Approved for public release, distribution unlimited / Underwater Acoustic Networks (UANs) hold enormous potential for both military and civilian applications. However, current networking protocols implemented are often sub-optimal, resulting in severely underutilized networks. We believe one of the key reasons for this shortcoming is a lack of good underwater acoustic propagation models for simulation packages used to evaluate UAN protocols. This thesis addresses this problem by developing a computationally-efficient approximation of a sophisticated analytical model called Monterey-Miami Parabolic Equation model (MMPE). The approximation can then be used to support UAN simulations. The characteristics of the problem make a statistical approach the methodology of choice for this study. Data was generated using the MMPE model. The data was used to develop a much less complex approximation for which an OpNet simulation module could be developed. The latter allows UAN operation to be modeled over a collection of nodes and over an interval of time, rather than a single point in time between two specific nodes, as modeled by the original equation. The result of this research can enable a more complete analysis of network enabling protocols and support more informed decisions regarding the appropriate node topology and protocols to use in order to increase network performance.

No description available.

by Julian Guerra. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web. / This work seeks to understand water turbine noise generation and to make preliminary estimations of the noise levels. Any structure attached to a turbine upstream its blades will generate unsteady fluctuating loads on the blade's surface, which are proportional to the radiated acoustic pressure. The noise levels of a simplified turbine based on existing designs surpass the ambient noise levels of the ocean at low frequencies (< 20 Hz) by approximately 50 dB ref 1 μPa and stay under the ambient noise levels at higher frequencies for a blade-passing frequency of 0.83 Hz and point of observation (100 m, 45 degrees, 45 degrees) from the hub. Streamlining the cross-section of the upstream structure as well as reducing its width decrease the noise levels by approximately 40 dB ref 1 μPa, at low frequencies and moderately increase them at higher frequencies. Increasing the structure-rotor distance decreases the noise levels with increasing frequencies (> 30 Hz).

Thesis (Sc. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1987. / "January 1987." Bibliography: p. 193-200.

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Bourke, Robert H. ; Coppens, Alan B. "September 1990." Description based on title screen as viewed on December 30, 2009. DTIC Identifiers: Raymode model, PE model. Author(s) subject terms: Oceanographic, acoustic survey, East Ionian Sea, PEmodel. Includes bibliographical references (p. 86-88). Also available in print.

Thesis (Ph. D.)--University of Rhode Island, 2003. / Typescript. Includes bibliographical references (pt. 2, leaves 288-304).

Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, June 2004. / Thesis advisor(s): Ching-Sang Chiu, Curtis A. Collins. Includes bibliographical references (p. 43-44). Also available online.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, March 2004. / Thesis advisor(s): Geoffrey Xie, John Gibson. Includes bibliographical references (p. 151-152). Also available online.

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, September 2003. / Thesis advisor(s): Kevin B. Smith, Daphne Kapolka. Includes bibliographical references (p. 69-71). Also available online.

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Kevin Smith, Roy Streit. Includes bibliographical references (p. 95-100). Also available online.