Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"Array measurements"”.
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LORE Approach for Phased Array Measurements and Noise Control of Landing Gears
… process was performed using phased arrays. To this end, phased array technologies were developed and a 26%-scale 777 main landing gear model was tested at the Virginia Tech Stability Wind Tunnel. Since phased array technologies present some issues leading to misinterpretation of …
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Seismic Site Response and Extraction of Dynamic Soil Behavior From Downhole Array Measurements
The presence of deep unconsolidated deposits in the upper Mississippi Embayment has an important impact on anticipated surface motions. PSHA-NL, probabilistic seismic hazard analysis with nonlinear site effects, can be used to estimate seismic hazard with the effect of deep deposits. This thesis …
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An investigation into inconsistencies between theoretical predictions and microphone array measurements of railway rolling noise
Theoretical models, such as TWINS, and microphone array measurements have been widely used to gain better understanding of rolling noise. However, the array measurements are often inconsistent with the TWINS predictions and give less prominence to the rail than the theoretical models. The …
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Seismic site response analysis and extraction of dynamic soil behavior and pore pressure response from downhole array measurements
… and pore pressure response from downhole array measurements. Downhole arrays are increasingly being deployed to measure motions at the ground surface and within the soil profile, with some arrays instrumented to measure the pore pressure response throughout the soil profile. The …
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Aeroacoustic Study of a Model-Scale Landing Gear in a Semi-Anechoic Wind Tunnel
… VT Anechoic Stability Wind Tunnel allowed noise measurements to be carried out using both a 63-elements microphone phased array and a linear array of 15 microphones. The noise sources were identified from the flyover view under various flow speeds and the phased array positioned in both the near …
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Bayesian Hidden Markov Models for finding DNA Copy Number Changes from SNP Genotyping Arrays
… CNVs from single nucleotide polymorphism (SNP) arrays. A Bayesian framework to reconstruct the DNA copy number sequence from the observed sequence of SNP array measurements is proposed. A Markov chain Monte Carlo (MCMC) algorithm, with a forward-backward stochastic algorithm for sampling DNA …
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Modeling and analysis of gene expression arrays
Gene expression arrays are a technology used to measure quantities of messenger ribonucleic acid (mRNA). Application of the technology involves a variety of physical processes beginning with the acquisition of mRNA samples and ending with the fluorescence imaging of a gene expression array. This …
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Efficient localization in a dispersive waveguide : applications in terrestrial continental shelves and on Europa
… conventional plane-wave beamforming of acoustic array measurements. The method is advantageous over existing source localization methods, since (1) no knowledge of the environment is required except that the received field should not be dominated by purely waterborne propagation, (2) range can be …
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Aeroacoustics of perforated drag plates for quiet transport aircraft
… by a perforated drag rudder. Acoustic phased array measurements of seven perforated plates in four different installation configurations were conducted in the Markham wind tunnel at Cambridge University to further investigate the noise mechanisms.
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Unsteady modes in the flowfield about an airfoil with a leading-edge horn-ice shape
… extrusion of a horn-ice shape casting, and an array of simulated icing configurations created using simple geometries. Time-averaged and unsteady static pressure measurements were acquired about the airfoil surface, along with unsteady wake velocity and surface hot-film array measurements. …
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Phase dynamics and magnetic field response of proximity-coupled superconductor arrays
… and measured electrical transport properties of arrays of proximity-coupled superconductor islands as a function of temperature, magnetic field, and bias current for several geometries. The weakly-coupled arrays, a physical realization of the frustrated XYmodel, show interesting behavior relating …
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Constrained Spectral Conditioning for the Spatial Mapping of Sound
… of aircraft models and/or components, arrays of microphones are utilized to spatially isolate distinct sources and mitigate interfering noise which contaminates single-microphone measurements. Array measurements are still biased by interfering noise which is coherent over the spatial …
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Aeroacoustics Applications to Jets and Rotors
<p>Aeroacoustics plays a critical role in the advancement of propulsion technologies for both conventional and emerging aerial systems. This dissertation investigates two key topics: noise suppression in supersonic rectangular jets and rotor noise characterization in hover and ground effect. Using …