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Computational Fluid Dynamics Investigation Of The Orientation Of A Pediatric Left Ventricle Assist Device Cannula To Reduce Stroke Events, Stephen Guimond
Computational Fluid Dynamics Investigation Of The Orientation Of A Pediatric Left Ventricle Assist Device Cannula To Reduce Stroke Events, Stephen Guimond
HIM 1990-2015
Ventricle Assist Devices (VADs), which are typically either axial or centrifugal flow pumps implanted on the aortic arch, have been used to support patients who are awaiting cardiac transplantation. Success of the apparatus in the short term has led to long term use. Despite anticoagulation measures, blood clots (thrombi) have been known to form in the device itself or inside of the heart. The Ventricle Assist Devices supply blood flow via a conduit (cannula) implanted on the ascending aorta. Currently, the implantation angle of the VAD cannula is not taken into consideration. Since the VADs supply a significant amount of …
Imitating Individualized Facial Expressions In A Human-Like Avatar Through A Hybrid Particle Swarm Optimization - Tabu Search Algorithm, Evan Husk
HIM 1990-2015
This thesis describes a machine learning method for automatically imitating a particular person's facial expressions in a human-like avatar through a hybrid Particle Swarm Optimization - Tabu Search algorithm. The muscular structures of the facial expressions are measured by Ekman and Friesen's Facial Action Coding System (FACS). Using a neutral face as a reference, the minute movements of the Action Units, used in FACS, are automatically tracked and mapped onto the avatar using a hybrid method. The hybrid algorithm is composed of Kennedy and Eberhart's Particle Swarm Optimization algorithm (PSO) and Glover's Tabu Search (TS). Distinguishable features portrayed on the …
Characterization Of An Advanced Neuron Model, Christopher Echanique
Characterization Of An Advanced Neuron Model, Christopher Echanique
HIM 1990-2015
This thesis focuses on an adaptive quadratic spiking model of a motoneuron that is both versatile in its ability to represent a range of experimentally observed neuronal firing patterns as well as computationally efficient for large network simulation. The objective of research is to fit membrane voltage data to the model using a parameter estimation approach involving simulated annealing. By manipulating the system dynamics of the model, a realizable model with linear parameterization (LP) can be obtained to simplify the estimation process. With a persistently excited current input applied to the model, simulated annealing is used to efficiently determine the …
Adding Cerebral Autoregulation To A Lumped Parameter Model Of Blood Flow, Russell Gentile
Adding Cerebral Autoregulation To A Lumped Parameter Model Of Blood Flow, Russell Gentile
HIM 1990-2015
A mathematical model of blood flow in infants with hypoplastic left heart syndrome (HLHS) was improved by adding cerebral autoregulation. This is the process by which blood vessels constrict or dilate to keep blood flow steady in certain organs during pressure changes. The original lumped parameter model transformed the fluid flow into an electrical circuit. Its behavior is described using a system of thirty-three coupled differential equations that are solved numerically using a fourth-order Runge-Kutta method implemented in MATLAB. A literature review that includes a discussion of autoregulation mechanisms and approaches to modeling them is followed by a description of …
Identification Of Spatiotemporal Nutrient Patterns And Associated Ecohydrological Trends In The Tampa Bay Coastal Region, Brent Wimberly
Identification Of Spatiotemporal Nutrient Patterns And Associated Ecohydrological Trends In The Tampa Bay Coastal Region, Brent Wimberly
HIM 1990-2015
Improvements for environmental monitoring and assessment were achieved to advance our understanding of sea-land interactions and nutrient cycling in a coastal bay.; The comprehensive assessment techniques for monitoring of water quality of a coastal bay can be diversified via an extensive investigation of the spatiotemporal nutrient patterns and the associated eco-hydrological trends in a coastal urban region. With this work, it is intended to thoroughly investigate the spatiotemporal nutrient patterns and associated eco-hydrological trends via a two part inquiry of the watershed and its adjacent coastal bay. The findings show that the onset of drought lags the crest of the …
Denial Of Convenience Attack To Smartphones Using A Fake Wi-Fi Access Point, Erich Dondyk
Denial Of Convenience Attack To Smartphones Using A Fake Wi-Fi Access Point, Erich Dondyk
HIM 1990-2015
In this thesis, we consider a novel denial of service attack targeted at popular smartphone operating systems. This type of attack, which we call a Denial of Convenience (DoC) attack, prevents non-technical savvy victims from utilizing data services by exploiting the connectivity management protocol of smartphones' operating systems when encountered with a Wi-Fi access point. By setting up a fake Wi-Fi access point without Internet access (using simple devices such as a laptop), an adversary can prompt a smartphone with enabled Wi-Fi features to automatically terminate a valid mobile broadband connection and connect to this fake Wi-Fi access point. This, …
Fabrication And Transport Studies Of N-Type Ofets Using Aligned Array Carbon Nanotubes Electrodes, Edwards Jimenez
Fabrication And Transport Studies Of N-Type Ofets Using Aligned Array Carbon Nanotubes Electrodes, Edwards Jimenez
HIM 1990-2015
We present fabrication of n-type organic field effect transistors (OFETs) using densely aligned array carbon nanotube (CNT) electrodes. The CNTs were aligned with a high linear density via dielectrophoresis (DEP) from an aqueous solution. In order to fabricate the CNT electrodes, aligned CNTs were cut by using electron beam lithography (EBL) and precise oxygen plasma etching. The n-type OFETs were fabricated in a bottom-contact configuration by depositing a thin film of C60 molecules between the CNT source and drain electrodes, and compared against a controlled C60 OFET with gold electrodes. The electron transport measurements of the OFETs using CNT electrodes …
Vertical Field Switching Blue Phase Liquid Crystals For Field Sequential Color Displays, Hui-Chuan Cheng
Vertical Field Switching Blue Phase Liquid Crystals For Field Sequential Color Displays, Hui-Chuan Cheng
Electronic Theses and Dissertations
Low power consumption is a critical requirement for all liquid crystal display (LCD) devices. A field sequential color (FSC) LCD was proposed by using red (R), green (G) and blue (B) LEDs and removing the lossy component of color filters which only transmits ~30% of the incoming white light. Without color filters, FSC LCDs exhibit a ~3X higher optical efficiency and 3X higher resolution density as compared to the conventional color filters-based LCDs. However, color breakup (CBU) is a most disturbing defect that degrades the image quality in FSC displays. CBU can be observed in stationary or moving images. It …
Systems Analysis For Urban Water Infrastructure Expansion With Global Change Impact Under Uncertainties, Cheng Qi
Electronic Theses and Dissertations
Over the past decades, cost-effectiveness principle or cost-benefit analysis has been employed oftentimes as a typical assessment tool for the expansion of drinking water utility. With changing public awareness of the inherent linkages between climate change, population growth and economic development, the addition of global change impact in the assessment regime has altered the landscape of traditional evaluation matrix. Nowadays, urban drinking water infrastructure requires careful long-term expansion planning to reduce the risk from global change impact with respect to greenhouse gas (GHG) emissions, economic boom and recession, as well as water demand variation associated with population growth and migration. …
Evaporation, Precipitation Dynamics And Instability Of Acoustically Levitated Functional Droplets, Abhishek Saha
Evaporation, Precipitation Dynamics And Instability Of Acoustically Levitated Functional Droplets, Abhishek Saha
Electronic Theses and Dissertations
Evaporation of pure and binary liquid droplets is of interest in thermal sprays and spray drying of food, ceramics and pharmaceutical products. Understanding the rate of heat and mass transfer in any drying process is important not only to enhance evaporation rate or vapor-gas mixing, but also to predict and control the final morphology and microstructure of the precipitates. Acoustic levitation is an alternative method to study micron-sized droplets without wall effects, which eliminates chemical and thermal contamination with surfaces. This work uses an ultrasonic levitation technique to investigate the vaporization dynamics under radiative heating, with focus on evaporation characteristics, …
Bst-Inspired Smart Flexible Electronics, Ya Shen
Bst-Inspired Smart Flexible Electronics, Ya Shen
Electronic Theses and Dissertations
The advances in modern communication systems have brought about devices with more functionality, better performance, smaller size, lighter weight and lower cost. Meanwhile, the requirement for newer devices has become more demanding than ever. Tunability and flexibility are both long-desired features. Tunable devices are ‘smart’ in the sense that they can adapt to the dynamic environment or varying user demand as well as correct the minor deviations due to manufacturing fluctuations, therefore making it possible to reduce system complexity and overall cost. It is also desired that electronics be flexible to provide conformability and portability. Previously, tunable devices on flexible …
Multi-Level Safety Performance Functions For High Speed Facilities, Mohamed Ahmed
Multi-Level Safety Performance Functions For High Speed Facilities, Mohamed Ahmed
Electronic Theses and Dissertations
High speed facilities are considered the backbone of any successful transportation system; Interstates, freeways, and expressways carry the majority of daily trips on the transportation network. Although these types of roads are relatively considered the safest among other types of roads, they still experience many crashes, many of which are severe, which not only affect human lives but also can have tremendous economical and social impacts. These facts signify the necessity of enhancing the safety of these high speed facilities to ensure better and efficient operation. Safety problems could be assessed through several approaches that can help in mitigating the …
Resilience Of Bridges Following Aftershocks, Diego Francisco Espinosa
Resilience Of Bridges Following Aftershocks, Diego Francisco Espinosa
Electronic Theses and Dissertations
The ability to predict the reduction in capacity of a structure after an earthquake is vital in the process of assessing a structure after a main-shock or an after-shock. Main-shocks are normally followed by a few aftershocks in a short period of time. Researchers in the past have focused for the most part on the effects of main-shocks on buildings. Very little research has been performed on the ability to predict the reduction in capacity of bridges in aftershocks. This thesis focuses on providing a way of assessing the reduction in capacity for main-shocks as compared to aftershocks and the …
Structural Identification Through Monitoring, Modeling And Predictive Analysis Under Uncertainty, Hasan Burak Gökçe
Structural Identification Through Monitoring, Modeling And Predictive Analysis Under Uncertainty, Hasan Burak Gökçe
Electronic Theses and Dissertations
Bridges are critical components of highway networks, which provide mobility and economical vitality to a nation. Ensuring the safety and regular operation as well as accurate structural assessment of bridges is essential. Structural Identification (St-Id) can be utilized for better assessment of structures by integrating experimental and analytical technologies in support of decision-making. St-Id is defined as creating parametric or nonparametric models to characterize structural behavior based on structural health monitoring (SHM) data. In a recent study by the ASCE St-Id Committee, St-Id framework is given in six steps, including modeling, experimentation and ultimately decision making for estimating the performance …
Evaluation Of Biosorption Activated Media Under Roadside Swales For Stormwater Quality Improvement And Harvesting, Andrew Charles Hood
Evaluation Of Biosorption Activated Media Under Roadside Swales For Stormwater Quality Improvement And Harvesting, Andrew Charles Hood
Electronic Theses and Dissertations
Stormwater runoff from highways is a source of pollution to surface water bodies and groundwater. This project develops a bio-detention treatment and harvesting system that is incorporated into roadside swales. The bio-detention system uses Bold & Gold™, a type of biosorption activated media (BAM), to remove nutrients from simulated highway runoff and then store the water in underground vaults for infiltration, controlled discharge, and/or irrigation and other non-potable applications. In order to design a bio-detention system, media characteristics and media/water quality relationships are required. Media characteristics determined through testing include: specific gravity, permeability, infiltration, maximum dry density, moisture content of …
Numerical Study On Reinforcement Mechanism Of Copper/Carbon Nanotubes Composite, Xiang Long
Numerical Study On Reinforcement Mechanism Of Copper/Carbon Nanotubes Composite, Xiang Long
Electronic Theses and Dissertations
Because of its high stiffness, carbon nanotubes (CNTs) are considered as one of the widely used reinforcement materials in the metal matrix composites. In this thesis, finite element (FE) models were built in Ls-Dyna3D to simulate Copper/CNTs composite deformation and fracture, and to explore CNTs reinforcement mechanisms. Several possible mechanisms were discussed. Deformation and failure of Cu/CNT composites were studied numerically using unit cell FE models, which consist of both metal matrix and CNTs. The simulation results have been verified by existing experiment data reported by Chen’s group. The matrix material was modeled as elasto-plastic ductile solids. The CNTs material …
State (Hydrodynamics) Identification In The Lower St. Johns River Using The Ensemble Kalman Filter, Hitoshi Tamura
State (Hydrodynamics) Identification In The Lower St. Johns River Using The Ensemble Kalman Filter, Hitoshi Tamura
Electronic Theses and Dissertations
This thesis presents a method, Ensemble Kalman Filter (EnKF), applied to a highresolution, shallow water equations model (DG ADCIRC-2DDI) of the Lower St. Johns River with observation data at four gauging stations. EnKF, a sequential data assimilation method for non-linear problems, is developed for tidal flow simulation for estimation of state variables, i.e., water levels and depth-integrated currents for overland unstructured finite element meshes. The shallow water equations model is combined with observation data, which provides the basis of the EnKF applications. In this thesis, EnKF is incorporated into DG ADCIRC-2DDI code to estimate the state variables. Upon its development, …
Synchronous Communication System For Saw Sensors Interrogation, Maxim Troshin
Synchronous Communication System For Saw Sensors Interrogation, Maxim Troshin
Electronic Theses and Dissertations
During past two decades a variety of SAW based wireless sensors were invented and research is still in progress. As different frequencies, varied bandwidths, coding techniques and constantly changing post processing algorithms are being implemented, there is a constant need for a universal and adjustable synchronous communication system able to interrogate new generations of SAW sensors. This thesis presents the design of a multiple FPGA based communication system with an operational frequency range of 450MHz-2.2GHz capable of producing user programmed modulated signal. The synchronous receiver is designed to have interchangeable chip, replacement of which would allow adjustment of the receiver’s …
Fire Retardant Polymer Nanocomposites: Materials Design And Thermal Degradation Modeling, Jinfeng Zhuge
Fire Retardant Polymer Nanocomposites: Materials Design And Thermal Degradation Modeling, Jinfeng Zhuge
Electronic Theses and Dissertations
Compared to conventional materials, polymer matrix composites (PMCs) have a number of attractive properties, including light weight, easiness of installation, potential to lower system-level cost, high overall durability, and less susceptibility to environmental deterioration. However, PMCs are vulnerable to fire such that they degrade, decompose, and sometimes yield toxic gases at high temperature. The degradation and decomposition of composites lead to loss in mass, resulting in loss in mechanical strength. This research aims to improve the structural integrity of the PMCs under fire conditions by designing and optimizing a fire retardant nanopaper coating, and to fundamentally understand the thermal response …
A Framework For Process Data Collection, Analysis, And Visualization In Construction Projects, Reza Akhavian
A Framework For Process Data Collection, Analysis, And Visualization In Construction Projects, Reza Akhavian
Electronic Theses and Dissertations
Automated data collection, simulation and visualization can substantially enhance the process of designing, analysis, planning, and control of many engineering processes. In particular, managing processes that are dynamic in nature can significantly benefit from such techniques. Construction projects are good examples of such processes where a variety of equipment and resources constantly interact inside an evolving environment. Management of such settings requires a platform capable of providing decision-makers with updated information about the status of project entities and assisting site personnel making critical decisions under uncertainty. To this end, the current practice of using historical data or expert judgments as …
Numerical Simulation Of Electrolyte-Supported Planar Button Solid Oxide Fuel Cell, Amjad Aman
Numerical Simulation Of Electrolyte-Supported Planar Button Solid Oxide Fuel Cell, Amjad Aman
Electronic Theses and Dissertations
Solid Oxide Fuel Cells are fuel cells that operate at high temperatures usually in the range of 600oC to 1000oC and employ solid ceramics as the electrolyte. In Solid Oxide Fuel Cells oxygen ions (O2- ) are the ionic charge carriers. Solid Oxide Fuel Cells are known for their higher electrical efficiency of about 50-60% [1] compared to other types of fuel cells and are considered very suitable in stationary power generation applications. It is very important to study the effects of different parameters on the performance of Solid Oxide Fuel Cells and for this purpose the experimental or numerical …
Critical Success Factors For Evolutionary Acquisition Implementation, Brig J. Bjorn
Critical Success Factors For Evolutionary Acquisition Implementation, Brig J. Bjorn
Electronic Theses and Dissertations
Due to extensive challenges to the efficient development and fielding of operationally effective and affordable weapon systems, the U.S. employs a complex management framework to govern defense acquisition programs. The Department of Defense and Congress recently modified this process to improve the levels of knowledge available at key decision points in order to reduce lifecycle cost, schedule, and technical risk to programs. This exploratory research study employed multiple methods to examine the impact of systems engineering reviews, competitive prototyping, and the application of a Modular Open Systems Approach on knowledge and risk prior to funding system implementation and production. In-depth …
Phase Field Modeling Of Thermotransport In Multicomponent Systems, Joshua Bush
Phase Field Modeling Of Thermotransport In Multicomponent Systems, Joshua Bush
Electronic Theses and Dissertations
Nuclear and gas turbine power plants, computer chips, and other devices and industries are running hotter than ever for longer than ever. With no apparent end to the trend, the potential arises for a phenomenon known as thermotransport to cause undesirable changes in these high temperature materials. The diffuse-interface method known as the phase-field model is a useful tool in the simulation and prediction of thermotransport driven microstructure evolution in materials. The objective of this work is to develop a phase-field model using practical and empirical properties of thermodynamics and kinetics for simulating the interdiffusion behavior and microstructural evolution of …
Effects Of Allotropic Transformations On Interdiffusion Behavior In Binary Systems, Ashley Elizabeth Ewh
Effects Of Allotropic Transformations On Interdiffusion Behavior In Binary Systems, Ashley Elizabeth Ewh
Electronic Theses and Dissertations
Diffusion plays a significant role in most materials systems by controlling microstructural development. Consequently, the overall properties of a material can be largely dependent upon diffusion. This study investigated the interdiffusion behavior of three binary systems, namely, Mo-Zr, Fe-Mo, and Fe-Zr. The main interest in these particular metals is for application in nuclear fuel assemblies. Nuclear fuel plates generally consist of two main components which are the fuel and the cladding. Due to diffusional interactions that can occur between these two components, a third is sometimes added between the fuel and cladding to serve as a diffusion barrier layer. Fe, …
Third Order Nonlinearity Of Organic Molecules, Honghua Hu
Third Order Nonlinearity Of Organic Molecules, Honghua Hu
Electronic Theses and Dissertations
The main goal of this dissertation is to investigate the third-order nonlinearity of organic molecules. This topic contains two aspects: two-photon absorption (2PA) and nonlinear refraction (NLR), which are associated with the imaginary and real part of the third-order nonlinearity (χ (3)) of the material, respectively. With the optical properties tailored through meticulous molecular structure engineering, organic molecules are promising candidates to exhibit large third-order nonlinearities. Both linear (absorption, fluorescence, fluorescence excitation anisotropy) and nonlinear (Z-scan, two-photon fluorescence, pump-probe) techniques are described and utilized to fully characterize the spectroscopic properties of organic molecules in solution or solid-state form. These properties …
Characterization, Morphology, Oxidation, And Recession Of Silicon Nanowires Grown By Electroless Process, Robert G. Mertens
Characterization, Morphology, Oxidation, And Recession Of Silicon Nanowires Grown By Electroless Process, Robert G. Mertens
Electronic Theses and Dissertations
This dissertation presents heretofore undiscovered properties of Silicon Nanowires (SiNWs) grown by electroless process and presents mathematical solutions to the special problems of the oxidation and diffusion of dopants for SiNWs. Also presented here is a mathematical description of morphology of oxidized SiNWs. This dissertation is comprised of several discussions relating to SiNWs growth, oxidation, morphology and doping. In here is presented work derived from a long-term study of SiNWs. Several important aspects of SiNWs were investigated and the results published in journals and conference papers. The recession of SiNWs was heretofore unreported by other research groups. In our investigations, …
Evaluation Of An On-Line Device To Monitor Scale Formation In A Brackish Water Reverse Osmosis Membrane Process, Jennifer C. Roque
Evaluation Of An On-Line Device To Monitor Scale Formation In A Brackish Water Reverse Osmosis Membrane Process, Jennifer C. Roque
Electronic Theses and Dissertations
A modified two-element membrane pressure vessel assembly has been used to monitor process operational changes in a full-scale reverse osmosis (RO) water treatment plant (WTP). This study evaluated the effectiveness of the assembly as an on-line monitoring device intended to detect scale formation conditions when connected to an operating RO process train. This study was implemented to support the requirements of a larger University of Central Florida (UCF) research project ongoing at the city of Sarasota’s Public Works and Utilities (City) water treatment facilities located in Sarasota, Florida. During the time-frame of this study, the City was in the process …
Microstructual Characteristics Of Magnesium Metal Matrix Composites, Dongho Shin
Microstructual Characteristics Of Magnesium Metal Matrix Composites, Dongho Shin
Electronic Theses and Dissertations
Magnesium (Mg) Metal matrix composites (MMCs) reinforced by ceramic reinforcements are being developed for a variety of applications in automotive and aerospace because of their strength-to-weight ratio. Reinforcement being considered includes SiC, Al2O3, Carbon fiber and B4C in order to improve the mechanical properties of MMCs. Microstructural and interfacial characteristics of MMCs can play a critical role in controlling the MMCs’ mechanical properties. This study was carried out to understand the microstructural and interfacial development between Mg-9wt.Al-1wt.Zn (AZ91) alloy matrix and several reinforcements including SiC, Al2O3, Carbon fibers and B4C. X-ray diffraction, scanning electron microscopy and transmission electron microscopy was …
Wireless Power Transfer For Space Applications: System Design And Electromagnetic Compatibility Compliance Of Radiated Emissions, Ramos Gabriel Vazquez
Wireless Power Transfer For Space Applications: System Design And Electromagnetic Compatibility Compliance Of Radiated Emissions, Ramos Gabriel Vazquez
Electronic Theses and Dissertations
This dissertation evaluates the possibility of wireless power transfer (WPT) systems for space applications, with an emphasis in launch vehicles (rockets). After performing literature review for WPT systems, it was identified that magnetic resonance provides the more suited set of characteristics for this application. Advanced analysis, simulation and testing were performed to magnetic resonance WPT systems to acquire system performance insight. This was accomplished by evaluating/varying coupling configuration, load effects and magnetic element physical characteristics (i.e. wire material, loop radius, etc.). It was identified by analysis, circuit simulation and testing that the best coupling configuration for this application was series-series …
Evaluating Corrosion Control Alternatives For A Reverse Osmosis, Nanofiltration And Anion-Exchange Blended Water Supply, Rebecca J. Wilder
Evaluating Corrosion Control Alternatives For A Reverse Osmosis, Nanofiltration And Anion-Exchange Blended Water Supply, Rebecca J. Wilder
Electronic Theses and Dissertations
The research reported herein describes the study activities performed by University of Central Florida (UCF) on behalf of the Town of Jupiter Water Utilities (Town). The Town recently changed its water treatment operations from a combination of reverse osmosis (RO), lime softening (LS) and anion-exchange (IX) to a combination of RO, IX and nanofiltration (NF). Although this treatment change provided enhanced water to the surrounding community in terms of better contaminant removal and reduced DBP formation potential, integration of the NF process altered finished water quality parameters including pH, alkalinity and hardness. There was concern that these changes could result …