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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

Aplicação de redes Bayesianas na análise de risco do processo de descarga do navio-tanque em um terminal portuário especializado. / Application of Bayesian networks in the risk analysis of the process of unloading of flammable bulk liquids from a tanker to a port terminal specified - the Bulk Liquid Terminal - BLT

Francisco de Assis Basilio de Moraes 13 March 2015 (has links)
Sistemas de transporte marítimo são essenciais para o Comércio Global, em especial, navios-tanques e seus centros de carga e descarga de produtos líquidos ou gasosos inflamáveis; portanto, é crucial entender como estes sistemas podem falhar, para que seus operadores sejam capazes de manter a sua capacidade de operação. É preciso que cada e toda análise quantitativa de risco compreenda algumas das atividades básicas que devem ser desenvolvidas, para permitir a quantificação dos riscos envolvidos e associados, na operação do sistema ou do processo. Basicamente, devem ser calculadas as probabilidades de ocorrência dos eventos indesejados identificados, bem como a magnitude de suas consequências. O objetivo deste trabalho é aferir se a técnica denominada Rede Bayesiana RB é a mais adequada, comparando-a com as técnicas de árvores de falhas e de eventos, para realizar uma Análise de Risco da operação ou processo de descarga de líquidos inflamáveis, como etanol anidro e/ou produtos petrolíferos, de um naviotanque para um terminal portuário específico Terminal de Granéis Líquidos TGL com foco na interface entre dois sistemas: o navio e o porto, observado o elemento humano, ou seja, o erro humano (Análise da Confiabilidade Humana). Além disso, será realizado um estudo das consequências do vazamento de um líquido inflamável transportado pelo navio, olhando para o pior cenário, a partir da ruptura da tubulação ou do compartimento do navio-tanque. A análise tem por base as recomendações da Organização Internacional Marítima OIM (em inglês, IMO). A OIM tem adotado a Avaliação Formal da Segurança AFS (em inglês, Formal Safety Assessment FSA), como seu modo oficial de receber as sugestões de seus membros para criar ou modificar qualquer regulamentação correlacionada. Este processo é composto de cinco passos que a OIM descreve na guia AFS (IMO, 2002). Este trabalho irá mostrar todas as etapas, mas irá focar, com especial atenção, a segunda etapa Risk Assessment, porque será aplicada ao caso sob análise, envolvendo o comportamento humano. Existem muitas técnicas e muito trabalho envolvido na estimação das probabilidades dos eventos. O mesmo ocorre para a avaliação de suas consequências. Uma vez definida a quantidade total de vazamento, um software poderá ser usado para calcular as consequências. O mesmo será feito para na Análise de Risco, utilizando RB, e, neste ponto, o trabalho apresenta uma nova contribuição. / Maritime transportation systems are essential for World Trade, in special, Tankers ships and yours loading and unloading facilities; therefore, it is crucial to understand how these systems may fail, to be able to maintain their capacity. It need that each and every quantitative risk assessment comprises some basic activities that have to be developed to allow the quantification of the risks involved in the operation of a system or process. Basically, it must be estimated the likelihood of the identified undesired events as well as the magnitude of their consequences. The objective of this study is to assess if the technique called Bayesian Networks BN is the best suited, with respect to the Fault Tree Analysis FTA and the Event Tree Analysis ETA, to perform an Risk Analysis of the operation or process of unloading of flammable bulk liquids, such as anhydrous ethanol and/or oil products, from a Tanker to a port terminal specified the Bulk Liquid Terminal BLT, focusing on the interface between the two systems: ship and port with the inclusion of the human factor, i.e., human error: Human Reliability Analysis HRA. Furthermore, a consequence analysis of a specific liquid bulk leakage will be performed, looking at the worst scenario case, from the rupture of a pipeline or tank from a Tanker. The analysis came from based on the recommendations of the International Maritime Organization IMO. The IMO has adopted the FSA (Formal Safety Assessment) as its official way of receiving suggestions of its members to create or modify any regulation correlated. It is a process composed by five steps that IMO has described in its Guidelines for FSA (IMO, 2002). This thesis will to show all steps, but will look carefully to step two (Risk Assessment) because it will be applied in the example situation, involving human behavior (HRA). There are many techniques and much work involved in the estimation of the likelihood of the events. The same occurs for the evaluation of their consequences. Once defined the total leaked quantity, software will be used to calculate the consequences. The same will be done to Risk Analysis, using BN, and at this point, the work is a new contribution.
32

Methodology for definition of new operating sectors fo DP assisted offloading operations in spread-moored platforms. / Metodologia para definição de novos setores operacionais para operações de offloading com navios DP em plataformas ancoradas em Spread Mooring.

Ana Luísa de Barros Orsolini 22 February 2017 (has links)
This thesis defines and applies a methodology for analyzing the possibility of extending the operating sector of DP shuttle tankers for offloading operations in Spread Moored FPSO Platforms. Extending the operating sector is beneficial to increase operations\' availability and to reduce DP power demand under certain environmental conditions. This study is important, since several emergency disconnections have occurred during offloading in Santos Basin because the shuttle tanker was pushed out of the green sector by environmental resultants that pointed to the West. However, this proposal has to be carefully analyzed in order to guarantee the operations\' safety and not to increase the risks of collision between FPSO and shuttle tanker, of oil pollution and of personnel safety. The methodology consists in five basic steps: Preliminary Risk Analysis to assess the potential hazards associated with the new sector; evaluation of the uptime gain through static analysis; evaluation of DP power demand inside the original and extended sector; real time simulations to evaluate the operation in a realistic environment; and, finally, field tests to validate the proposal. This thesis presents the contextualization of the problem, a bibliographical research, theoretical concepts, the detailed methodology and results of each step. The results show that the average uptime gain is significant both in Campos and Santos Basins - up to 9% and 13% respectively - and that the additional risks created by the sector extension are well mitigated if some recommendations are put into place. The conclusion of this thesis is that extending the operating sector is not only beneficial but also safe. / Esta dissertação define e aplica uma metodologia para analisar a possibilidade de extensão do setor operacional de navios aliviadores DP para operações de offloading em plataformas FPSO ancoradas em Spread-Mooring. Esta proposta apresenta como vantagens o aumento da disponibilidade das operações e redução na demanda de energia do navio DP em certas condições ambientais. O estudo é importante tendo em vista que várias desconexões de emergência já ocorreram durante operações de alívio na Bacia de Santos, porque o navio-tanque foi empurrado para fora do setor verde por resultantes ambientais que apontavam para oeste. No entanto, a proposta deve ser cuidadosamente analisada para garantir que o novo setor não aumenta os riscos de colisão, de poluição ambiental e de segurança às pessoas. A metodologia consiste em cinco etapas básicas: Análise Preliminar de Riscos (APR); avaliação do ganho de disponibilidade da operação; avaliação da demanda de energia do sistema DP nos setores original e estendido; simulações de manobra em tempo real; e, finalmente, testes em campo para validação da proposta. Esta dissertação apresenta a contextualização do problema, pesquisa bibliográfica, conceitos teóricos, a metodologia detalhada e os resultados de cada etapa. Os resultados mostram que o ganho médio de disponibilidade é significativo nas bacias de Campos e de Santos - até 9% e 13%, respectivamente - e que os riscos adicionais criados pela extensão do setor são devidamente mitigados se as recomendações levantadas na APR forem implementadas. A conclusão desta dissertação é que estender o setor operacional é, não somente benéfico, mas também seguro.
33

運輸與存貨問題的可行性分析與研究 / Analysis on Transportation and Inventory Problems

林志漢, Lin, Chih - Han Unknown Date (has links)
在本篇論文裡, 我們提出一個"油輪排程規畫"的方法。處理在計畫期間中, 有關原油供應商的供給, 油輪的運輸與需求地儲油庫存貨管理的問題。藉由一些性質的探討來分析運輸排程與存貨管理。由供應油商契約量中供應量的情形, 提出最大累積可提運量表, 並藉由該表來輔助我們做排程; 由分油的概念與訂貨週期的制定, 分析運輸工具的排程狀況與儲油庫油量存貨的關係; 由運輸與儲油庫油料之間的互動關係, 提出管理的方案; 最後再藉由理想存貨量的關念來確立租用臨時運輸工具的可行性。並藉由所提出的性質來處理租用運輸工具的排程。在各個階段的處理過程中, 包括分析限制條件是否滿足的情形等, 總共提出了四個演算法, 找出滿足整個問題限制條件的可行排程。最後, 引用實務上的例子, 來說明油輪排程規畫的方法。 / In this paper, we consider an inventory problem of which the lead time depends on vehicles chosen from a restricted set. The inventory itself hasother constraints that must satisfy the demand and capacity limitation. Inspecific, a problem that considers scheduling oil tankers for transportingcrude oils from supplies to a refinery is represented. With the help of some properties discovered while analyzing the problem of oil tanker scheduling with inventory management, such as largest accumulated supplies from oil suppliers, demand intervals and reorder intervals, and an ideal inventory level, we develope an oil tanker scheduling model to determine each vehicle's schedule and satisfy all constraints. The model consists of four heuristic algorithms which are described step by step asthe solution procedure. A realworld example from an oil company is used to illustrate the four algorithms and suggest a feasible schedule for transporting crude oils. In short, we not only give 1 overall viewpoint of inventory and transportation problems but also provide a heuristic procedurefor solving it.
34

Escort tug performance prediction: a CFD method

Smoker, Brendan 20 December 2012 (has links)
As the demand for energy continues to increase around the world, more vessels used in the transport of energy, such as Liquid Natural Gas (LNG) and crude oil tankers are being built to transport energy to market overseas. The escort tug has been developed in order to assist in the safe transit of such vessels in confined waterways. Designed to apply emergency braking and steering forces to the stern of a tanker while underway, an escort tug features a hull shape that generates large hydrodynamic lift and drag forces when operating at high angles of attack, this is known as indirect mode. This escorting mode is highly effective at speeds 8 knots and above, often generating towline forces well in excess of bollard pull. Escort performance prediction is a vital aspect of the design of escort tugs. It is important to know a priori if a design will meet the necessary performance criteria. In the past, performance predictions have relied heavily on model testing and empirical methods. With the recent emergence of Computational Fluid Dynamics (CFD) as a commercially viable design tool for naval architects, extensive escort performance predictions can now be carried out more accurately in less time and at less cost than was previously possible. This thesis describes the methodology of a CFD based escort performance prediction method that is accurate and cost effective. / Graduate
35

Orbital Fueling Architectures Leveraging Commercial Launch Vehicles for More Affordable Human Exploration

Tiffin, Daniel Joseph 28 January 2020 (has links)
No description available.
36

Midskepps eller aktern? : En studie om arbetsmiljö & säkerhet vid anslutning av landström till tankfartyg / Midship or stern? : A study on work environment & safety when connecting shore power to tanker vessels

Carlsson, Jonas, Falkerby, Tim January 2024 (has links)
Syftet med denna studie var att undersöka om landströmsanslutningar bör placerares midskepps vid manifoldern, alternativt i aktern på tankfartyg. Fokus låg på att hitta bästa placeringen utifrån säkerhet och arbetsmiljö ombord på fartyget och i hamnen. Detta studerades genom kvalitativa intervjuer med sex olika aktörer inom området för att få ta del av deras erfarenheter och åsikter kring ämnet. Parallellt genomfördes även en faktainsamling där standarder, regelverk samt tidigare forskning på området samlades in. Resultatet från intervjuerna sammanställdes och jämfördes sedan mot materialet från faktainsamlingen.  De krav som ställs i olika standarder kan, oavsett placering, innebära säkerhets- och arbetsmiljö nackdelar men respondenterna var övertygade om att man med rätt utrustning och rutiner kan upprätthålla en säker och god arbetsmiljö. Utifrån säkerhet ansåg flera respondenter att en placering långt ifrån manifoldern, där fartygets last hanteras är att föredra även om det finns andra säkerhetsmässiga nackdelar med en sådan placering. Arbetsmiljömässigt hade respondenterna flera för- och nackdelar med båda placeringarna som främst rörde problematiken kring kabelhanteringen. / The purpose of this study was to investigate whether shore power connections should be placed midships at the manifold, or alternatively, aft on tanker vessels. The focus was on determining the best location based on safety and working conditions onboard the vessel and in the port. This was studied by conducting qualitative interviews with six different stakeholders in the field to gain insight into their experiences and opinions on the subject. Concurrently, a data collection was conducted where standards, regulations, and previous research in the field were gathered. The results from the interviews were compiled and compared against the material from the data collection.  Regardless of the placement, there are safety and working environment disadvantages that are also stipulated as requirements in various standards, but the respondents were convinced that with the right equipment and procedures, a safe and good working environment can be maintained. Concerning safety, several respondents believed that a placement far from the manifold where the vessel's cargo is handled is preferable, even though there are other safety disadvantages associated with such placement. In terms of the work environment, the respondents identified several pros and cons with both placements, primarily related to the issue of cable handling.
37

Modern piracy the impact on maritime security.

Mansfield, Charles T. January 2008 (has links) (PDF)
Thesis (Master of Military Studies)--USMC Command and Staff College, 2008. / Title from PDF title screen. Text document in PDF format. Includes bibliographical references (p. 21-22).
38

On Leave

Martin, Hugh J. 01 June 2021 (has links)
No description available.

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