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 8 of 8 for “"geometrical spreading"”.
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Anisotropic geometrical-spreading correction and its application in azimuthal AVO analysis
Includes bibliographical references.
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The determination of QLg and Qc as a function of frequency in the crust of Virginia and its environs
… of attenuation may be affected by incorrect geometrical spreading models, 2) the size of the study area may affect the estimates, and 3) estimates of Q<sub>(Lg,C)</sub> made for broad regions may be biased by zones of differing tectonic activity. Of these factors, only the effects of changing …
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Accuracy bounds for normal-incidence acoustic structure estimation
… classes of simple physical models, which exclude geometrical spreading and attenuation, are developed: one in which the properties of the medium change continuously with depth, and one in which they change discretely. Given these reasonable models, estimation accuracy is studied by computing a …
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Numerical investigation of air vehicle noise propagation effects
… method. The Burgers equation incorporates geometrical spreading, atmospheric absorption and nonlinear distortion effects. Towards this study, the HELISHAPE descent case experimental database is used. Blade Vortex Interaction (BVI) noise, the dominant noise contributor during descent, is …
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Coalescence of nonlinear acoustic waves, with application to supersonic jet noise
… the intersection angle, waveform duration, and geometrical spreading. Experiments are discussed that employ a spark source to generate controlled, coalescing waves in order to examine the phenomenon. The interacting waves are tracked using schlieren imaging to compare waveform steepening in …
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Seismic Source and Attenuation Studies in the Central and Eastern United States
To better understand the ground motion and associated seismic hazard of earthquakes in the central and eastern United States (CEUS), this dissertation focuses on the source parameters and wave propagation characteristics of both tectonic earthquakes and induced earthquakes in the CEUS. The …
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Q Models for Lg Wave Attenuation in the Central United States
A series of small- to moderate-sized earthquakes occurred in Arkansas, Oklahoma and Texas from 2010 to 2012, coinciding with the arrival of the EarthScope Transportable Array (TA). The data the TA recorded from those earthquakes provide a unique opportunity to study attenuation of the Lg phase in …
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Sviluppo di metodologie di localizzazione nel contesto del Comprehensive Nuclear Test-Ban Treaty
… was not used. We have obtained that the relevant geometrical spreading, noticeable in the standard locations (namely the locations produced by the analysts of the International Data Center (IDC) of the CTBT Organization, assumed as our reference), has been considerably reduced by the application …