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" Management Controls System, Firm Contingencies and Performance of Small and Medium Manufacturing Enterprises in Lagos, Nigeria "
Mustapha, Abdulrasaq
Sanni, Mubaraq
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Latin Dissertation
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| Record Number
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1101741
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| Doc. No
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TLets705550
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| Main Entry
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del Pozo de Poza, Isabel
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| Title & Author
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Assessment of fairness and equity in trajectory based air traffic management\ del Pozo de Poza, Isabel
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| College
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University of Glasgow
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| Date
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2012
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| student score
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2012
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| Degree
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Ph.D.
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| Abstract
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This thesis investigates the application of the concepts of fairness and equity in Air Traffic Management (ATM), specifically focusing on trajectory-based operations. One of the main objectives of these new type of operations, which are at the core of the two major ongoing ATM modernisation initiatives (SESAR in Europe and NextGen in the United States), is to enable Air Navigation Service Providers (ANSPs) to better accommodate the trajectories preferred by the different airspace users. In this context, it is pivotal to ensure that all airspace users are dealt with impartially by the ANSP responsible for monitoring, adjusting and clearing their trajectories. Thus, fairness and equity considerations need to be integrated in the definition and implementation of trajectory-based operations. In view of the lack of a rigorous approach to the integration of the concepts of fairness and equity in trajectory-based operations, this thesis proposes fairness and equity metrics to assess the impact of the decisions of ANSPs on the distribution of cost penalties among different users. In this context, a cost penalty is defined as the increment in operational cost for the user that results from being cleared to fly a trajectory that is different from its preferred one. In addition, this thesis proposes methods to incorporate the aforementioned metrics to the decision-making process of ANSPs in the context of trajectory-base operations, so that the trajectories assigned to the users may be fair to all of them. In a first step, this dissertation derives specifically for ATM the concepts of justice, fairness and equity from traditional disciplines such as Philosophy, Economics or Sociology. These theoretical notions are the foundations for developing the mathematical expressions to obtain quantitative values of fairness and equity in the context of future trajectory-based operations. These fairness and equity metrics are initially defined considering that each flight is an independent airspace user and later generalised to the possibility of airspace users simultaneously operating several flights in the same operational context, e.g. a scenario including several airlines where each one is operating several flights. Secondly, the practical application and incorporation of the developed metrics into the existing ATM systems is explored. Two different methodologies to apply the proposed fairness and equity metrics in practice are presented, each one addressing a specific example where using such metrics could benefit future trajectory-based operations. Specifically, the proposed methodologies deal with how to incorporate fairness and equity considerations in the design and evaluation of so-called trajectory management algorithms, which will be used by future ATM systems to adjust the airspace users’ preferred trajectories so that they remain conflict-free within a given time frame, e.g. during the arrival phase. The usability of the metrics according to the proposed methodologies is illustrated by means of specific and ATM-relevant examples. On the one hand, the integration of the fairness metric into a trajectory conflict resolution algorithm is presented with a view to enlarge the optimisation criteria of trajectory modifications, i.e. inclusion of fairness considerations during trajectory adjustments. On the other, a comparative assessment is described with regard to fairness and equity of three different conflict resolution algorithms for a given environment, i.e. operational context, route network and traffic situation. To complement the above, a preliminary robustness analysis of the proposed fairness and equity metrics has been conducted. This analysis is an important part of this work, addressing explicitly the need of particular characteristics in the ATM environment for successfully making use of fairness and equity metrics, identifying situations that can affect the effective application of metrics and establishing the provisions to guarantee it. This study is based on concepts from the field of Decision Theory where the ATM system is modelled to reflect the de-confliction of trajectories based on user preferences in a two-player game with a fairness-oriented ANSP. In summary, this thesis proposes a new framework to incorporate fairness and equity in future air traffic operations based on quantitative metrics. The framework includes methodologies to apply these metrics in practice with a view to enabling the fair or equitable distribution of cost penalties among users in trajectory-based operations.
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| Subject
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TL Motor vehicles. Aeronautics. Astronautics
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| Added Entry
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University of Glasgow
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