Engineering Commons^™

Optimizing Transportation Systems With Information Provision, Personalized Incentives And Driver Cooperation, Sayeeda Ayaz

Doctoral Dissertations

Poor performance of the transportation systems has many detrimental effects such as higher travel times, increased travel costs, higher energy consumption, and greenhouse gas emissions, etc. This thesis optimizes the transportation systems by addressing the traffic congestion problem and climate change impact resulting from the inefficient operation of these systems. I first focus on the key player of the transportation systems e.g., human being/traveler, and model travelers' route choice behavior with real-time information. In this study, I define looking-ahead behavior in route choice as a traveler's taking into account future diversion possibilities enabled by real-time information in a network with …

Modified Transient Hot-Wire Needle Probe For Experimentally Measuring Thermal Conductivity Of Molten Salts, Brian N. Merritt

Theses and Dissertations

Molten salts are high-temperature heat transfer fluids intended for cooling and/or storage purposes in a variety of energy applications. The current work seeks to ultimately study the thermophysical properties of fluoride and chloride salts, which are commonly considered for use in advanced nuclear reactors. Thermophysical properties like thermal conductivity are fundamental to ensuring safe, efficient, and competitive designs for advanced commercial nuclear reactors. Measurement challenges with liquid salts such as electrical conduction, corrosion, convection, and thermal radiation have hindered traditional approaches in their attempts to accurately quantify these properties at high temperatures. Here, a needle probe is developed, which modifies …

Development Of A Two-Axis Cyclic Loading Device For Mechanical Testing Of Glenoid Component Fixation, Cintya Tavares

Electronic Thesis and Dissertation Repository

The fundamental mechanism of aseptic glenoid component loosening, the rocking horse phenomenon, is a reaction to glenohumeral articular forces that are not centered on the component. While glenoid component loosening remains a problem, the underlying mechanisms that lead to fixation failure at the bone-component contact remain controversial. Several studies employing the ASTM F2028 technique have successfully recreated the rocking horse effect. However, no obvious strategy to decrease component loosening has been presented. This thesis investigates the behavior of forces that lead to component loosening on cyclically loaded components using three different protocols and testing apparatuses—a Stewart Platform, a cyclic loading …

Accelerating Multiparametric Mri For Adaptive Radiotherapy, Shraddha Pandey

USF Tampa Graduate Theses and Dissertations

MR guided Radiotherapy (MRgRT) marks an important paradigm shift in the field of radiotherapy. Superior tissue contrast of MRI offers better visualization of the abnormal lesions, as a result precise radiation dose delivery is possible. In case of online treatment planning, MRgRT offers better control of intratumoral motion and quick adaptation to changes in the gross tumor volume. Nonetheless, the MRgRT process flow does suffer from some challenges that limit its clinical usability. The primary aspects of MRgRT workflow are MRI acquisition, tumor delineation, dose map prediction and administering treatment. It is estimated that the acquisition of MRI takes around …

Spatiotemporal Changes Of Lagged Compound Dry And Wet Spells In The Northwest North America Under Climate Change, Reza Rezvani

Electronic Thesis and Dissertation Repository

Recently, an upsurge in the occurrence of hydroclimatic extremes and their temporal swings is observed in several regions around the world. Such transitions to the contrasting extremes such as the drought to flood in California (2016 – 17) has raised concerns about the increasing variability and rapid transitions between hydrological extremes and their associated compounding economic and environmental impacts. The intensification of the global hydrological cycle associated with climate change can further alter the drivers of such extremes and their interactions. Therefore, it is important to understand the characteristics of consecutive flood and drought events, including their spatiotemporal frequency and …

Adaptive Multi-Scale Place Cell Representations And Replay For Spatial Navigation And Learning In Autonomous Robots, Pablo Scleidorovich

USF Tampa Graduate Theses and Dissertations

Place cells are one of the most widely studied neurons thought to play a vital role in spatial cognition. Extensive studies show that their activity in the rodent hippocampus is highly correlated with the animal’s spatial location, forming “place fields” of smaller sizes near the dorsal pole and larger sizes near the ventral pole. Despite advances, it is yet unclear how this multi-scale representation enables navigation in complex environments.

In this dissertation, we analyze the place cell representation from a computational point of view, evaluating how multi-scale place fields impact navigation in large and cluttered environments. The objectives are to …

Design Of Stick-Framed Wood Roofs Under Extreme Wind Loads, Caspar Bain

Electronic Thesis and Dissertation Repository

Light-frame wood construction comprises nearly 90% of the housing industry in
Canada and the United States. The roofs of these houses can be constructed either
entirely on site or using prefabricated trusses. Assembling the roof structure on site,
otherwise known as stick-framing, is a framing technique with current code guidelines
that are based on past practice and limited consideration of wind loads. This makes
these roof structures susceptible to failure in high-speed wind events, such as tornadoes. Around 90% of all tornadoes in Canada fall in or below the EF-2 category,
making it a possible target for design of wood-frame …

Investigation Of Polymer Nanocomposites With Silicon Dioxide Fillers As Helium Cooled High-Temperature Superconducting Cable Dielectrics, Jordan Thomas Cook

Theses and Dissertations

In this thesis, three polymer nanocomposite configurations are fabricated for investigation as dielectrics in helium-cooled high-temperature superconducting (HTS) cables. Polyimide, polyamide, and polymethyl methacrylate are utilized as host polymers. The composite samples are synthesized through an in situ process, dispersing silicon dioxide nanoparticles throughout the polymer hosts. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to validate the synthesis of each composite configuration. Thin film samples of each configuration were also tested for their dielectric strength at both room (300 K) and cryogenic (92 K) temperatures. When going from room to cryogenic temperatures, all materials demonstrated a significant …

Numerical Investigations Of The Fluid Flow And Heat Transfer And Construction Of Control System For The Canadian Supercritical Water-Cooled Reactor Power Plant, Huirui Han

Electronic Thesis and Dissertation Repository

Canada participated in the Generation IV nuclear reactors with the Supercritical Water-Cooled Reactor (SCWR) concept. This work focuses on the numerical studies of the fluid flow and heat transfer of the supercritical water in the nuclear reactor fuel bundle, and the construction of the linear dynamic model and the design of the control system for the Canadian SCWR power plant.

Firstly, the fluid flow and heat transfer of the supercritical water in the vertical tube and the rod bundle is numerically investigated to evaluate whether the existing turbulent models could successfully caption the wall temperature variations at supercritical conditions by …

An Explicit Model For Simplified Flutter Analysis Of Long-Span Bridges, Tibebu Hunegn Birhane

Electronic Thesis and Dissertation Repository

The collapse of the First Tacoma Bridge in 1940 at a wind speed of about 18m/s triggered the need to recognize aerodynamic stability as a design constraint for long-span bridges. The advancement in understanding and modeling of dynamic wind effects has played a significant role in the realization of long-span bridges with a clear span of up to 2 km. However, the need to span longer, the risk of windstorms exceeding the strongest recorded in the past, and consequently, the quest for optimized design solutions continue to evolve.

A rigorous nature of aerodynamic stability analysis techniques poses a challenge to …

Improving Wireless Networking From The Learning And Security Perspectives, Zhe Qu

USF Tampa Graduate Theses and Dissertations

Due to the high development of wireless networking and artificial intelligence, most of the data are generated from mobile devices, which distribute in different environments. As such, how to improve the performance of machine learning-based networking and its security should be carefully considered. To reduce the communication burden and protect private information from users, Federated Learning (FL) is a possible solution for learning-based wireless networking. Although FL achieves much success until now, it also remains some specific issues to be solved. In this dissertation, we propose two FL wireless networking frameworks and discuss two potential security issues.

In the FL …

Tuning The Structural Properties Of Cellulose Acetate Thin Films: A Demonstration Of Confinement And Antiplasticization In Cellulose Acetate Butyrate, Keegan Reece Parkhurst

Graduate Theses - Chemical Engineering

No abstract provided.

Software Protection And Secure Authentication For Autonomous Vehicular Cloud Computing, Muhammad Hataba

Dissertations

Artificial Intelligence (AI) is changing every technology we deal with. Autonomy has been a sought-after goal in vehicles, and now more than ever we are very close to that goal. Vehicles before were dumb mechanical devices, now they are becoming smart, computerized, and connected coined as Autonomous Vehicles (AVs). Moreover, researchers found a way to make more use of these enormous capabilities and introduced Autonomous Vehicles Cloud Computing (AVCC). In these platforms, vehicles can lend their unused resources and sensory data to join AVCC.

In this dissertation, we investigate security and privacy issues in AVCC. As background, we built our …

Novel Texture-Based Probabilistic Object Recognition And Tracking Techniques For Food Intake Analysis And Traffic Monitoring, Robert Jacob Dibiano

LSU Doctoral Dissertations

More complex image understanding algorithms are increasingly practical in a host of emerging applications. Object tracking has value in surveillance and data farming; and object recognition has applications in surveillance, data management, and industrial automation. In this work we introduce an object recognition application in automated nutritional intake analysis and a tracking application intended for surveillance in low quality videos. Automated food recognition is useful for personal health applications as well as nutritional studies used to improve public health or inform lawmakers. We introduce a complete, end-to-end system for automated food intake measurement. Images taken by a digital camera are …

Development Of A Hybrid Stereotactic Guidance System For Percutaneous Liver Tumour Ablation, Joeana N. Cambranis Romero

Electronic Thesis and Dissertation Repository

Stereotactic Image-Guided Surgical Navigation System (IGSNS) supports percutaneous procedures by using medical imaging and tracking information, to assist the surgeons in the preprocedural planning and intraprocedural steps. This thesis describes the development of a stereotactic IGSNS for percutaneous liver tumour ablation, the goal of which is to assist in positioning the tip of the ablation applicator accurately to ensure complete tumour coverage. The main system improvement is the employment of a mini stereotactic patient-attach aiming device that is used as a pointer to ensure needle tip position prior to needle insertion. The thesis chapters describe the development and validation of …

Study Of Stochastic Market Clearing Problems In Power Systems With High Renewable Integration, Saumya Sakitha Sashrika Ariyarathne

Operations Research and Engineering Management Theses and Dissertations

Integrating large-scale renewable energy resources into the power grid poses several operational and economic problems due to their inherently stochastic nature. The lack of predictability of renewable outputs deteriorates the power grid’s reliability. The power system operators have recognized this need to account for uncertainty in making operational decisions and forming electricity pricing. In this regard, this dissertation studies three aspects that aid large-scale renewable integration into power systems. 1. We develop a nonparametric change point-based statistical model to generate scenarios that accurately capture the renewable generation stochastic processes; 2. We design new pricing mechanisms derived from alternative stochastic programming …

Cascadia Subduction Zone Earthquake Vertical Ground Acceleration Investigation And Potential Impact On Bridges In The Pacific Northwest, Rachel Caroline Bassil

Civil and Environmental Engineering Master's Project Reports

The effects of vertical ground accelerations during subduction zone earthquakes currently are not sufficiently understood. There are numerous case studies and evidence that effects of vertical ground accelerations can significantly impact the performance of bridges during a seismic event, but most previous research has been focused on shallow crustal earthquakes. Current bridge design codes provide little guidance for accounting for vertical ground accelerations in seismic design, in part because additional information is needed about the characteristics of vertical ground motions during Cascadia Subduction Zone (CSZ) earthquakes in the Pacific Northwest.

For this study, recorded seismic data from recent subduction zone …

Understanding Unsteady Corner Separation Within Wing-Body Junction Flows, Paul G. Winner

Doctoral Dissertations and Master's Theses

Wing-body junction flows, formed at the interface between a wing and fuselage surface, are a complex, coupled, three-dimensional, turbulent flow field. This thesis focused on the unsteady corner separation that develops at the trailing edge of this wing-body junction under certain conditions. A NACA 0015 wing mounted on a flat plate at an angle of attack of 13°was used as the model junction flow field. The wing had an aspect ratio of 8 with a linear washout twist of 15°. The Reynolds number based on the wing chord was Re_c = 4.5 × 10⁵. Time-dependent stereoscopic particle …

Heuristics For Capacity Allocation And Queue Assignment In Congested Service Systems With Stochastic Customer Demand And Immobile Servers, Adam Colley

Operations Research and Engineering Management Theses and Dissertations

We propose easy-to-implement heuristics for a problem referred to in the literature as the facility location problem with immobile servers, stochastic demand, and congestion, or the service system design problem. The problem is typically posed as one of allocating capacity to a set of M/M/1 queues to which customers with stochastic demand are assigned with the objective of minimizing a cost function composed of a fixed capacity-acquisition cost, a variable customer-assignment cost, and an expected-waiting-time cost. The expected-waiting-time cost results in a non-linear term in the objective function of the standard binary programming formulation of the problem. Thus, the solution …

Performance Analytics Of Cloud Networks, Derek Phanekham

Computer Science and Engineering Theses and Dissertations

As the world becomes more inter-connected and dependent on the Internet, networks become ever more pervasive, and the stresses placed upon them more demanding. Similarly, the expectations of networks to maintain a high level of performance have also increased. Network performance is highly important to any business that operates online, depends on web traffic, runs any part of their infrastructure in a cloud environment, or even hosts their own network infrastructure. Depending upon the exact nature of a network, whether it be local or wide-area, 10 or 100 Gigabit, it will have distinct performance characteristics and it is important for …

Histomechanical Compatibility Of Coronary Artery Bypass Grafts, Colton J. Kostelnik

Theses and Dissertations

Coronary artery disease is a localized form of atherosclerosis that can severely restrict blood flow to the heart often requiring a surgical intervention known as coronary artery bypass grafting (CABG) to reestablish perfusion to this essential circulation. To some extent, the selection of the autograft tissue is at the surgeon’s discretion with factors such as stenosis location and the existing tissue’s pathological state contributing to a choice that could be deterministic in surgical outcomes. Many post-operative complications and premature graft failures originate from graft-target tissue incompatibilities and altered blood flow patterns. We hypothesize that mechanical mismatching between the graft material …

Supporting The Discovery, Reuse, And Validation Of Cybersecurity Requirements At The Early Stages Of The Software Development Lifecycle, Jessica Antonia Steinmann

Doctoral Dissertations and Master's Theses

The focus of this research is to develop an approach that enhances the elicitation and specification of reusable cybersecurity requirements. Cybersecurity has become a global concern as cyber-attacks are projected to cost damages totaling more than $10.5 trillion dollars by 2025. Cybersecurity requirements are more challenging to elicit than other requirements because they are nonfunctional requirements that requires cybersecurity expertise and knowledge of the proposed system. The goal of this research is to generate cybersecurity requirements based on knowledge acquired from requirements elicitation and analysis activities, to provide cybersecurity specifications without requiring the specialized knowledge of a cybersecurity expert, and …

Functionality Of The Gracilis Collateral Is Impaired Following Arteriogenesis And Cell Transplantation, Ada A. Tadeo

Biomedical Engineering

Peripheral Arterial Disease involves narrowed arteries, reducing blood flow to limbs. Increasing blood flow to those extremities is possible by redirecting the blood to flow through natural bypasses (i.e. collateral arteries), which can enlarge via arteriogenesis to maintain blood supply once the prominent arteries have become occluded. This study aims to investigate how arteriogenesis affects collateral function, if myoblast transplantation can stimulate collateral growth, and how that in turn may affect collateral function. Femoral artery ligation was performed to mimic the blockage that occurs in patients with ischemic diseases on lean mice and mice with diet induced obesity (DIO). A …

A Hybrid Experimental-Computational Study: Prediction Of Flow Fields And Full-Field Pressure Distributions On Three-Tab Asphalt Roofing Shingles Subjected To Hurricane Velocity Winds, Troy A. Myers

Theses and Dissertations

A novel hybrid experimental-computational study is performed to predict the flow fields and pressure distributions on the measured shapes of flexible, three-tab asphalt roofing shingles undergoing increasing uplift when exposed to hurricane velocity winds. StereoDIC analysis is performed to measure the transient full-field deformed shapes of full-size three-tab asphalt shingles when subjected to hurricane velocity winds for two hours. Steady state computational fluid dynamics (CFD) simulations of the shingled roof facsimile-plenum region representative of the experiments are successfully performed. The simulations are performed to predict wind loading of the uplifted shingle shapes by utilizing the measured full-field three-dimensional uplifted shapes …

Effect Of Passive Clean Air Injection Into The Wake Region Of A Moving Ground Vehicle, Angelos Kaminis

Doctoral Dissertations and Master's Theses

The wake region on a moving ground vehicle is responsible for 70% of the aerodynamic drag when the speed of 90km/h is achieved. The topic of wake region manipulation has been revisited multiple times and with varying techniques. When manipulating the flow utilizing a fully passive method, pressure drag can be reduced, increasing the overall performance of the vehicle. To ensure high velocity fluid injection, a venturi shaped roof was implemented with an inlet size of 352mm x 12.7mm, and 2 outlets of size 88.011mm x 25.4mm resulting in an area of 4,470.959 for both inlet and outlet to maintain …

Wireless Coupled Feed Structure For Additively Manufactured Conformal Antennas, Blake Roberts

Doctoral Dissertations and Master's Theses

Due to advancements in additive manufacturing, it is possible to create electromagnetic devices that can be conformally printed directly onto 3D surfaces using conductive inks and dielectric pastes. Instance, the traditional antenna radomes that had the purpose of protecting the antenna on its inside can now become the antenna itself. With the components on the surface of the structure, instead of inside if it, a direct feed line would require cutting through dielectric layers and creating a direct electrical connection, also called vertical interconnect access (VIA). Such interconnects are frequent sources of failures, especially in applications that are subject to …

Improving Char Combustion Models Using Micro-Ct, Automated Image Analysis, And Pore-Resolving Simulations, Dongyu Liang

Dissertations (1934 -)

Combustion of pulverized coal and biomass in furnaces and boilers involves millions of particles with a distribution of sizes and morphologies. Because char particles typically react under zone II conditions, in which pore-diffusion and heterogenous reaction both influence the rate of conversion, the morphology of the porous particles affects reactor-scale outputs. To understand the impacts of complex morphology, 3-D pore-resolving simulations employing real char geometries obtained from high-resolution X-ray microtomography are first used to study combustion of 150 coal char particles and 30 biomass char particles. Localized reactant penetration into the innermost regions of the particles is observed, facilitated by …

Continuous Myoelectric Prediction Of Future Ankle Kinematics And Kinetics For The Control Of Active Powered Prostheses, Erika Virginia Zabre González

Dissertations (1934 -)

The purpose of this dissertation is to develop a continuous predictive model of gait that incorporates user intent, vis-à-vis surface electromyography (EMG) signals of the lower limb, to continuously predict future ankle kinematics and kinetics across multiple terrains and their transitions for the control of an active ankle-foot prosthesis. Continuously predicting variations in gait, particularly during transitions and noncyclic activities, is limited in lower limb prostheses. Despite performance improvements in active lower limb prostheses, there remains a need for robust and accurate control that incorporates direct user intent (e.g., myoelectric control) to limit physical and cognitive demands and provide more …

Quality-Of-Service Provisioning For Smart City Applications Using Software-Defined Networking, Basima Kurungadan

Theses

In the current world, most cities have WiFi Access Points (AP) in every nook and corner. Hence upraising these cities to the status of a smart city is a more easily achievable task than before. Internet-of-Things (IoT) connections primarily use WiFi standards to form the veins of a smart city. Unfortunately, this vast potential of WiFi technology in the genesis of smart cities is somehow compromised due to its failure in meeting unique Quality-of-Service (QoS) demands of smart city applications. Out of the following QoS factors; transmission link bandwidth, packet transmission delay, jitter, and packet loss rate, not all applications …

Experimental Investigations Of Yarn Pull-Out Behavior In Kevlar®: Influence Of Applied Metallic Coatings And Effect Of Dynamic Loading, Julie Ann Roark

Theses and Dissertations

Flexible woven Kevlar® textile fabrics are widely used in protective armor applications. Yarn pull-out, comprised of yarn uncrimping (i.e., straightening) and yarn translation, is a major energy absorption mechanism during ballistic impact onto these fabrics, especially for impact velocities below the ballistic limit. Yarn pull-out is influenced by various parameters including inter-yarn friction, pull-out distance, pull-out velocity, transverse pre-tension, fiber diameter, fabric architecture, fabric waviness, fabric count and yarn modulus.

The first part of this thesis investigates yarn pull-out behavior of commercially available Kevlar® KM2+ individual yarns coated with metallic layers (copper, aluminum, aluminum nitride, silver) via a directed vapor …