Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Microfabrication (3)
- Aeronautical telemetry (2)
- Array signal processing (2)
- Backprojection (2)
- FPGA (2)
-
- MIMO (2)
- Quadrotor (2)
- ARROW (1)
- ARROWs (1)
- Aaron R. Hawkins (1)
- Air-coupled (1)
- Ambiguity function (1)
- Antennas (1)
- Atomic vapor (1)
- BSSFP (1)
- Bayesian filter (1)
- Beam steering (1)
- Beamforming (1)
- Bio-inspired swarms (1)
- Biomarkers (1)
- Biophotonics (1)
- Biotechnology (1)
- Brett Hansen (1)
- Bridge deck (1)
- CMOS (1)
- Calibration (1)
- Channel characterization (1)
- Circuit (1)
- Classification algorithms (1)
- Color (1)
- Publication Type
Articles 1 - 30 of 30
Full-Text Articles in Engineering
Liquid Core Waveguide Sensors With Single And Multi-Spot Excitation, Lynnell Uilani Wai Yee Zempoaltecatl
Liquid Core Waveguide Sensors With Single And Multi-Spot Excitation, Lynnell Uilani Wai Yee Zempoaltecatl
Theses and Dissertations
Using silicon based microfabrication and materials, a photonic platform, capable of single bioparticle analysis, has been developed. This platform combines liquid and hollow core waveguides on the micron-scale (5 µm x 12 µm) to isolate femtoliter sized sample volumes. Fluorescence excitation and signals in the visible range are directed into and out of the sample volume at an orthogonal angle to maximize signal-to-noise. In order to guide light in a low-index material antiresonant reflecting optical waveguides (ARROWs) were incorporated into the platform. This thesis reveals the development path of these structures over several device generations including innovations in material, geometries, …
Automatic Modulation Recognition For Aeronautical Telemetry, Jacob William Frogget
Automatic Modulation Recognition For Aeronautical Telemetry, Jacob William Frogget
Theses and Dissertations
This these explores automatic modulation recognition as applied to PCM/FM, SOQPSK- TG and ARTM CPM. It found that the likelihood based approach is intractable. The statistical features of the amplitude, phase and frequency are ineffective at distinguishing these modulation types. A method based on the phase changes between symbols is developed and shows that as long as symbol timing is established, this method can effectively distinguish PCM/FM, SOQPSK-TG and ARTM CPM for signal-to-noise ratios above 30 dB. Another method, the Bianchi-Loubaton- Sirven technique, was able to distinguish PCM/FM and SOQPSK-TG but was unable to distinguish ARTM CPM. A happy byproduct …
Delamination Detection In Concrete Using Disposable Impactors For Excitation, Anjali Narendra Patil
Delamination Detection In Concrete Using Disposable Impactors For Excitation, Anjali Narendra Patil
Theses and Dissertations
Delaminations in concrete bridge decks result primarily from corrosion of the reinforcing bars (or rebar). This corrosion leads to volumetric expansion of the rebar. When the rebar expands, concrete cracks, and there is a localized separation of the concrete cover from the underlying concrete. Impact-echo testing is an effective technique to map delaminations on concrete bridge decks. However, mapping speed is limited by necessary retrieval of the impactor for traditional tests. To achieve higher scanning speeds, it is advantageous to use both a non-contact measurement (air-coupled impact-echo) and disposable-impactor excitation. Disposable impactors have the potential advantage of achieving greater deck …
Intercalibration Of Quikscat And Oscat Land Backscatter, John Colin Barrus
Intercalibration Of Quikscat And Oscat Land Backscatter, John Colin Barrus
Theses and Dissertations
The Ku-band SeaWinds-on-QuikSCAT scatterometer (QuikSCAT) operated continuously from 1999 to 2009. Though its primary mission was to estimate global ocean winds, QuikSCAT has proven useful in a variety of geophysical studies using land backscatter measurements. The end of the primary QuikSCAT mission in 2009 has prompted interest for continuing the QuikSCAT land dataset with other scatterometers. The Oceansat-2 scatterometer (OSCAT), launched in 2009, is a viable candidate for continuing the QuikSCAT time series because of the similarities of both sensors in function and design. An important difference in the sensors is that they operate at slightly different incidence angles. Continuing …
Polarization Diversity In The Presence Of Multipath Propagation, Grant Taylor Wagner
Polarization Diversity In The Presence Of Multipath Propagation, Grant Taylor Wagner
Theses and Dissertations
The possibility of polarization diversity using left and right hand circular polarization (LHCP and RHCP) in the presence of multipath propagation is examined. We show that there are differences in the received signal for LHCP and RHCP for a number of realistic scenarios. Because multipath propagation can produce different LHCP and RCHP signals, there exists the possibility for diversity improvement involving the two polarizations.
Cooperative Target Tracking Enhanced With The Sequence Memoizer, Everett A. Bryan
Cooperative Target Tracking Enhanced With The Sequence Memoizer, Everett A. Bryan
Theses and Dissertations
Target tracking is an important part of video surveillance from a UAV. Tracking a target in an urban environment can be difficult because of the number of occlusions present in the environment. If multiple UAVs are used to track a target and the target behavior is learned autonomously by the UAV then the task may become easier. This thesis explores the hypothesis that an existing cooperative control algorithm can be enhanced by a language modeling algorithm to improve over time the target tracking performance of one or more ground targets in a dense urban environment. Observations of target behavior are …
Methods And Metrics For Human Interaction With Bio-Inspired Robot Swarms, Sean C. Kerman
Methods And Metrics For Human Interaction With Bio-Inspired Robot Swarms, Sean C. Kerman
Theses and Dissertations
In this thesis we propose methods and metrics for human interaction with bio-inspired robot teams. We refine the concept of a stakeholder and demonstrate how a human can use stakeholders to lead a swarm as well as switch the swarm between different collective behaviors. We extend the human interaction metrics of interaction time and interaction effort presented in [1] to swarm systems and introduce the concept of interaction effort. These metrics allow us to understand how well the system performs under human influence. We employ systems theory to estimate these metrics, which is useful because this can be done without …
Proteins In High Electric Fields, David Michael Landry
Proteins In High Electric Fields, David Michael Landry
Theses and Dissertations
Being able to control protein function directly and in real time is attractive. In this thesis, I discuss controlling protein activity using alternating current electric fields on the order of 1 MV/m. Since protein structures result in localized and/or protein-wide charge gradients, it is expected that a sufficiently high electric field applied across a protein should result in structural distortions which can temporarily alter or halt protein function. The field is set to oscillate above the influences of the electrochemical double layer effects (1 kHz) and below the level needed for hydrodynamic rotation of proteins (10 MHz). A device is …
Water Fat Separation With Multiple-Acquisition Balanced Steady-State Free Precession Mri, Michael A. Mendoza
Water Fat Separation With Multiple-Acquisition Balanced Steady-State Free Precession Mri, Michael A. Mendoza
Theses and Dissertations
Magnetic resonance imaging (MRI) is an important medical imaging technique for visualizing soft tissue structures in the body. It has the advantages of being noninvasive and, unlike x-ray, does not rely on ionizing radiation for imaging. In traditional hydrogen-based MRI, the strongest measured signals are generated from the hydrogen nuclei contained in water and fat molecules.Reliable and uniform water fat separation can be used to improve medical diagnosis. In many applications the water component is the primary signal of interest, while the fat component represents a signal which can obscure the underlying pathology or other features of interest. In other …
Interface Design And Synthesis For Structural Hybrid Microarchitectural Simulators, Zhuo Ruan
Interface Design And Synthesis For Structural Hybrid Microarchitectural Simulators, Zhuo Ruan
Theses and Dissertations
Computer architects have discovered the potential of using FPGAs to accelerate software microarchitectural simulators. One type of FPGA-accelerated microarchitectural simulator, namedthe hybrid structural microarchitectural simulator, is very promising. This is because a hybrid structural microarchitectural simulator combines structural software and hardware, and this particular organization provides both modeling flexibility and fast simulation speed. The performance of a hybrid simulator is significantly affected by how the interface between software and hardware is constructed. The work of this thesis creates an infrastructure, named Simulator Partitioning Research Infrastructure (SPRI), to implement the synthesis of hybrid structural microarchitectural simulators which includes simulator partitioning, simulator-to-hardware …
An Incremental Trace-Based Debug System For Field-Programmable Gate-Arrays, Jared Matthew Keeley
An Incremental Trace-Based Debug System For Field-Programmable Gate-Arrays, Jared Matthew Keeley
Theses and Dissertations
Modern society increasingly relies upon integrated circuits (ICs). It can be very costly if ICs do not function properly, and large portions of designer effort are spent on their verification. The use of field-programmable gate arrays (FPGAs) for verification and debug of ICs is increasing. FPGAs are faster than simulation and cost less than fabricating an ASIC prototype. However, the major challenge of using FPGAs for verification and debug is observability. Designers must use special techniques to observe the values of FPGA's internal signals. This thesis proposes a new method for increasing the observability of FPGAs and demonstrates its feasibility. …
Simulating The Performance Of Tracking A Spinning Missile At C-Band, Darren Robert Kartchner
Simulating The Performance Of Tracking A Spinning Missile At C-Band, Darren Robert Kartchner
Theses and Dissertations
The amplitude fluctuation induced by a spinning missile acts as a disturbance on tracking schemes that use sequential lobing (e.g., conscan). In addition, if a tracking system converts from S-band to C-band, the beamwidth is narrower and the wrap-around antenna on the missile requires more patches, and so the margin of error for tracking decreases. Tracking performance is simulated with a spinning missile with ballistic and fly-by trajectories while running at C-band. The spinning missile causes a periodic component in the pointing error, and when the scan frequency is an integer multiple of the roll rate, several tracking schemes lose …
Dynamic Nanochannels For Biosensing Applications, Joseph B. Oxborrow
Dynamic Nanochannels For Biosensing Applications, Joseph B. Oxborrow
Theses and Dissertations
Inexpensive label-free detection of biomarker panels in serum could revolutionize earlycancer diagnosis and treatment. Such detection capabilities may be possible with dynamicnanochannels in conjunction with electrical impedance measurement. In Dr. Greg Nordin's lab I designed, fabricated and tested several iterations of these sensors with polydimethyl-siloxane microfluidics. The final design yielded a dynamic nanochannel array sensor thatshowed a 140% impedance change when exposed to 14µM bovine serum albumin in phos-phate buffered saline. For the geometry and noise limits of the tested device, simulationsindicated that a minimum detectable concentration of 20pM with specifically bound strep-tavidin should be possible. However, the polydimethylsiloxane approach …
Microfluidic Valves Made From Polymerized Polyethylene Glycol Diacrylate, Gregory P. Nordin
Microfluidic Valves Made From Polymerized Polyethylene Glycol Diacrylate, Gregory P. Nordin
Faculty Publications
Pneumatically actuated, non-elastomeric membrane valves fabricated from polymerized polyethylene glycol diacrylate (poly-PEGDA) have been characterized for temporal response, valve closure, and long-term durability. A ∼100 ms valve opening time and a ∼20 ms closure time offer valve operation as fast as 8 Hz with potential for further improvement. Comparison of circular and rectangular valve geometries indicates that the surface area for membrane interaction in the valve region is important for valve performance. After initial fabrication, the fluid pressure required to open a closed circular valve is ∼50 kPa higher than the control pressure holding the valve closed. However, after ∼1000 …
Real-Time Color Treebasis Feature Matching On A Limited-Resource Hardware System, Garrett Sean Hartman
Real-Time Color Treebasis Feature Matching On A Limited-Resource Hardware System, Garrett Sean Hartman
Theses and Dissertations
This research has been conducted in order to create a robust, lightweight feature detecting and matching algorithm that builds upon the foundation set by the TreeBASIS algorithm. The goal is to create a color-based version of the TreeBASIS algorithm that uses less hardware resources than the original, is more accurate in its matching capabilities, can successfully be deployed on a resource-limited FPGA platform, and can process in real time. This thesis first presents the newly designed hardware tri-channel FAST Feature Detector that finds features in color. Next the TreeBASIS algorithm is analyzed to discover what improvements can be made in …
Gesture Analysis For Human-Computer Interface Using Profile-Matching Stereo Vision, Yung Ping Chang
Gesture Analysis For Human-Computer Interface Using Profile-Matching Stereo Vision, Yung Ping Chang
Theses and Dissertations
This thesis presents a novel profile shape matching stereo vision algorithm. This algorithm is able to obtain 3D information in real time from a pair of stereo images. This algorithm produces the 3D information by matching the profile intensity shapes on the same row of the two images from a stereo image pair. The advantage of this profile shape matching algorithm is that the detection of correspondences relies on intensity profile shape not on intensity values, which subject to lighting variations. The user can choose an interval of disparity, and then an object in a desired distance range can be …
Improvements In Diffusion Weighted Imaging Through A Composite Body And Insert Gradient Coil System, Peter Austin Jepsen
Improvements In Diffusion Weighted Imaging Through A Composite Body And Insert Gradient Coil System, Peter Austin Jepsen
Theses and Dissertations
Diffusion Magnetic Resonance Imaging (DMRI) is a class of Magnetic Resonance Imaging (MRI) techniques with broad medical applications ranging from characterization of tumors and brain damage to potential prediction of stroke. Gradient coil and signal-to- noise ratio (SNR) constraints limit spatial resolution, accuracy, and scan time in DMRI. Achieving high b-values (measures of a scan's sensitivity to diffusion) often require scans with long diffusion gradient pulses, leading to significant magnetic resonance (MR) signal decay before the signal can be sampled. This signal loss reduces the accuracy of diffusion parameter estimation. The ability to sample the MR signal sooner while maintaining …
Experiments With Gmti Radar Using Micro-Doppler, Benjamin Walter Dilsaver
Experiments With Gmti Radar Using Micro-Doppler, Benjamin Walter Dilsaver
Theses and Dissertations
As objects move, their changing shape produces a signature that can be measured by a radar system. That signature is called the micro-Doppler signature. The micro-Doppler signature of an object is a distinguishing characteristic for certain classes of objects. In this thesis features are extracted from the micro-Doppler signature and are used to classify objects. The scope of the objects is limited to humans walking and traveling vehicles. The micro-Doppler features are able to distinguish the two classes of objects. With a sufficient amount of training data, the micro-Doppler features may be used with learning algorithms to predict unknown objects …
Subthreshold Op Amp Design Based On The Conventional Cascode Stage, Kurtis Daniel Cahill
Subthreshold Op Amp Design Based On The Conventional Cascode Stage, Kurtis Daniel Cahill
Theses and Dissertations
Op amps are among the most-used components in electronic design. Their performance is important and is often measured in terms of gain, bandwidth, power consumption, and chip area. Although BJT amplifiers can achieve high gains and bandwidths, they tend to consume a lot of power. CMOS amplifiers utilizing the strong inversion region alone use less power than BJT amplifiers, but generally have lower gains and bandwidths. When CMOS SPICE models were improved to accurately simulate all regions of inversion, researchers began to test the performance of amplifiers operating in the weak and moderate inversion regions. Previous work had dealt with …
Backprojection For Synthetic Aperture Radar, Michael Israel Duersch
Backprojection For Synthetic Aperture Radar, Michael Israel Duersch
Theses and Dissertations
Synthetic aperture radar (SAR) is a type of radar capable of high-resolution coherent imaging. In order to produce coherent imagery from raw SAR data, an image formation algorithm is employed. The various image formation algorithms have strengths and weaknesses. As this work shows, time-domain backprojection is one algorithm whose strengths are particularly well-suited to use at low-altitudes. This work presents novel research in three areas regarding time-domain backprojection. The first key contribution of this work is a detailed analysis of SAR time-domain backprojection. The work derives a general form of backprojection from first principles. It characterizes the sensitivities of backprojection …
Arrow-Based On-Chip Alkali Vapor-Cell Development, John Frederick Hulbert
Arrow-Based On-Chip Alkali Vapor-Cell Development, John Frederick Hulbert
Theses and Dissertations
The author presents the successful development of an on-chip, monolithic, integrated rubidium vapor-cell. These vapor-cells integrate ridge waveguide techniques with hollow-core waveguiding technology known as Anti-Resonant Reflecting Optical Waveguides (ARROWs). These devices are manufactured on-site in BYU's Integrated Microelectronic Laboratory (IML) using common silicon wafer microfabrication techniques. The ARROW platform fabrication is outlined, but the bulk of the dissertation focuses on novel packaging techniques that allow for the successful introduction and sealing of rubidium vapor into these micro-sized vapor-cells. The unique geometries and materials utilized in the ARROW platform render common vapor-cell sealing techniques unusable. The development of three generations …
Techniques For Li-Bdn Synthesis For Hybrid Microarchitectural Simulation, Tyler S. Harris
Techniques For Li-Bdn Synthesis For Hybrid Microarchitectural Simulation, Tyler S. Harris
Theses and Dissertations
Computer designers rely upon near-cycle-accurate microarchitectural simulation to explore the design space of new systems. Unfortunately, such simulators are becoming increasingly slow as systems become more complex. Hybrid simulators which offload some of the simulation work onto FPGAs can increase the speed; however, such simulators must be automatically synthesized or the time to design them becomes prohibitive. Furthermore, FPGA implementations of simulators may require multiple FPGA clock cycles to implement behavior that takes place within one simulated clock cycle, making correct arbitrary composition of simulator components impossible and limiting the amount of hardware concurrency which can be achieved. Latency-Insensitive Bounded …
Analysis Of An Improved Imu-Based Observer For Multirotor Helicopters, John Charles Macdonald, Robert C. Leishman, Randal W. Beard, Timothy W. Mclain
Analysis Of An Improved Imu-Based Observer For Multirotor Helicopters, John Charles Macdonald, Robert C. Leishman, Randal W. Beard, Timothy W. Mclain
Faculty Publications
Multirotor helicopters are increasingly popular platforms in the robotics community. Making them fully autonomous requires accurate state estimation. We review an improved dynamic model for multirotor helicopters and analyze the observability properties of an estimator based on this model. The model allows better use of IMU data to facilitate accurate state estimates even when updates from a sensor measuring position become less frequent and less accurate. We demonstrate that the position update rate can be cut in half versus typical approaches while maintaining the same accuracy. We also find that velocity estimates are at least twice as accurate no matter …
Modeling, Parameter Estimation, And Navigation Of Indoor Quadrotor Robots, Stephen C. Quebe
Modeling, Parameter Estimation, And Navigation Of Indoor Quadrotor Robots, Stephen C. Quebe
Theses and Dissertations
This thesis discusses topics relevant to indoor unmanned quadrotor navigation and control. These topics include: quadrotor modeling, sensor modeling, quadrotor parameter estimation, sensor calibration, quadrotor state estimation using onboard sensors, and cooperative GPS navigation. Modeling the quadrotor, sensor modeling, and parameter estimation are essential components for quadrotor navigation and control. This thesis investigates prior work and organizes a wide variety of models and calibration methods that enable indoor unmanned quadrotor flight. Quadrotor parameter estimation using a particle filter is a contribution that extends current research in the area. This contribution is novel in that it applies the particle filter specifically …
Improved Channel Probing For Secret Key Generation With Multiple Antenna Systems, Britton T. Quist
Improved Channel Probing For Secret Key Generation With Multiple Antenna Systems, Britton T. Quist
Theses and Dissertations
Establishing secret keys from the commonly-observed randomness of reciprocal wireless propagation channels has recently received considerable attention. In this work we propose improved strategies for channel estimation between MIMO or beamforming systems for secret key generation. The amount of mutual information that can be extracted from the channel matrix estimates is determined by the quality of channel matrix estimates. By allocating increased energy to channel estimation for higher gain beamforming combinations at the expense of low-gain combinations, key establishment performance can be increased. Formalizing the notion of preferential energy allocation to the most efficient excitations is the central theme of …
An Investigation Into Ground Moving Target Indication (Gmti) Using A Single-Channel Synthetic Aperture Radar (Sar), Joseph W. Winkler
An Investigation Into Ground Moving Target Indication (Gmti) Using A Single-Channel Synthetic Aperture Radar (Sar), Joseph W. Winkler
Theses and Dissertations
Synthetic aperture radar (SAR) was originally designed as an airborne ground-imaging radar technology. But it has long been desired to also be able to use SAR imaging systems to detect, locate, and track moving ground targets, a process called Ground Moving Target Indication (GMTI). Unfortunately, due to the nature of how SAR works, it is inherently poorly suited to the task of GMTI. SAR only focuses targets and image features that remain stationary during the data collection. A moving ground target therefore does not focus in a conventional SAR image, which complicates the process of performing GMTI with SAR systems. …
Microfabrication Processes And Advancements In Planar Electrode Ion Traps As Mass Spectrometers, Brett Jacob Hansen
Microfabrication Processes And Advancements In Planar Electrode Ion Traps As Mass Spectrometers, Brett Jacob Hansen
Theses and Dissertations
This dissertation presents advances in the development of planar electrode ion traps. An ion trap is a device that can be used in mass analysis applications. Electrode surfaces create an electric field profile that trap ionized molecules of an analyte. The electric fields can then be manipulated to mass-selectively eject ions out of the trap into a detector. The resulting data can be used to analyze molecular structure and composition of an unknown compound. Conventional ion traps require machined electrode surfaces to form the electric trapping field. This class of electrode presents significant obstacles when attempting to miniaturize ion traps …
Covariance Modeling And Space-Time Coding For Mimo Systems, Farnaz Karimdady Sharifabad
Covariance Modeling And Space-Time Coding For Mimo Systems, Farnaz Karimdady Sharifabad
Theses and Dissertations
The full spatial covariance matrix of the multiple input multiple-output (MIMO) channel is an important quantity in channel modeling, communication system signal processing, and performance analysis, and therefore this matrix forms the heart of the research outlined in this dissertation. The work begins with an investigation of a generalized framework for computing the full MIMO spatial covariance based on the power angular spectrum (PAS) of the multipath field and the transmit and receive antenna element radiation patterns. For the case of uniform linear arrays and when the PAS clusters satisfy uniform, truncated Gaussian, or truncated Laplacian distributions, a series expansion …
Directional Electric Field Sensing Using Slab Coupled Optical Fiber Sensors, Daniel Theodore Perry
Directional Electric Field Sensing Using Slab Coupled Optical Fiber Sensors, Daniel Theodore Perry
Theses and Dissertations
This thesis provides the details of a multi-axis electric field sensor. The sensing element consists of three slab coupled optical fiber sensors that are combined to allow directional electric field sensing. The packaged three-axis sensor has a small cross-sectional area of 0.5 cm x 0.5 cm achieved by using an x-cut crystal. The method is described that uses a sensitivity-matrix approach to map the measurements to field components. The calibration and testing are described resulting in an average error of 1.5º.This work also includes a description of the packaging method used as well as a thorough analysis of the directional …
Final Report: Multipath Modeling And Mitigation Using Multiple Antennas (M4a), Michael Rice
Final Report: Multipath Modeling And Mitigation Using Multiple Antennas (M4a), Michael Rice
Faculty Publications
This report documents the effort under contract W900KK-09-C-0016. The contract comprised four phases spanning 15 April 2009 to 1 December 2012. The relationship between the effort associated with each phase and the contents of this report are as follows: Phase 1 was devoted exclusively to the channel sounding experiments with the UH-1H helicopter. The experimental setup, procedure, and results for the channel sounding experiments at Cairns Army Airfield and Patuxent River are described in Chapter 2. Good, usable data at upper L-band was captured during the Cairns Army Airfield experiments. Phase 2 was devoted to the channel sounding experiments with …