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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.
31

Medelhavsområdets regionalisering : Handel och investeringar enligt nav-och-ekerteorin

Grythberg, Daniel January 2005 (has links)
Sedan 1990-talet har antalet regionala handelsavtal ökat kraftigt och världshandeln präglas inte av den globala frihandel som WTO eftersträvar, utan snarare av handelssammanslutningar med en stor aktör i centrum. Genom den så kallade Barcelonaprocessen har EU, ett av de största naven i världshandeln, knutit bilaterala avtal med sina grannländer kring Medelhavet och på så sätt gett upphov till ett struktur som kallas hub-and-spoke, nav-ocheker. I denna uppsats utreds detta begrepp och de effekter som strukturen har på handel och flödet av utländska direktinvesteringar. Vi ser tecken på att dessa flöden har ökat för Marocko och Tunisien under de senaste åren och finner det troligt att effekterna blir ännu större i övriga Medelhavsländer
32

Utvärdering av svensk vindkraft : Skillnaden mellan skogs- och traditionella placeringar

Lindahl, Andreas January 2009 (has links)
During the last years commercial Wind Power Turbines (WPT) has become larger regardingto the generator sizes and hub heights. Available hub heights around 100 meters is nowcommon, which has led to profitability for WPT located in forests where there normally are tolow wind speeds. The current knowledgement regarding turbulence and the variation in thewind profile for the outcome of the power production for the WPT in forests is limited.In this Master of Science thesis an investigation concerning forest located wind power plantshas been made. The purpose has been to investigate if plants located in forest perform lesscompared to wind power turbines located at more common locations.The analyses are based on statically material for determining the availability,production/generator size, production/hub height, production/swept area and how thetopography affect the production results.The analyses show that the variation in production result for WPT located in forest comparedto turbines located at other locations is small. The availability is high and the productionresults are good.
33

The hub port selecting behavior model of container liners¡XAn example of Kaohsiung Harbor's container liners

Liu, Chih-heng 08 February 2010 (has links)
Kaohsiung Harbor is the most significant container harbor of Taiwan. Embracing the excellent geographical features for container transportation, it used to be the most attractive hub port for most of container liners. However, because of Taiwan¡¦s conservative cross-strait policy and the transformation of industries, Kaohsiung Harbor became less and less attractive for its clients in recent decade. To figure out a solution for the authority of Kaohsiung Harbor, the researcher used the Grounded Theory to interview 10 container transportation experts. Then find out 97 concept of how container liners choose their hub port when they¡¦re planning their routes. After this, the researcher integrates those concepts into 16 categories and finds their organic connection in between. Finally, researcher refines 5 central categories out of the 16 categories. Base on the relations between the central categories, researcher creates the hub port selecting model of container liners. According to what researcher found, we acknowledge that within this model, the most important hub port selecting factor for container liners is Operation Cost, then goes to Efficiency, Influence of Authority, Government Policy, and Safety.
34

The influence of Cross-Strait direct shipping on Kaohsiung container Hub position

Yeh, Shih-ren 28 July 2004 (has links)
The rapid economic development in China has led to increasing freight transport, as well as fierce competition among the hubs in the region, such as Hong Kong, Busan, Kaohsiung Harbor, and new harbors in Shenzhen and Shanghai. The transport not only support the rapid development of harbors in the region but also result in intense port competition. The competitive advantages, such as location, facility, efficiency, and highly concentrated ship routes, possessed by the harbors are not everlasting. In the face of changing environment and competition, the competitive advantages may be lost. When competing in a different niche market, the location advantage may turn into disadvantage, even damaging its leading position in worse cases. In response to changes, harbor administrators should probe into the future trend in changes of the freight transport market, discuss all possible scenarios, sense the potential risks and opportunities, seize the opportunities and utilize the existing advantages to build up the competitive advantages for the future. Compared to Kaohsiung Harbor, harbors in China, such as Shanghai and Shenzhen, as the entry gates to the main economic and trade zone in China and the central region in terms of sources of goods, have developed into regional pivot harbors. Due to the barrier of Cross-Strait direct shipping, some scholars in Taiwan believe that Kaohsiung Harbor is facing the problem of becoming periphery. However, even after the direct route comes into practice, the competition from harbors in China may be a threat to Kaohsiung Harbor, even occur haidding effects to take over its existing transit goods. The position of Kaohsiung Harbor may be challenged. This study investigates the potential influence of Cross-Strait direct shipping and the competition from China on the quantity of containers, route planning, and shipping business investment with questionnaire survey on sea transportation businesses, and constructs possible scenarios in short-term (2004-206), medium term (2007-2010), long-term (2011-2020). Before the Cross-Strait direct shipping into practice, Kaohsiung Harbor will continue to grow due to continuous economic development in the region. If the Cross-Strait direct shipping comes into practice or the Chinese government permits more direct shipping harbor, Southern China, Fukien, and Zhujiang Delta will become the main regions in terms of sources of goods. However, the rate of growth may not meet the expectation. In the long-term (2011-2020), due to the rapid of the quantity of containers in China and the transit ability of harbors in China, the route structure and the shipping business investment in Kaohsiung Harbor will suffer more obvious disadvantageous impact.
35

Computer-Aided Design of Multi-Speed Hub System for Bicycles

Chen, Hung-Hsuan 25 July 2005 (has links)
The multi-speed drive hub mainly makes for change speed with planetary gear trains. It has some advantages such as small, change the shelf steadily to move and difficult to receive external environmental impact. So the multi-speed drive hub has already become the focal point that every bicycle's factory researches and develops gradually. The purpose of this work is to develop a system methodology for the computer-aided design of multi-speed bicycle drive hubs. First, analyzing multi-speed drive hub patents to identify the basic characteristics and requirement of multi-speed drive hub, and using a systematized method synthesizes the feasible gear trains. Second, a method is proposed to determine the feasible multi-speed sequence tables for each planetary gear train. Third, a method is formulated to find the gear ratios and gear teeth according to the feasible multi-speed sequence tables. Fourth, a method is to design and dispose the governors of multi-speed drive hubs easily. Finally, using Visual Basic 6.0 procedure language develop a computer software easy to use by utilizing the above-mentioned procedures, and the results of this work will be benefit to the development and design of multi-speed bicycle drive hubs.
36

A Study on the Creative Design Methodology of the Multi-Speed Drive Hub for Bicycles

Shu, Jiun-jung 02 July 2007 (has links)
The multi-speed internal gear hub of a bicycle is a well-closed gear shifting system that works perfectly under any challenging riding environment, and is developed specifically to improve fragile chain-drive derailleur using planetary gear trains. In recent years, bicycle internal hub gears have been developed toward multi-speed transmission, and in the development process of internal gear hubs, the structure of speed changing mechanism has changed from a single planetary gear train to multiple planetary gear trains, and is becoming more complex. The primary purpose of this Study aims to establish a systemized and efficient design process, and develop an effective theory and method for designing multiple-speed internal gear hubs with the design concept and common features of multiple-speed internal gear hub products developed in recent years, to favor the innovation and development of internal gear hubs. First, existing multiple speed internal hub products are analyzed and summarized for their basic features, limitations, and demands as the reference for the design of multiple speed internal gear hubs, and a catalog of usable planetary structures is systematically established with the coupling and connection of basic high and low ratio speed changing modules. Secondly, usable planetary structures that offer best performance of geometric progression speed ratio distribution of gear hub are matched with gear positions, and a table of gear sequence is confirmed; third, based on the maximum external diameter required by design, tooth numbers for every gear in a hub are defined according to the relationship between tooth number and speed ratio, as well as the gear sequences; and finally, the systematic design process above is applied to the development of an easy-to-use computer aided design software with the lowest possible number of variables using Visual Basic 6.0 for designers, in order to favor the innovation and development of internal gear hubs.
37

Three essays on competition and market power in airlines' hub-and-spoke networks

Carbonneau, Shane Edward 05 August 2013 (has links)
In this dissertation, I investigate hub carriers' competitive advantage in directional markets within their hub and spoke networks. In the first chapter, I examine whether the competitive advantage of hub carriers in attracting hub-to-spoke passengers relative to spoke-to-hub passengers affects rivals' entry decisions in a symmetric way. The hub carrier advantage in attracting passengers at its concentrated hub airport creates an environment in which variation in the composition of demand in hub-to-spoke markets affects entry in a profoundly different way than demand variation in spoke-to-hub markets. In the second chapter, I examine hub carrier fares and price-cost margins in hub and spoke airport pairs. Exploiting variation across airport-pairs, I find that an increase in the proportion of business travelers in hub-to-spoke markets increases fares in these markets, while an increase in the proportion of business travelers in spoke-to-hub markets decreases fares. This result is consistent with the structural asymmetries found in the first chapter. However, the source of these concentration advantages remains ambiguous. These advantages could be due to cost benefits, demand effects, or market power. Exploiting the variation between hub-to-spoke and spoke-to-hub markets within airport pairs isolates the market power effect on fares. I find that difference in hub carrier airport shares explains most of the variation in its hub-to-spoke and spoke-to-hub price-cost margins. Unobserved quality and cost heterogeneity do not bias the result. In the final chapter we look at the relationship between market power and price discrimination. In the presence of price discrimination, at least one price does not equal marginal cost. Therefore, if price discrimination exists, there must be market power. While this logic is sound, it has led many policymakers to believe that price discrimination and market power are positively correlated. We present a model where measured price-discrimination can be low while market power is high and price discrimination can be high while market power is low, thus demonstrating that there is no theoretical connection between the strength of price discrimination and that of market power. We then present new evidence that price discrimination is negatively correlated with market power in the US airlines industry. / text
38

Airport Dominance and Airline Pricing Power: An Investigation of Hub Premiums in the Chinese Domestic Market

Chen, Ruowei 12 1900 (has links)
Concerns on market power conferred by airport dominance and the debates of hub premiums have attracted longstanding attention from governments and academics alike. Most previous studies mainly focus on the fully deregulated markets such as the United States and Europe, what remains unknown is how such effects change when a country evolves from a tightly controlled regime to a deregulated market. This research analyses the effects of airport dominance on airline pricing power with the empirical study based on the Chinese domestic market using fixed- effect panel data models. Results from the regression analysis indicate that airport dominance is the most important source of pricing power in the gradually deregulated Chinese domestic market. Hub carriers are able to charge higher prices to premium class passengers and non-hub carriers can benefit from the “umbrella effects” of hub premiums. However, hub carriers are not able to translate their airport dominance to pricing power in the economy class market, whereas non-hub carriers even have to reduce the prices as their market shares at major airports increase. This study contributes to the literature by explicitly segmenting the market into economy and premium classes. The results have important policy implications.
39

An Iterative Hub Location And Routing Problem For Postal Delivery Systems

Cetiner, Selim 01 January 2003 (has links) (PDF)
In this study, we consider the Turkish postal delivery system and develop an effective solution approach for the combined hub location and routing problem where the location of hub nodes are determined, the nonhub regional postal offices are allocated to the hubs, and the optimal set of routes are determined for each hub. Since the realized post-routing distances between origin-destination pairs are different from those used in the hub-location model, we develop an algorithm that finds the route-compatible hub configuration and allocation paths. The algorithm is the one that iterates between the hub-location phase and a routing phase. Our strategy consists of updating the distances used in the first phase in order to produce a solution that contains the cognition of routes. Some special structures in the routed network are also identified and used for improving the solution. Computational experience is reported.
40

Modellierung und Optimierung von Hub-and-Spoke-Netzen mit beschränkter Sortierkapazität

Blunck, Steffen. January 2005 (has links) (PDF)
Universiẗat, Diss., 2005--Karlsruhe.

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