A model for rolled gossamer structures is presented which predicts …

Towards A Practical Method For Monitoring Kinetic Processes In Polymers With Low-Frequency Raman Spectroscopy, Robert Vito Chimenti

Theses and Dissertations

Unlike liquids and crystalline solids, glassy materials exist in a constant state of structural nonequilibrium. Therefore, a comprehensive understanding of material kinetics is critical for understanding the structure-property-processing relationships of polymeric materials. Amorphous materials universally display low-frequency Raman features related to the phonon density of states resulting in a broad disorder band for Raman shifts below 100 cm-1, which is related to the conformational entropy and the modulus. This disorder band is dominated by the Boson peak, a feature due to phonon scattering because of disorder and can be related to the transverse sound velocity of the material, and a …

Mineral Matter Behavior During The Combustion Of Biomass And Coal Blends And Its Effect On Particulate Matter Emission, Ash Deposition, And Sulfur Dioxide Emission, Rajarshi Roy

Theses and Dissertations

Combustion of coal is one of the primary sources of electricity generation worldwide today. Coal contains different chemicals that cause particulate matter(PM) and sulfur dioxide (SO2) emissions. These are health hazards and are responsible for deteriorating the ambient air quality. Particulate matter also forms ash deposits inside the coal combustor, which in turn decreases the energy efficiency of the power plants. Using biomass as a fuel in these utility boilers can potentially reduce the problems of particulate matter emissions and ash deposition, and can significantly reduce the SO2 emissions. However, biomass needs to be pretreated to make its properties similar …

Laboratory Evaluation Of Early-Age Concrete Comprising Type Il Cement And Natural Pozzolans, Battsagaan Ilch

Theses and Dissertations

The objective of this laboratory research was to investigate the effects of a higher water-cementitious materials ratio on selected properties of concrete mixtures comprising natural pozzolans. The scope of work included testing of six concrete mixtures, including one for each of three natural pozzolans at two water-cementitious materials ratios of 0.44 and 0.48 and one concrete mixture without pozzolan at a water-cementitious materials ratio of 0.44, which was treated as a baseline in this research. The stiffness and strength of each concrete mixture were measured at 1, 3, and 7 days using concrete specimens that were cast immediately after mixing. …

Development And Evaluation Of Full Performance-Based Procedures For The Estimation Of Liquefaction-Induced Building Settlement In A Non-Free-Field Condition Using Cumulative Absolute Velocity, Dallin Nathan Smith

Theses and Dissertations

Liquefaction induced settlement is an earthquake hazard engineers face when developing infrastructure. Current methods for estimating liquefaction induced settlement are done in a free field condition. This assumption is not an accurate way to describe the soil because in most cases the soil will bear some kind of infrastructure. Evaluation of liquefaction induced settlement in a non-free-field condition is a more appropriate way. Using the Bullock et al. CAV model, Bullock et al liquefaction induced settlement model, and probabilistic seismic hazard software from the USGS, a full performance-based procedure for the estimation of liquefaction-induced building settlement in the non-free-field condition …

User-Centered Design Of Compliant Mechanism And Origami-Based Products, Bethany Maria Parkinson

Theses and Dissertations

In user-centered design, the way users feel when interacting with products is taken under consideration in the design process. In this research, the user-centered design of compliant mechanism and origami-based products is explored. Examples of user-centered compliant mechanism and origami-based design projects are presented: first, for novel furniture designs, in which the safety, comfort, and visual aesthetics are important; and second, for compliant handheld dart launchers, where the feel of blaster actuation is taken into consideration. The feel of a product and a person's emotional response to it are important to products meant to be interacted with, but especially in …

Developing A Sql Injection Exploitation Tool With Natural Language Generation, Kate Isabelle Boekweg

Theses and Dissertations

Websites are a popular tool in our modern world, used daily by many companies and individuals. However, they are also rife with vulnerabilities, including SQL injection (SQLI) vulnerabilities. SQLI attacks can lead to significant damage to the data stored within web applications and their databases. Due to the dangers posed by these attacks, many countermeasures have been researched and implemented to protect websites against this threat. Various tools have been developed to enhance the process of detecting SQLI vulnerabilities and active SQLI attacks. Many of these tools have integrated machine learning technologies, aiming to improve their efficiency and effectiveness. Penetration …

Phosphorus Soprtion Experiments: Impacts On Water Column Phosphate Concentrations In Utah Lake, Rebecca Layne Butters

Theses and Dissertations

Utah Lake, located in north-central Utah, USA, is a freshwater lake with a large surface area, shallow depth, and phosphorus-rich sediment with significant water-sediment interaction. These factors cause unique phosphorus behavior relative to other lake ecosystems, governed by sediment-water interactions. We hypothesize that benthic sediments and suspended solids act, by sorption processes, to maintain water column P concentrations that are largely insensitive to P inflows. We conducted a Phosphorus Addition Experiment to characterize sorbed P fluxes in the lake. Our experimental procedure included bench-scale laboratory experiments testing Utah Lake water and sediment with dilute and augmented P levels, as well …

Development Of A Molten Salt Reactor Design And Design Framework For Overall Reactor Performance Prediction And Optimization, Andrew William Larsen

Theses and Dissertations

This dissertation introduces a novel approach to nuclear reactor design, emphasizing molten salt reactors (MSRs) to address the global need for safer, more efficient, and sustainable energy sources. It confronts the inherent challenges of nuclear fission reactors--proliferation risks, cost efficiency, waste management, and passive accident prevention--by developing an innovative MSR model and a machine learning (ML)-based optimization framework. The molten salt microreactor (MSMR), devised by researchers at Brigham Young University, utilizes thermally conductive plates for efficient heat dissipation during operational anomalies, ensuring safety within operational limits. This design was rigorously tested using STARCCM+ for fluid dynamics modeling and RELAP5-3D for …

Barriers To Contract Negotiation In Construction Projects And Strategies To Foster Trust, Luke Thomas Peterson

Theses and Dissertations

This study explores the impact of contract negotiation within construction projects by utilizing a modified Delphi approach, which integrates interviews alongside the traditional Delphi surveys. This methodology combines the structured feedback loop of Delphi surveys with the qualitative depth provided by interviews. This offers a more comprehensive understanding of contract negotiation dynamics in construction projects. It identifies systemic challenges as primary barriers to negotiation, highlighting the need for a cultural shift towards prioritizing negotiation and flexibility within the industry. The study reveals that time and cost considerations are relatively minor compared to interpersonal skills and trust-building. It cautions against damaging …

Transferable User-Friendly Machine Learning For Normal Boiling Point Prediction, Frank Tafadzwa Mtetwa

Theses and Dissertations

The estimation of thermophysical properties of chemical compounds holds considerable importance across a multitude of fields, ranging from material science to process design. Among these properties, the normal boiling point (NBP) stands out as a pivotal parameter in scientific and engineering contexts, as it elucidates the state of a substance under standard conditions commonly encountered in nature. Additionally, NBP is extensively documented in various reference materials and databases. Given its paramount importance and widespread availability, prediction methodologies for other properties such as critical temperature, liquid density, vapor pressure, surface tension, liquid viscosity, liquid thermal conductivity, and flash point often rely …

Mechanical Characterization Of Hemp, Jute, And Flax Based Natural Fibre Composites For Non-Structural Applications In Aircraft And Automobiles, Ravi Kumar B

Theses and Dissertations

Demand for reducing energy consumption and detrimental environmental impacts after the effective lifetime of an engineering material are the major driving factors for the development of natural fibre reinforced composites (NFRCs) in various sectors. Compared to synthetic fibre like carbon-fibres or Kevlar, natural fibres provide several benefits including light weight, inexpensive, recyclability, superior specific strength, biodegradable, non-toxic during handling, and less energy intensive during manufacturing. This doctoral work presents observations from mechanical tests and interpretations on the suitability of natural fibre reinforced composites for less heavily loaded engineering applications areas.

In the first stage, jute, flax, and hemp fibres were …

Methods For Finding Best Coset Codes For Physical-Layer Security, Andrew Glenn Swain

Theses and Dissertations

Finding best coset codes for secrecy over the binary erasure wiretap channel remains a difficult problem. Greater understanding of the structure of coset codes is necessary to reduce the problem space in which we search for these best codes. This dissertation presents new necessary conditions for a code to be best, including a condition that states that a code must maximize the minimum distance of both itself and its dual. It introduces and evaluates the accuracy of new heuristics to approximate the code's equivocation based on a code's weight enumerator polynomial. We also present a new tool for visualizing the …

Predicted Strength And Ductility Of Roof Truss Diaphragms With Tension-Only Rod Bracing And Hillside Washer Rod Connections, Emma Jean Brown

Theses and Dissertations

Metal buildings with roof truss diaphragms and tension-only rod bracing are a common structural system for single story industrial and commercial buildings. Despite the widespread use of metal building diaphragms in modern construction, there is limited knowledge on their strength and ductility under seismic loads. In this study, finite element models of diaphragm subassemblies and a full-size diaphragm were created to determine the strength and ductility of metal building diaphragms with tension-only rod bracing using hillside washer rod connections. Finite element models of two-tier diaphragm specimens that had been previously tested in the laboratory were created. Girders and purlins were …

High-Performance Concrete Comprising Silica Fume: Evaluation Of The Decommissioned Salt Lake City Airport Parking Structure, Trevor William Pratt

Theses and Dissertations

The objective of this research was to quantify the benefits of silica fume through a detailed investigation of the concrete decks within the now-demolished Salt Lake City International Airport parking structure, which was constructed in 1991, after it had been in service for almost 30 years. Several tests were performed to evaluate each of five areas within the parking structure. The results of field testing included data obtained from visual inspection, chain dragging, Schmidt hammer testing, and cover meter readings, while the results of laboratory testing included data obtained from chloride concentration, modulus of elasticity, electrical impedance, rapid chloride permeability, …

A Hybrid Communication System Using 5g Cellular And Ads-B For Uavs In High-Density Airspaces, Coulton Lee Karch

Theses and Dissertations

Robust communication is required to provide a safe airspace for the large numbers of unmanned aerial systems that are coming to the National Airspace System (NAS). This thesis explores methods for providing robust communication to large numbers of vehicles in the NAS. Automatic dependent surveillance-broadcast (ASD-B) is a transmission system that can transmit to and is currently required on all manned aircraft. Unfortunately, ADS-B suffers connectivity problems when supporting large numbers of unmanned aerial systems (UAS). The 5G Cellular protocol can support large numbers of UAS, but connectivity suffers with an increase in distance and interference. Using a 5G cellular …

Improving Wifi Sensor Network Security Through Unassociated Device Communication Using Wireless Latency Shift Keying, Jacob Edward Johnson

Theses and Dissertations

IEEE 802.11 (WiFi) only has two modes of trust--complete trust or complete untrust. The lack of nuance leaves no room for sensors that a user does not fully trust, but wants to connect to their network, such as a WiFi sensor. Solutions exist, but they require advanced knowledge of network administration. We solve this problem by introducing a new way of modulating data in the latency of the network, called Latency Shift Keying. We use specific characteristics of the WiFi protocol to carefully control the latency of just one device on the network. We build a transmitter, receiver, and modulation …

Gps-Denied Localization Of Landing Evtol Aircraft, Aaron C. Brown

Theses and Dissertations

This thesis presents a dedicated GPS-denied landing system designed for electric vertical takeoff and landing (eVTOL) aircraft. The system employs active fiducial light pattern localization (AFLPL), which provides highly accurate and reliable navigation during critical landing phases. AFLPL utilizes images of a constellation comprised of modulating infrared lights strategically positioned on the landing site, to determine the aircraft pose through the use of a perspective-n-point (PnP) solver. The AFLPL system underwent thorough development, enhancement, and implementation to address and demonstrate its potential in navigation and its inherent limitations. A proposed method addresses the limitations of AFLPL by using an extended …

Development Of Deep Neural Architecture For Continuous Sign Language Video Generation, Natarajan B

Theses and Dissertations

This dissertation presents a deep neural network based sign language video generation framework for translating the multilingual sentences into sign videos. This thesis addresses the challenges persist with the sign language video generation such as (i) Handling longer sequences of input sentences and new words (ii) Pose estimation with higher accuracy (iii) High quality photo realistic sign gesture video generation (iv) Improving realism in sign video generation. Hence, the thesis focuses four contributions to address the above issues.

The first contribution of this thesis automates the translation of multilingual sentences into sign glosses without manual intervention by incorporating Hybrid Neural …

Techno-Economic Analysis Of Solar Pv Systems Under Various Environmental Conditions, Ramkiran B

Theses and Dissertations

World Energy Council has predicted that the global electricity demand will peak in 2030. The need for renewable energy has grown rapidly due to the rising energy demand in this ever-growing population. Green house gas emissions are predominantly due to the energy generation and consumption of fossil fuels. On the other hand, fossil fuels supply nearly 74% of India's energy demand, making India one of the world's largest coal consumers.

According to World Resource Institute, India ranks fourth in the world in terms of carbon emissions. Investments in renewable energy sources and energy-saving technologies should be part of a solution …

Tunable Dual-Phase Dual-Drug Delivery System Using A Plga Microparticle/Pva Hydrogel Composite, Timothy John Eck

Theses and Dissertations

Current drug-eluting coatings have demonstrated controlled long-term, sustained release but have only tried to mitigate short-term burst release as a negative side effect. For applications like wound healing, there is a need for a drug-eluting coating which is adjustable in both short- and long-term release, independent of each other. We present a tunable dual-phase dual-drug delivery coating composed of drug-loaded polymer microparticles and drug-loaded hydrogel which can control short term and long term release individually in this study. This coating was created using lidocaine and dexamethasone encapsulated in poly(D,L-lactide-co-glycolide) particles combined with lidocaine- and dexamethasone-loaded poly(vinyl alcohol) hydrogel. Hydrogel drug …

Systems, Models, And Simulation For Novel Microfabrication Of Silicon Carbide And Metal Mesh Filters, Hunter R. J. Stevenson

Theses and Dissertations

As the boundaries of Moore's Law rapidly approach, research is increasingly turning to exotic materials and metamaterials to advance the capabilities of electronic and micromechanical systems. This thesis presents systems, models, and simulation techniques for novel microfabrication in the realms of silicon carbide (SiC) and metal mesh filters. Through the unification of femtosecond laser pulses, high numerical aperture (NA) objective lenses, and system power and motion control, a system capable of achieving arbitrary 3D features without line-of-sight with aspect ratios up to 109:1 in SiC is developed. Additionally, a model of a direct-write femtosecond-laser-ablation fabricated metal mesh filter (MMF) is …

Modified Coulomb Approach For Squat Silos, Mitchell Cade South

Theses and Dissertations

Traditional methods for calculating lateral pressures in silos, such as Janssen's Method and Coulomb's Method, have limitations due to the underlying assumptions of each methodology. This research investigates an approach which adapts Coulomb's Method to account for the cylindrical geometry of silos. The Silo Wedge Method (SWM) distinguishes between two cases based on the aspect ratio (height/diameter) of the silo. Comparative analysis reveals that the SWM accurately matches Coulomb's Method for linear retaining walls when the silo aspect ratio approaches zero. As the aspect ratio increases above 0.25, the SWM exhibits behavior similar to Janssen's Method. This suggests a potential …

Sustainability In Civil And Construction Engineering, Connotations, Paradigms, And Perceptions, Xiaomei Wang

Theses and Dissertations

Over the last four decades, the concept of sustainability has evolved significantly, gaining prominence since the Brundtland report in 1987. Operating at the intersection of built and natural environments, Civil and Construction Engineering (CCE) projects and designs inherently impact the natural surroundings. In this context, the concept of sustainability serves not only as a guiding principle to mitigate depletion but also as a pathway to achieving balance among diverse societal needs so every creature can survive and thrive. Despite considerable efforts in this domain, the definition of sustainability within the CCE discipline remains elusive. Paradoxically, the popularity and vagueness of …

Development Of Zr(Iv) Mof-Enabled Nerve Agent Electrochemical Hydrolysis Sensors, Tyler James Marlar

Theses and Dissertations

Nerve agents are acetylcholinesterase inhibitors and among the most toxic chemical warfare agents ever synthesized. Detection of these chemicals is critical for the protection of populations and strategic resources. G-series nerve agents are volatile compounds. V-series nerve agents are persistent phosphonothioate compounds. Persistent nerve agents do not readily volatilize and can contaminate environmental resources for extended periods. While nerve agents are inherently non-electroactive, they can be hydrolyzed to electroactive products compatible with electrochemical sensing. Zr(IV) MOFs are next-generation nanoporous materials, which have been shown to rapidly catalyze nerve agent hydrolysis. In this work, the catalytic processes of MOF-808, a specific …

Detection Of Endocrine-Disrupting Chemicals In Personal Care Products Using A Polyhedral Oligomeric Silsesquioxane-Based Hybrid Material, Aarthi K

Theses and Dissertations

Personal care products (cosmetics) are a diverse group of goods, that includes all the essential routines including the personal hygiene products used in our day-to-day life. It contains a variety of ingredients in its formulation, including preservatives, flavor, UV filters, and other additives. Few of the chemicals utilized are found to impair human health and have serious environmental impacts. The major chemicals include parabens, triclosan, oxybenzone, phthalates, heavy metals, fragrances, etc, Though the Scientific Committee on Consumer Safety (SCCS) has set the usage limits for the chemicals used, exposure to these chemicals from multiple products may exceed the exposure limit. …