The efficiency of linear algebra operations for sparse matrices on modern high performance computing system is often constrained by the available memory bandwidth. We are interested in sparse matrices whose sparsity pattern is unknown. In this thesis, we study the efficiency of major storage schemes of sparse matrices during multiplication with dense vector. A proper reordering of columns or rows usually results in reduced memory traffic due to the improved data reuse. This thesis also proposes an efficient column ordering algorithm based on binary reflected gray code. Computational experiments show that this ordering results in increased performance in computing the product of a sparse matrix with a dense vector. / xi, 76 leaves : ill. ; 29 cm.

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The first part of this thesis presents a convenient and flexible calibration method to estimate the relative rotation and translation among multiple cameras. A simple planar pattern is used for accurate calibration and is not required to be simultaneously observed by all cameras. Thus the method is especially suitable for widely spaced camera array. In order to fairly evaluate the calibration results for different camera setups, a novel accuracy metric is introduced based on the deflection angles of projection rays, which is insensitive to a number of setup factors. / The objective of this thesis is to develop a multiview system that can synthesize photorealistic novel views of the scene captured by sparse cameras distributed in a wide area. The system cost is largely reduced due to the small number of required cameras, and the image capture is greatly facilitated because the cameras are allowed to be widely spaced and flexibly placed. The key techniques to achieve this goal are investigated in this thesis. / Cui, Chunhui. / "November 2010." / Adviser: Ngan King Ngi. / Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 140-155). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.