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Game-Theoretic Frameworks And Strategies For Defense Against Network Jamming And Collocation Attacks, Ahmed Hemida
Game-Theoretic Frameworks And Strategies For Defense Against Network Jamming And Collocation Attacks, Ahmed Hemida
Electronic Theses and Dissertations
Modern networks are becoming increasingly more complex, heterogeneous, and densely connected. While more diverse services are enabled to an ever-increasing number of users through ubiquitous networking and pervasive computing, several important challenges have emerged. For example, densely connected networks are prone to higher levels of interference, which makes them more vulnerable to jamming attacks. Also, the utilization of software-based protocols to perform routing, load balancing and power management functions in Software-Defined Networks gives rise to more vulnerabilities that could be exploited by malicious users and adversaries. Moreover, the increased reliance on cloud computing services due to a growing demand for …
Dynamic Behavior And Performance Of Different Types Of Multi-Effect Desalination Plants, Mohamed Abdelkareem
Dynamic Behavior And Performance Of Different Types Of Multi-Effect Desalination Plants, Mohamed Abdelkareem
Electronic Theses and Dissertations
Water and energy are two of the most vital resources for the socio-economic development and sustenance of humanity on earth. Desalination of seawater has been practiced for some decades and is a well-established means of water supply. However, this process consumes large amounts of energy and the global energy supply is also faced with some challenges. In this research, multi-effect desalination (MED) has been selected due to lower cost, lower operating temperature and efficient in terms of primary energy and electricity consumption compared to other thermal desalination systems. The motivation for this research is to address thermo-economics and dynamic behavior …
Mechanical Properties Of Brittle Ceramics: Case Study Of Boron Rich Ceramics And Acropora Cervicornis Coral Skeleton, Alejandro Carrasco-Pena
Mechanical Properties Of Brittle Ceramics: Case Study Of Boron Rich Ceramics And Acropora Cervicornis Coral Skeleton, Alejandro Carrasco-Pena
Electronic Theses and Dissertations
Ceramics are ubiquitous in man-made and natural structures. Their mechanical properties highly depend on their composition, microstructure and level of defects in the bulk of the material, the latter affecting the integrity of the components; such is the case of boron-rich ceramics where large agglomerates create high stressed regions, or coral skeleton where porosity determines their strength against hydrodynamic forces present in the ocean tides. Therefore, studying the properties of ceramic materials using invasive and non-invasive methods helps in the understanding of the link between the properties and the performance of the structures. The aim of this research was to …
Development Of Daily, Monthly, Inter-Annual, And Mean Annual Hydrological Models Based On A Unified Runoff Generation Framework, Marwan Kheimi
Development Of Daily, Monthly, Inter-Annual, And Mean Annual Hydrological Models Based On A Unified Runoff Generation Framework, Marwan Kheimi
Electronic Theses and Dissertations
The main goal of this dissertation develops a unified model structure for runoff generation based on observations from a large number of catchments. Furthermore, obtaining a comprehensive understanding of the physical controlling factors that control daily, monthly, and annual water balance models. Meanwhile, applying the developed Unified model on different climate conditions, and comparing it with different well-known models. The proposed model was compared with a similar timescale model (HyMOD, and abcd) and applied on 92 catchments from MOPEX dataset across the United States. The HyMOD and abcd are a well-known daily and monthly hydrological model used on a variety …
Energy Expenditure And Stability During Self-Paced Walking On Different Slopes, Alanna Raffaelli
Energy Expenditure And Stability During Self-Paced Walking On Different Slopes, Alanna Raffaelli
Electronic Theses and Dissertations
Metabolic power and cost of transport (COT) are common quantifiers for effort when performing tasks including walking and running. Most studies focus on using a range of normal walking speeds over level ground or varied slopes. However, these studies use fixed-speed conditions. Fatigue, stability, metabolic expenditure, heart rate, and many other factors contribute to normal walking speed varying over time. This study aimed to show that allowing a subject to walk with a self-paced speed should correlate to a minimum COT at a given slope. This study also aimed to determine if a preferred slope exists based on minimizing metabolic …
Conceptualization And Fabrication Of A Bioinspired Mobile Robot Actuated By Shape Memory Alloy Springs, Lietsel Richardson
Conceptualization And Fabrication Of A Bioinspired Mobile Robot Actuated By Shape Memory Alloy Springs, Lietsel Richardson
Electronic Theses and Dissertations
This work is an experimental study and fabrication of design concepts to validate the feasibility of smart materials and their applications in bio-inspired robotics. Shape-Memory Alloy (SMA) springs are selected as the smart material actuators of interest to achieve locomotion in the proposed mobile robot. Based on a previous design of the robot, this work focuses on both implementing a new locomotion concept and reducing size and weight of the previous design, both using SMA based actuators. Objectives are met in consideration of the conceptual mechanics of circular robot locomotion. The first prototype is a variation of the original design. …
Applications Of Deep Learning Models For Traffic Prediction Problems, Rezaur Rahman
Applications Of Deep Learning Models For Traffic Prediction Problems, Rezaur Rahman
Electronic Theses and Dissertations
Deep learning coupled with existing sensors based multiresolution traffic data and future connected technologies has immense potential to improve traffic operation and management. But to deal with complex transportation problems, we need efficient modeling frameworks for deep learning models. In this study, we propose two different modeling frameworks using Deep Long Short-Term Memory Neural Network (LSTM NN) model to predict future traffic state (speed and signal queue length). In our first problem, we present a modeling framework using deep LSTM NN model to predict traffic speeds in freeways during regular traffic condition as well as under extreme traffic demand, such …
Point Cloud Technology For Analysis Of Existing Structures, Jacob Cano
Point Cloud Technology For Analysis Of Existing Structures, Jacob Cano
Electronic Theses and Dissertations
For this thesis, a study was completed on two different structures on the UCF Orlando campus through the use of both structural plans and point cloud technology. The results sought to understand the viability of point cloud technology as an accurate tool for the static and dynamic modal analysis of existing structures. For static analysis, a portion of the framing of Spectrum Stadium was rendered, modeled, analyzed and compared to a previous case study. The results emphasized how different users can render dissimilar member sizes and lengths due to human judgment on point cloud visuals. The study also found that …
Streamflow Prediction In Ungauged Basins Located Within Data-Scarce Regions, Mohammadhossein Alipour
Streamflow Prediction In Ungauged Basins Located Within Data-Scarce Regions, Mohammadhossein Alipour
Electronic Theses and Dissertations
Preservation and or restoration of riverine ecosystem requires quantification of alterations inflicted by water resources development projects. Long records of streamflow data are the first piece of information required in order to enable this analysis. Ungauged catchments located within data-scarce regions lack long records of streamflow data. In this dissertation, a multi-objective framework named Streamflow Prediction under Extreme Data-scarcity (SPED) is proposed for streamflow prediction in ungauged catchments located within large-scale regions of minimal hydrometeorologic observation. Multi-objective nature of SPED allows for balancing runoff efficiency with selection of parameter values that resemble catchment physical characteristics. Uncertain and low-resolution information are …
Characterization Of Florida Landfills With Elevated Temperatures, Ryan Joslyn
Characterization Of Florida Landfills With Elevated Temperatures, Ryan Joslyn
Electronic Theses and Dissertations
The occurrence of elevated temperatures within landfills is a very challenging issue for landfill operators to detect and correct. Little is known regarding the causes of elevated temperatures (ETs) and the number of landfills currently operating under such conditions. Therefore, the goal of this research was to determine which landfills within Florida have been impacted by ETs, and to develop a more complete understanding of the factors that may lead to these landfills becoming elevated temperature landfills (ETLFs). Historical landfill gas wellhead data, waste deposition reports, and landfill site geometry were collected for 27 landfill cells through the FDEP OCULUS …
Vibration Reduction Of Mistuned Bladed Disks Via Piezoelectric-Based Resonance Frequency Detuning, Garrett Lopp
Vibration Reduction Of Mistuned Bladed Disks Via Piezoelectric-Based Resonance Frequency Detuning, Garrett Lopp
Electronic Theses and Dissertations
Recent trends in turbomachinery blade technology have led to increased use of monolithically constructed bladed disks (blisks). Although offering a wealth of performance benefits, this construction removes the blade-attachment interface present in the conventional design, thus unintentionally removing a source of friction-based damping needed to counteract large vibrations during resonance passages. This issue is further exacerbated in the presence of blade mistuning that arises from small imperfections from otherwise identical blades and are unavoidable as they originate from manufacturing tolerances and operational wear over the lifespan of the engine. Mistuning is known to induce vibration localization with large vibration amplitudes …
Development Of A Single Sensor Approach For Capturing Three-Dimensional, Time Resolved Flame And Velocity Information, Jonathan Reyes
Development Of A Single Sensor Approach For Capturing Three-Dimensional, Time Resolved Flame And Velocity Information, Jonathan Reyes
Electronic Theses and Dissertations
Performing non-intrusive measurements is the key to acquiring accurate information representative of what is being observed. The act of measuring often changes the environment being observed altering the information that is being obtained. Due to this, the community of fluid scientists have gravitated towards using laser-based measurements to observe the phenomena occurring in their experiments. The study of fluids has advanced since this point, utilizing techniques such as planar laser induced florescence (PLIF), particle image velocimetry (PIV), laser doppler velocimetry (LDV), particle doppler anemometry (PDA), etc. to acquire chemical species information and velocity information. These techniques, though, are inherently two-dimensional …
Decentralized Consensus-Based Control Allocation For Some Dynamical Systems, August Mark
Decentralized Consensus-Based Control Allocation For Some Dynamical Systems, August Mark
Electronic Theses and Dissertations
In this dissertation, three separate studies, wherein techniques from graph theory and consensus control are used to address control allocation problems, are presented. In the first study, a decentralized allocator is presented for synthetic jet actuators and control surfaces onboard a small unmanned aerial vehicle to cooperatively generate desired aerodynamic moments. First order linear dynamics are assumed for both the synthetic jet actuators and control surfaces. A weighted consensus algorithm with limited feedback is used for the aerodynamic moment contribution allocator considering constraints. In the second study, the same allocation problem as in the first study is considered, but the …
Resource Optimization In Visible Light Communication Using Internet Of Things, Akash Dey
Resource Optimization In Visible Light Communication Using Internet Of Things, Akash Dey
Electronic Theses and Dissertations
In the modern day, there is a serious spectrum crunch in the legacy radio frequency (RF) band, for which visible light communication (VLC) can be a promising option. VLC is a short-range wireless communication variant which uses the visible light spectrum. In this thesis, we are using a VLC-based architecture for providing scalable communications to Internet-of-Things (IoT) devices where a multi-element hemispherical bulb is used that can transmit data streams from multiple light emitting diode (LED) boards. The essence of this architecture is that it uses a Line-of-Sight (LoS) alignment protocol that handles the hand-off issue created by the movement …
Forward Osmosis For Algae Dewatering And Electrical Field-Driven Membrane Fouling Mitigation, Faris Munshi
Forward Osmosis For Algae Dewatering And Electrical Field-Driven Membrane Fouling Mitigation, Faris Munshi
Electronic Theses and Dissertations
Efficient and low-energy microalgae harvesting is essential for sustainable biofuel production. Forward osmosis (FO) can provide a potential alternative for algae separation with low energy consumption by using osmotic pressure. In this study, an aquaporin-based polyethersulfone (PES) membrane was evaluated for algae dewatering using FO with three different types of draw solutions (DSs: NaCl, KCl and NH4Cl), and under different cross flow velocities (CFVs). 81% of algae dewatering was achieved with a 29% flux drop. Among three different DSs, although NH4Cl was the best candidate for improved water flux and low reverse salt flux (RSF), it could accelerate cell division, …
Fluctuations In Walking Speeds And Spatiotemporal Gait Parameters When Walking On A Self-Paced Treadmill At Level, Incline, And Decline Slopes, Cesar Castano
Electronic Theses and Dissertations
On a daily basis, humans walk over a variety of terrains. Studies have shown that spatiotemporal gait parameters, such as stride length, stride frequency, stride variability, etc., change when humans walk down a decline and up an incline compared to level ground. However, these studies have been limited to using fixed speed treadmills or analyzing a small number of strides when conducted over ground. Thus, there is a need to investigate the fluctuations in spatiotemporal gait parameters of humans walking at their self-selected speed, which requires recording hundreds of strides. Here we hypothesized that subjects will walk with a slower …
Variable Fluid Flow Regimes Alter Endothelial Adherens Junctions And Tight Junctions, Dilshan Ranadewa
Variable Fluid Flow Regimes Alter Endothelial Adherens Junctions And Tight Junctions, Dilshan Ranadewa
Electronic Theses and Dissertations
Variable blood flow regimes influence a range of cellular properties ranging from cell orientation, shape, and permeability: all of which are dependent on endothelial cell-cell junctions. In fact, cell-cell junctions have shown to be an integral part of vascular homeostasis through the endothelium by allowing intercellular signaling and passage control through tight junctions (TJs), adherens junctions (AJs), and gap junctions (GJs). It was our objective to determine the structural response of both AJs and TJs under steady and oscillatory flow. Human brain microvascular endothelial cells (HBMECs) were cultured in a parallel plate flow chamber and exposed to separate trails of …
Analysis Of Hydrodynamic And Bathymetric Gradients In Canaveral National Seashore Following Living Shoreline And Oyster Restorations, David Spiering
Analysis Of Hydrodynamic And Bathymetric Gradients In Canaveral National Seashore Following Living Shoreline And Oyster Restorations, David Spiering
Electronic Theses and Dissertations
Coastal vulnerability has been gaining recognition as a critical issue, especially with the increasing predictions of sea level rise. Susceptibility to extreme events, eutrophication, and shoreline modification has left many coastal regions in a degraded state. Shoreline protection has traditionally taken the form of seawalls and offshore breakwaters which can be detrimental to both the local ecosystems and adjoining shorelines. The objective of this thesis is to analyze the hydrodynamic and bathymetric variation that occurs within Mosquito Lagoon, Florida following living shoreline and oyster reef restorations. The shoreline sites were sampled using a Before-After-Control-Impact (BACI) design and data were analyzed …
Heterogeneous Reconfigurable Fabrics For In-Circuit Training And Evaluation Of Neuromorphic Architectures, Ramtin Mohammadizand
Heterogeneous Reconfigurable Fabrics For In-Circuit Training And Evaluation Of Neuromorphic Architectures, Ramtin Mohammadizand
Electronic Theses and Dissertations
A heterogeneous device technology reconfigurable logic fabric is proposed which leverages the cooperating advantages of distinct magnetic random access memory (MRAM)-based look-up tables (LUTs) to realize sequential logic circuits, along with conventional SRAM-based LUTs to realize combinational logic paths. The resulting Hybrid Spin/Charge FPGA (HSC-FPGA) using magnetic tunnel junction (MTJ) devices within this topology demonstrates commensurate reductions in area and power consumption over fabrics having LUTs constructed with either individual technology alone. Herein, a hierarchical top-down design approach is used to develop the HSCFPGA starting from the configurable logic block (CLB) and slice structures down to LUT circuits and the …
Classifying And Predicting Walking Speed From Electroencephalography Data, Allen Rahrooh
Classifying And Predicting Walking Speed From Electroencephalography Data, Allen Rahrooh
Electronic Theses and Dissertations
Electroencephalography (EEG) non-invasively records electrocortical activity and can be used to understand how the brain functions to control movements and walking. Studies have shown that electrocortical dynamics are coupled with the gait cycle and change when walking at different speeds. Thus, EEG signals likely contain information regarding walking speed that could potentially be used to predict walking speed using just EEG signals recorded during walking. The purpose of this study was to determine whether walking speed could be predicted from EEG recorded as subjects walked on a treadmill with a range of speeds (0.5 m/s, 0.75 m/s, 1.0 m/s, 1.25 …
Value-Of-Information Based Data Collection In Underwater Sensor Networks, Fahad Khan
Value-Of-Information Based Data Collection In Underwater Sensor Networks, Fahad Khan
Electronic Theses and Dissertations
Underwater sensor networks are deployed in marine environments, presenting specific challenges compared to sensor networks deployed in terrestrial settings. Among the major issues that underwater sensor networks face is communication medium limitations that result in low bandwidth and long latency. This creates problems when these networks need to transmit large amounts of data over long distances. A possible solution to address this issue is to use mobile sinks such as autonomous underwater vehicles (AUVs) to offload these large quantities of data. Such mobile sinks are called data mules. Often it is the case that a sensor network is deployed to …
Leveraging The Intrinsic Switching Behaviors Of Spintronic Devices For Digital And Neuromorphic Circuits, Steven Pyle
Leveraging The Intrinsic Switching Behaviors Of Spintronic Devices For Digital And Neuromorphic Circuits, Steven Pyle
Electronic Theses and Dissertations
With semiconductor technology scaling approaching atomic limits, novel approaches utilizing new memory and computation elements are sought in order to realize increased density, enhanced functionality, and new computational paradigms. Spintronic devices offer intriguing avenues to improve digital circuits by leveraging non-volatility to reduce static power dissipation and vertical integration for increased density. Novel hybrid spintronic-CMOS digital circuits are developed herein that illustrate enhanced functionality at reduced static power consumption and area cost. The developed spin-CMOS D Flip-Flop offers improved power-gating strategies by achieving instant store/restore capabilities while using 10 fewer transistors than typical CMOS-only implementations. The spin-CMOS Muller C-Element developed …
A Study Of Nonlinear Dynamics Of Eeg Responses To Simulated Unmanned Vehicle Tasks, Ziqing Xu
A Study Of Nonlinear Dynamics Of Eeg Responses To Simulated Unmanned Vehicle Tasks, Ziqing Xu
Electronic Theses and Dissertations
In the contemporary world, mental workload becomes higher as technology evolves and task demand becomes overwhelming. The operators of a system are usually required to complete tasks with higher complicity within a shorter period of time. Continuous operation under a high level of mental workload can be a major source of risk and human error, thus put the operator in a hazardous working environment. Therefore, it is necessary to monitor and assess mental workload. In this study, an unmanned vehicle operation with visual detection tasks was investigated by means of nonlinear analysis of EEG time series. Nonlinear analysis is considered …
Hybrid Life Cycle Sustainability Assessment-Based Multi-Objective Optimization: A Case For Sustainable Fleet Mix, Burak Sen
Electronic Theses and Dissertations
Sustainable transportation idea includes not only switching from conventional energy sources to alternative fuel resources, but also diverging from private vehicle use and shifting to alternative transportation modes. As a part of alternative transportation mode, utilizing alternative fuels in public transportation operation supports sustainable transportation at it full-glance. Given their implications in terms of air quality and sustainable movement of people, transit buses, which provide the primary public transportation service, are considered an ideal domain for the deployment of alternative fuels. An input-output (IO) model is developed based on Eora database – a detailed IO database that consists of national …
Fundamental Core Effects In Co-Cr-Fe-Ni Based High Entropy Alloys, Abhishek Mehta
Fundamental Core Effects In Co-Cr-Fe-Ni Based High Entropy Alloys, Abhishek Mehta
Electronic Theses and Dissertations
High entropy alloys (HEAs) are near equiatomic multi-principal-element-alloys (MPEAs) which are different from traditional solvent-based multicomponent alloys. Based on initial work by Yeh and Co-workers, they were proposed to exhibit four "core" effects: high entropy, sluggish diffusion, lattice distortion, and cocktail effect. Present work investigates two of the four "core" effects, i.e. high entropy and sluggish diffusion effects, in Co-Cr-Fe-Ni based transition metal high entropy alloys. Solid-to-solid diffusion couple approach was adopted to investigate, these core effects. Experimental results contradicts the "high entropy" effect based on thermodynamics analysis: that the HEAs with low entropy of mixing may be thermodynamically more …
Normally-Off Computing Design Methodology Using Spintronics: From Devices To Architectures, Arman Roohi
Normally-Off Computing Design Methodology Using Spintronics: From Devices To Architectures, Arman Roohi
Electronic Theses and Dissertations
Energy-harvesting-powered computing offers intriguing and vast opportunities to dramatically transform the landscape of Internet of Things (IoT) devices and wireless sensor networks by utilizing ambient sources of light, thermal, kinetic, and electromagnetic energy to achieve battery-free computing. In order to operate within the restricted energy capacity and intermittency profile of battery-free operation, it is proposed to innovate Elastic Intermittent Computation (EIC) as a new duty-cycle-variable computing approach leveraging the non-volatility inherent in post-CMOS switching devices. The foundations of EIC will be advanced from the ground up by extending Spin Hall Effect Magnetic Tunnel Junction (SHE-MTJ) device models to realize SHE-MTJ-based …
Comparative Nutrient Removal With Innovative Green Soprtion Media For Groundwater And Stormwater Co-Treatment, Dan Wen
Electronic Theses and Dissertations
As indicated by the National Academy of Engineering, the understanding of nitrogen cycle has been deemed as one of 14 grand challenges in engineering of the 21st century. Due to rapid population growth and urbanization, the stormwater runoff increased in quantity as well as its nutrient concentrations, which may trigger serious environmental issues such as eutrophication in aquatic systems and ecosystem degradation. This study focuses on stormwater and groundwater quality control via Biosorption Activated Media (BAM) which can be applied to enhance the nutrient removal potential as an emerging Best Management Practices (BMPs). BAM was tested in this study with …
High Performance Liquid Crystal Devices For Augmented Reality And Virtual Reality, Md Javed Rouf Talukder
High Performance Liquid Crystal Devices For Augmented Reality And Virtual Reality, Md Javed Rouf Talukder
Electronic Theses and Dissertations
See-through augmented reality and virtual reality displays are emerging due to their widespread applications in education, engineering design, medical, retail, transportation, automotive, aerospace, gaming, and entertainment. For augmented reality and virtual reality displays, high-resolution density, high luminance, fast response time and high ambient contrast ratio are critically needed. High-resolution density helps eliminate the screen-door effect, high luminance and fast response time enable low duty ratio operation, which plays a key role for suppressing image blurs. A dimmer placed in front of AR display helps to control the incident background light, which in turn improves the image contrast. In this dissertation, …
Nano-Biophysical Approaches For Assessing Nanoparticle Interactions With Biological Systems, Zachary Untracht
Nano-Biophysical Approaches For Assessing Nanoparticle Interactions With Biological Systems, Zachary Untracht
Electronic Theses and Dissertations
Understanding interactions between nanoparticles and biological systems is fundamental for the development of emerging nano-biotechnology applications. In this thesis, I present an investigation of zinc oxide (ZnO) nanoparticles interactions with biomolecules in two separate studies. The first section of my thesis covers tracking and detection of ZnO nanoparticles using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). ZinkicideTM is a bactericidal ZnO nanoparticle which has been developed for agriculture. The characterization of Zinkicide in biological media and in solution has been difficult due to its high dispersibility and ultra-small size. SDS-PAGE is considered a golden standard for protein qualitative interpretations. In …
Gan Power Devices: Discerning Application-Specific Challenges And Limitations In Hemts, Andrew Binder
Gan Power Devices: Discerning Application-Specific Challenges And Limitations In Hemts, Andrew Binder
Electronic Theses and Dissertations
GaN power devices are typically used in the 600 V market, for high efficiency, high power-density systems. For these devices, the lateral optimization of gate-to-drain, gate, and gate-to-source lengths, as well as gate field-plate length are critical for optimizing breakdown voltage and performance. This work presents a systematic study of lateral scaling optimization for high voltage devices to minimize figure of merit and maximize breakdown voltage. In addition, this optimization is extended for low voltage devices ( < 100 V), presenting results to optimize both lateral features and vertical features. For low voltage design, simulation work suggests that breakdown is more reliant on punch-through as the primary breakdown mechanism rather than on vertical leakage current as is the case with high-voltage devices. A fabrication process flow has been developed for fabricating Schottky-gate, and MIS-HEMT structures at UCF in the CREOL cleanroom. The fabricated devices were designed to validate the simulation work for low voltage GaN devices. The UCF fabrication process is done with a four layer mask, and consists of mesa isolation, ohmic recess etch, an optional gate insulator layer, ohmic metallization, and gate metallization. Following this work, the fabrication process was transferred to the National Nano Device Laboratories (NDL) in Hsinchu, Taiwan, to take advantage of the more advanced facilities there. Following fabrication, a study has been performed on defect induced performance degradation, leading to the observation of a new phenomenon: trap induced negative differential conductance (NDC). Typically NDC is caused by self-heating, however by implementing a substrate bias test in conjunction with pulsed I-V testing, the NDC seen in our fabricated devices has been confirmed to be from buffer traps that are a result of poor channel carrier confinement during the dc operating condition.