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 20 of 1738 for “"Attenuation"”.
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Arenavirus Attenuation Mechanisms
Arenaviridae derives from the Latin word ‘arena’ meaning ‘sand’. When scientists first looked at arenavirus virions by transmission electron microscopy, they saw pleomorphic particles that had a sandy appearance. This sandy appearance was due to host ribosomes being incorporated into the virions. …
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Active noise attenuation
Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1980.
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Interval attenuation estimation
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1998.
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Attenuation of volcanic seismic signals
… fluid-solid boundaries. The amplitude decay or attenuation of these earthquake signals can be decomposed into radiative and intrinsic components, and in this way yield information about both the geometry and fluid properties of the resonating source body. This thesis presents a study of the …
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Statistical methods of earthquake attenuation
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Civil Engineering, 1987
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Genetic Determinants of Junin Virus Attenuation
… population at risk. However, the mechanism of attenuation of this strain is still largely unknown. Therefore, the identification and functional characterization of viral genetic factors implicated in JUNV pathogenesis or attenuation would significantly improve the understanding of the molecular …
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Blast wave attenuation using liquid sheets
… examined it was found that, with regard to the attenuation of the 2-4 kHz region of the spectra, all the liquid sheet results showed an improvement in relation to the rigid sheet results.
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Sn attenuation in the Northeast China
… In this thesis a study of seismic wave attenuation characterized from regional earthquakes in northeast China is presented. Regional phase Sn wave is used to map lateral variations of shear wave Q. This method allows us to measure, in some detail, to map the effective shear wave …
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Ultrasonic transducers for wideband attenuation measurements
… The principle of the measurement is based on the attenuation characteristics of the medium over a frequency range extending from 0.1 MHz to 10 MHz. This wide range and the highly attenuating medium (typically 3 dB/cm) require therefore that the ultrasonic transducers exhibit efficient wideband …
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Attenuation Field Estimation Using Radio Tomography
Radio Tomographic imaging (RTI) is an exciting new field that utilizes a sensor network of a large number of relatively simple radio nodes for inverse imaging, utilizing similar mathematical algorithms to those used in medical imaging. Previous work in this field has almost exclusively focused on …
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Propapation and attenuation characteristics of multilayered media
… use of complex sound speeds to simulate bottom attenuation is reviewed. A numerical instability inherent to the technique that arises during the use of complex sound speeds is investigated. The algorithm is also applied to a deep ocean profile, and the solution characteristics discussed. …
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Backscatter and Attenuation Characterization of Ventricular Myocardium
… In this Dissertation, integrated backscatter and attenuation analyses were performed on midgestational fetal hearts to assess potential differences in the left and right ventricular myocardium. The hearts were interrogated using a 50 MHz transducer that enabled finer spatial resolution than could …
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Study of sound attenuation in elliptic ducts
… dissipative mufflers usually have a sound attenuation over a wider frequency range. However, pressure drop and particle clogging limit their application. The sound attenuation characteristics of a muffler is dependent on various factors like shape and size of the muffler, orientations of …
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Attenuation in igneous rocks at seismic frequencies
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1979.
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Modeling the dynamic behavior of rain attenuation
… duration statistics for one site using measured attenuation data at another site. This technique is evaluated by comparing predicted and experimental results for several locations, frequencies, elevation angles and polarizations.
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Adaptive Stochastic Systems: Estimation, Filtering, And Noise Attenuation
… <p>Next we consider problems in noise attenuation in systems with unmodeled dynamics and stochastic signal errors. A robust two-phase design procedure is developed which first estimates the signal in a simplified form, and then applies a control to tune out the noise. Worst-case error …
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AN INVESTIGATION OF SEISMIC ATTENUATION IN MARINE SEDIMENTS
… have been relatively few investigations into the attenuation properties of unconsolidated sediments using marine surface seismic data. Several methods of measuring attenuation were assessed for reliability in a noise-free case and with the addition of noise using a set of synthetically absorbed …
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