Approved for public release, distribution is unlimited / This thesis analyzes a range of possible future scenarios governing security conditions in the Persian Gulf, in order to determine future requirements for forward-deployed Naval forces in the region. Examination of the past 30 years of U.S. Naval activity in the Persian Gulf provides examples of a full spectrum of deployment options ranging from a nominal presence in the 1970's to the recent deployment of forces unmatched in naval history. Two contrasting scenarios, "best case" and "worst case" are proposed by way of establishing a framework to evaluate the naval presence requirements that may arise in the future. Factors that could effect naval presence in the Gulf are success or failure of nationbuilding in Iraq, the path Iran takes regarding weapons of mass destruction, the progress of the Global War on Terrorism and the perception of American forces by the Arab world. These scenarios reveal the need for sustained naval presence in order to meet the future trends in the Persian Gulf. The Navy's recently implemented Fleet Response Plan calls for "deployment for a purpose." The purpose of naval forces in the Persian Gulf is clear: to provide persistent maritime dominance, power projection and effective crisis response. / Lieutenant, United States Naval Reserve

O Brasil possui uma matriz de transporte onde apenas 13% das cargas utilizam vias marítimas, o que não condiz com a realidade de seu território, onde sua extensa área e litoral fazem do modal aquaviário uma importante alternativa na movimentação de cargas. Nesse contexto, o presente trabalho simulou um sistema de cabotagem onde navios circulam entre três portos dedicados, localizados em Suape, Santos e Rio Grande, e tem como objetivo dimensionar o número de berços por porto e a número e tamanho dos navios necessários para transportar, exclusivamente por contêineres, uma parcela da carga rodoviária. O trabalho considera as atividades de pré-operação, operação (carregamento e descarregamento), pós-operação, viagem entre portos e eventuais filas de entrada, em uma abordagem estocástica desses fatores, além do balanceamento e movimentação de contêineres vazios. Os resultados mostram que o tamanho da infraestrutura necessária para a implementação de um sistema dedicado à cabotagem é viável e seria uma alternativa para melhorar o sistema de transporte de carga entre os estados estudados. / Only 13% of Brazilian loads are transported by ships, which does not match the reality of its territory, where its extensive area and coastline make the waterway mode an important alternative in cargo handling. In this context, the present work aims to simulate a short sea shipping system where ships circulate between three dedicated ports, located in Suape, Santos and Rio Grande, in order to size the number of berths per port and the number and size of the ships necessary to transport, exclusively by containers, a portion of the road load. The work considers the pre-operation, operation (loading and unloading), post-operation, travel between ports and eventual entry queues, in a stochastic approach of these factors, and beside that the balancing and movement of empty containers. The results show that the infrastructure size required for the implementation of a short sea shipping system is feasible and would be an alternative to improve the system of cargo transportation among the states studied.

Autonomous electric vehicles are set to replace most conventional vehicles in the near future. Extensive research is being done to improve efficiency at the individual and fleet level. There is much potential benefit in optimizing the deployment and rebalancing of Autonomous Electric Taxi Fleets (AETF) in cities with dynamic demand and limited charging infrastructure. We propose a Fleet Management System with an Online Optimization Model to assign idle taxis to either a region or a charging station considering the current demand and charging station availability. Our system uses real-time information such as demand in regions, taxi locations and state of charge (SoC), and charging station availability to make optimal decisions in satisfying the dynamic demand considering the range-based constraints of electric taxis. We integrate our Fleet Management System with MATSim, an agent-based transport simulator, to simulate taxis serving real on-demand requests extracted from the San Francisco taxi mobility dataset. We found our system to be effective in rebalancing and ensuring efficient taxi operation by assigning them to charging stations when depleted. We evaluate this system using different performance metrics such as passenger waiting time, fleet efficiency (taxi empty driving time) and charging station utilization by varying initial SoC of taxis, frequency of optimization and charging station capacity and power.

Autonomous electric vehicles are set to replace most conventional vehicles in the near future. Extensive research is being done to improve efficiency at the individual and fleet level. There is much potential benefit in optimizing the deployment and rebalancing of Autonomous Electric Taxi Fleets (AETF) in cities with dynamic demand and limited charging infrastructure. We propose a Fleet Management System with an Online Optimization Model to assign idle taxis to either a region or a charging station considering the current demand and charging station availability. Our system uses real-time information such as demand in regions, taxi locations and state of charge (SoC), and charging station availability to make optimal decisions in satisfying the dynamic demand considering the range-based constraints of electric taxis. We integrate our Fleet Management System with MATSim, an agent-based transport simulator, to simulate taxis serving real on-demand requests extracted from the San Francisco taxi mobility dataset. We found our system to be effective in rebalancing and ensuring efficient taxi operation by assigning them to charging stations when depleted. We evaluate this system using different performance metrics such as passenger waiting time, fleet efficiency (taxi empty driving time) and charging station utilization by varying initial SoC of taxis, frequency of optimization and charging station capacity and power.

A análise de pneus em frotas de caminhões de longa distância atualmente é realizada apenas para efeito de controle de estoque e determinação de causas de falhas. A metodologia de análise de confiabilidade apresentada neste trabalho, utilizando dados obtidos de pneus sucatados, sistematiza a mensuração e análise de perda de vida útil causada por cada tipo de falha: as amostras são analisadas, verificando-se qual distribuição de probabilidade que melhor modela as amostras avaliadas quando comparadas às distribuições Weibull, normal, log-normal e exponencial; o modelo sugere uma forma de efetuar análises de confiabilidade das falhas mais freqüentes, sendo estas classificadas segundo as perdas de tempo de vida do produto. A metodologia ora proposta foi aplicada na análise de confiabilidade de pneus 295/80R22.5 empregados em frota de transporte rodoviário. Para tanto foram analisadas sucatas provenientes de 10 frotas, verificando-se que a confiabilidade do pneu é melhor representada por uma distribuição de Weibull. A aplicação desta metodologia possibilita a identificação das principais causas das falhas mais críticas, permitindo à empresa focar os esforços em medidas preventivas adequadas e definir o tempo de remoção antes da falha para obter o menor custo. / Long distance truck tire analysis is done nowadays only for the purposes of warehouse control and failure cause determination. The analysis methodology presented in this study, using tire data obtained in scrap tires, systematizes the measurement and analysis of useful tire life time losses caused by each failure type: the samples are analyzed, verifying which probability distribution best fits the evaluated samples when comparing Weibull, normal, log-normal and exponential distributions; the model suggests a way to carry out the reliability analysis of the most common failures classifying them according to product life losses. The proposed methodology was used to analyze the reliability of 295/80R22.5 tires applied in highway transport fleets. For that purpose scrap tires samples from 10 fleets were analyzed and one can verify tire reliability is better represented by a Weibull distribution. The application of this methodology makes it possible to identify the main causes of the most critical failures, allowing the fleet to focus efforts on appropriate preventive measures and define replacement time before failure to obtain the lowest cost.

[pt] Esta dissertação tem como objetivo contribuir para o gerenciamento de frotas de grande porte, buscando uma maior rapidez e eficiência na distribuição de veículos ao longo do tempo/espaço, visando maximizar o lucro total da empresa. Problemas de gerenciamento de frotas dinâmicas são normalmente formulados como uma rede dinâmica, mas há uma grande dificuldade ao se trabalhar com problemas desse tipo, especialmente quando se busca uma solução sobre um horizonte de planejamento longo. Visando contornar essa dificuldade, Powell & Carvalho (1998) desenvolveram uma nova abordagem para problemas desse tipo: a Logistics Queuing Network (LQN). A utilização do algoritmo LQN na prática (através de um software) permitiria uma tomada de decisão mais rápida e eficiente, sendo bastante útil, em especial para empresas de transportes. Assim, implementou-se o algoritmo LQN, através do desenvolvimento de um software para o gerenciamento de frotas de grande porte, por meio do qual podese constatar o potencial de aplicação desse algoritmo. / [en] The objective of this dissertation is to contribute to the large-scale fleet management, looking for a greater efficiency and speed in vehicle distribution over time and space, while maximizing total profit. Dynamic fleet management problems are normally formulated as a dynamic network, but it`s really difficult to work with problems of this class, especially when we look for a solution over a large planning horizon. In order to overcome this problem, Powell & Carvalho (1998) developed a new formulation for these problems: the Logistics Queuing Network. The use of its algorithm in real problems (using a software) would allow quickly and more efficient decisions in transports, being really useful especially for transports enterprises. For this reason, the algorithm LQN was implemented, through the development of a software for the large-scale fleet management, so we could verify the potential application of this algorithm.

Nesta tese, nós apresentamos uma compilação de três artigos de otimização aplicados no contexto de transporte urbano de ônibus. O principal objetivo foi estudar e implementar heurísticas com base em Pesquisa Operacional para otimizar problemas de (re)escalonamento de veículos off-line e on-line considerando várias garagens e frota heterogênea. No primeiro artigo, foi proposta uma abordagem heurística para o problema de escalonamento de veículos múltiplas garagens. Acreditamos que as principais contribuições são o método de geração de colunas para grandes instâncias e as técnicas de redução do espaço de estados para acelerar as soluções. No segundo artigo, adicionamos complexidade ao considerar a frota heterogênea, denotada como multiple depot vehicle type scheduling problem (MDVTSP). Embora a importância e a aplicabilidade do MDVTSP, formulações matemáticas e métodos de solução para isso ainda sejam relativamente inexplorados. A principal contribuição desse trabalho foi o método de geração de colunas para o problema com frota heterogênea, já que nenhuma outra proposta na literatura foi identificada no momento pelos autores. Na terceira parte desta tese, no entanto, nos concentramos no reescalonamento em tempo real para o caso de quebras definitivas de veículos. A principal contribuição é a abordagem eficiente do reescalonamento sob uma quebra. A abordagem com redução de espaço de estados, solução inicial e método de geração de colunas possibilitou uma ação realmente em tempo real. Em menos de cinco minutos, reescalonando todas as viagens restantes. / In this dissetation we presented a three articles compilation in urban bus transportation optimization. The main objective was to study and implement heuristic solutions method based on Operations Research to optimizing offline and online vehicle (re)scheduling problems considering multiple depots and heterogeneous fleet. In the first paper, a fast heuristic approach to deal with the multiple depot vehicle scheduling problem was proposed. We think the main contributions are the column generation framework for large instances and the state-space reduction techniques for accelerating the solutions. In the second paper, we added complexity when considering the heterogeneous fleet, denoted as "the multiple-depot vehicle-type scheduling problem" (MDVTSP). Although the MDVTSP importance and applicability, mathematical formulations and solution methods for it are still relatively unexplored. We think the main contribution is the column generation framework for instances with heterogeneous fleet since no other proposal in the literature has been identified at moment by the authors. In the third part of this dissertation, however, we focused on the real-time schedule recovery for the case of serious vehicle failures. Such vehicle breakdowns require that the remaining passengers from the disabled vehicle, and those expected to become part of the trip, to be picked up. In addition, since the disabled vehicle may have future trips assigned to it, the given schedule may be deteriorated to the extent where the fleet plan may need to be adjusted in real-time depending on the current state of what is certainly a dynamic system. Usually, without the help of a rescheduling algorithm, the dispatcher either cancels the trips that are initially scheduled to be implemented by the disabled vehicle (when there are upcoming future trips planned that could soon serve the expected demand for the canceled trips), or simply dispatches an available vehicle from a depot. In both cases, there may be considerable delays introduced. This manual approach may result in a poor solution. The implementation of new technologies (e.g., automatic vehicle locators, the global positioning system, geographical information systems, and wireless communication) in public transit systems makes it possible to implement real-time vehicle rescheduling algorithms at low cost. The main contribution is the efficient approach to rescheduling under a disruption. The approach with integrated state-space reduction, initial solution, and column generation framework enable a really real-time action. In less than five minutes rescheduling all trips remaining.

[pt] Cada vez mais o transporte de cargas rodoviário desempenha um papel fundamental para a execução dos processos logísticos dentro das empresas. Atualmente as empresas têm optado por utilizar serviços de outras para desempenhar essa função, através da terceirização de serviço. Porém, por observar que muitas vezes as expectativas com relação ao nível de serviço ficam abaixo do esperado, ou ainda por insatisfação dos clientes com a forma de execução dessas empresas terceirizadas, as empresas optam por manter uma frota própria, que prioriza o nível de serviço evitando falhas e consequentemente a depreciação da sua reputação. A partir de análises dos serviços logísticos prestados por uma empresa terceirizada para uma empresa de cosméticos na região metropolitana de Curitiba foi verificada a necessidade de uma nova estratégia no sistema de transportes de cargas, a fim de se obter uma melhora no nível de serviço de entrega e consequentemente a melhora na satisfação dos clientes. O resultado após sete meses de implantação do serviço com frota própria, com a utilização de nove veículos, foi mais eficiente que o serviço prestado anteriormente pela empresa terceirizada, por viabilizar um aumento do número de entregas aos clientes finais em até dois dias úteis, melhorar o nível de serviço nas entregas, gerando assim, um aumento da satisfação dos clientes e proporcionar para a empresa uma redução nos seus custos de transporte. / [en] Cargo road transportation plays a key role in the execution of logistics processes within companies. Currently, companies have chosen to use other services to perform this function, called out sourcing service. However, by observing that the quality of service is less than expected, or that the customers are not satisfied with the service provided by the carriers contracted, companies choose to maintain its own fleet, which prioritizes the quality of service avoiding failures and therefore the depreciation of its reputation. Logistic services analysis provided by a cosmetic company in Curitiba, Brazil verified the need for a new strategy in the transport system in order to obtain an improvement in the level of delivery service and consequently the improvement in customer satisfaction. After seven months with its own transport fleet, comprising nine vehicles, the freight was more efficient than the service provided by the company previously outsourced, resulting in an increase in the number of deliveries to the customers in two days, improving the status of service deliveries, thus providing an increase in customer satisfaction and a reduction in the expenses for their transportation costs.

A madeira é uma commoditie de extrema importância no Brasil e possui grande diversidade de utilização sendo matéria-prima para obtenção de energia, na forma de carvão e biomassa, produção de celulose e papel, construção civil, indústria farmacêutica etc. O modal rodoviário é a principal forma de transporte de carga florestal no Brasil, como também na região deste estudo denominada como \"Arco de Desflorestamento\". O objetivo deste trabalho foi elaborar um panorama do transporte rodoviário de madeira bruta e em toras, possibilitando o entendimento e a melhor compreensão da atividade de forma a subsidiar discussões a cerca da legislação e políticas públicas visando sua adequação à realidade da região em questão. O trabalho se estruturou em torno de um capítulo introdutório sobre o panorama atual, seis capítulos com estudos científicos e um capítulo contendo uma revisão bibliográfica geral de contextualização do cenário proposto. Os resultados destacaram a detecção de agentes internos: condutor, empresa, terceiros e externos: instituições fiscalizatórias, sociedade civil, e o mercado de madeira são componentes que interferem direta ou indiretamente na atividade. Críticas no processo de formação de preço do frete foram constatadas e novas metodologias para esta formação foram elaboradas. Novas equações para a determinação do frete foram propostas inserindo as variáveis quantitativas: volume de madeira (m³), distância (km) e horas efetivas (h), além das qualitativas como satisfação na atividade e permanência na atividade. O melhor coeficiente do modelo de frete encontrado foi R² = 0,973 e R² (adj) = 0,972. Em relação à frota constatou-se que a Combinação Veicular de Carga - CVC que mais se destaca é o biminhão (49,66%). Verificou-se também que o comprimento variável das toras, somado aos diâmetros muitas vezes irregulares nas diferentes extremidades do fuste, impede que a carga seja acomodada e disposta de forma organizada. Este fato gera um aumento dos espaços vazios que traz consequências graves à segurança do transporte rodoviário florestal ocasionando o excesso de comprimento, altura e lateral. A carga transportada ainda restringe o tipo de carroceria que é exclusiva para atividade, fato este que limita a possibilidade de transporte de outros tipos de cargas. O levantamento constatou que a frota possui uma idade média avançada (18,22 anos), fato este que dificulta os condutores adequarem-se à legislação em vigor que fixa requisitos técnicos de segurança para o transporte de toras de madeira bruta por veículo rodoviário de carga. Pontos falhos foram detectados na legislação, destacando-se as obrigatoriedades impostas pela resolução não se encontrarem em consonância com a realidade da frota, principalmente pela idade avançada, causando críticas dos condutores ao governo. Como resultado final deste estudo foi elaborado o panorama da atual situação e levantados os principais problemas, assim como indicadas possíveis soluções em termos de iniciativas e programas do governo para a renovação da frota de transporte de madeira bruta e em toras na região. / The wood is a very important commodity in Brazil and is very useful as has great diversity in the feedstock being material for several products such as: energy wood (coal and biomass), cellulosic production (pulp and paper), pharmaceutical, nautical industries and construction. In Brazil different transport modal to transporting forest load is used, but the mainly transport is through the road and in the region studied the name \"Arc of deforestation\" is the major way to dispose wood production. The need to provide an overview of transporting raw wood and logs make easier understanding and provide improvements in transport legislation and guide to policies to fit the reality of the region in question. This work was structured with an introductory chapter about the general problem, and six chapters more, based on scientific articles and literature review. This work in a general view obtained important results for constructing the panorama. The results showed different components agents internal (driver, direct and indirect companies), and external agents (institution of monitoring government, the society and the wood market) that can interfere directly or indirectly in the activity. The traditional methodology about freight was criticized and new methodologies were proposed to improve the method. New models for freight were also proposed inserting quantitative and qualitative variables and the best model coefficient was R² = 0.973 and R² (adj) = 0.972. The best model variables selected in this study were: timber volume (m³), distance (km), effective hours (he) for quantitative variables and for qualitative variables: satisfaction in the activity, and permanence in the work. Regarding the truck fleet it was found that about the CVC (combination vehicular cargo) truck trailer (6 axes) was the most ordinary in this study (49.66%). It has been found that the length of logs plus the irregular diameters in the different extremities of the logs impossible the correct stacking timber. Because of the spaces originates from the bad accommodation of the logs has serious consequences for the safety of wood road transporting generating an excessive cargo in length, height and width. This is a form of equivalence volumetric. Another problem is that the trailers exclusive for the activity and this fact limits the possibility of carrying other types of cargo, decreasing the competitiveness. This study allowed to establish that the fleet has an old average age and this fact hinders truck drivers to fit on the present legislation (Resolution n. 246 of July 2007.) This resolution fixes technical safety requirements for the road transportation of logs. In this resolution were detected a critical point that the obligation imposed is not compatible with the reality and the old average age of fleet (18.2 years), provoking criticism by the truck drivers about the government. This study was able to satisfy to proposed a new overview raising problems, indicating improvements and suggestions such as: initiatives and government programs for the renewal of the fleet log road transportation and changes in the public politicians.

A job is not only an economic factor for the individual; the work also has a great impact on the individual's well-being. It is therefore a prerequisite for employees to be happy at work, which places demands on the workplace. The purpose of the study is to investigate what soldiers and officers have for experiences of job satisfaction. This is answered by studying a specific company on an aircraft fleet within the Swedish Armed Forces based on these research questions: How do the informants experience their work situation at the company? What difficulties and opportunities can be identified based on the informants' work situation and how can these be understood? The thesis is based on a qualitative method and the empirical data has been collected through interviews with four officers and four soldiers. The theoretical framework is based on previous research on employees and job satisfaction, Herzberg's two-stage model and Karasek and Theorell's demand- control-support model. The results of the study show that both the soldiers and the officers feel that the high workload of the company causes the work situation to be perceived as worse. The informants also feel that they do not get paid for the work they do, that the workload prevents them from developing, that everyone does not get feedback in the way they had wanted and that the goals and requirements that are set for the function sometimes are too unclear. Furthermore, the results show that the officers and soldiers generally agree on how well-being is generally experienced at the company. The main difference between the soldiers and the officers is that the soldiers feel that their work situation is affected for the worse because they do not have the same powers to make decisions within the organization. What the informants especially feel is contributing to a more pleasant work situation is the good cohesion between the employees. The informants feel that their work situation is affected to a lesser extent by a number of aspects, but nevertheless the majority of the informants want to continue working at the company.