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Thesis (M.B.A.)--University of Hong Kong, 1982.

This Master's Thesis evaluates the previous and the current state of the Belarusian Railways and its importance for Belarus, it points out possible perspectives for further development of belarusian transport on Trans-Siberian Railroad. The thesis also answers to the question why in recent years such a strong interest in the Trans- Siberian Transport appeared. The work is prepared on the basis of available information and self-acquired research and analysis carried out by the author. During the writing of the thesis was also used information obtained from interviews with experts in the areas of rail transport in Belarus. The conclusions of the work are beneficial not only for students but also for anyone interested in railway transport sector and in transport in Trans-Siberian Railroad. The reader will learn about the results of evaluating the state of Belarusian Railways and perspectives of their further development in terms of Trans- Siberian Railroad.

The master thesis focuses at the pricing process of FCL shipments between Europe and Asia. After the general process description of internal processes there are shown two concrete examples, one under EXW condition and the other one under DAP condition. At the same time the thesis present also the railway connection between Asia and Europe as a certain alternative to the maritime and airfreight transportation under some condition.

The master´s thesis deals with the international personal transportation on relation between Czech capital city, Prague and the biggest city of east Slovakia region, Košice. It aims mainly on services, which transport companies currently provide, and presents them according to their attractiveness from the customers´ point of view. The analysis of offered services enables us to describe quality of traveling between Prague and Košice. At the same time, it creates a picture about competition between operating companies on railways mainly. This paper focuses on railway transport but does not omit the bus transport neither. The end of the diploma thesis belongs to assessment of situation of current personal transportation and tries to forecast its future development.

This dissertation examines the challenges associated with disruptions in supply chain financing and the railway transportation network. The study is divided into six chapters: In Chapter 1, we introduce the core problems under investigation. Chapter 2 investigates supply chain financing, emphasizing trade credit and bank credit—two predominant external financing mechanisms. Given the inherent uncertainties in demand, interest rates, and supplier credit ratings, this chapter introduces a stochastic programming model accounting for demand uncertainty. Subsequently, a robust optimization program is applied, whose complexity demands a specialized solution methodology. By analyzing a case study centered around a prominent U.S. retailer, the research reveals key insights into decision-making processes related to financing, the effects of bargaining power on portfolio mix and profits, and the relative importance of interest rate uncertainties over supplier credit ratings. Chapter 3 introduces a game-theoretical model designed to hedge financing risks in supply chains, with a focus on the application of insurance for both trade and bank credits. To support the design of effective supply chain finance contracts, three distinct contracts are developed, aiming to synchronize both financial and material flows within the supply chain. A significant feature of this chapter is the data-driven approach employed to address the potential bankruptcy risks that can arise from borrowing loans. Alongside this, a novel solution algorithm is introduced to solve the proposed non-convex models. A case study involving Ford Motor Company and a Chicago-based retailer enriches the research with real-world context. The findings offer several managerial insights: the strategic advantages of different insurance services vary based on the risk attitudes and profit margins of participants. For example, when a retailer operates with a lower profit margin, the use of Trade Credit Insurance (TCI) is recommended in conjunction with a risk-seeking retailer, while a risk-averse retailer might diminish the benefits of TCI. Conversely, with high profit margin retailers, the adoption of Payment Protection Insurance (PPI) is advised under all conditions. In Chapter 4, a game-theoretical model for risk mitigation within railway transportation is introduced. This model addresses random disruptions by employing strategies like repair, re-routing, third-party services, and leasing capacity from competing rail companies. Through a U.S. case study, the efficacy of these strategies is examined, with renting railcars emerging as a particularly potent approach to enhance resilience and reduce third-party expenses. The research further suggests that negotiations extending delivery dates can significantly diminish post-disruption costs. Finally, Chapter 5 summarizes the primary contributions of this research, laying the groundwork for prospective studies in this domain. / Thesis / Doctor of Philosophy (PhD)

L’intégration de systèmes de production décentralisés et de stockage d’énergie dansles réseaux d’électrification ferroviaires est envisagée comme une solution pour améliorerles performances électriques et énergétiques des réseaux électriques ferroviaire qui fontface à une forte augmentation de trafic. Cette solution doit permettre de réduire les coûtsd’investissement et d’exploitation des réseaux ferroviaires (moins de consommation, desrenforcements d’infrastructures limités) par rapport aux solutions conventionnelles.Ces travaux de thèse visent à définir une méthodologie de conception optimale et de gestionénergétique des systèmes de production et de stockage de l’énergie dans un environnementferroviaire. La méthodologie proposée devra constituer pour les ingénieurs une aide à laconception et au dimensionnement des futurs réseaux ferroviaires.Une méthodologie basée sur des modèles d’optimisation non linéaire a été développée.Elle propose une approche originale du traitement des charges mobiles et des dispositifsnon linéaires du réseau (sous-stations, moyens de stockage, rhéostat de freinage) pourl’optimisation. Elle permet de déterminer le dimensionnement et la loi de pilotage optimauxd’un système de stockage intégré à un réseau d’électrification ferroviaire.La méthodologie a été appliquée à une section de réseau urbain électrifiée en 1500Vcontinu. Un système de stockage d’énergie est alors utilisé pour résoudre un problème dequalité d’alimentation et réduire la consommation énergétique. Les résultats obtenus montrentles gains apportés par le stockage et fournissent un guide pour le choix du mode de stockage(batterie, supercondensateur, volant d’inertie) le plus pertinent pour l’application considérée.Des perspectives sont finalement ouvertes pour l’extension de notre méthodologie auxsystèmes de production décentralisés, aux réseaux électrifiés en courant alternatifs et auxautres types de solutions technologiques (FACTS, HVB. . . ). / Integration of decentralized production and energy storage systems into railwayelectrification networks are considered as a solution in order to improve their electrical andenergetic performances when facing a major traffic increase. This solution shall allow to reducethe investment and exploitation costs of railway networks (less energy consumption, lessreinforcement work on infrastructures) compared to conventional solutions.The work presented in this manuscript aim to define a methodology for optimal sizing andenergetic management of energy production and/or storage systems for a railway network. Theproposed methodology must help engineers while designing future railway networks.A methodology based on a non linear optimization model has been developed. A novelapproach of the modeling of mobile loads and non linear components of the network (feedingsubstations, energy storage systems, braking rheostats) is proposed for optimization process.It allows the computation of the optimal sizing and control law of an energy storage systemimplemented in a railway electrification network.This methodology has been applied to a DC 1500V electrified urban network section. Anenergy storage system has been introduced in order to solve power quality issues and to reduceenergy consumption. The results shows the benefits of the energy storage system and providesindications to choose the better energy storage system technology (batteries, super-capacitors,flywheel) for the considered application.Future developments shall be the extension of our methodology to decentralized productionsystems, AC electrified railway networks and other technological solutions (FACTS, HVB...).

Ce travail est le résultat d'une collaboration entre le laboratoire LAPLACE, la "Seconda Università degli Studi di Napoli" (SUN) et la Société National des Chemins de fer Français SNCF. Le sujet de recherche concerne l'utilisation de dispositifs électroniques de puissance dans les sous stations ferroviaires 25kV/50Hz afin d’améliorer la qualité de l'énergie électrique. Dans le transport ferroviaire, le système d'électrification monophasé 25kV/50Hz est largement diffusé en particulier pour les lignes ferroviaires à grande vitesse. Bien qu'aujourd'hui les systèmes d’alimentation en courant continu soient encore largement utilisés, l'adoption du courant alternatif monophasé offre des avantages économiques pour les infrastructures d'environ 30% en termes d'investissement, d'exploitation et d'entretien. Initialement, compte tenu de la simplicité du circuit, il n'y avait aucune nécessité d'intégrer de l'électronique de puissance dans les sous stations. Toutefois, au cours de la décennie passée, l'intérêt pour ces équipements est apparu car ils peuvent apporter une solution d'optimisation du réseau lorsque le trafic augmente ou lorsqu’une nouvelle sous station est envisagée. Deux principaux types de dispositifs sont installés aujourd'hui sur le réseau ferré français : les compensateurs de puissance réactive et les compensateurs de déséquilibre de tension. Cette thèse présente de nouvelles topologies de compensateurs basées sur le concept d’impédances contrôlées par gradateur MLI. Comparées aux solutions existantes, ces topologies ont des caractéristiques particulièrement intéressantes en termes de pertes dans les semi-conducteurs et de volume des composants réactifs. Le manuscrit contient trois parties principales: La première partie présente le principe de l’électrification en 25kV/50Hz et souligne l’intérêt d’installer des moyens de compensation statique dans les sous stations. Après une description des solutions actuellement utilisées, le concept d’impédance contrôlée par gradateur MLI (CCI : Chopper Controlled Impedance ) est ensuite présenté. La deuxième partie du travail concerne l'utilisation du concept de CCI pour la compensation de puissance réactive. La sous-station SNCF de Revest est considérée comme cas d’étude. Celle-ci est équipée d'un transformateur monophasé de 60MVA dont le primaire est connecté à une ligne de transport 225kV. Deux topologies de compensateur de puissance réactive, basées sur des montages abaisseur ou élévateur de tension sont présentées. Le dimensionnement des gradateurs est effectué sur la base d'une campagne de mesures réalisée à la sous station. Des simulations numériques utilisant des formes d’ondes réelles de courant et de tension sont présentées. Des résultats expérimentaux effectués à la plateforme de test de la SNCF sur un prototype de 1,2MVAR permettent de valider le concept de CCI. La dernière partie du travail concerne le problème du déséquilibre de tension en amont de la sous station. Un circuit de Steinmetz « actif », toujours basée sur des gradateurs MLI, est présenté et étudié. La sous station SNCF d'Evron est alors considérée comme cas étude. Celle-ci comporte un transformateur de 32MVA et est connectée à une ligne de transmission 90kV. Les mesures effectuées sur le site permettent le dimensionnement du compensateur ainsi que l’utilisation des formes d'onde réelles de courant et de tension dans les simulations numériques. Une comparaison avec des solutions classiques basées sur des onduleurs 2 niveaux et 3 niveaux souligne les avantages de la solution proposée. Ainsi, les résultats des calculs et des simulations montrent que l'énergie stockée dans les éléments réactifs est réduite d’un facteur six et que les pertes dans les semi-conducteurs sont réduites de 40%. Des résultats expérimentaux obtenus sur une maquette de 1.5 kVA permettent de valider le principe du circuit de Steinmetz actif. / This work is the result of collaboration between the LAPLACE laboratory, the “Seconda Università degli Studi di Napoli” (SUN) and the French national railways operator SNCF. The research topic treated herein concerns the use of power electronic devices in 25kV/50Hz railways substations to achieve power quality improvements. In railway transportation, single-phase 25kV-50Hz electrification system is widely diffused especially for high-speed railway applications. Although electrified DC systems are still widely applied, the adoption of AC single-phase system offers economical advantages for the infrastructures of about 30% in terms of investment, exploitation and maintenance. In early ages, due to its very simple diagram, there was no necessity to integrate power electronics in substations. However, for the last decade, the interest in power electronic equipments raised since they can provide the solution for network optimization when traffic increases or when a difficulty is foreseen for a substation implementation. Two types of devices are implemented today on the French Railway Network: Reactive Power compensators and Voltage Unbalance compensators. This thesis presents an investigation into new topologies based on the concept of “Chopper Controlled Impedances”(CCI). Compared to existing solutions, the new topologies show interesting features in terms of semi-conductor losses reduction and volume of reactive components. The manuscript is developed through three main parts: Firstly, the French railways system is introduced and the interest in installing power electronic compensators in substations is highlighted. After a brief description of currently used solutions, the CCI concept is presented: the use of Pulse Width Modulated AC Choppers allows achieving structures which behave as variable impedances. In the second part, the use of CCI structures in reactive power compensation is investigated. The SNCF substation of Revest is under study. It is equipped by a 60MVA single phase transformer with the primary side connected to a 225kV transmission line. Based on the step-down or step-up functioning mode of CCIs, two topologies of reactive power compensator are presented. The converter design is developed on the base of a measurement campaign carried out at the substation. Numerical simulations using real current and voltage waveforms are presented. Finally, experimental results carried out at the SNCF test platform on a 1.2MVAR prototype are shown. In the last part, the problem of voltage unbalance is treated. Using the concept of CCI, the feasibility of an active Steinmetz circuit based on AC choppers is explored. As a case study, the substation of Evron is considered. It is a 32MVA substation connected to a 90kV transmission line. Measurements carried out on the substation site allow the compensator design and the possibility to consider real waveforms for current and voltage in numerical simulations. A comparison with classical solution based on two levels VSI and three levels NPC-VSI highlights the advantages of the proposed solution. Calculation and simulation results show that the stored energy in reactive elements is reduced by a factor six whereas the semiconductor losses are 40% lower. Experimental results obtained on a scaled demonstrator (1.5 kVA) validate the principle of the active Steinmetz circuit.

Este trabalho propõe uma metodologia para escolha de modal de transporte a partir da aplicação do método de análise hierárquica a um conjunto de critérios levando em consideração o ponto de vista dos donos da carga. Parte-se de uma pesquisa de critérios adotados na escolha de modal sob contextos que incluem variação de cargas avaliadas, de disponibilidade de infraestrutura e serviços logísticos. Avalia-se ainda o método de análise hierárquica, AHP, que permite a decisão multicriterial com fatores quantitativos e qualitativos. Propõe-se uma metodologia de escolha de modal considerando o que é importante para o embarcador baseado no método AHP. Os critérios levantados na literatura são condensados em um conjunto hierarquizado de 3 critérios (custo logístico total; atendimento a particularidades da carga; e confiabilidade) e 7 subcritérios (custo logístico total; acessibilidade, flexibilidade, e oferta de instalações logísticas; pontualidade, perdas e danos, e informações ao cliente). A metodologia resultante é genérica e pode ser aplicada a um conjunto abrangente de situações logísticas. A título de exemplo, a metodologia é aplicada a três casos de transporte, para a escolha entre a alternativa rodoviária direto ou intermodal com ferrovia, variando-se a distância (média ou longa distância) e a carga transportada (açúcar a granel ou contêiner, para exportação). Os resultados são comparados e discutidos em termos dos pesos relativos dos critérios na escolha do embarcador, e das respectivas contribuições à decisão em face dos atributos das alternativas. Conclui-se que a avaliação multicriterial, contemplando critérios quantitativos e qualitativos, proporciona uma análise abrangente da hierarquia e contribuição dos critérios e a distinção dos pontos críticos na competição entre modais. / This study proposes a method for determining modal choice in transport problems based on an analytic hierarchy technique, considering the cargo owners point of view. Initially, a research of criteria used in modal choice in several contexts is carried out: cargos evaluated, availability of infrastructure and logistic services, standpoint of the evaluator. A review of the AHP method (which allows for multicriterial decisions with qualitative and quantitative factors) ensues. The author proposes a method for assisting in the modal choice from the cargo owners standpoint, based on the AHP technique. The criteria collected from the literature review are condensed in a hierarchical set of 3 criteria (total logistic costs; compliance with specificities of the cargo; and reliability) and 7 subcriteria (total logistic costs; accessibility, flexibility, and availability of logistic facilities; timeliness, susceptibility to loss or damage; and information to customers). The resulting method is generic and can be applied to a comprehensive range of logistic situations. The proposed method is then applied, as an example, to three freight cases, to aid the modal choice between direct roadway transportation or intermodal transport based on rail freight, with varying distances (medium or long distance haul) and the cargo being transported (bulk sugar or container, both for export). The results are compared and discussed in terms of the relative weights of each of the 7 subcriteria in the cargo owners modal decision, and the respective contributions to the decision in light of the attributes of the alternatives. The study concludes that the multicriterial evaluation, contemplating quantitative and qualitative criteria, yields a more comprehensive analysis of the important criteria hierarchy and the distinction of key issues in modal competition.

Esta pesquisa tem por objetivo o estudo das relações espaciais potencializadas por uma rede de transporte ferroviário que extrapolasse os limites da Região Metropolitana de São Paulo, mostrando-se como possibilidade para a transformação qualitativa do espaço em direção à sua homogeneização. Para isso, buscou-se construir um conjunto de referências de infraestrutura e serviços ferroviários para o transporte de passageiros a partir dos sistemas europeus, sobretudo o sistema francês. Simultaneamente, foram levantadas e analisadas criticamente as políticas recentes voltadas para implementação desse tipo de infraestrutura no estado de São Paulo, visando estabelecer um panorama sobre os preceitos envolvidos na sua elaboração. Por f im, a p artir d a a valiação e i nterpretação de t odos e sses a spectos, o trabalho propõe dois ensaios: um primeiro de caráter conceitual, buscando estruturar a prática de planejamento para os novos sistemas; e um segundo de caráter propositivo, para a conformação de uma rede ferroviária integrada entre as diferentes escalas hierárquicas traçadas. / This research aims to study the spatial relations as result of a railway transportation network, which extrapolates the limits of the Metropolitan Region o f S ão P aulo, and xplores t he p ossibilities o f a qualitative transformation of the space towards its homogenization. Firstly, the work assemble references concerning infrastructure and railway services in the Western-European context, notably the French railway system. Secondly, the various recent policies of railway system\'s implementation in the state of São Paulo were gathered and analyzed, setting up an overview of their elaborations\' directives. Finally, the work proposes two essays: a) a conceptional one, which set bases for planning practices for new railway transportation systems; and b) a propositional one, which defines an integrated railway network between the different hierarchic scales.