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Full-Text Articles in Engineering

Monitoring Heart Rate Variability In Relation To Sleep Quality, Yi-Tzu Wang May 2017

Monitoring Heart Rate Variability In Relation To Sleep Quality, Yi-Tzu Wang

Theses and Dissertations

The development and analysis of heart rate variability for sleep quality monitoring have been concerned for many years in human being. Sleep is a physiological process that is essentially maintaining the function of human body. Heart rate variability have undergone much-needed development to assess the effects such as sleep disorder, insomnia, high blood pressure, stress and even diabetes. Accurately evaluating physiological signals that are practical to measure the sleep quality in individuals monitoring heart rate variability is an important activation of diverse biological systems during sleep. A noteworthy role of measuring the heart rate variability is played by the autonomic …

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The Impact Of Different Propagation Environments On The Performance Of Wireless Sensor Networks, Abdallah Mubark Aldosary May 2017

The Impact Of Different Propagation Environments On The Performance Of Wireless Sensor Networks, Abdallah Mubark Aldosary

Theses and Dissertations

This dissertation presents a methodology for evaluating the performance of wireless sensor network (WSN) protocols in different propagation environments. To create this methodology, practical RF propagation models that include many of the substantial features of different propagation environments are utilized, and radio energy models for different propagation environments are developed. Accurate environment-specific radio frequency (RF) propagation models should be utilized in order to improve the overall process of decision-making during pre-deployment of WSNs, to facilitate the deployment of the WSN, and to enhance the battery efficiency of sensing nodes so that the network lifetime can be prolonged. The investigating of …

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Application-Driven Traffic Sensor System Acceptance Tests For Intelligent Transportation Systems, Thiago Goncalves Pereira Mendonca May 2017

Application-Driven Traffic Sensor System Acceptance Tests For Intelligent Transportation Systems, Thiago Goncalves Pereira Mendonca

Theses and Dissertations

Transportation agencies strive to keep people and goods moving. Operation and maintenance of transportation infrastructure is key to accomplish their objectives. Intelligent Transportation Systems (ITS) applications rely on massive detection grids that collectively demand significant maintenance resources. Resource constraints force transportation agencies to look for innovative ways to optimize their operational and maintenance costs while serving their users at intended performance levels. This paper presents a Systems Engineering (SE) view to derive traffic detection sensor requirements for components and subsystems based on application-specific needs. The goal of the approach is to obtain stakeholders view of an acceptable performance based on …

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An Extrinsic Fabry-Perot Interferometric Sensor Using Intermodal Phase Shifting And Demultiplexing Of The Propagating Modes In A Few-Mode Fiber, Julius Chatterjee May 2017

An Extrinsic Fabry-Perot Interferometric Sensor Using Intermodal Phase Shifting And Demultiplexing Of The Propagating Modes In A Few-Mode Fiber, Julius Chatterjee

Theses and Dissertations

This dissertation demonstrates a fiber-optic phase shifted Fabry-Perot interferometer (PS-FPI) as a sensor using modal demultiplexing. Single wavelength Fabry-Perot interferometers suffer from fringe ambiguity and loss of sensitivity at fringe extremes. These hindrances cause it to be a secondary choice when being selected for a measurement task at hand, and more often than not, white light based sensors are selected in favor of the single wavelength Fabry-Perot sensors. This work aims to introduce a technique involving the demultiplexing of the propagating linearly polarized (LP) modes in few mode fibers to obtain two fringe systems from the same sensing cavity. This …

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Planar Electromagnetic Band Gap For Broadband Switching Noise Mitigation In High-Speed Pcb, Kevin H. Nguyen May 2017

Planar Electromagnetic Band Gap For Broadband Switching Noise Mitigation In High-Speed Pcb, Kevin H. Nguyen

Theses and Dissertations

Electromagnetic band gap (EBG) structure with novel meandered lines for mitigation of simultaneous switching noise (SSN) from multiple switch mode power supplies on a high speed digital circuit card assembly is investigated. The electromagnetic band gap structure is designed for a wideband operation from 200 MHz to 15 GHz. The application interest for this planar structure can be used as high impedance surfaces to suppress EMI noise for EMC compliance in Mil-Std-461, which is an electromagnetic compatibility standard for military equipment operating in the frequency range from 10 KHz to 18 GHz. ANSYS HFSS was used for simulation of these …

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Cfd Analysis Of Resistance Characteristics Of High-Speed Displacement Hull Forms Fitted With Hull Vane®, Venkata Karthik Avala May 2017

Cfd Analysis Of Resistance Characteristics Of High-Speed Displacement Hull Forms Fitted With Hull Vane®, Venkata Karthik Avala

Theses and Dissertations

Improving the performance and resistance of a high-speed monohull forms has been of interest to Naval Architects for several decades. A considerable amount of research has been carried out in this area by using stern flaps and other appendages. This research thesis investigates the resistance characteristics of high-speed round bilge hull forms fitted with a Hull Vane® in the stern region of the vessel. The Hull Vane® is a fixed foil located below the waterline at the aft of the stern of the vessel. The Hull Vane® reduces the generation of waves at the aft and improves the vessel's motions. …

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Optimization Framework For Deployment Of Wireless Sensor Networks, Tajudeen Olawale Olasupo May 2017

Optimization Framework For Deployment Of Wireless Sensor Networks, Tajudeen Olawale Olasupo

Theses and Dissertations

In order to tackle the problem of network connectivity and sensing coverage in random placement of sensor nodes over an area of interest, this research presents an optimization and visualization framework for characterization and prediction of optimal deployments of large-scale wireless sensor networks (WSNs). This study presents efficient image processing algorithms for classification of deployment terrain in order to optimize deployment and connectivity coverage with required minimum number of nodes and transmission power. It reports formation of efficient models for WSN signal propagation under different terrain conditions. The study describes the developmental approach of the WSN optimization framework and visualization …

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The Significance Of A High Resolution 2d Hydraulic Model Including Green Infrastructure For Assessment Of Coastal Community Vulnerability And Resilience, Katie M. Miller Apr 2017

The Significance Of A High Resolution 2d Hydraulic Model Including Green Infrastructure For Assessment Of Coastal Community Vulnerability And Resilience, Katie M. Miller

Theses and Dissertations

This paper outlines the development of an enhanced hydraulic flood model that uses a fine-scale grid to analyze significant areas of flooding for improved flood predictions and resiliency planning. This study modeled the extent of Atlantic City and Camden, New Jersey. The capabilities of the model were compared to coarser national models, HAZUS-MH and SLOSH, to understand the significance of fine-scale hydraulic modeling. The results illustrated that the HAZUS and SLOSH models showed gaps in some areas and lacked accuracy due to lower resolution. This paper also describes how these developed models show the impacts of severe storms, and the …

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Methods And Systems For Self-Organizing Non-Stationary Balloon Mesh Free Space Optical Networks, Muhammad Baig Awan Apr 2017

Methods And Systems For Self-Organizing Non-Stationary Balloon Mesh Free Space Optical Networks, Muhammad Baig Awan

Theses and Dissertations

The Free Space Optical Networks are characterized by dynamic performance of optical wireless links as well as the atmospheric conditions and the mobility of free space optical nodes. In this dissertation, we focus on how to enhance the performance of free space optical network due to the mobility of free space optical nodes. The objective is to define and evaluate algorithms to establish continuous free space optical links in a stratospheric balloon mesh network. The main resource is the optical transceiver, which can be tuned to only one wavelength. Considering the constraint of single wavelength per transceiver, the wavelengths must …

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Effect Of Plasma Dynamics On Gallium Nitride Nanorod And Growth By Molecular Beam Epitaxy, Dever Paul Norman Apr 2017

Effect Of Plasma Dynamics On Gallium Nitride Nanorod And Growth By Molecular Beam Epitaxy, Dever Paul Norman

Theses and Dissertations

GaN is a wide bandgap semiconductor known for its use in high-frequency switching electronics and laser diodes, its stability as a high-temperature transistor material, and a radiation resistance which makes it an ideal material for space applications. Additionally, the discovery of the bandgap tunability of nitride materials using GaN has led to successful development of adjustable wavelength LED devices. However, the success of devices far outpaces the understanding of their material growth, making advances difficult to build upon. Plasma- Assisted Molecular Beam Epitaxy (PA-MBE) is an ideal growth method for achieving very precise structures for detailed study. Although plasma itself …

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Evaluating The Impact Of Different Types Of Stabilized Bases On The Overall Performance Of Flexible Pavements, Andrae Anthony Francois Apr 2017

Evaluating The Impact Of Different Types Of Stabilized Bases On The Overall Performance Of Flexible Pavements, Andrae Anthony Francois

Theses and Dissertations

This study was initiated with the aim of evaluating the impact of stabilized and untreated base layers on the performance (i.e., fatigue and rutting) of flexible pavements. Four field sections constructed using stabilized base layers (i.e., bituminous (asphalt emulsion), calcium chloride (CaCl-2), Portland cement, and geogrid stabilized base layers) and a control section constructed using untreated RAP aggregates were analyzed in this study. Falling Weight Deflectometer (FWD) tests were conducted on all the field sections and the collected data was used to backcalculate the elastic moduli for all layers. The influence of the stabilized bases and the untreated RAP base …

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Optimal Control For Wind Turbine System Via State-Space Method, Mudhafar Lazam Shanoob Apr 2017

Optimal Control For Wind Turbine System Via State-Space Method, Mudhafar Lazam Shanoob

Theses and Dissertations

Renewable energy is becoming a fascinating research interest in future energy production because it is green and does not pollute nature. Wind energy is an excellent example of renewable resources that are evolving. Throughout the history of humanity, wind energy has been used. In ancient time, it was used to grind seeds, sailing etc. Nowadays, wind energy has been used to generate electrical power. Researchers have done a lot of research about using a wind source to generate electricity. As wind flow is not reliable, there is a challenge to get stable electricity out of this varying wind. This problem …

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Application Of Ground Penetrating Radar To Highway-Related Problems, Rauf Rejab Hussein Apr 2017

Application Of Ground Penetrating Radar To Highway-Related Problems, Rauf Rejab Hussein

Theses and Dissertations

The Broadway Bridge, constructed in 1923, crosses the Arkansas River in the downtown area of Little Rock, AR and was the main crossing point between Little Rock and North Little Rock. The structural deterioration of the bridge reached a level beyond patch and repair. Accordingly, the Arkansas Highway and Transportation Department (AHTD), in collaboration with the City of Little Rock, allocated the required resources ($98.4M) to demolish and replace the bridge. Due to the age of the bridge site and the limited knowledge of the subsurface utility layout, it became clear that geotechnical work be done in order to map …

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Design And Experiments Of A Sic Power Mosfet-Based Bidirectional Switching Power Pole (Bspp), Hussain Khthear Sayed Subhii Apr 2017

Design And Experiments Of A Sic Power Mosfet-Based Bidirectional Switching Power Pole (Bspp), Hussain Khthear Sayed Subhii

Theses and Dissertations

This research presents the design and experiments of a SiC power MOSFET-based bidirectional switching power pole (BSPP) by benefiting from the advantages of SiC power MOSFETs: high-speed switching, high power density, high operating temperatures, and low power losses. The main goal of this research is to design a printed circuit board (PCB) prototype with a minimum parasitic inductance to improve the switching transient performance of the SiC MOSFETs for the BSPP application. The effects of the parasitic inductance of the PCB power traces were investigated, for the BSPP application, based on the experimental, simulation, and theoretical analyses. The PCB prototypes …

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Full-Scale Pavement Testing Of Aggregate Base Material Stabilized With Triaxial Geogrid, Shaun Todd Hilton Apr 2017

Full-Scale Pavement Testing Of Aggregate Base Material Stabilized With Triaxial Geogrid, Shaun Todd Hilton

Theses and Dissertations

The objective of this research was to investigate the structural capacity of aggregate base materials stabilized with triaxial geogrid placed in a full-scale pavement involving control, or unstabilized, sections. Field testing was performed on a roadway in northeastern Utah that was 16 km (10 miles) long and included 10 test sections, seven stabilized sections and three control sections, each having five test locations. The pavement structure was comprised of a hot mix asphalt layer overlying an untreated aggregate base layer of varying thickness, depending on the test section. Except for the control sections, one or two layers of geogrid were …

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Non-Dimensional Modeling Of The Effects Of Weld Parameters On Peak Temperature And Cooling Rate In Friction Stir Welding, Bryan Jay Stringham Apr 2017

Non-Dimensional Modeling Of The Effects Of Weld Parameters On Peak Temperature And Cooling Rate In Friction Stir Welding, Bryan Jay Stringham

Theses and Dissertations

Methods for predicting weld properties based on welding parameters are needed in friction stir welding (FSW). FSW is a joining process in which the resulting properties depend on the thermal cycle of the weld. Buckingham's Pi theorem and heat transfer analysis was used to identify dimensionless parameters relevant to the FSW process. Experimental data from Al 7075 and HSLA-65 on five different backing plate materials and a wide range of travel speeds and weld powers was used to create a dimensionless, empirical model relating critical weld parameters to the peak temperature rise and cooling rate of the weld. The models …

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Selecting Surrogate Folds For Use In Origami-Based Mechanisms And Products, Jason Tyler Allen Apr 2017

Selecting Surrogate Folds For Use In Origami-Based Mechanisms And Products, Jason Tyler Allen

Theses and Dissertations

Origami-based design is increasing in popularity as its benefits and advantages become better understood and explored. However, many opportunities still exist for the application of origami principles to engineered designs, especially in the use of non-paper, thick sheet materials. One specific area utilizing thick sheet materials that is especially promising is origami-based mechanisms that require electrical power transfer applications. Many of these opportunities can be met by the use of surrogate folds. This thesis provides methods and frameworks that can be used by engineers to efficiently select and design surrogate folds for use in origami-based mechanisms and products. Surrogate folds …

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Strut-And-Tie Modeling Of Multistory, Partially-Grouted, Concrete Masonry Shear Walls With Openings, Jeffrey Ryan Buxton Apr 2017

Strut-And-Tie Modeling Of Multistory, Partially-Grouted, Concrete Masonry Shear Walls With Openings, Jeffrey Ryan Buxton

Theses and Dissertations

Construction practices are constantly evolving in order to adapt to physical locations and economic conditions. These adaptations may result in more cost-effective designs, but may also come at a cost of strength. In masonry shear walls, it is becoming more common to reduce the amount of grouting from every cell to only those with reinforcement, a practice known as partial-grouting. Partially-grouted masonry responds differently and in a more complex matter to lateral loads as compared to fully-grouted masonry. The response is made even more complex by wall discontinuities in the form of openings. The main objective of this study is …

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Estimating Short-Term Human Intent For Physical Human-Robot Co-Manipulation, Eric Christopher Townsend Apr 2017

Estimating Short-Term Human Intent For Physical Human-Robot Co-Manipulation, Eric Christopher Townsend

Theses and Dissertations

Robots are increasingly becoming safer and more capable. In the past, the main applications for robots have been in manufacturing, where they perform repetitive, highly accurate tasks with physical barriers that separate them from people. They have also been used in space exploration where people are not around. Due to improvements in sensors, algorithms, and design, robots are beginning to be used in other applications like materials handling, healthcare, and agriculture and will one day be ubiquitous. For this to be possible, they will need to be able to function safely in unmodelled and dynamic environments. This is especially true …

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The Effect Of Transit-Oriented Development Siteson Residential Home Pricing, Bradley S. Randall Apr 2017

The Effect Of Transit-Oriented Development Siteson Residential Home Pricing, Bradley S. Randall

Theses and Dissertations

For a number of years residential and commercial development has grown surrounding railways stations in many cities across the United States. One of the trends that has occurred in a number of cities relates to positive property value correlations between real estate values near transit stations and transit-oriented development (TOD) sites as compared to their counterparts not located near a railway station or freeway access. Many cities have noted that homeowners are willing to pay more to be near a TOD site and being near a site can represent a statistically significant factor in determining where to purchase a property. …

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Structural Lightweight Grout Mixture Design, Hannah Jean Polanco Apr 2017

Structural Lightweight Grout Mixture Design, Hannah Jean Polanco

Theses and Dissertations

This research focused on designing a grout mixture using lightweight aggregate that achieves the minimum 28-day compressive strength required for normal-weight grout, 2000 psi. This research specifically studied the effects of aggregate proportion, slump, and aggregate soaking on the compressive strength of the mixture. The variable ranges investigated were 3-4.75 parts aggregate to cement volumetrically, 8-11 in. slump, and 0 and 2 cycles of soaking. The statistical model developed to analyze the significance of variable effects included a three-way interaction between the explanatory variables. All three explanatory variables had a statistically significant effect on the grout compressive strength, but the …

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Seismic Analysis Of And Provisions For Dry-Stack Concrete Masonry Wall Systems With Surface Bond In Low-Rise Buildings, Joseph G. Eixenberger Apr 2017

Seismic Analysis Of And Provisions For Dry-Stack Concrete Masonry Wall Systems With Surface Bond In Low-Rise Buildings, Joseph G. Eixenberger

Theses and Dissertations

Masonry is one of the oldest forms of construction materials that is still in use today. However, construction practices in the modern age demand faster and more economical practices. Dry-stack masonry, or masonry that doesn't use mortar to bind the blocks together, is a unique system to make masonry more economical. Though several systems of dry-stack masonry have been suggested little to no data exists as most of these systems are patented. This research used dry-stacked normal weight concrete masonry units with an eccentrically placed reinforcement. The wall system is connected through a surface bond and lacks any geometric connection. …

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Decellularization And Recellularization Processes For Whole Porcine Kidneys, Nafiseh Poornejad Apr 2017

Decellularization And Recellularization Processes For Whole Porcine Kidneys, Nafiseh Poornejad

Theses and Dissertations

Concern over kidney disease has increased dramatically in recent years within the medical community. It is estimated that approximately one in fifteen Americans, nearly 20 million people, experience chronic kidney disease with most of those diagnosed progressing to kidney failure. The ultimate treatment available for end stage renal failure is whole kidney transplantation. However, there are very few kidneys available for patients to receive and those patients who are fortunate enough to receive an organ must remain on immunosuppressive medication for the remainder of their lives. The United States Department of Health & Human Services have reported that 18 people …

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Experimental And Computational Analysis Of An Axial Turbine Driven By Pulsing Flow, Mark H. Fernelius Apr 2017

Experimental And Computational Analysis Of An Axial Turbine Driven By Pulsing Flow, Mark H. Fernelius

Theses and Dissertations

Pressure gain combustion is a form of combustion that uses pressure waves to transfer energy and generate a rise in total pressure during the combustion process. Pressure gain combustion shows potential to increase the cycle efficiency of conventional gas turbine engines if used in place of the steady combustor. However, one of the challenges of integrating pressure gain combustion into a gas turbine engine is that a turbine driven by pulsing flow experiences a decrease in efficiency. The interaction of pressure pulses with a turbine was investigated to gain physical insights and to provide guidelines for designing turbines to be …

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Evaluation Of Low Cost Controllers For Mobile Based Virtual Reality Headsets, Summer Lindsey Apr 2017

Evaluation Of Low Cost Controllers For Mobile Based Virtual Reality Headsets, Summer Lindsey

Theses and Dissertations

Virtual Reality (VR) is no longer just for training purposes. The consumer VR market has become a large part of the VR world and is growing at a rapid pace. In spite of this growth, there is no standard controller for VR. This study evaluated three different controllers: a gamepad, the Leap Motion, and a touchpad as means of interacting with a virtual environment (VE). There were 23 participants that performed a matching task while wearing a Samsung Gear VR mobile based VR headset. Measures of performance, preference, presence, and enjoyment were collected and compared across controller. Overall, it was …

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Assessing The Hydrodynamic And Economic Impacts Of Biofouling On The Hull Of Surface Vessels Using Numerical Methods, Letchi Evrard Quentin Anoman Apr 2017

Assessing The Hydrodynamic And Economic Impacts Of Biofouling On The Hull Of Surface Vessels Using Numerical Methods, Letchi Evrard Quentin Anoman

Theses and Dissertations

Marine fouling on the hull of surface vessels is a topic of increasing importance in the maritime field for its environmental and financial impacts. Recent research developments have introduced mathematical models dealing with the frictional resistance associated with fouling, thus enabling to single out their impact on ship hydrodynamics. Herein, two implementations of these models are presented. The first implementation used Computational Fluid Dynamics to assess the additional drag induced by fouling for a specific ship model. With the software STAR CCM+, Reynolds Averaged Navier-Stokes equations have been used to model turbulence, wall laws parameters have been adapted to suit …

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Correlating Strength And Stiffness Data Of The Pencel Pressuremeter And Triaxial Compression Tests In Florida Sands, Jacob William Jansen Apr 2017

Correlating Strength And Stiffness Data Of The Pencel Pressuremeter And Triaxial Compression Tests In Florida Sands, Jacob William Jansen

Theses and Dissertations

The poorly graded sands found throughout Florida provide geotechnical engineers with a difficult challenge when performing testing samples in laboratory tests. These challenges have caused lab tests such as the triaxial compression test to be overlooked. Since geotechnical engineers estimate strength and stiffness parameters from basic field tests, they often produce overly conservative designs. Understanding how the automated in-situ PENCEL Pressuremeter (PPMT) test correlates with the triaxial compression test can reduce the time and costs associated with laboratory triaxial testing. Results from triaxial tests yield a Young’s Elastic Modulus, shear strength, and internal friction angle. Results from a PPMT test …

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Empirical Study Of In-Plane Shrinkage And Bulging Of Circular Cylinders Fabricated With The Fused Deposition Modeling Additive Manufacturing Method, Kirill Martusevich Apr 2017

Empirical Study Of In-Plane Shrinkage And Bulging Of Circular Cylinders Fabricated With The Fused Deposition Modeling Additive Manufacturing Method, Kirill Martusevich

Theses and Dissertations

This thesis presents a set of empirical studies, leading to three Design for Additive Manufacturing (DfAM) tools for estimating diametric shrinkage and the longitudinal variation of diameter in circular cylinders produced by the Fused-Deposition Modeling (FDM) method. First, four experiments are conducted by additively printing 50 cylinders and taking 1900 measurements in order to study the variation of diametric shrinkage along the cylinder axis and the variation of shrinkage as functions of four parameters of the cylinder: top and bottom thicknesses, diameter, height, and shell thickness. These four subjects of study are addressed as five research questions and are answered …

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Improvements, Algorithms And A Simulation Model For A Compact Phased-Array Radar For Uas Sense And Avoid, Adam Kaleo Roberts Apr 2017

Improvements, Algorithms And A Simulation Model For A Compact Phased-Array Radar For Uas Sense And Avoid, Adam Kaleo Roberts

Theses and Dissertations

Unmanned aerial systems (UAS) are an influential technology which can enhance life in multiple ways. However, they must be able to sense and operate safely with manned aircraft. Radar is an attractive sensor for UAS because of its all-weather performance. It is challenging, though, to meet the size, weight, and power (SWaP) limitations of UAS and especially small-UAS while still maintaining the needed sensing capability. A working FMCW radar prototype has been created which meets the SWaP requirement of small-UAS. A simulation model for the radar was developed to test the processing algorithms of the radar and proved to be …

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High-Speed Programmable Fpga Configuration Memory Access Using Jtag, Ammon Bradley Gruwell Apr 2017

High-Speed Programmable Fpga Configuration Memory Access Using Jtag, Ammon Bradley Gruwell

Theses and Dissertations

Over the past couple of decades Field Programmable Gate Arrays (FPGAs) have become increasingly useful in a variety of domains. This is due to their low cost and flexibility compared to custom ASICs. This increasing interest in FPGAs has driven the need for tools that both qualify and improve the reliability of FPGAs for applications where the reconfigurability of FPGAs makes them vulnerable to radiation upsets such as in aerospace environments. Such tools ideally work with a wide variety of devices, are highly programmable but simple to use, and perform tasks at relatively high speeds. Of the various FPGA configuration …

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