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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.
31

Cruise Ship Preliminary Design: The Influence of Design Features on Profitability

Epstein, Justin 18 December 2014 (has links)
This thesis provides a means to estimate the physical and performance characteristics of a preliminary cruise ship design. The techniques utilized to estimate these characteristics are showcased in the user-friendly interface known as the Cruise Ship Analysis Tool (CSAT). Using the CSAT, the implications that design feature decisions in the preliminary design stage have on a cruise ship’s profitability is analyzed. Then, the most profitable design feature assemblage among a finite number of varying design feature combinations is estimated and compared among cruise ship designs with different passenger carrying capacities. Profitability is analyzed using the measure of merit (MOM) known as net present value (NPV). If a preliminary cruise ship design has a positive NPV at a reliable rate of return and ship operating life, the design is considered to be a profitable investment if implemented. The greater the NPV, the more profitable the investment is considered to be.
32

Performing masculinity : the star persona of Tom Cruise

O'Donnell, Ruth January 2012 (has links)
Tom Cruise was one of the most financially successful stars of the 1980s and 1990s and remains an important Hollywood player. In his time at Paramount, he negotiated new deals which redefined how stars earned revenue from their films. Yet little substantial study has been made of him or his persona. Cruise came to prominence in the 1980s, an epoch which redefined the terms of masculinity, moving away from a particular martial ideal following American defeat in Vietnam. His persona addresses the consequent anxieties surrounding these significant social changes. In addition to this, his image can be understood within a psychoanalytic framework to be offering a 'compromise formation' to the difficulties of psychosexual development. Cruise appears to offers a challenge to the father, but in reality recedes from Oedipal threat. Chapter One examines the nascent Cruise star persona and its development across his films. The chapter provides a historical overview and contextualisation of the persona. Chapter Two explores how the persona offers a 'performative' model of masculinity based on a heroic martial ideal, as well as his positioning as an object of spectacle and the onscreen homoerotic relationships he enjoys. Chapter Three looks at the star's association with the racial 'other' and preoccupation with male friendships at the expense of heterosexual romance. Objectification through spectacle, which black characters and Cruise share in his films, indicate a symbolic shared powerlessness within the hegemony. Chapter Four argues that this lack of status is characterised by Cruise's struggle against male authority figures, which represent both corporate America and the punishing father. This relays the trauma of Oedipal struggle, which Cruise attempts to evade. Chapter Five looks in further depth at the Cruise persona's preoccupation with male bonds and lack of interest in women, both indicative of a regression from the phallic to the earlier anal/cannibalistic psycho-sexual stage, as he is unable to overcome the symbolic father . The thesis concludes by suggesting Cruise's persona is a compromise: it presents a triumphant young man who in reality is oppressed by patriarchal forces. This compromise is premised on youth and is threatened as Cruise ages, exaggerated by social changes within America. Biologically and socially, Cruise's persona is no longer tenable.
33

Two-period, stochastic, supply-chain models with recourse for naval surface warfare

Avital, Ittai 03 1900 (has links)
Approved for public release; distribution is unlimited. / We model the minimum-cost procurement and allocation of anti-ship cruise missiles to naval combat ships as a two-period stochastic integer program. Discrete scenarios in two periods define "demands" for missiles (i.e., targets and number of missiles required to kill those targets), which must be met with sufficiently high probabilities. After the former combat period, ships may replenish their inventories from a depot if desired and if the available depot inventory suffices. A force commander optimizes ship-to-target assignments to meet demands. The basic model solves slowly, so we add constraints to enforce reasonable operational directives, and add valid inequalities. These improvements reduce the solution time by 95% for the test case. Instances with up to six ships and five scenarios in each period then solve in less than one hour on a 2 GHz personal computer. / Lieutenant Commander, Israel Navy
34

Hermite-Gaussian modes and mirror distortions in the free electron laser

Vigil, Ricardo. 06 1900 (has links)
The free electron laser (FEL) is proposed to meet the Navy's need for a speed-of-light high energy laser weapon capable of engaging a variety of targets including anti-ship cruise missiles, small boats, and theater ballistic missiles. A key attribute of FELs is good optical beam quality; in other words, they operate in only a few of the lowest-order transverse Gaussian modes. For weapons applications, a good mode quality is desired because it delivers the highest intensity on target ensuring a high level of lethality. A few higher-order modes can arise from the interaction of the electron beam with the optical beam, or from misalignments of the electron beam or resonator mirrors. High intensity on FEL optics can lead to mirror distortion due to heating and insufficient cooling of the mirror substrate. Mirror distortions, including astigmatism, can cause higher-order modes to appear affecting FEL performance. Therefore, it is important to quantify these higher-order modes because doing so uniquely identifies the optical field and may allow for corrective optics to single out the best modes for FEL lethality. This thesis will review free electron laser theory, and for the first time develop analytical solutions to quantify Hermite-Gaussian higher-order modes, develop a diagnostic for modal analysis, and determine the tolerance limits on mirror distortions.
35

High-power amplifier free electron lasers

Voughs, Tyrone Y. 06 1900 (has links)
The free electron laser (FEL) is among the latest technologies of interest to the U.S. military, in particular, the Navy. In naval applications, FEL laser would serve as a self-defense weapon system, protecting the ship from an array of threats including anti-surface cruise missiles and small boats. This system's potential range and deep magazine makes it ideal as point defense against incoming missiles. Its inexpensive cost of only a few dollars per engagement and multi-mission capability makes this future weapon system superior to the short-range missile-defense systems employed today. The most powerful FEL is currently located in Jefferson Lab, operating at 10 kW, two orders of magnitude short of the 1 MW power level required for weapons application. This thesis will describe the components and theory of operation of the FEL, as well as analyze two competing designs for the next step in the evolution of the future weapon system, the 100 kW FEL, proposed by Brookhaven and Los Alamos National Labs. Due to advances in NPS simulation techniques for the amplifier configuration, a more in depth analysis including the effects of electron beam tilt and shift is performed for the first time on these proposed designs.
36

Tourist experiences and word-of-mouth: the mediating effect of memory

Park, Seunghyun "Brian" January 1900 (has links)
Doctor of Philosophy / Department of Hospitality Management and Dietetics / Rebecca Gould / Chihyung Ok / Offering memorable experiences to customers is an effective marketing strategy in hospitality and tourism. However, the effects of memorable experiences have remained largely unexamined. Two research models were proposed through a literature review to present the antecedents that effectively lead to memorizing travel experiences. Since researchers in customer service management have recently claimed the significance of creating good memories related to consumption experiences, this study developed the discussion on links among the antecedents and memory and hypothesized the sequential relationships among the constructs. Study 1 examined the relationships between antecedents (experience quality, hedonic value, utilitarian value, and satisfaction) and post-experience memory in cruise tourism. Using an online survey, 375 vacationers who traveled on an ocean cruise ship were recruited. Structure Equation Modeling showed that the experience quality of cruise travel consisting of seven experience dimensions had a positive influence on helping memory formation through hedonic value and utilitarian value. The results underscored the critical effect of memory on word-of-mouth. This study documented that hedonic value driven by travel experience quality had a more important role in delivering the effect to memory than utilitarian value. However, in the research model of study 1, satisfaction was not connected to memory. Mediation effect analysis individually tested the partial mediating role of memory in the relationship between hedonic value/utilitarian value/satisfaction and word-of-mouth. Study 2 examined the effects of emotions on memory, particularly the potential moderating effect of arousal on the relationship between valence and memory. This study not only proposed the direct influence of arousal and valence on memory, but also hypothesized the quasi-moderating effect of arousal in amplifying the influence of valence on increasing memory. The results of hierarchical regression analysis using the dataset of 375 samples presented the direct relationships between arousal/valence and memory were shown although the hypothesis regarding the moderating role of arousal was rejected. Two emotional dimensions (arousal and valence) were found to be significant predictors of increased memory quality, but the moderating effect of arousal was not supported. Based on the findings of this study, practical implications for the tourism industry are provided, along with future research ideas.
37

SYNTHESIZING COOPERATIVE ADAPTIVE CRUISE CONTROL WITH SHARED AUTONOMY

Zhang, Hancheng 01 May 2019 (has links)
In this thesis, we present research on synthesizing autonomous driving with shared autonomy using Unity Engine. Adaptive Cruise Control (ACC) is considered as level 1 autonomous vehicle, which has been studied by academia and commercialized by industry. Cooperative Adaptive Cruise Control (CACC) system is an expansion of ACC, in which communication is set up between members to share driving information. Shared autonomy is a subject about human-computer interactivities. In our research, we developed a highly customizable 3D environment. We can simulate various driving scenarios and analyze the performance of different driving methods from human driving to CACC. The result of simulation proves the safety and efficiency of CACC, and the project also provides a potential of assisting the improvement of autonomous vehicles.
38

Adaptive cruise control utilizing Look-Ahead infromation

Rost, Johanna January 2009 (has links)
No description available.
39

Utvärdering och implementering av automatiska farthållare i fordonssimulator

Borst, Rikard January 2006 (has links)
<p>Vehicle simulators are becoming more common in vehicle industries. Company earns lot of money on simulations instead of real tests. Real tests are necessary but not made so extensively as before.</p><p>In this thesis the building of an vehice simulator will be described and a comparison between three different cruise controls. The three cruise controls are PI-regulator, a regulator who regulates after positions in the terrain and a MPC-regulator. The reason for choosing this three is to see the difference between simple regulation and more complex regulation with respect to fuel consumption, travel time and complexity.</p><p>The vehicle simulator is made in Matlab/Simulink, Visual Studio and Open Scene Graph. The facilities needed for runnning the simulator is a relative good computer with a grapics card on at least 128 MB RAM plus a steering wheel and pedals for brake and gas to achieve best feeling. A keyboard can be used but it reduces almost all feeling.</p><p>After several simulations a conclusion was made. The MPC-regulator was the regulator who consumed least fuel and travel time. The regulator who regulates after positions in the terrain was not too far away. It would be interesting to do more research about it. In fact it is only a PI-regulator who makes ``clever'' decisions when a hill with enough slope appears. With enough slope means a downhill where the vehicle can accelerate without the use of fuel and an uphill where the vehicle can not keep its speed with maximum use of fuel.</p><p>A conclusion was stated that the friction and height profile influenced on settings for the PI-regulator and with some adjustments on this settings, fuel could be saved.</p>
40

Big Ships, Small Towns: The Impact of New Port Developments in the Cruise Tourism Industry. The case of Falmouth Jamaica

Kerswill, Matthew 04 June 2013 (has links)
ABSTRACT The cruise sector constitutes one of the fastest growing sectors of the tourism industry. With the continued growth of the industry comes the need to develop new ports to accommodate the increased volume of ships as well as the increasing size of modern cruise ships. It is important to understand how the development of new cruise ports impacts the local community. Therefore, the purpose of this study is to identify the attitudes and perceptions of residents regarding the impacts of the new cruise ship port development in Falmouth, Jamaica. The Historic Port of Falmouth was developed through a partnership between Royal Caribbean and the Port Authority of Jamaica and is the largest purpose-built port of call in the Caribbean. A case study approach was utilized to identify the attitudes and perceptions of residents regarding the impacts of the new port development in Falmouth, Jamaica. The study consisted of semi-structured interviews, and participant observation. The research took place in Falmouth in March 2012. A total of 23 interviews were carried out with residents who had varying levels of involvement with tourism. The three overarching themes emanating from the analysis of the data are: Big Ships, Big Disappointment, What could be improved? and All is Not Lost at Sea. Findings revealed that Falmouth residents are disappointed with the development because they have not received the economic benefits they were promised by Royal Caribbean. Despite the residents’ frustration and disappointment with the port, many still believe that it has given some opportunity for residents to improve their quality of life. The powerlessness of members of small Caribbean communities in the face of large tourism developers is evident throughout the study.

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