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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.
141

Analysis of the impacts of Internet-based business activities on the container shipping industry : the system dynamics modeling approach with the framework of technological evolution

Auh, Jae Hyuck, 1969- January 2003 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2003. / Includes bibliographical references (p. 381-392). / The internet-based business (e-business) activities have become a new technological challenge to the container shipping industry (CSI) in recent years. Despite the growing importance of e-business in the CSI, little systematic and theoretical research on e-business has been undertaken so far. This research therefore attempts to understand the potential impacts of e-business on the container shipping industry and to provide carriers with the managerial recommendations responding to the impacts of e-business. An integrated system dynamics model is developed to simulate the potential impacts of e-business on the container shipping industry and to explore the successful managerial strategies for carriers with regard to e-business. In order to increase the confidence of the model, the general business dynamics in the CSI are reviewed and the historical impacts of new technologies on the container shipping industry are analyzed using the framework of technological evolution. Furthermore, the technology strategies of six different e-business models in the CSI are evaluated using the proposed three frameworks to identify the most promising e-business model. / The research finds that the profitability of carriers will be improved in the long term if they successfully develop the logistics service offering (LSO) with e-business in a cost efficient way. However, despite the improved profitability from the LSO and e-business, the container shipping service could be commoditized further unless changes are made to the current practice of expanding the containership capacity. In addition, the improved profits from the LSO and e-business will drive the structural changes in the container shipping industry. In order to improve the carriers' profitability over a long period of time, it is recommended that carriers continue to add new services on top of the container shipping service while expanding the containership capacity more wisely and conservatively. / by Jae Hyuck Auh. / Ph.D.
142

Nonlinear wave interactions with submerged obstacles with or without current

Liu, Youming January 1994 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994. / Includes bibliographical references (leaves 209-219). / by Yuming Liu. / Ph.D.
143

Design of a lightweight, multipurpose underwater vehicle

Davis, Mark E. (Mark Edward) January 1993 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1993. / Includes bibliographical references (leaf 71). / by Mark E. Davis. / M.S.
144

Efficient container fleet expansion

Maillis, Michael Ilias January 1983 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1983. / THESIS AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Michael Ilias Maillis. / M.S.
145

An experimental method for measuring dynamic pressures above a cavitating propeller

Kirtley, Jacqueline Brener, 1974- January 1998 (has links)
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1998. / Includes bibliographical references (leaves 71-72). / The basic objective of this project was to create an experiment and apparatus for measuring dynamic pressures above a cavitating propeller which could be used in modeling the differences between types of cavitation. A large, aluminum plate was designed to hold the pressure probes above the chosen 5 bladed surface ship propeller in an 5 x 5 array. The array of probes, along with upstream and downstream reference probes, acquired the dynamic pressures generated by the observed intermittent cavitations. Two computer applications were written to work with the apparatus: one for calibrating the pressure probes, and one for acquiring the data set of 20,000 samples per channel at 3,600 Hz. Contour plot animations and FFT analysis supported the experimental data and the experiment as a reusable apparatus for recording dynamic pressures to be used in cavitation computer models. / by Jacqueline Brener Kirtley. / S.M.
146

Airline O-D control using network displacement concepts

Wei, Yuanyuan (Yuanyuan Julie) January 1997 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997. / Includes bibliographical references (p. 120). / by Yuanyuan (Julie) Wei. / M.S.
147

Deformation and rupture of cylindrical shells under dynamic loading

Hoo Fatt, Michelle S. (Michelle Stephanie) January 1992 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1992. / Includes bibliographical references (leaves 137-143). / by Michelle S. Hoo Fatt. / Ph.D.
148

Steady and unsteady dynamics of an azimuthing podded propulsor related to vehicle maneuvering

Stettler, Jeffrey W. (Jeffrey Wayne) January 2004 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2004. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Includes bibliographical references (p. 173-177). / While the implementation of azimuthing propulsors powered by internal electric motors (often called "podded propulsors") into the commercial ship market has been swift, the understanding of their hydrodynamics through research, particularly in the area of maneuvering performance, has been very limited. This thesis research investigates the steady and unsteady dynamic maneuvering forces associated with an azimuthing podded propulsor, and provides supporting theoretical insight toward understanding their mechanisms and prediction. Because of the wide range of potential applications of azimuthing podded propulsion in the marine field, dynamic force phenomena applicable to maneuverability of both large and small scale vehicles are investigated. These include quasi-steady vectored maneuvering forces, of importance to all maneuvering vehicles or ships, as well as unsteady or transient maneuvering forces, which have more significance to the maneuverability of smaller vehicles, particularly for precision control applications. The ultimate goal of the research is to provide a comprehensive understanding of the maneuvering forces associated with an azimuthing podded propulsor, such that future maneuvering and control applications, and computational fluid dynamics studies in the field, can be appropriately focused. The research efforts are focused in four main areas. First, a number of relevant dynamic models for the maneuvering of a surface vehicle with an azimuthing propulsor are developed. Second, an extensive test program measures and characterizes the nature of quasi-steady vectored maneuvering forces associated with a podded propulsor in azimuth to ±180⁰ for the entire range of forward propeller speeds, as well as unsteady or transient maneuvering forces due to rapid changes in azimuth angle or propeller rate. / (cont.) This test program is aimed at quantifying the steady and unsteady parameters associated with the developed dynamic models. Third, two flow visualization techniques are utilized to visualize, document, and correlate the helical wake characteristics, velocities and forces for both quasi-steady and unsteady propulsor states. A new fluorescent paint flow visualization technique is developed and applied for small, moderate and4 large propulsor azimuth angles, and a laser particle image velocimetry (PIV) technique is adapted for small and moderate propulsor azimuth angles. Finally, a set of comprehensive physics-based models are developed to foster the understanding of the mechanisms associated with the steady and unsteady force dynamics. The quasi-steady models are based upon a combination of momentum-based, blade-element, and vortex wake propeller theories, as applied to an azimuthing podded propulsor. The unsteady force models are based upon unsteady wake or "dynamic inflow" methods. Additionally, an interesting phenomenon associated with the formation of a vortex ring during rapid propeller rate increase is presented and discussed. The steady and unsteady test results, flow visualizations, and theoretical models, are shown to be consistent in terms of the magnitudes and character of the azimuthing maneuvering forces. Limited comparisons of quasi-steady propulsor forces at small, moderate and large azimuth angles are also made with forces predicted by a modified combined blade-element-momentum (BEM) method, as well as the unsteady vortex-lattice propeller code MPUF-3A, with and without modified inflows to account for propulsor pod wake. The results illustrate inherent complexities related to use of existing computational fluid dynamics tools with azimuthing podded propulsors. / by Jeffrey W. Stettler. / Ph.D.
149

The remote interaction planning and visualization tool

Damus, Robert Shibli, 1977- January 2001 (has links)
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2001. / Includes bibliographical references (leaves 120-123). / by Robert Shibli Damus. / S.M.
150

Models for intermodal depot selection

Gao, Qiang January 1997 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997. / Includes bibliographical references (p. 154-157). / Qiang Gao. / Ph.D.

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