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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.
1

Strategies to design a cost-effective hub network for sparse air travel demand in Africa

Ssamula, Bridget 24 July 2008 (has links)
The aviation industry worldwide is changing dynamically in reaction to trends such as globalisation and with the need to increase market share to remain competitive. The African aviation industry still faces many problems in the institutional, technical and operational areas. Despite its potential for enhancing economic development, air travel to and from Africa remains a small percentage of world air travel. The African air route network is characterised by sparse demand, with long sector distances, low frequencies and high fares. This study investigates cost-effective hub-and-spoke (H&S) network design strategies for the African route network. An H&S network would minimise the cost of air transport and improve accessibility and connectivity. The study challenges the typical characteristics of H&S networks which are usually found in denser route networks. The design methodology used was the one most appropriate for the African region, using the datasets and tools available. As a first-cut analysis for Africa, the results of the research contribute to understanding the effectiveness of H&S networks in markets with sparse demand. A cost model previously developed by the author to calculate operating costs on a route was used. It eliminated the need to assume discount coefficients on links, as passenger demand increases, in a field with limited data. The cost indicators derived from the model were used as criteria for choosing the most efficient hubs within a cluster. These were compared with the hub location criteria in the literature which use distances and passengers. It was found that using the cost indicators gives a reasonably consistent method that lowers passenger travel time. The optimum number of clusters and hubs was found to be four. The geo-political network design method yielded the lowest network costs. The hubs are centrally located within the clusters: Morocco in the north, South Africa in the south, Kenya in the east and Nigeria in the west. They are characterised by high passenger demand and short node-hub sectors. There are significant benefits to be gained from using this hub network design, resulting from the economies of scale with higher passenger densities on routes. Furthermore, the benefits of higher service frequencies and better connectivity outweigh the extra travel time when routing through hubs. The study found that for sparse networks, the cheapest hub-location options have high passenger demand. The sector distance is crucial in lowering operating costs as smaller, more efficient short range aircraft can be operated. It is therefore more efficient to assign nodes to the closest hub to lower node-hub costs. The optimum number of hubs/clusters is thus determined by the distance threshold for the efficient aircraft. The effect of changing the cluster boundaries on network costs also depends on the change in node-hub distances between the clusters. As sparsity reduces, the economies-of-scale benefits outweigh the increasing operating costs of longer distances, allowing efficient operation of larger-capacity aircraft. This means that the location of the hubs and the number of clusters becomes more flexible, implying that node-hub links can become longer, reducing both the clusters and the number of hubs. / Thesis (PhD)--University of Pretoria, 2008. / Civil Engineering / PhD / Unrestricted
2

Činnost Evropské cyklistické federace jako součást evropské turistiky / Activities of the European Cyclists' Federation as a part of European tourism

Snopová, Karolína January 2016 (has links)
Title: Activities of the European Cyclists' Federation as a part of European tourism Objectives: The thesis is focused on cycling tourism in relation to European tourism, European Union policy and global policy of the world organizations. The aim is to present the activities of the European Cyclists' Federation, characterize the organization and analyze its biggest project - the development of the European network of long-distance cycling routes EuroVelo. This case study also shows the way of cooperation of a non-governmental organization, the European Union and world organizations in order to support the development of cycling tourism and fulfill the objectives of the European Union policy and global policy of world organizations. Methods: The information has been obtained by document analysis and by communication with the former Vice President of the European Cyclists' Federation and currently a member of the Executive Board of EuroVelo within the ECF. Results: Used methods have brought enough information to create complete description of the European Cyclists' Federation and its activities including the EuroVelo project. The result is a complex text that shows the importance of cycling (and thus activities of ECF) for the society and demonstrates the cooperation of organizations at all levels in...
3

Efficiency and security in data-driven applications

Zhang, Kaijin, ZHANG 04 June 2018 (has links)
No description available.
4

Исследование и оптимизация городских автобусных перевозок на примере пассажирского автотранспортного предприятия АП-3 г. Екатеринбурга : магистерская диссертация / Research and optimization of urban bus transport on the example of passenger transport enterprise AP-3 Yekaterinburg

Пазылидинов, И. А., Pazylidinov, I. A. January 2018 (has links)
In this work, the current state and prospects of development of urban passenger transport in the operating conditions of the city of Yekaterinburg of the Sverdlovsk region are investigated and analyzed. The analysis and evaluation of the management and organization of passenger traffic to urban passenger transport in the city of Yekaterinburg. The solution of the problem of dispatching control and organization of passenger traffic in the urban cycle by mathematical modeling and optimization is considered. A General view of the simulation model of the automated system of urban passenger transport management by levels is developed. It also proposes the structure of management and organization of urban passenger transport. / В данной работе исследована и проанализирована современное состояние и перспективы развитие городского пассажирского транспорта в условиях эксплуатации города Екатеринбург Свердловской области. Изложена анализ и оценка эффективности управления и организации пассажиропотока городским пассажирским транспортам в городе Екатеринбург. Рассмотрена решение проблемы диспетчеризации управления и организации пассажирских перевозок в городском цикле математическим методом моделирования и оптимизации. Разработан общий вид имитационной модели автоматизированной системы управлении городского пассажирского транспорта по уровням. А также предлагается структура управления и организации городского пассажирского транспорта.

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