Institute of Transportation, MOTC

Hsien-Hung Shih, 2008.06
Department of Transportation Technology and Management National Chiao Tung University

　　This dissertation aims to investigate the positive and negative influences that
small-world properties have on an air transportation network as well as a social network of passengers. A series of models are systematically constructed in accordance with four
important issues emphasized on: small-world network theory in the study of network connectivity and efficiency of complementary international airline alliances; transmission
and control of an emerging influenza pandemic in a small-world airline network; word-of-mouth marketing in a small-world network for low-cost carriers; and the application of small-world theory to airport delay problem. The first part of this dissertation attempts to conceptually apply the shortcuts of a small-world network to explore the effects of international airline alliances on the connectivity of airline networks, and to examine whether the airline alliance network is a small-world network or not. The difference in the connectivity efficiency between pre- and post-alliance situations is also measured. The second part of this dissertation aims to explore the human-to-human transmission of emerging influenza via air travel activities. Two dynamic models that illustrate the transmission behaviors of the influenza virus on scheduled flights and at airport terminals are formulated so as to evaluate the expected burdens of the pandemic without and with control measures. The third part of this dissertation turns the emphasis on the first-purchase behavior of potential passengers for low-cost carriers (LCCs). It aims to explore how the WOM information is transmitted through the social connections in a small-world social network, how the perception of LCCs is revised over time, and how the WOM affects the adoption of LCCs by short-haul business passengers. The last part of this dissertation focuses on exploring the influences of small-world properties of an airport network on the delay propagation across flights and airports. An epidemic-like model is used to illustrate ii the delay propagation over flights and airports. Several capacity-allocation strategies are proposed and are evaluated in terms of the total cost.

　　A series of case studies are performed to demonstrate the applications of this dissertation. The results show that the connectivity of the alliance network is better than before, and it exhibits small-world properties. The alliance effectively improves accessibility from high-medium traffic airports to low traffic airports. After the alliance, the shortest paths between origin-destination pairs will involve more transfers but less total travel time. The results also show that, as soon as the influenza is spread to the top 50 global airports, the transmission is greatly accelerated. Under the constraint of limited resources, a strategy that first applies control measures to the top 50 airports after day 13 and then soon afterwards to all other airports may result in remarkable containment effectiveness. As the infectiousness of the disease increases, it will expand the scale of the pandemic, and move the start time of the pandemic ahead. In addition, the results show that it may cause a mistaken forecast of adoption if without taking into account the influence of WOM. As soon as the ratio of the price of a LCC to the price of a FSC is over a half, the attractiveness of the LCC to business passengers is gradually diminished. The comparisons of different societies show that LCC may apply a slightly higher price to a lower risk-averse society, while this pricing strategy does not markedly affect its adoption pattern since LCC still has an advantage of price over FSC. In the average pattern for all 265 airports, the total cost and the total number of affected flights for a strategy that tends to allocate slots to long-haul flights are the lowest among all strategies, which is the same as those observations at past studies. When an airport has a high proportion of inter-regional flights scheduled to arrive and has low capacity due to weather condition, a strategy that uses the first-scheduled-first-served allocation principle will be an economic and equitable allocation strategy for this kind of airport. This strategy is also the best allocation strategy for those airports that are highly connected to other airports. Finally, based on the average patterns of all airports, a strategy that tends to allocate slots to long-haul flights not only decreases the total cost, but also indirectly reduces the occurrence and the scope of the inter-regional delay propagation.