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Now showing items 31-40 of 867

#### Spectral feature classification of oceanographic processes using an autonomous underwater vehicle

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2000-06)

The thesis develops and demonstrates methods of classifying ocean processes using
an underwater moving platform such as an Autonomous Underwater Vehicle (AUV).
The "mingled spectrum principle" is established which concisely ...

#### Geoacoustic inversion by mode amplitude perturbation

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-02)

This thesis introduces an algorithm for inverting for the geoacoustic
properties of the seafloor in shallow water. The input data required by the
algorithm are estimates of the amplitudes of the normal modes excited by ...

#### Response of a pendulum spar to 2-dimensional random waves and a uniform current

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1978-08)

A linearized theory for the response of a circular pendulum
spar in 2-dimensional waves and a uniform current is developed. The linear forces on the cylinder are predicted using an approximate potential flow theory for ...

#### Shear of small vertical scale observed in the permanent oceanic thermocline

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1971-01)

Two shear experiments performed in the permanent thermocline are described and analyzed in this thesis. The first employed dye streak techniques to gain fractional meter vertical resolution. Shears
with small vertical ...

#### Numerical and experimental analysis of initial water impact of an air-dropped REMUS AUV

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2005-02)

The initial water impact of a free-falling object is primarily related to the fluid forces on the wetted surface of the object. The shape-dependent added-mass coefficients express the fluid forces integrated
over the body, ...

#### Nonlinear interactions among standing surface and internal gravity waves

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1972-06)

A laboratory study has been undertaken to measure the momentum transfer from surface to internal gravity waves in a nonlinear, resonant interaction. The interacting waves form triads for which σ1s - σ2s ± σI = 0 and κ1s - ...

#### Propapation and attenuation characteristics of multilayered media

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1979)

An algorithm is proposed to numerically integrate the inhomogeneous
depth-separated wave equation using a state variable technique. The solution
obtained for two simple shallow water models is shown to agree well
with ...

#### Drag coefficients of vibrating synthetic rope

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1971-09)

The drag, amplitude, frequency tension, diameter and length of synthetic ropes vibrating because of vortex-induced forces, and net vibrating at different tensions were measured. Photographs were taken of the vortices. Drag ...

#### Chemosynthetic communities in the deep sea : ecological studies

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1989-05)

Deep-sea benthic communities dependent on chemosynthetic primary
production are associated with areas of active venting of chemically-modified
seawater. Patterns in the distribution of species that occur
at hydrothermal ...

#### Large-area visually augmented navigation for autonomous underwater vehicles

(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2005-06)

This thesis describes a vision-based, large-area, simultaneous localization and mapping (SLAM) algorithm that respects the low-overlap imagery constraints typical of autonomous underwater vehicles (AUVs) while exploiting ...