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Articles 1 - 30 of 384
Full-Text Articles in Engineering
An Integrated Model Of Optofluidic Biosensor Function And Performance, Joel Greig Wright, Jr.
An Integrated Model Of Optofluidic Biosensor Function And Performance, Joel Greig Wright, Jr.
Theses and Dissertations
Optofluidic flow-through biosensor devices have been in development for fast bio-target detection. Utilizing the fabrication processes developed by the microelectronics industry, these biosensors can be fabricated into lab-on-a-chip devices with a degree of platform portability. This biosensor technology can be used to detect a variety of targets, and is particularly useful for the detection single molecules and nucleic acid strands. Microfabrication also offers the possibility of production at scale, and this will offer a fast detection method for a range of applications with promising economic viability. The development of this technology has advanced to now warrant a descriptive model that …
Two-Photon 3-Dimensional Photoelectrochemical Etching Of Single Crystal Silicon Carbide, Peter Robert Nyholm
Two-Photon 3-Dimensional Photoelectrochemical Etching Of Single Crystal Silicon Carbide, Peter Robert Nyholm
Theses and Dissertations
This thesis presents the first use of a novel direct-write, non-line-of-sight, two-photon photoelectrochemical etching technique for etching of single crystal silicon carbide substrates. The use of this technique has resulted in structuring of 3-dimensional structures in high quality single crystal silicon carbide wafers. The 3-dimensional structures demonstrated cannot be formed by any single or combination of traditional silicon carbide machining techniques. This thesis outlines the development of the optical, electrical, and diagnostic components required to achieve two-photon photoelectrochemical etching in silicon carbide. The diagnostic sub-assemblies --a single pixel confocal detector assembly and an in-situ optical microscope assembly-- and their design …
Inter-Core Interference Mitigation In A Mixed Criticality System, Michael Glenn Hinton
Inter-Core Interference Mitigation In A Mixed Criticality System, Michael Glenn Hinton
Theses and Dissertations
In this thesis, we evaluate how well isolation can be achieved between two virtual machines within a mixed criticality system on a multi-core processor. We achieve this isolation with Jailhouse, an open-source, minimalist hypervisor. We then enhance Jailhouse with core throttling, a technique we use to minimize inter-core interference between VMs. Then, we run workloads with and without core throttling to determine the effect throttling has on interference between a non-real time VM and a real-time VM. We find that Jailhouse provides excellent isolation between VMs even without throttling, and that core throttling suppresses the remaining inter-core interference to a …
Increasing Isolation Between Closely Spaced X-Band Planar Transmit/Receive Antennas, Jacob Bartschi
Increasing Isolation Between Closely Spaced X-Band Planar Transmit/Receive Antennas, Jacob Bartschi
Undergraduate Honors Theses
Coupling between Tx/Rx antennas is a common and much-researched problem that is especially difficult when the antennas both placed close together and on the same plane. New systems with smaller footprints require this kind of placement while still maintaining the same levels of isolation as before. Traditional solutions for coupling involve large and heavy machined parts that are unsuited to compact systems. Many techniques have been proposed over the decades, but few have been applied to X-band antennas in closely spaced configurations. This thesis investigates those techniques, applies them to closely spaced X-band antennas, and compares them to conventional methods …
Analysis Of Feature Extraction In Knee Cartilage Semantic Segmentation Convolutional Neural Networks, Logan Thorneloe
Analysis Of Feature Extraction In Knee Cartilage Semantic Segmentation Convolutional Neural Networks, Logan Thorneloe
Undergraduate Honors Theses
Recent advances in deep learning and convolutional neural networks (CNNs) have shown promise for automatic segmentation in magnetic resonance images. However, because of the stochastic nature of the training process, it is difficult to interpret what information networks learn to represent. This study explores multiple difference metrics between networks to determine semantic relationships between knee cartilage tissues. It explores how differences in learned weights and output activations between networks can be used to express these relationships. These findings are further supported by training multi-class networks to segment multiple tissues to compare network accuracy across different tissue combinations. This study shows …
A Comparison Of Lithium-Ion Cathode Vertical Homogeneity As Influenced By Drying Rate And Drying Method, Alexander Jay Smart
A Comparison Of Lithium-Ion Cathode Vertical Homogeneity As Influenced By Drying Rate And Drying Method, Alexander Jay Smart
Theses and Dissertations
During lithium-ion battery electrode fabrication, slurry drying conditions influence the resulting microstructure of electrodes. It has been found that the drying conditions can result in non-uniform cathode microstructures and material distributions. Accelerated drying, for example, is widely assumed to cause the binder in an electrode to migrate within the slurry, which can contribute to adhesion failure, and ultimately capacity fade and reduced battery life. While there are some conflicting studies regarding the aspects of accelerated drying that cause binder migration, there is not a widely used standard metric for measuring the gradient of binder across the thickness of an electrode. …
Irregular Quadrature Amplitude Modulation For Adaptive Physical-Layer Security, Hunter Searle, Marco A. C. Gomes, Joao P. Vilela, Willie K. Harrison
Irregular Quadrature Amplitude Modulation For Adaptive Physical-Layer Security, Hunter Searle, Marco A. C. Gomes, Joao P. Vilela, Willie K. Harrison
Undergraduate Honors Theses
This thesis propose adding an irregular quadrature amplitude modulation (QAM) constellation to a wireless transmission scheme in order to obtain greater control over the signal-tonoise ratio (SNR) required to successfully decode the signal. By altering the separation between adjacent symbols, the minimum required SNR is raised without degradation in the performance of the scheme. This allows the system to adapt to preferable channel conditions for the authorized user, making it harder for eavesdroppers to intercept and decode the transmission, thus making the communication safer. In addition, we show that by overlaying a coset code onto the QAM constellation, a new, …
Improving The Single Event Effect Response Of Triple Modular Redundancy On Sram Fpgas Through Placement And Routing, Matthew Joel Cannon
Improving The Single Event Effect Response Of Triple Modular Redundancy On Sram Fpgas Through Placement And Routing, Matthew Joel Cannon
Theses and Dissertations
Triple modular redundancy (TMR) with repair is commonly used to improve the reliability of systems. TMR is often employed for circuits implemented on field programmable gate arrays (FPGAs) to mitigate the radiation effects of single event upsets (SEUs). This has proven to be an effective technique by improving a circuit's sensitive cross-section by up to 100x. However, testing has shown that the improvement offered by TMR is limited by upsets in single configuration bits that cause TMR to fail.This work proposes a variety of mitigation techniques that improve the effectiveness of TMR on FPGAs. These mitigation techniques can alter the …
Optimization And Hardware Implementation Of Syba-An Efficient Feature Descriptor, Samuel Gaylin Fuller
Optimization And Hardware Implementation Of Syba-An Efficient Feature Descriptor, Samuel Gaylin Fuller
Theses and Dissertations
Feature detection, description and matching are crucial steps in many computer vision algorithms. These rely on feature descriptors to be able to match image features across sets of images. This paper discusses a hardware implementation and various optimizations of our lab's previous work on the SYnthetic BAsis feature descriptor (SYBA). Previous work has shown that SYBA can offer superior performance to other binary descriptors, such as BRIEF. This hardware implementation on an FPGA is a high throughput and low latency solution, which is critical for applications such as: high speed object detection and tracking, stereo vision, visual odometry, structure from …
Phased Array Digital Beamforming Algorithms And Applications, David Moyle Marsh
Phased Array Digital Beamforming Algorithms And Applications, David Moyle Marsh
Theses and Dissertations
With the expansion of unmanned aircraft system (UAS) technologies, there is a growing need for UAS Traffic Management (UTM) systems to promote safe operation and development. To be successful, these UTM systems must be able to detect and track multiple drones in the presence of clutter. This paper examines the implementation of different algorithms on a compact, X-band, frequency modulated continuous wave (FMCW) radar in an effort to enable more accurate detection and estimation of drones. Several algorithms were tested through post processing on actual radar data to determine their accuracy and usefulness for this system. A promising result was …
Real-Time Visual Multi-Target Tracking In Realistic Tracking Environments, Jacob Harley White
Real-Time Visual Multi-Target Tracking In Realistic Tracking Environments, Jacob Harley White
Theses and Dissertations
This thesis focuses on visual multiple-target tracking (MTT) from a UAV. Typical state-of-the-art multiple-target trackers rely on an object detector as the primary detection source. However, object detectors usually require a GPU to process images in real-time, which may not be feasible to carry on-board a UAV. Additionally, they often do not produce consistent detections for small objects typical of UAV imagery.In our method, we instead detect motion to identify objects of interest in the scene. We detect motion at corners in the image using optical flow. We also track points long-term to continue tracking stopped objects. Since our motion …
Machine Learning Methods For Nanophotonic Design, Simulation, And Operation, Alec Michael Hammond
Machine Learning Methods For Nanophotonic Design, Simulation, And Operation, Alec Michael Hammond
Theses and Dissertations
Interest in nanophotonics continues to grow as integrated optics provides an affordable platform for areas like telecommunications, quantum information processing, and biosensing. Designing and characterizing integrated photonics components and circuits, however, remains a major bottleneck. This is especially true when complex circuits or devices are required to study a particular phenomenon.To address this challenge, this work develops and experimentally validates a novel machine learning design framework for nanophotonic devices that is both practical and intuitive. As case studies, artificial neural networks are trained to model strip waveguides, integrated chirped Bragg gratings, and microring resonators using a small number of simple …
Statistical Analysis And Extraction Of Quantitative Data From Elliptical-Signal-Model Bssfp Mri, Meredith Ireene Dupaix Taylor
Statistical Analysis And Extraction Of Quantitative Data From Elliptical-Signal-Model Bssfp Mri, Meredith Ireene Dupaix Taylor
Theses and Dissertations
Osteoarthritis is the most common type of arthritis, and is characterized by the loss of articular cartilage in a joint. This eventually leads to painful bone on bone interactions. Since the loss of cartilage is permanent, the main treatment for this disease is pain management until a full joint replacement is needed. To test new potential treatments a consistent way to measure cartilage thickness is needed. The current standard used in the knee to represent cartilage uses joint space width measured from x-rays. This measurement is highly variable, and does not directly show cartilage. Unlike x-rays, magnetic resonance imaging (MRI) …
Model Testing Of Soil Bacteria Population Dynamics, Adam Harlan Heninger
Model Testing Of Soil Bacteria Population Dynamics, Adam Harlan Heninger
Theses and Dissertations
This is one of the first time series studies of bacteria in soils supporting actively growing corn crops. Mathematically modeling bacteria population dynamics has the potential as a tool to more precisely assess the economic optimal nitrogen fertilizer rate for farmers. As a first step in this modeling effort, we examine the possibility that the bacteria population growth might be described by a dynamic model developed in the food sciences describing bacteria growth in food meant for human consumption. We make the assumption that air temperature above the soil can be used as an approximation for soil temperature. Also, because …
Increased Cyclist Safety Using An Embedded System, Matthew Ryan Heydorn
Increased Cyclist Safety Using An Embedded System, Matthew Ryan Heydorn
Theses and Dissertations
In order to reduce bicycle-vehicle collisions, we design and implement a cost effectiveembedded system to warn cyclists of approaching vehicles. The system uses an Odroid C2 singleboard computer (SBC) to do vehicle and lane detection in real time using only vision. The system warns cyclist are warned of approaching cars using both a smartphone app and an LED indicator. Due to the limited performance of the Odroid C2 and other low power and low cost SBCs,we found that existing detection algorithms run either too slowly or do not have sufficient accuracy to be practical. Our solution to these limitations is …
Radio Frequency Interference Cancellation,Appraisal, Detection, And Correction, Michael J. Lambert
Radio Frequency Interference Cancellation,Appraisal, Detection, And Correction, Michael J. Lambert
Theses and Dissertations
Radio Astronomy, the study of distant objects in the radio spectrum, is set at defiance against all other users of the electromagnetic spectrum. Where traditional use would fill the electromagnetic spectrum with as much transmission and information as possible, Radio Astronomy would rather no man-made signals existed. Since that is not possible, they grumble and have to deal with unwanted transmissions impinging upon their instruments. I have demonstrated that subspace projection can remove these unwanted signals from Radio Astronomical data in post processing. I demonstrate it both on simulated data and on data taken from the Very Large Array radio …
Analog Adaptive Calibration For Arbitrary Phased Array Configuration, Mark William Nielson
Analog Adaptive Calibration For Arbitrary Phased Array Configuration, Mark William Nielson
Theses and Dissertations
The development of phased array antenna systems requires considerable resources and time. Due to this constraint, the Naval Air Command (NAVAIR) needs a phased array that can be physically reconfigured to meet the demands of multiple missions without added development time or cost. This work develops and demonstrates a solution to this problem by implementing an adaptive calibration approach to the development of electronically steerable antennas (ESAs). In contrast to previous analog adaptive beamformer systems, this system allows for an arbitrary antenna configuration with a variable number of antenna elements and locations. A simulation model of arbitrary phased array configurations …
Neutron Beam Testing Methodology And Results For A Complex Programmable Multiprocessor Soc, Jordan Daniel Anderson
Neutron Beam Testing Methodology And Results For A Complex Programmable Multiprocessor Soc, Jordan Daniel Anderson
Theses and Dissertations
The Xilinx Multiprocessor System-on-Chip (MPSoC) is a complex device that uses 16nm FinFET technology to combine multiple processors, a large amount of FPGA resources, and many I/O interfaces on a single chip die. These features make the MPSoC a high-performance and architecturally flexible device. The potential computing power makes the MPSoC ideal for many embedded applications including terrestrial and space applications. The MPSoC, however, does not have extensive radiation history as many other devices have. The extent of the effect that ionized particles may have on the MPSoC is not well established. To solve this problem, neutron radiation testing can …
Characterization Of Mechanical Properties Of Thin-Film Li-Ion Batteryelectrodes From Laser Excitation And Measurements Ofzero-Group Velocity Resonances, Jing Yao
Theses and Dissertations
The mechanical properties of thin-film Li-ion battery electrodes are controlled by the micro structure of the constituent materials. In this work, a non-contact and non-destructive measurement of the mechanical properties of electrode films is performed by measurement of zero group velocity (ZGV) resonances. The ZGV Lamb wave modes of a solid bi-layer consisting of a thin metallic layer and a thin compliant coating layer are shown to be dependent on the Young's moduli, thicknesses, densities and Poisson ratios of the layers. Theoretical models are used to quantify the sensitivity of the ZGV resonances to changes in mechanical properties. Experimental ZGV …
The Sap Link: A Controller Architecture For Secure Industrial Control Systems, Matthew Cody Wyman
The Sap Link: A Controller Architecture For Secure Industrial Control Systems, Matthew Cody Wyman
Theses and Dissertations
Industrial Control Systems are essential to modern life. They are utilized in hundreds of processes including power distribution, water treatment, manufacturing, traffic management, and amusement park ride control. These systems are an essential part of modern life and if compromised, could result in significant economic loss, safety impacts, damage to the environment, and even loss of life. Unfortunately, many of these systems are not properly secured from a cyber attack. It is likely that a well-funded and motivated attack from a nation-state will successfully compromise an industrial control system's network. As cyber war becomes more prevalent, it is becoming more …
Planar Linear Ion Traps With Microscale Radii For Portable Mass Spectrometry, Trevor Keith Decker
Planar Linear Ion Traps With Microscale Radii For Portable Mass Spectrometry, Trevor Keith Decker
Theses and Dissertations
Radio frequency (RF) ion traps based on the quadrupole device developed by Paul and Steinwedel utilize a dynamic electric field to spatially confine the trajectory of charged particles and may be employed as mass spectrometers by selectively ejecting trapped molecules based on the mass to charge ratio. Because of the inherent sensitivity and specificity of this process, ion trap mass spectrometers have become a popular scientific instrument. In the past two decades there has been a push to develop portable ion trap mass spectrometers for in situ mass analysis by geometrically scaling traps to smaller sizes. This decreases the power …
Assuring Intellectual Property Through Physical And Functional Comparisons, Adam Kendall Hastings
Assuring Intellectual Property Through Physical And Functional Comparisons, Adam Kendall Hastings
Theses and Dissertations
Hardware trojans pose a serious threat to trusted computing. However, hardware trojan detection methods are both numerous and onerous, making hardware trojan detection a difficult and time-consuming procedure. This thesis introduces the IP Assurance Framework, which drastically improves the time it takes design teams to test for hardware trojans. The IP Assurance Framework is implemented in two ways: The first method, Physical Assurance, compares instantiated IP blocks to a golden model via physical-level comparisons, while the second method, Functional Assurance, compares IP to a golden model using logical-level comparisons. Both methods are demonstrated to distinguish between tampered and untampered IP …
Vision-Based Emergency Landing Of Small Unmanned Aircraft Systems, Parker Chase Lusk
Vision-Based Emergency Landing Of Small Unmanned Aircraft Systems, Parker Chase Lusk
Theses and Dissertations
Emergency landing is a critical safety mechanism for aerial vehicles. Commercial aircraft have triply-redundant systems that greatly increase the probability that the pilot will be able to land the aircraft at a designated airfield in the event of an emergency. In general aviation, the chances of always reaching a designated airfield are lower, but the successful pilot might use landmarks and other visual information to safely land in unprepared locations. For small unmanned aircraft systems (sUAS), triply- or even doubly-redundant systems are unlikely due to size, weight, and power constraints. Additionally, there is a growing demand for beyond visual line …
Nanofluidic Applications Of Silica Membranes, John Michael Stout
Nanofluidic Applications Of Silica Membranes, John Michael Stout
Theses and Dissertations
This work presents membrane development applicable in nanofluidic devices. These membranes can also be termed suspended thin films, supported on two or more edges. I first discuss motivation and background for developing these structures. Then I derive the formative principles for nanofluidic systems. Following the derivation of the Navier-Stokes and Washburn equations, I discuss applying these theories to planar nanofluidic capillaries and finish the derivation by discussing the forces that drive liquid flow in nanochannels. I next discuss the membrane development process, starting with my work in static height traps, and develop the concept of analyzing nanoparticles using suspended membranes. …
Vertical Electrical Impedance Measurements On Concrete Bridge Decks Using A Large-Area Electrode, Jeffrey David Barton
Vertical Electrical Impedance Measurements On Concrete Bridge Decks Using A Large-Area Electrode, Jeffrey David Barton
Theses and Dissertations
In regions where chloride-based deicing salts are applied to bridge decks, corrosion of the interior steel reinforcement is a major problem. Vertical electrical impedance (VEI) is an effective measurement technique to quantitatively assess the cover protection on bridges against aggressive chemical penetration of reinforced concrete. In its current form, traditional vertical electrical impedance is time-consuming and destructive because a direct connection to the reinforcing steel is required to provide a ground reference. A new method using a large-area electrode (LAE) permits VEI measurement without a direct electrical connection to the steel reinforcement. The LAE creates a nondestructive, semi-direct, low impedance …
Automated Impact Response Sounding For Accelerated Concrete Bridge Deck Inspection, Jacob Lynn Larsen
Automated Impact Response Sounding For Accelerated Concrete Bridge Deck Inspection, Jacob Lynn Larsen
Theses and Dissertations
Infrastructure deterioration is an international problem requiring significant attention. One particular manifestation of this deterioration is the occurrence of sub-surface cracking (delaminations) in reinforced concrete bridge decks. Of many techniques available for inspection, air-coupled impact-echo testing, or sounding, is a non-destructive evaluation technique to determine the presence and location of delaminations based upon the acoustic response of a bridge deck when struck by an impactor. In this work, two automated air-coupled impact echo sounding devices were designed and constructed. Each device included fast and repeatable impactors, moving platforms for traveling across a bridge deck, microphones for air-coupled sensing, distance measurement …
Body Armor Shape Sensing With Fiber Optic Sensors, Frederick Alexander Seng
Body Armor Shape Sensing With Fiber Optic Sensors, Frederick Alexander Seng
Theses and Dissertations
In this dissertation, the rate of the BFD during body armor impact is characterized with fiber Bragg gratings for the first time ever. The depth rate is characterized using a single fiber optic sensor, while the entire shape rate can be characterized using multiple fiber optic sensors. This is done with a final depth accuracy of less than 10% and a timing accuracy of 15% for BFDs as deep as 50 mm and impact event of less than 1 millisecond. The shape sensing method introduced in this dissertation is different from traditional fiber optic sensor shape reconstruction methods in the …
Adjustment Of Rapidscat Backscatter Measurements For Improved Radar Images, Garrett Scott Mcdonald
Adjustment Of Rapidscat Backscatter Measurements For Improved Radar Images, Garrett Scott Mcdonald
Theses and Dissertations
RapidScat is a spaceborne wind scatterometer mounted on the International Space Station (ISS). The RapidScat mission lasted from September 2014 to November 2016. RapidScat enables the measurement of diurnal patterns of sigma-0 measurements. This capability is possible because of the non-sun-synchronous orbit of the ISS, in which the local time of day (LTOD) of sigma-0 measurements gradually shifts over time in any given location. The ISS platform is a relatively unstable platform for wind scatterometers. Because of the varying attitude of the ISS, RapidScat experiences a constant variation of its pointing vector. Variations of the pointing vector cause variations in …
Using Quantitative Mri To Measure Cartilage Health, Laurel Jane Hales
Using Quantitative Mri To Measure Cartilage Health, Laurel Jane Hales
Theses and Dissertations
Osteoarthritis (OA) is one of the leading causes of disability world-wide. It affects 12% of all Americans ages 25-74 [1]. One of the challenges with OA, is that there are currently no clinically viable methods to measure the health of the cartilage before cartilage loss. There are no ways to replace or heal the cartilage after it has been lost. It is known that the early stages of OA involve a decrease in the amount of glycosaminoglycans (GAG), one of the main molecules in cartilage. This decrease in GAG leads to a change in the fixed charge density of the …
High Throughput Fpga Configuration Using A Custom Dma Configuration Controller, Peter William Zabriskie
High Throughput Fpga Configuration Using A Custom Dma Configuration Controller, Peter William Zabriskie
Theses and Dissertations
SRAM-based Field Programmable Gate Arrays (FPGAs) must be programmed with configuration data every time they are powered on. In addition to initially programming an FPGA, there are many other applications that require access to FPGA configuration memory such as partial reconfiguration, fault injection, and memory scrubbing. This thesis describes a system that provides high-speed, programmable configuration management for Xilinx FPGAs through external interfaces. This system is an improvement upon the JTAG Configuration Manager (JCM) previously created at BYU. The JCM consists of a custom I/O board paired with a MicroZed development board which includes a Xilinx ZYNQ SoC. This platform …