In this thesis we consider the problem of the dynamic fluid-structure interaction between a finite elastic structure and the acoustic field in an unbounded fluid-filled exterior domain. We formulate the exterior acoustic problem as an integral equation over the structure surface. However, the classical boundary integral equation formulations of this problem do not have unique solutions at certain characteristic frequencies (which depend on the surface) and it is necessary to employ modified boundary integral equation formulations which are valid for all frequencies. The modified integral equation formulation used here involves certain arbitrary parameters and we shall study the effect of these parameters on the stability and accuracy of the numerical methods used to solve the integral equation. We then couple the boundary element analysis of the exterior acoustic problem with a finite element analysis of the elastic structure to investigate the interaction between the structure and the acoustic field. Recently there has been some controversy over whether or not the coupled problem suffers from the non-uniqueness problems associated with the classical integral equation formulations of the exterior acoustic problem. We resolve this question by demonstrating that the solution to the coupled problem is not unique at the characteristic frequencies and that we need to employ an integral equation formulation valid for all frequencies. We discuss the accuracy of our numerical results for both the acoustic problem and the coupled problem, for a number of axisymmetric and fully three-dimensional problems. Finally, we apply our method to the problem of a piezoelectric sonar transducer transmitting an acoustic signal in water, and observe reasonable agreement between our theoretical predictions and some experimental results.

Underwater has always been attractive and curiosity for human beings. Exploring, employing and being part of underwater has been a challenge for them at all times. The first underwater structures were products of engineering studies and have been used for fields of scientific researches and observations, military purposes and obtaining energy for centuries. However, underwater is a new medium for human for accommodation and entertainment purposes / and correspondingly new subject which is worth to study for architects. Designing underwater structures became a race between architects and engineers during last years. Accordingly, underwater hotel and restaurant projects were realized. Currently, underwater structures can uttered as a fantasy and a new understanding for architecture, however in the future underwater may be suggested as a new accommodation area. The thesis aims to point out the design considerations of underwater structures from not merely engineering, but also architectural aspects. Designing underwater has its own principles and characteristics and these should be asserted under the light of the study on former structures. On the other hand, basic criteria and purposes of architectural aspects for underwater structures should be defined to meet requirements of human. To achieve that, parameters will be pointed out and interpreted according to the conditions and limitations of the environment in order to set the fundamentals for architectural approaches to underwater design. A comparative study on contemporary examples will be made to evaluate these parameters and comments will be made under the light of the evaluation.

This thesis describes a vision-based method for ROV¡¦s underwater pipeline recognition task. In this research, we tried to overcome the poor image quality of the underwater circumstance and the condition when seaweed is in the scene. Edge information and line feature of the pipeline are used in this method. Edge image is obtained after preprocessing to extract line feature. In this thesis we focused on the recognition of pipeline, trying to provide useful navigation information for further development of the ROV¡¦s control system.

Thesis (M.S.M.E.)--University of Washington, 2009. / Includes bibliographical references (p.75-77). Also available on the World Wide Web.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains viii, 113 p. : ill. (some col.), col. map. Vita. Includes abstract. Includes bibliographical references.

Thesis (M.S.M.E.)--University of Washington, 2009. / Title from Web page (viewed on Feb. 3, 2010). Includes bibliographical references (p.75-77).

Thesis (Ph. D.)--University of Rhode Island, 2003. / Typescript. Includes bibliographical references (leaves 139-146).

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, June 2004. / Thesis advisor(s): Kevin B. Smith. Includes bibliographical references (p. 57-58). Also available online.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, June 2004. / Thesis advisor(s): Young S. Shin. Includes bibliographical references (p. 69-70). Also available online.

Thesis (M.S.) in Electrical Engineering--University of Maine, 2002. / Includes vita. Includes bibliographical references (leaf 104).