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dc.contributor.authorKeller, Mitchel Todden_US
dc.date.accessioned2010-06-10T15:10:25Z
dc.date.available2010-06-10T15:10:25Z
dc.date.issued2009-11-24en_US
dc.identifier.urihttp://hdl.handle.net/1853/33810
dc.description.abstractTanenbaum, Trenk, and Fishburn introduced the concept of linear discrepancy in 2001, proposing it as a way to measure a partially ordered set's distance from being a linear order. In addition to proving a number of results about linear discrepancy, they posed eight challenges and questions for future work. This dissertation completely resolves one of those challenges and makes contributions on two others. This dissertation has three principal components: 3-discrepancy irreducible posets of width 3, degree bounds, and online algorithms for linear discrepancy. The first principal component of this dissertation provides a forbidden subposet characterization of the posets with linear discrepancy equal to 2 by completing the determination of the posets that are 3-irreducible with respect to linear discrepancy. The second principal component concerns degree bounds for linear discrepancy and weak discrepancy, a parameter similar to linear discrepancy. Specifically, if every point of a poset is incomparable to at most D other points of the poset, we prove three bounds: the linear discrepancy of an interval order is at most D, with equality if and only if it contains an antichain of size D; the linear discrepancy of a disconnected poset is at most the greatest integer less than or equal to (3D-1)/2; and the weak discrepancy of a poset is at most D. The third principal component of this dissertation incorporates another large area of research, that of online algorithms. We show that no online algorithm for linear discrepancy can be better than 3-competitive, even for the class of interval orders. We also give a 2-competitive online algorithm for linear discrepancy on semiorders and show that this algorithm is optimal.en_US
dc.publisherGeorgia Institute of Technologyen_US
dc.subjectSemiordersen_US
dc.subjectPartially ordered setsen_US
dc.subjectLinear discrepancyen_US
dc.subjectOnline algorithmsen_US
dc.subjectInterval ordersen_US
dc.subject.lcshPartially ordered sets
dc.subject.lcshIrregularities of distribution (Number theory)
dc.titleSome results on linear discrepancy for partially ordered setsen_US
dc.typeDissertationen_US
dc.description.degreePh.D.en_US
dc.contributor.departmentMathematicsen_US
dc.description.advisorCommittee Chair: Trotter, William T.; Committee Member: Dieci, Luca; Committee Member: Mihail, Milena; Committee Member: Tetali, Prasad V.; Committee Member: Yu, Xingxingen_US


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