Theses and Dissertations from UMD
Permanent URI for this communityhttp://hdl.handle.net/1903/2
New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item Mechanisms for Trajectory Options Allocation in Collaborative Air Traffic Flow Management(2018) Mohanavelu Umamagesh, Prithiv Raj; Lovell, David J; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Flight delays are primarily due to traffic imbalances caused by the demand for airspace resource exceeding its capacity. The capacity restriction might be due to inclement weather, an overloaded air traffic sector, or an airspace restriction. The Federal Aviation Administration (FAA), the organization responsible for air traffic control and management in the USA, has developed several tools known as Traffic Management Initiatives (TMI) to bring the demand into compliance with the capacity constraints. Collaborative Trajectory Option Program (CTOP) is one such tool that has been developed by the FAA to mitigate the delay experienced by flights. Operating under a Collaborative Decision Making (CDM) environment, CTOP is considered as the next step into the future of air traffic management by the FAA. The advantages of CTOP over the traditional the TMIs are unequivocal. The concerns about the allocation scheme used in the CTOP and treatment of flights from the flight operators/airlines have limited its usage. This research was motivated by the high ground delays that were experienced by flights and how the rerouting decisions were made in the current allocation method used in a CTOP. We have proposed four alternative approaches in this thesis, which incorporated priority of flights by the respective flight operator, aimed at not merely reducing an individual flight operator’s delay but also the total delay incurred to the system. We developed a test case scenario to compare the performances of the four proposed allocation methods against one another and with the present allocation mechanism of CTOP.Item PROBLEMS ORIGINATING FROM THE PLANNING OF AIR TRAFFIC MANAGEMENT INITIATIVES(2018) Estes, Alexander; Ball, Michael O; Applied Mathematics and Scientific Computation; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)When weather affects the ability of an airport to accommodate flights, a ground delay program is used to control the rate at which flights arrive at the airport. This prevents excessive congestion at the airport. In this thesis, we discuss several problems arising from the planning of these programs. Each of these problems provides insight that can be applied in a broader setting, and in each case we develop generalizations of these results in a wider context. We show that a certain type of greedy policy is optimal for planning a ground delay program when no air delays are allowed. More generally, we characterize the conditions under which policies are optimal for a dynamic stochastic transportation problem. We also provide results that ensure that certain assignments are optimal, and we apply these results to the problem of matching drivers to riders in an on-demand ride service. When flights are allowed to take air delays, then a greedy policy is no longer optimal, but flight assignments can be produced by solving an integer program. We establish the strength of an existing formulation of this problem, and we provide a new, more scalable formulation that has the same strength properties. We show that both of these methods satisfy a type of equity property. These formulations are a special case of a dynamic stochastic network flow problem, which can be modeled as a deterministic flow problem on a hypergraph. We provide strong formulations for this general class of hypergraph flow problems. Finally, we provide a method for summarizing a dataset of ground delay programs. This summarization consists of a small subset of the original data set, whose elements are referred to as "representative" ground delay programs. More generally, we define a new class of data exploration methods, called "representative region selection" methods. We provide a framework for evaluating the quality of these methods, and we demonstrate statistical properties of these methods.