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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.
11

[en] AN OPTIMIZATION BASED DECISION SUPPORT SYSTEM PROPOSED FOR SHIP SCHEDULING: A PRACTICAL APPROACH / [pt] PROPOSTA DE UM SISTEMA DE SUPORTE À DECISÃO PARA PROGRAMAÇÃO DE NAVIOS BASEADO EM OTIMIZAÇÃO: UM CASO PRÁTICO

GUSTAVO SOUTO DOS SANTOS DIZ 29 November 2012 (has links)
[pt] O aumento da produção de petróleo brasileiro e o consequente aumento na demanda por transporte marítimo levaram a PETROBRAS a buscar ferramentas para aumentar a eficiência de seu transporte marítimo. Neste sentido, a atividade de programação de navios busca alocar os navios a um conjunto de cargas definido a priori, respeitando as restrições comerciais e operacionais, a fim de transportá-las com o menor custo possível. Com o intuito de auxiliar o programador nesta atividade, esta dissertação propõe um sistema de suporte à decisão (SSD) baseado em otimização para a programação de navios. O SSD proposto foi desenhado especificamente para a atividade de longo curso de navios de petróleo da PETROBRAS, sendo este gerado a partir da adaptação de modelos disponíveis na literatura acadêmica. Os testes comparativos realizados com o protótipo do SSD na atividade de longo curso de navios de petróleo mostraram que a ferramenta tem um significativo potencial de redução de custo. O SSD proposto se apresentou como uma opção viável para auxiliar a programação de navios da companhia na busca pela redução de custos de transporte marítimo. / [en] The increasing production of Brazilian oil and the consequent increase in the demand for shipping, led PETROBRAS to seek tools to increase the efficiency of its shipping. In this sense, the activity of ship scheduling seeks to assign vessels to a set of cargos, respecting business and operational restrictions in order to transport them with the lowest possible cost. To assist the ship scheduling planner in this activity, this dissertation proposes an optimization based decision support system (DSS) for ship scheduling. The proposed DSS was designed specifically for the long-term tanker scheduling activity at PETROBRAS and it was implemented based on models available in the academic literature. The comparative tests using the DSS prototype proposed in this dissertation showed that it has a potential for significant cost reduction. The proposed DSS was considered a viable tool to assist the ship scheduling planners in reducing shipping costs.
12

Námořní pirátství a ekonomické souvislosti / Maritime piracy and economic context

Urbanová, Zuzana January 2011 (has links)
This diploma thesis deals with issue of maritime piracy, which is nowadays one of the significant international problems. Maritime piracy has substantial economic and other consequences, which increasingly motivate the international community to solve the maritime piracy problem. This thesis primarily focuses on these consequences and on ways of solving the maritime piracy problem.
13

[en] MATHEMATICAL MODELING OF CRYOGENIC SPILLS AND POOL FIRES IN THE LIQUEFIED NATURAL GAS (LNG) MARITIME TRANSPORTATION / [pt] MODELAGEM MATEMÁTICA DE DERRAMES CRIOGÊNICOS E DE INCÊNDIOS EM POÇA NO TRANSPORTE MARÍTIMO DE GÁS NATURAL LIQUEFEITO (GNL)

ALAN DA SILVA ESTEVES 11 January 2011 (has links)
[pt] Gás Natural Liquefeito (GNL) vem sendo transportado desde 1959 em navios metaneiros, elos essenciais na movimentação do GNL entre as locações de produção e consumo. Este trabalho apresenta modelagens para: (i) mecânica do derrame e espalhamento de fluido criogênico no mar, decorrente de punção no casco desses vasos, e (ii) subsequente incêndio de difusão turbulenta. A revisão bibliográfica contempou seis décadas, e não foram encontradas evidências de que os temas, espalhamento criogênico e incêndio da poça com difusão turbulenta, tivessem sido tratados em único trabalho. Essa lacuna foi identificada, e os assuntos foram acoplados de forma inédita e implementados em dois códigos computacionais. O derrame/espalhamento é modelado com formulação integral conservativa, tendo como parâmetros a área do rasgo, área máxima da poça derramada e tempos de descarga e vaporização do criogênico no mar. O escoamento foi modelado com rasgos de 1 a 100 m(2) coerentes com a indústria de GNL, formando poças semicirculares. A modelagem da pluma térmica contempla poças circulares entre 10 e 500 m de diâmetro, bem como zonas de combustão e intermitência da pluma térmica. Provê esquema consistente e robusto para o desenvolvimento de parâmetros adimensionalizados de escala, possibilitando correlacionar e extrapolar o comprimento da pluma visível, com a inclinação e o arrasto da mesma, com o poder emissivo de sua superfície e a vazão mássica de vaporização do combustível criogênico na poça. Avalia também: (i) a variação axial do poder emissivo com a altura da pluma visível, (ii) a queima do combustível ao longo da zona luminosa (base do incêndio), e (iii) o transporte de radiação térmica emitida por gases cinza e partículas de fuligem na zona de combustão, considerando a emissão e absorção nas regiões oticamente fina e espessa da pluma térmica. / [en] Liquefied Natural Gas (LNG) has been carried since 1959 in methane carriers, which are the essential link in the movement of LNG between the locations of production and consumption. This thesis presents modeling to: (i) the fluid mechanics of spills/scattering at sea of a cryogenic fluid, due to puncture the hull of these vessels, and (ii) the subsequent burning of the pool by turbulent diffusion fire. The literature review contemplated six decades, and no evidence was found that the themes such as scattering of cryogenic pool followed by turbulent diffusion fires were treated in a single work. This gap was identified, and the subjects were connected in an unprecedented manner and implemented in two computer codes. The spill/scattering is modeled with conservative integral formulation, having as parameters the area of maximum pool poured on the sea and unloading and vaporization times of cryogenic. The flow was modeled with tears between 10 and 100 m(2), consistent with the LNG industry, forming semicircular pools. The modeling of the fire thermal plumes considers circular pools with diameters varying between 10 and 500 m, and combustion and intermittency zones of the thermal plume. Provides a consistent and robust scheme for the development of dimensionless scale parameters, allowing to correlate and extrapolate the length of the visible plume, with the its tilt and drag, its surface emissive power and with cryogenic fuel vaporization mass flow rate in the pool. It also evaluates: (i) the axial variation of emissive power with height of the visible plume, (ii) the burning of fuel along the luminous zone (the base of the fire), and (iii) the transport of thermal radiation emitted by gray gases and soot particles within the combustion zone, considering the emission and absorption in optically thin and thick regions of the thermal plume.
14

[en] DISTRIBUTION OF PETROLEUM IN THE INTERNATIONAL MARKET A DECISION SUPPORT TOOL BASED ON PRACTICAL CASE STUDY / [pt] DISTRIBUIÇÃO DE PETRÓLEO NO MERCADO INTERNACIONAL: UM INSTRUMENTO DE SUPORTE À DECISÃO BASEADO EM ESTUDO DE CASO PRÁTICO

MIRNA RODRIGUES SANTANA ROCHA 25 February 2019 (has links)
[pt] O crescente aumento de produção de petróleo no Brasil, combinado com um ambiente de negócios internacionais competitivo e um mercado consumidor posicionado em vários continentes, exigem que a PETROBRAS busque soluções logísticas e estratégicas para atender seus clientes no exterior, de forma competiti-va e rentável. Neste sentido, esta dissertação busca descrever o mercado mundial de petróleo e o ambiente de distribuição de petróleo da Petrobras no mercado in-ternacional, e apresentar um instrumento simples para apoio à tomada de decisão na cadeia de suprimentos de petróleo, especialmente no que se refere à programa-ção de navios em viagens de longo curso. Isto auxiliará os profissionais na área de logística e comercialização, na comparação de possíveis estratégias de distribui-ção de petróleo para atender o mercado internacional. Para desenvolver o método utilizou-se como alternativa o fornecimento de petróleo do Brasil para o mercado consumidor localizado no Golfo do México, denominado USG, principal porta de entrada do petróleo importado, via marítima, para os EUA (EIA, 2012), e também responsável, em 2.011, por 33 por cento do petróleo exportado pela Petrobras (PETROBRAS, 2011). / [en] The increase in petroleum production in Brazil combined with a competitive international businesses environment and a consumer market positioned on several continents, demand PETROBRAS to seek logistics and strategic solutions to serve overseas clients in a competitive, profitable way. In this sense, this dissertation aims to describe the world market of petroleum and the environment of Petrobras petroleum distribution in the international market, in addition to present a simple tool to support decision making in the chain of petroleum supply, especially as regards programming of ships in long-term travel. It will help professionals in the logistics and commercialization areas, in comparison of possible strategies of petroleum distribution so as to serve the international market. In order to develop the method it was used as an alternative the supply of petroleum from Brazil to the consumer market located in the Gulf of Mexico, called USG, the main entrance door to imported petroleum, via maritime transport, to the USA (EIA, 2012), and also responsible, in 2011, for 33 percent of the petroleum exported by Petrobras (PETROBRAS, 2011).
15

Critérios competitivos e manutenção de relacionamento entre fornecedores de transporte marítimo internacional e exportadores do Rio Grande do Sul

Phonlor, Patrícia Ross 29 March 2007 (has links)
Made available in DSpace on 2015-03-05T18:39:03Z (GMT). No. of bitstreams: 0 Previous issue date: 29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / As operações logísticas possuem importante papel no comércio internacional. Ao mesmo tempo, as exportações têm se destacado como força motriz da política econômica brasileira. Com o aumento das exportações nos últimos anos, a busca por redução de custos, o aumento na qualidade e na satisfação das necessidades dos clientes tem recaído com grande peso sobre a área de operações. Neste sentido, o presente trabalho teve como objetivos identificar critérios competitivos e a forma de relacionamento para manutenção do serviço prestado por provedores de transporte marítimo internacional a empresas exportadoras localizadas no estado do Rio Grande do Sul. Foi realizada pesquisa do tipo survey com exportadores de dois dos setores que mais exportam no estado – Máquinas & Equipamentos e Agronegócios. Os resultados indicam que os critérios competitivos pertencentes ao construto Desempenho de Serviços: agilidade de retorno, equipe capacitada, entrega no prazo, preço, disponibilidade de espaço e equipamentos foram os que mais / Logistics operations play an important role in international business. At the same time, exports are a major driver in the Brazilian economy policies. As exportation rates have increased quickly in the last years, companies have been compelled to seek cost reduction, quality improvements and client satisfaction. Thus, this study aimed to identify competitive criteria and relationship patterns in the services continuity in the international sea transport industry. The companies analyzed are located in the state of Rio Grande do Sul. A survey was carried out in two of the major exporters industries in that state – Machinery and Agribusiness. The results showed that competitive criteria employed in Services Performance: feedback capacity, staff’s skills, on time delivery, price, ships’ space availability and equipment were found to be more important for the relationship maintenance in the international sea export industry and Brazilian exporters. Therefore, these criteria are key aspects for the relationship co
16

Pojištění v námořní nákladní přepravě z mezinárodního hlediska - vybrané aspekty / Insurance in maritime transport of goods from international points of view - selected aspects

Novotný, Filip January 2018 (has links)
The thesis diploma is focused on the issue of insurance in maritime transport of goods from international point of view. Marine insurance is very important part of sea transport and belongs among the most important components of its smooth functioning. The objective of the thesis diploma is to introduce and explain the topic of marine insurance in comprehensive manner, using domestic and foreing law, literature and judicial decisions. The thesis diploma is focused on English law which is considered to be the most developed in this field. The reason I chose this topic is my personal interest in both marine insurance and sea transport, since I consider both fields to be very important part of international commerce. The first chapter is dedicated to the definition of relevant terms, subsumption of sea transport into a legal framework of carriage and forwardning relations and division of sea transport. The first chapter provides as well a list of important legal enactments relevant to the topic of the thesis diploma. The second chapter is the core of the work, since it provides closer explanation of the contract of insurance in Czech and English law. In terms of the second chapter the work pays attention to the process of formation of insurance contracts in English law, and to the importance of a...
17

[en] PERFORMANCE MEASUREMENT SYSTEM: A CASE STUDY ON PETROBRAS MARITIME TRANSPORTATION / [pt] SISTEMAS DE MEDIÇÃO DE DESEMPENHO: UM ESTUDO DE CASO NO TRANSPORTE MARÍTIMO DA PETROBRAS

RENATA GOMES FRUTUOSO BRAZ 14 January 2009 (has links)
[pt] O tema sistema de medição de desempenho tem sido muito estudado, tanto na academia, quanto na indústria. A área de Transporte Marítimo da Petrobras identificou a necessidade de reavaliar o seu sistema de medição de desempenho, o que motivou esta dissertação, que possui como objetivo elaborar uma proposta de melhoria com foco no desenho de um novo sistema de medição de desempenho com o intuito de aperfeiçoar o atual sistema. Para atingir esse objetivo, foi realizada a avaliação do atual sistema de medição de desempenho, identificando, descrevendo e analisando, as principais medidas de desempenho atualmente utilizadas pela área de Transporte Marítimo da Petrobras relacionadas ao desempenho da frota. O método de pesquisa utilizado consistiu na revisão da literatura acadêmica, na obtenção de dados extraídos dos sistemas de informação da empresa, na realização de entrevistas semi-estruturadas e estruturadas e entrevistas de validação para avaliar o atual sistema de medição de desempenho da frota, propor melhorias e verificar a extensão das mudanças sugeridas. Como resultado, foi identificada a necessidade de revisão de três das cinco medidas, resultando em uma proposta de sete medidas para avaliar o desempenho da frota, proposta esta validada pela área de Transporte Marítimo, por meio da realização de entrevistas. A validação do método proposto para a medição de algumas das medidas de desempenho foi reforçada com a utilização de dados históricos para posterior análise e apresentação aos gerentes e demais entrevistados da área de Transporte Marítimo. / [en] Performance measurement systems is an issue that has been intensively studied, both by scholars and by the practioners. The Maritime Transportation area of Petrobras has identified the need to re-evaluate its performance measurement system, which motivated this thesis, which has the purpose of proposing an improved performance measurement system. In order to achieve that, the current performance measurement system has been assessed, identifying, describing and analyzing the main performance measures currently used by the Maritime Transportation area in connection with the performance of its fleet. The research method applied consisted in literature review, collecting data from the company`s information systems, carrying out semi-structured and structured interviews, as well as validation interviews, in order to assess the current performance measurement system of the fleet, propose improvements and verify the extent of the suggested modifications. As a result, it has been identified the need to review three out of five measures, resulting in a proposition of seven measures to evaluate the performance of the fleet, such proposition being validated by the Maritime Transportation area through interviews. The validation of the proposed measuring method for some of the performance measures has been reinforced by the use of historical data for further anlysis and presentation to the managers and other interviewed persons in the Maritime Transportation area.
18

[pt] MODELO DE OTIMIZAÇÃO PARA AVALIAÇÃO DO SUPRIMENTO DE GASOLINA E DIESEL NA REGIÃO NORDESTE DO BRASIL / [en] OPTIMIZATION MODEL FOR EVALUATING THE SUPPLY OF GASOLINE AND DIESEL IN THE BRAZIL S NORTHEAST REGION

THIAGO DIAS DE OLIVEIRA 07 April 2015 (has links)
[pt] O aumento expressivo no consumo de combustíveis no Brasil trouxe grandes desafios para a cadeia de suprimento no país. Ao longo dos últimos cinco anos (2009-2013), o mercado brasileiro de gasolina e diesel cresceu 62,8 porcento e 32,0 porcento, respectivamente. Porém, os investimentos em produção e infraestrutura não acompanharam este crescimento, tornando estes desafios cada vez maiores. Na região Nordeste do país, que é suprida majoritariamente por cabotagem, a infraestrutura para movimentação dos derivados de petróleo está aquém daquela necessária, trazendo ineficiências à cadeia de suprimentos e aumentando significativamente os custos envolvidos nas operações. Para avaliação do suprimento desta região, foi proposto um modelo de programação matemática que considera todas as restrições que impactam diretamente o suprimento de gasolina e diesel, identificando inclusive aquelas restrições que são ocasionadas por outros agentes da cadeia, como por exemplo, insuficiência de tancagem dos clientes, restrição de calados dos portos e elevadas taxas de ocupação dos portos públicos, aumentando os custos de sobrestadia. Para complementar a análise, alternativas para direcionamento de investimento dos distribuidores de forma eficiente, minimizando os custos da cadeia de suprimento, foram avaliadas. O modelo também foi utilizado na discussão dos níveis de serviço praticados pela Petrobras no atendimento da demanda de gasolina e diesel nos polos da região. O trabalho teve uma abordagem da cadeia de suprimento voltada para o planejamento tático, se mostrando como uma ferramenta eficiente para suporte à tomada de decisões. / [en] The significant increase of fuel consumption in Brazil has brought major challenges to the supply chain in the country. Over the last five years (2009- 2013), the Brazilian market for gasoline and diesel has increased 62.8 percent and 32.0 percent, respectively. However, investments in production and infrastructure have not kept up this growth, increasing the challenges. In the Northeast region of the country, which is supplied largely by coastal shipping, the infrastructure for the petroleum products movement falls short of what is needed bringing several inefficiencies to the supply chain and significantly increasing the costs involved in operations. To assess the supply of this region, a mathematical programming model was proposed which considers all the constraints that directly impact the supply gasoline and diesel, including identifying those constraints that are caused by other actors in the chain, such as insufficient costumer s tankage, draught restriction of ports and high occupancy rates of public ports, raising the cost of demurrage. To complement the analysis, alternative scenarios to allocate the distributor s investments efficiently were evaluated to minimize the costs of the supply chain. The proposed model was also used to discuss the service levels committed by Petrobras in meet the demand for gasoline and diesel at the region. The study had an approach to supply chain oriented for tactical planning, showing as an efficient tool to support decision making.
19

La toxoplasmose chez les Inuits : investigation de l'écologie de toxoplasma gondii dans l'Arctique canadien

Simon, Audrey 04 1900 (has links)
Toxoplasma gondii, un protozoaire très répandu dans le monde, peut infecter de nombreuses espèces homéothermes incluant les mammifères et les oiseaux qui développent alors une toxoplasmose. L’impact de la toxoplasmose en termes de santé publique est majeur, particulièrement chez les personnes immunodéprimées et les foetus. Les niveaux d’infection humaine dans certaines régions de l’Arctique Canadien sont parmi les plus élevés au monde et ce, malgré l’absence de félidés qui sont les seuls hôtes capables d’excréter T. gondii. Plusieurs études ont suggéré la consommation de viande crue de mammifères marins et notamment de phoques comme source d’infection des Inuits. Notre travail de recherche visait à comprendre les mécanismes de dispersion de T. gondii dans les écosystèmes aquatiques menant à la contamination du milieu marin de l’Arctique par des oocystes, et à évaluer l’importance de cette voie de dispersion dans l’infection des phoques et conséquemment dans celle des Inuits. Notre hypothèse était que les oocystes de T. gondii, excrétés durant l’hiver par des félidés dans le Subarctique et transportés par les rivières pendant la fonte printanière, contaminaient les estuaires de l’Arctique Canadien. Dans un premier temps, une étude transversale de séroprévalence chez les phoques de l’Arctique Canadien a montré que ces populations étaient infectées par T. gondii et pouvaient ainsi a priori constituer une source d’infection pour les Inuit. Des variations spatio-temporelles de la séroprévalence étaient observées suggérant un lien potentiel avec des variations dans la contamination environnementale par les oocystes. Un schéma conceptuel explicitant les mécanismes de transport et de devenir des oocystes de T. gondii, du phénomène de la fonte de la neige jusqu’à l’exposition des organismes marins, a été proposé dans le chapitre suivant. Des interactions entre les différents mécanismes identifiés, qui agissent sur des échelles spatio-temporelles variées, devraient favoriser l’apparition de concentrations relativement élevées aux estuaires permettant ainsi l’exposition et potentiellement l’infection de phoques. Pour évaluer la contamination environnementale par les oocystes excrétés par la population de lynx du bassin versant de l’Arctique Canadien (les seuls félidés majoritairement distribués dans ce vaste territoire), nous avons mené une étude sérologique de type transversale dans cette population. Cette étude a permis de montrer que des lynx étaient infectés par T. gondii et a également suggéré que la dynamique des cycles de populations lynx-lièvres pouvait être un processus important dans la transmission de T. gondii. Finalement, la modélisation du transport hydrique des oocystes a indiqué que les concentrations hypothétiques d’oocystes dans l’eau de la fonte pourraient être suffisantes pour permettre l’exposition au niveau des estuaires de bivalves filtreurs, qui sont des proies pour les phoques et donc potentiellement des sources infectieuses pour ces derniers. Dans des écosystèmes nordiques en pleine mutation, la compréhension des mécanismes de transmission d’agents pathogènes d’origine hydrique comme T. gondii est plus que nécessaire, notamment dans le but de protéger les populations fragilisées de ces régions. / Toxoplasmosis results from infection with Toxoplasma gondii, a widespread protozoan that can infect many species including warm-blooded mammals and birds. The public health impact of toxoplasmosis is important, particularly in immunocompromised individuals and the foetus. Levels of human infection in parts of the Canadian Arctic are among the highest in the world, despite the absence of felids that are the only hosts that can excrete T. gondii. Several studies have suggested that consumption of raw meat of marine mammals including seals is a source of infection for the Inuit. Our research sought to understand the dispersal mechanisms of T. gondii in aquatic ecosystems leading to contamination of the marine environment of the Arctic by oocysts, and to assess the importance of this route of dispersion for infection in seals and consequently in the Inuit. We hypothesized that the T. gondii oocysts excreted during the winter by felids in the subarctic area and transported by rivers during spring melt contaminated the estuaries of the Canadian Arctic. Initially, a cross-sectional study of seroprevalence in seals from the Canadian Arctic showed that these populations were infected with T. gondii and thus a priori could be a source of infection for Inuit. Spatio-temporal variations in seroprevalence were observed suggesting a potential link with variations in environmental contamination by oocysts. A conceptual diagram of the possible mechanisms of transport and fate of T. gondii oocysts, from the melting snow to the exposure of marine organisms, is proposed in the following chapter. Interactions between the various mechanisms identified, which act on various temporal and spatial scales, should favour the appearance of relatively high concentrations in estuaries allowing exposure and potential infection of seals. To assess environmental contamination by oocysts excreted by the lynx population living in the watershed of the Canadian Arctic (the only felines largely distributed in this vast territory), we conducted a serological cross sectional study in this population. This study showed that lynx were infected with T. gondii and also suggested the dynamics of lynx-hare population cycles as an important process in the transmission of T. gondii. Finally, the modeling of hydrological transport of oocysts indicated that the hypothetical concentrations of oocysts in meltwater could be sufficient to permit significant exposure in estuarine filter-feeding bivalves on which seals prey and therefore potentially representing sources of infection for them. In changing northern ecosystems, understanding the mechanisms of transmission of waterborne pathogens, including T.gondii is essential, especially in order to protect vulnerable populations that live in these regions.
20

Darbo santykių ypatumai dirbant laivuose / The Peculiarities of Employment Relations of Seamen

Plekavičiūtė, Neringa 06 June 2005 (has links)
Lithuania as a marine state is strongly motivated to create a favourable employment relationship system satisfying the interests of seamen. All marine states are interested that their citizens would work in national fleets and would not be forced to look for work on the ships of other states or on the ships of “convenient flags”. Work analyses the peculiarities of work on ships on the basis of legal act differentiation, i.e. it analyses how employment relationships are regulated by general and specific legal acts. The analysis of employment relationships of different institutions is performed by comparing provisions applied to employees in general and to seamen exclusively in order to highlight the peculiarities of work on ships. The work is based on international: ILO and EU and Lithuanian legal acts. The peculiarities of work on ships is revealed examining main aspects of employment relationships. Employment requirements for seamen as well as employment contracts with seamen and the terms and conditions thereof: payment, work and rest time, vacations – are analysed. Work safety, implementing authorities and liability for injuries of the employees are also discussed. The analysis of the project of ILO consolidated maritime labour conventions is provided. This instrument is intended to facilitate the procedure of ILO standard ratification, i.e. to enable the member states to implement more ILO maritime labour conventions into national law by one ratification act and this way... [to full text]

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