Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1995. / Includes bibliographical references (leaves 181-188). / by Chun-Yi Hu. / Ph.D.

Thesis (Nav.E. and S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, February 2001. / Includes bibliographical references (leaves 113-114). / Waterborne mines pose an asymmetric threat to naval forces. Their presence, whether actual or perceived, creates a low-cost yet very powerful deterrent that is notoriously dangerous and time consuming to counter. In recent years, autonomous underwater vehicles (AUV) have emerged as a viable technology for conducting underwater search, survey, and clearance operations in support of the mine countermeasures (MCM) mission. With continued advances in core technologies such as sensing, navigation, and communication, future AUV MCM operations are likely to involve many vehicles working together to enhance overall capability. Given the almost endless number of design and configuration possibilities for multiple-AUV MCM systems, it is important to understand the cost-benefit trade-offs associated with these systems. This thesis develops an analytical framework for evaluating advanced AUV MCM system concepts. The methodology is based on an existing approach for naval ship design. For the MCM application, distinct performance and effectiveness metrics are used to describe a series of AUV systems in terms of physical/performance characteristics and then to translate those characteristics into numeric values reflecting the mission-effectiveness of each system. The mission effectiveness parameters are organized into a hierarchy and weighted, using Analytical Hierarchy Process (AHP) techniques, according to the warfighter's preferences for a given operational scenario. Utility functions and modeling provide means of relating the effectiveness metrics to the system-level performance parameters. Implementation of this approach involves two computer-based models: a system model and an effectiveness model, which collectively perform the tasks just described. The evaluation framework is demonstrated using two simple case studies involving notional AUV MCM systems. The thesis conclusion discusses applications and future development potential for the evaluation model. / by Trent R. Gooding. / Nav.E.and S.M.

Thesis (Nav.E. and S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1998. / Includes bibliographical references (p. 133-136). / The 1990 Naval Sea Systems Command Ship Design, Acquisition and Construction (DAC) Study provides a stepping stone for the implementation of improvements towards optimizing ship performance, cutting acquisition costs, and reducing design cycle time. With respect to performance, significant advances in computing power coupled with customer oriented design (QFD, AHP, evolutionary optimization, etc) provide both improvements and direct means to measure effectiveness of improvements. As for cost, implementation of world class building and design techniques (concurrent engineering, group technology, CAD/CAM/CAE, etc) coupled with higher fidelity costing methods (ACEIT, PODAC, etc) provide savings and direct measures of effectiveness. Cycle time improvements have also been implemented (IPTs, Open System Architecture, 3-D Product Models, etc). However, ship design managers have been unable to identify and quantify design process effectiveness with respect to the impact of those proposed cycle time improvements. In order to understand the impact of cycle time improvements, it is necessary to examine the mechanisms which have lead to increased cycle time including external influences (such as increasing technological complexity and budgetary pressures), internal process delays (information flow delays and approval delays) and feedback processes (design iteration, error propagation and design change.) Modeling of such mechanisms, using the methods of System Dynamics, provides a means to study past programs (in particular, the DDG-51Destroyer program of the 1980' s), and to study the anticipated savings that can be generated with the introduction of process improvements. Of particular interest in modeling the naval ship design process with System Dynamics is the flow of design information. Traditional process analysis methods based on the design spiral represent the progression of design tasks as a linear process. However, actual design data propagation (a fundamental property resulting from the physical and architectural relationships of total ship systems) shows the process to be highly non-linear. These nonlinearities are captured by system dynamics, providing a simulation tool that more fully captures the impacts of process improvements as they relate to the naval ship design process. / by Thomas A. Laverghetta. / Nav.E.and S.M.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1998. / Includes bibliographical references (p. 315-329). / by Matthew P. Tedesco. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1995. / "June 1995." / Includes bibliographical references (leaves 90-91). / by Leonidas M. Th. Kamabanis. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2001. / Includes bibliographical references (leaves 67-69). / This paper demonstrates a technique for computing the long-range sound pressure field around a penetrable conical seamount. The pressure field is generated by a harmonic point source. The seamount is positioned in a vertically stratified ocean. It is modeled as an outgrowth of the sediment layer covering the ocean bottom. First, the seamount is decomposed into superposed rings of diameters increasing with the depth. Thus the problem reduces to a cylindrically layered system. Then, the method of normal modes is used to compute the sound pressure field in each layer. In order to maintain numerical stability, the Direct Global Matrix approach is used. The radial eigenfunctions are expressed as functions of normalized Hankel and Bessel functions, and the linear system that arise is organized in an unconditionally stable matrix. The results show a perturbation zone behind the seamount. It is bounded by two lines going from the source and tangent to the ring that is at the depth of the source. The values of the sound pressure inside the perturbation zone can be higher or lower than the values outside of it, according to the dimensions of the seamount. / by Jérémie Eskenazi. / S.M.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1988. / Includes bibliographical references. / Peter Capozucca. / M.S.

Thesis (Ocean. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1995. / Includes bibliographical references. / by Juliana Atmadja. / Ocean.E.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1990. / Includes bibliographical references (leaves 166-172). / by Dimitris E. Nakos. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1998. / Includes bibliographical references (leaves 130-133). / by Shmuel Shahak. / M.S.