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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.
21

Pairing Generation for Airline Crew Scheduling

Bayer, Daniel Andreas January 2012 (has links)
Airline planning is a complex and difficult process. The biggest airlines in the world plan for and operate fleets of over 700 aircraft using tens of thousands of crew members. As such, small percentages in savings translate to millions of dollars. In this thesis, we study the pairing and duty generation problem in the context of airline crew scheduling, and propose approaches to improve the computational speed and the solution quality. We propose several enumeration algorithms to generate all possible duty periods of a given schedule to improve on the time required to generate duty periods; and present a set of column generation models to improve on the solution quality. When tested on a real test case study, the proposed approaches are found to improve the computational times from 142 seconds down to less than one second, and the cost savings of 13.7%.
22

The political and economic implications of the international routes of Aeroflot.

Gidwitz, Betsy. January 1900 (has links)
Thesis (Ph. D.)--University of Washington. / Bibliography: l. 790-834.
23

An investigation into the notions of 'success' and 'failure' held by senior UK airline executives and their perceptions of the causes of 'success'

Beech, J. G. January 2003 (has links)
This study explores the notions of 'success' and 'failure' held by senior executives in the UK and Irish airline industry. Previous studies of this industry have tended to be from a positivist perspective, focusing on financial performance at the level of 'airline' or 'airline industry'. This study takes the airline executive as the unit of analysis and is conducted from a phenomenological perspective. A methodology using interviews, causal mapping and postal questionnaires is applied to surface the notions of 'success' and 'failure' and the perception of the causes of 'success' held by board-level airline executives. Standardised data published by the Civil Aviation Authority Economic Research Group is used to establish a range of objective measures, both financial and operational, and these objective measures are compared with the rankings of the senior executives' perceptions of the success of UK and Irish airlines. The research establishes that senior airline executives do not see 'success' in terms of financial objective measures such as Added Value or Operating Ratio; they use profit as the primary financial measure of 'success' and frequently hold notions of 'success' that are based in other functional areas such as operations and marketing. The causes of 'success' are seen as coming from the breadth of functional areas. The influence of HRM factors becomes clearer at deeper levels of abstraction when considering 'success'. There is limited evidence of the stereotyping of perceptions when the success of specific airlines is considered, but not for airlines' success in general. Recommendations for further research into the management of human resources within airlines are made.
24

Contributions to the solution of the crew scheduling problem

Paek, Gwan-Ho January 1992 (has links)
No description available.
25

Rescheduling of Airline Pilot Training Activities Following Disruptions

Beskow, Gregory John 20 June 2001 (has links)
Public dependence on air transportation has grown to its largest point in history. Along with this increased dependence is a heightened awareness of safety concerns and the need for pilots to cover all scheduled flights. All commercial pilots are certified for the particular aircraft they are flying by satisfactorily completing a Federal Aviation Administration (FAA) approved course. During the training course, a number of training devices are used including a Full Flight Simulator (FFS) and a Flight Training Device (FTD). The procurement, installation, operation, and maintenance costs of these devices are expensive. In addition, the amount of time pilots spend in training is costly because they continue to be paid their salary rate although they are unable to fly revenue-generating flights for the airline. Due to these high costs, training is scheduled very tightly, with the goals of maximizing training device utilization and minimizing the pilot's training footprint (time spent in training). Any disruption to the tight schedule, such as a simulator breakdown, or pilot illness, renders the original schedule obsolete and demands rescheduling of activities. In this research, the rescheduling problem is investigated through the development and application of several different rescheduling approaches. The problem is decomposed by first investigating a single resource model and insights gained from this experimentation are transferred to the multiple resource model. The solution approaches developed for experimentation include: right-shift rescheduling (RSR), rescheduling of affected activities (RAFF), and rescheduling of all activities (RALL). Performance measures used to compare the various approaches include the minimization of the pilot footprint, the minimization of pilot tardiness, and the minimization of the deviation that a revised schedule has from the original schedule. A case study and a series of experiments involving random disruptions to original schedules were used to analyze the solution approaches. For the data sets analyzed, the RAFF algorithm outperformed other methods with respect to the majority of the measure collected. Analysis performed on the amount of slack in the original schedule revealed that diminishing returns were observed beyond a certain level of slack. Further analysis on the impact of the location of this slack showed that the majority of the slack should be placed at the end of the schedule, or the slack should be dispersed almost evenly over the entire schedule. / Master of Science
26

Empirical Essays in Industrial Organization: Application in Airline and Automobile Industries

Bhattacharjee, Prasun 16 June 2011 (has links)
This dissertation consists of three essays in empirical industrial organization with applications in U.S. airline and automobile industries. Chapter 1 motivates the aim of this dissertation with a brief summary of the main goals and findings of the subsequent chapters. The main focus of this dissertation is to higlight the changing environments in the U.S. airline and automobile industries in recent years and investigate their implications for the nature of industry competitiveness. Following the recession of 2000 and post 9/11 events, the U.S. airline industry has undergone major restructuring which has defined the way airlines compete today. Chapter 2 of this dissertation explores the impact of the presence of Low Cost Carriers (LCCs) on consumer welfare in this newly restructured market environment. Previous studies on LCC competition have not addressed the welfare issue and have only been limited to impact of LCC entry on average airfare. Departing from previous literature, this question is posed using a discrete choice model of demand for differentiated products. In chapter 3 we use a structural oligopoly model for differentiated products similar to chapter 2 to unveil the nature of conduct that exists in markets with endpoints which qualify as hubs of legacy carriers. In contrast to previous literature on airline hub market conduct, this chapter investigates the nature of conduct that exists in markets defined exclusively by network carrier hubs as a whole group incorporating product differentiation in the model framework. Finally chapter 4 uses the same methodological framework outlined in chapter 3 to explore the importance of frequent incidence of manufacturer incentives in shaping market conduct in the automobile industry. Unlike past literature on automobile market conduct, this is achieved using proprietary dealer level average transaction price data obtained from J.D. Power and Associates (JDPA) with a focus on the Big Three automakers. Specifically we use the widely successful Employee Discount Pricing (EDP) promotional program of 2005, the first of its kind, as a backdrop to identify changes in the nature of short run conduct among the Big Three that might be signalled by such promotional programs. / Ph. D.
27

Improving Strategic Alliance Monitoring to enhance the Performance of Partners in the Airline Industry : A case-study of the SAS Group

Krasnova, Alla, Ibtasar, Sara January 2010 (has links)
No description available.
28

Airline Integrated Planning and Operations

Gao, Chunhua 09 May 2007 (has links)
Efficient integrated/robust planning and recovery models were studied. The research focus was to integrate fleet assignment and crew scheduling, and, in addition, to provide solutions robust to real time operations. The contributions include: (1) To understand how schedule development and fleet assignment stages influence crew scheduling performance, schedule analysis methods were proposed to evaluate the crew friendliness of a schedule for a given fleet. (2) To meet the computational challenges of crew scheduling in integrated planning, a duty flow model was proposed which can efficiently find suboptimal legal pairing solutions. (3) A new robust crew scheduling method based on spoke purity was proposed. Computational results indicated that with little or no extra cost, a more robust crew pairing solutions can be expected. (4) By imposing station purity, an integrated and robust planning model which integrates fleet assignment and crew connections was proposed. The impact of crew base purities and fleet purities on FAM profit, crew scheduling, and computational efficiency were investigated. (5) Airline integrated recovery method was studied. A recovery scope for integrated recovery was proposed to limit the ripple effect caused by disruptions. Based on the defined recovery scope, a new integrated recovery model and Bender¡¯s decomposition solution approach was studied.
29

Essays on alliances, antitrust immunity, and carve-out policy in international air travel markets

Thomas, Tyson January 1900 (has links)
Doctor of Philosophy / Department of Economics / Philip G. Gayle / This dissertation seeks to answer questions regarding changes in the competitive environment in international air travel markets which has undergone rapid changes since the early 1990s. Specifically, the research in this dissertation examines policies regarding cooperation among airlines in international air travel markets as well as how cooperation affects an airline's product quality. These issues are explored in two essays which comprise my dissertation. The first essay explores the efficacy of a policy known as a carve-out. Airlines wanting to cooperatively set prices for their international air travel service must apply to the relevant authorities for antitrust immunity (ATI). While cooperation may yield benefits, it can also have anti-competitive effects in markets where partners competed prior to receiving ATI. A carve-out policy forbids ATI partners from cooperating in markets policymakers believe will be most harmed by anti-competitive effects. We examine carve-out policy applications to three ATI partner pairings, and find evidence of tacit collusion in carve-out markets in spite of the policy, calling into question whether consumers benefited from application of the policy in the cases studied. The second essay examines the relationship between product quality and airline cooperation. Much of the literature on airline cooperation focuses on the price effects of cooperation. The key contribution of our paper is to empirically examine the product quality effects of airline cooperation. Two common types of cooperation among airlines involve international alliances and antitrust immunity (ATI), where ATI allows for more extensive cooperation. The results suggest that increases in the membership of a carrier's alliance or ATI partners are associated with the carrier's own products having more travel-convenient routing quality. Therefore, a complete welfare evaluation of airline cooperation must account for both price and product quality effects.
30

Flight Delay-Cost Simulation Analysis and Airline Schedule Optimization

Yuan, Duojia, S3024047@student.rmit.edu.au January 2007 (has links)
In order to meet the fast-growing demand, airlines have applied much more compact air-fleet operation schedules which directly lead to airport congestion. One result is the flight delay, which appears more frequently and seriously; the flight delay can also significantly damage airline's profitability and reputation The aim of this project is to enhance the dispatch reliability of Australian X Airline's fleet through a newly developed approach to reliability modeling, which employs computer-aided numerical simulation of the departure delay distribution and related cost to achieve the flight schedule optimization. The reliability modeling approach developed in this project is based on the probability distributions and Monte Carlo Simulation (MCS) techniques. Initial (type I) delay and propagated (type II) delay are adopted as the criterion for data classification and analysis. The randomicity of type I delay occurrence and the internal relationship between type II delay and changed flight schedule are considered as the core factors in this new approach of reliability modeling, which compared to the conventional assessment methodologies, is proved to be more accurate on the departure delay and cost evaluation modeling. The Flight Delay and Cost Simulation Program (FDCSP) has been developed (Visual Basic 6.0) to perform the complicated numerical calculations through significant amount of pseudo-samples. FDCSP is also designed to provide convenience for varied applications in dispatch reliability modeling. The end-users can be airlines, airports and aviation authorities, etc. As a result, through this project, a 16.87% reduction in departure delay is estimated to be achieved by Australian X Airline. The air-fleet dispatch reliability has been enhanced to a higher level - 78.94% compared to initial 65.25%. Thus, 13.35% of system cost can be saved. At last, this project also achieves to set a more practical guideline for air-fleet database and management upon overall dispatch reliability optimization.

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