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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Scattering of acoustic and elastic waves by surfaces of arbitrary shape

Banaugh, Robert Peter. January 1962 (has links)
Thesis (Ph. D. in Engineering Science - Mechanical Engineering)--University of California, Berkeley, June 1962. / TID-4500 (17th Ed.). Bibliography: l. 108-110.
22

Nonlinear parametric wave model compared with field data

Melo, Jose Luis Branco Seabra de. January 1985 (has links)
Thesis (M.S.)--Naval Postgraduate School, 1985. / Includes bibliographical references (p. 60).
23

Ocean swell wave groups from wave record analysis

Smith, Raymond C. January 1974 (has links)
Thesis (M.S.)--Naval Postgraduate School, 1974. / Includes bibliographical references (p. 40).
24

Verification of Fleet Numerical Weather Central wave analyses

Massicot, William Harvey. January 1972 (has links)
Thesis (M.S.)--Naval Postgraduate School, 1972. / Cover title. "March 1972." Includes bibliographical references (leaf 85).
25

Interpretation of equatorial current meter data as internal waves

Blumenthal, Martin Benno. January 1900 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1987. / "January 1987." Includes bibliographical references (p. 376-381).
26

Propagation of Alfvén waves in the WVU HELIX device

Compton, Christopher S. January 2006 (has links)
Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains iv, 22 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 22).
27

The effect of breaking waves on a coupled model of wind and ocean surface waves /

Kukulka, Tobias. January 2006 (has links)
Thesis (Ph. D.)--University of Rhode Island, 2006. / Typescript. Includes bibliographical references (leaves 178-183).
28

Estimation of planetary wave parameters from the data of the 1981 Ocean Acoustic Tomography Experiment /

Chiu, Ching-Sang. January 1900 (has links)
Thesis (D.S.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1985. / "October 1985." Includes bibliographical references (p. 251-255).
29

Velocity-dip analysis in the plane-wave domain

Cabrera Gomez, Jose Julian January 1990 (has links)
Plane-wave decomposition and slant stack transformation have recently gained much interest as viable routes to perform a variety of prestack processing tasks, such as velocity estimation, migration, filtering, deconvolution, and velocity inversion. To further complement the current advances, the problem of earth model parameter estimation and prestack structural imaging are addressed in this work. Unlike existing methods, the algorithms presented here make a novel and systematic use of the plane-wave domain to determine migration and interval velocities, interface dip angles and common-shot gather reflector images. To start, a method is developed to estimate migration velocities and interface dip angles in earth models composed of planar, dipping reflecting interfaces separating homogeneous layers, and where straight-ray travelpaths to the reflecting interfaces can be assumed. The method consists of transforming a common-shot gather into the plane-wave domain, where a semblance analysis search along cosinusoid trajectories is performed. Since the cosinusoid trajectories are functions of the migration velocity and interface dip angle, selection of the maximum semblance values yields the best estimates to the desired earth model parameters. To remove the straight-ray assumption of the velocity-dip analysis method, a recursive technique is developed to estimate interval velocities and interface dip angles via a ray tracing algorithm. This technique essentially generates plane-wave domain traveltimes for a range of interval velocities and interface dip angles, and computes the error between the generated and observed plane-wave traveltimes. The minimum error determines the best estimates of the earth model parameters. With the information attained in the velocity-dip analysis algorithm, a plane-wave based imaging method is developed to produce prestack common-shot gather images of the reflecting interfaces. The method consists of transforming a common-shot gather into the plane-wave domain, where a velocity-dip semblance analysis is performed. Then, the plane-wave components are downward extrapolated and recombined via a dip-incorporated inverse slant-stack transformation to produce the spherical-wave field that would have been recorded by receivers placed on the reflecting interfaces. The dip incorporation consists of redefining the angle of emergence of the plane waves. Finally, a simple mapping algorithm converts the offset and time coordinates of the reconstructed wave field to the true horizontal location and two-way vertical time of the reflection points. This results in the desired prestack migrated images of the reflecting interfaces. In this thesis, a novel algorithm to perform plane-wave decomposition via Fourier transforms is also proposed. This algorithm consists of the application of the double fast Fourier transform to the input data, followed by complex vector multiplications with essentially the Fourier representation of the Bessel function J0 . A numerical singularity is avoided by applying an analytical expression that approximately accounts for the singular point contribution. An inverse fast Fourier transform from frequency to time gives the desired plane-wave seismogram. The techniques proposed in this work have yielded encouraging results on synthetic and field data examples. The examples demonstrate, for the first time, the systematic use of the plane-wave domain in processing seismic reflection data from common-shot gather data to the plane-wave domain, to velocity and dip angle analysis and to prestack structural imaging. It is believed that the results from this work will help researchers as well as practising geophysicists to become better acquainted with plane-wave domain processing. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
30

Low-frequency vorticity waves over strong topography

Gratton, Yves January 1983 (has links)
This thesis addresses the general problem of vorticity waves propagating over steeply sloping topography, in the presence of stratification and rotation. From the inviscid unforced long-wave equations for a two-layer fluid on an f-plane, it is shown that, as long as the ratio of the upper to lower layer depths is small, semi-enclosed and enclosed basins can sustain low-frequency, short scale, surface-intensified motions. Simple analytical solutions are to be found only if the upper to lower layer depths ratio is small. Then, we obtain a set of equations which describes a barotropic wave which forces a baroclinic response through topographic coupling. Two bottom profiles are considered: linear and parabolic. Solutions are found with and without the small slope approximation. It is shown that the small slope approximation underestimates all the parameters of low-frequency topographic waves, even when the slope is small. The theory is compared with observations from the Strait of Georgia and with a numerical model of the Saint Lawrence estuary. It is found that, for bathymetric profiles similar to those of the Strait of Georgia (linear) and the Saint Lawrence (parabolic), bur model provides a better fit to the topography, leads to surface-intensified motions and produces cross-channel velocities very similar to those observed in situ. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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