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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

Evropské letecké uzly v kontextu sítě a její odolnosti vůči narušení / European air hubs in the context of network and its resistance against disturbances

Šulc, David January 2019 (has links)
EUROPEAN AIR HUBS IN THE CONTEXT OF NETWORK AND ITS RESISTANCE AGAINST DISTURBANCES Abstract The submitted master thesis is addressing the theme of connectivity of European Air Transport Network, its properties and resistance against negative influences based on data from flight schedules for winter season 2018. The main objective of the thesis is to analyse European Air Transport Network from the point of connectivity in order to find out the most important airport hubs according to their geographic conditions, community structure and resistance of the whole network. Used methods are based on the Graph Theory and the centrality measures as indicators of connectivity. The empiric part of the thesis is divided into three parts. The aim of the first part is to find out, what airports are the most important in the European Air Transport Network. In the second part are explored properties and structure of the network. The last part is aiming to analyse the resistance of the European Air Transport Network from the view of robustness and resilience. Among the most important air hubs in Europe belong airports, that are serving world cities and tourist attractive localities. There is a strong dominance of the Schiphol airport in Amsterdam, the El Prat airport in Barcelona and the Frankfurt Airport. The European Air...
12

Economic regulation of offer and demand of flexibility in gas network / L'économie de la reglementation de la flexibilité de l'offre et de la demande du transport gazier

Carvalho Metanias Hallack, Michelle 24 June 2011 (has links)
La thèse discute des conséquences des changements majeurs du modèle de la demande de gaz décrits précédemment. L´exigence de flexibilité à court terme a été l´une des principales caractéristiques de la demande de gaz pour la production d´électricité. Ainsi, la capacité de l´industrie du gaz à fournir des services flexibles à court terme a été valorisée par le biais du marché de l´électricité. Cela signifie une augmentation de la valeur économique des services permettant d´adopter une position attentiste vis-à-vis de la consommation avant toute prise de décision. Différents secteurs de l´industrie du gaz ont été affectés par les variations de la demande, c´est le cas de la production des champs de gaz, du stockage et des mécanismes d´importation du gaz qui ont été incités à la flexibilité. L´introduction des outils de flexibilité, qu’impliquent les variations de la demande, dépend directement des services de réseau. Par conséquent la concrétisation de la valeur économique de la flexibilité de l´industrie gazière dépend des services de réseau.Le réseau de transports de gaz est un élément-clé de l´industrie gazière portant sur deux types de flexibilités physiques: la mobilité et l´aptitude au stockage. Les propriétés physiques du gaz naturel permettent la flexibilité par la gestion des différentiels de pression. Les différentiels de pression contrôlent les mouvements de gaz. Le réseau est de loin le principal mécanisme de transport de gaz et donc un élément majeur de la filière du gaz permettant le commerce de cette matière première. Cependant, le réseau peut aussi être l´une des parties les plus couteuses de l´industrie gazière et, une fois les investissements réalisés ils ne sont ni remboursables, ni récupérables par un autre moyen car ils n'ont pas d’autres utilisations, ce sont les coûts irrécupérables. Malgré cela, la spécificité de le utilisation des actifs des réseaux évolue au cours du développement du réseau.L´intervention des réseaux de transport dans la prestation de services de flexibilité du gaz est une condition obligatoire de la flexibilité du système gazier. Premièrement parce que les services de réseau sont complémentaires de tout autre instrument de flexibilité tels que le stockage souterrain, les infrastructures GNL et le commerce de gaz. Deuxièmement, parce que les services du réseau de transport gazier, tel le que stock en conduite, peuvent également être compétitifs vis à vis d´autres instruments de flexibilité dégroupé.Par conséquent, la régulation du réseau doit prendre en compte l´impact à court et à long terme des règles d´incitation. Compte tenu du fait que le développement du réseau dépend des exigences de flux prévisibles, des variations importantes de la demande de gaz et les changements de flux qui en découlent auront un impact sur l´activité d´exploitation des réseaux gaziers. D´un côté le développement du réseau dépend de la prévision des besoins de flux, et de l´autre, la flexibilité des infrastructures du réseau conditionne nécessairement celle de l´utilisation. Par conséquent, les variations de la demande, responsable de l´accroissement des exigences de flexibilité ainsi que des variations des flux de gaz qui en découlent doivent avoir un impact sur l´exploitation du réseau de gaz et sur l´incitation aux investissements d’infrastructure. / This thesis discusses the consequences of the major changes in gas demand patterns. The requirement of short term flexibility has been one of the main features of electricity generation gas demand. As consequence, the capacity of gas industry to provide short term flexibility services has been valorized through electricity market. It means an increasing economic value to services allowing waiting and seeing before consumption decision. Different parts of the gas industry was impacted by the changes on demand, for instance gas fields productions, storage and gas importation mechanisms were incited to offer flexible provisions. The introduction of tools to provide flexibility required by demand depends on network services. It means the realization of the flexibility value of gas industry depends on gas network services. The gas transport network is the key part of gas industry, and it may provide two kinds of gas physical flexibility: mobility and storability. The physical properties of natural gas allow flexibility by means of pressure differential management. The change on pressures may compress natural gas and the pressures differences drive gas motions. The network has been, by far, the main mechanism to carry gas, thus an essential part of the gas industry chain to allow commodity trade. Network, however, may be one of the most expensive parts of gas industry, and, after the investment done, it becomes sunk costs. But the specificity of networks assets changes in the course of network development. The use of transport network in the provision of gas flexibility services is a necessary condition to provide flexibility in the gas system. First, because network services are complementary of any other flexibility tool, as underground storage, LNG infrastructures and gas trade. Second, because gas transport network services, as line-pack storage, may also be competitive to the others unbundled flexibility tools. Therefore, network regulation needs to take into account the short and the long term impact of the rules incentives. Given that network development depends on expected flow requirements, strong change on gas demand and the consequent changes on gas flows must impact gas network operation. On the one hand, network development depends on expected flow requirements, and on the other, provisions of flexibility depend necessarily on the flexible use of network infrastructures. Hence, changes on gas demand increasing flexibility requirements and the consequent changes on gas flow must impact gas network operation and must impact the incentive on infrastructures investment.
13

Pre-cross-connected protection architectures for transparent optical transport networks

Grue, Aden 11 1900 (has links)
This thesis presents a collection of studies on the topic of survivable transparent optical networks. As backbone networks increase in capacity, the issue of their survivability grows correspondingly in importance. The transparent optical network offers many advantages as the optical backbone network of the future, but also faces several challenges with regards to network protection. The fundamental question addressed by this thesis is therefore “How can we achieve high availability and failure resiliency in transparent optical transport networks?” We cover the design, characterization, and comparison of several protection architectures, many of them novel, that share the property of pre-cross-connection, a property that is important for protection of transparent networks. The architectures studied include span p-trees, PXTs, path p-trees, p-cycles, FIPP p-cycles, and UPSR-like p-cycles. We first present detailed studies of the PXT, span p-tree, and path p-tree architectures. This includes the development of efficient design algorithms and structural analysis of efficient designs. The results indicate a clear hierarchy of efficiency, with cycles being the most efficient, followed by trails, and then trees. However, we discover that architectures with lower average efficiency can be used to complement more efficient structures in rare cases. We also present a new design method for PXTs that is as capacity-efficient as the prior established method, but produces designs with greatly improved structural characteristics. We then move on to address PXT protection under a collection of real-world design constraints. The results show that PXTs strike a balance between efficiency and flexibility under these constraints. A further study on the problem of failure localization in transparent p-cycle networks demonstrates the possibility of integrating low cost failure localization capabilities into p-cycle network designs. Finally, we propose UPSR-like p-cycles as a way to combine the simplicity and speed of dedicated protection with the flexibility of mesh-based approaches. The results from our design experiments show that this architecture is able to take advantage of mesh topologies in a way that traditional ring-based approaches cannot. We also demonstrate methods by which UPSR-like p-cycle networks can deliver superior dual failure restorability to a select class of high priority services. / Communications
14

Pre-cross-connected protection architectures for transparent optical transport networks

Grue, Aden Unknown Date
No description available.
15

An Analysis Of The Pan-european Transport Network

Dogan, Torgay 01 September 2005 (has links) (PDF)
This thesis analyses the process of the creation of the Pan-European Transport Network connecting the European Union with the neighbouring regions and Caucasus and Central Asia in the long run. The thesis focuses on the incentives in establishing a continental transport network stemming from the nature of the capitalist relations between market and national and supranational forces in the margins of the global economy. In this context, the parallel processes of the acceleration of the European integration and the establishment of the Pan-European Transport Network are explored. Furthermore, in the thesis, the components of the Pan-European Transport Network, namely the Trans-European Transport Networks (TEN-T), the Pan-European Transport Corridors and Areas (including Turkey), and the Eurasian transport routes are analysed. The thesis seeks to show that the Pan-European Transport Network has been planned to ensure the economic and political cohesion of the European Union and regulate the trade relations between Europe and Asia, including the transportation of the energy resources. The lack of specific analyses on the main problem of the thesis and the incrementalism in the processes of the European integration and development of the Pan-European Transport Network induce the interpretation of the raw and first hand information, such as technical reports, intergovernmental declarations, official documents, speeches and press releases.
16

A influência da malha de transporte de superfície na evolução da economia espacial na região metropolitana do Vale do Paraíba e Litoral Norte / The influence of surface transport mesh in development of spatial economy in the metropolitan region of paraíba valley and north coast

Valdemir Aparecido da Silva 04 December 2015 (has links)
Essa dissertação tem como objetivo apresentar a evolução espacial na região Metropolitana do Vale do Paraíba e Litoral Norte RM Vale/SP, com suas consequências em razão de suas proximidades e ou distâncias da malha de transporte de superfície existente, historiando os três modais: ferroviário, hidroviário e rodoviário; narrando suas participações no processo de crescimento da RM Vale/SP e como resultado o mapeamento do cenário de disparidades no seu crescimento associados aos diversos fenômenos da Teoria de Economia Espacial convergentes com o papel da atual malha de transporte de superfície. O método de pesquisa utilizado é o exploratório e documental, tendo como base de dados os indicadores econômicos obtidos do Instituto Brasileiro de Geografia e Estatística IBGE, em razão da criação da RM Vale/SP ser recente (janeiro de 2012) e, portanto, não haver resultados nesta configuração. Os resultados serão apresentados na configuração de microrregiões administrativas da mesorregião do Vale do Paraíba, conforme estrutura utilizada pelo IBGE. Conclui-se ser possível afirmar que há vantagem das cidades próximas da Malha de Transporte de Superfície, porém é essencial associar essa vantagem aos diferentes fenômenos da Teoria de Economia Espacial e ainda às intervenções do Estado e com relação à agregação de valor econômico para o desenvolvimento, não é possível afirmar, pois há diversos tipos de valor econômico agregados, conforme características de cada sub-região que podem promover o crescimento e desenvolvimento não dependendo diretamente de Malha de Transporte de Superfície. / This essay has as objective presenting the spatial development in the Metropolitan region of Paraiba Valley and the North Coast RM Vale/SP, with their consequences, because of its vicinity and or distances the existing surface transport netting, by telling the three modes: rail, road and waterway; in order to narrate their participation in the growth process of RM Vale/SP and as resulting the mapping of the scenario of disparities in growth associated with several phenomena of convergent Theory of Space Economy to the role of the current surface transport netting. The research method used is the exploratory and documentary based on economic indicator database obtained from the Brazilian Institute of Geography and Statistics-IBGE, in reason of the creation of the RM Vale/SP be recently created (January 2012) and, therefore, there are no results in this configuration. The results will be presented in the Paraiba Valley administrative micro regions, as structure used by the IBGE. It is accomplished to be possible saying that there is an advantage of the nearby towns of Surface Transport Means, but it is essential to associate this advantage to the different phenomena of the Theory of Space Economy and the interventions of the State and with regard by adding value to economic development, it is not possible to say, hence there are several kinds of aggregated economic value, as features of each sub region that can promote the growth and development not to be depended directly on Surface Transport Means.
17

Simulační scénáře pro analýzu chování transportních sítí / Simulation scenarios for analysis of behavior of transport networks

Koláčková, Aneta January 2019 (has links)
This master’s thesis deals with the issue of mobile networks, protocol suite TCP/IP and routing protocols. It focuses in particular on the functioning of the transport part of the third and fourth generation mobile networks and intends to fnd the most suitable options for their emulation. The master’s thesis compares two selected emulation programs through a series of tests that were performed on a server created for these purposes. The main outputs are two detailed comprehensive scenarios and solutions have been developed. The frst scenario deals with the overall transport network confguration. The second scenario is based on the frst one and is focused on troubleshooting of particular issues in this network. Their implementation helps to analyze the behavior of the transport part of the mobile network.
18

Optimalizace dopravní sítě / Transport Network Optimization

Všetečka, Martin January 2015 (has links)
The thesis proposes an optimization algorithm used a genetic algorithm. Optimization problem is demonstrated on issues of left turn which meets the requirements for systematic optimization - complexity of the problem, which can not be solved analytically, and the possibility of using templates, which enable automation of design and calculation of all variants.
19

FREIGHT TRANSPORT NETWORK DESIGN WITH SUPPLY CHAIN NETWORK EQUILIBRIUM MODELS AND PARTICLE SWARM OPTIMISATION ALGORITHMS / サプライチェーンネットワーク均衡モデルと粒子群最適化法を用いた貨物輸送ネットワークの設計に関する研究

Febri Zukhruf 24 September 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18568号 / 工博第3929号 / 新制||工||1604(附属図書館) / 31468 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 谷口 栄一, 准教授 宇野 伸宏, 准教授 山田 忠史 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
20

Analysis of Autonomous Buses impact on transportation between Stockholm’s universities

Urtasun López, Marc January 2019 (has links)
The city of Stockholm is developing fast and its population is strongly growing,new solutions for urban mobility must be found. Implementations in the publictransport network are needed and the use of automated buses is a present topicfor efficient and sustainable transportation. The Vetenskapsstaden area has threeof the main university campus coexisting, this leads to a generation of campusto-campus trips which creates an impact in the Stockholm’s public transport.The unique environment and singular users arise the aim to execute a potentialsolution to release ridership from the public transport network. This thesisanalyzes and evaluates whether a new automated bus line is needed or not inthe studied area. A cost model will study the proposed solutions through therated decision variables: frequency and capacity, commercial speed and differentrates of demand. The relative efficiency of the proposed implementations isstudied compared with the costs of the current public transport modes used inthe area. Numerical analysis and results are given for two different scenarios:implementing one bus line connecting the three campuses or three lines betweencampuses. The former scenario shows to be more sensitive to the studied variablesand presents higher costs whereas the second-option costs have a robust responseand lower overall price evaluation. For both infrastructure models, the rateof demand is crucial to evaluate the advantages of a potential solution. Theestablished method and criteria contributes to a better understanding of theimpact of autonomous buses to low-demand analytic models.

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