2026-09-19T05:57:08.419729700Zhttps://opus.uleth.ca/server/oai/request
oai:opus.uleth.ca:10133/49802017-11-15T18:30:52Zcom_10133_3346com_10133_1com_10133_296col_10133_3347col_10133_298
ULethbridge OPUS Repository supervisor Gaur, Daya author Ansari, Lazima author University of Lethbridge. Faculty of Arts and Science 2017-11-15T18:30:52Z 2017-11-15T18:30:52Z 2017 https://hdl.handle.net/10133/4980 Large-scale optimization of combinatorial problems is one of the most challenging areas. These problems are characterized by large sets of data (variables and constraints). In this thesis, we study large-scale optimization of the data placement problem with zero storage cost. The goal in the data placement problem is to find the placement of data objects in a set of fixed capacity caches in a network to optimize the latency of access. Data placement problem arises naturally in the design of content distribution networks. We report on an empirical study of the upper bound and the lower bound of this problem for large sized instances. We also study a semi-Lagrangean relaxation of a closely related k-median problem. In this thesis, we study the theory and practice of approximation algorithm for the data placement problem and the k-median problem. en_US data placement problem k-median problem Lagrangean relaxation large-scale optimization latency of access zero storage cost Large-scale optimization for data placement problem Thesis 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 URL http://localhost:4000/bitstreams/0790e3a2-720b-456f-bf1d-cfaea67eec0a/download File MD5 6c18faef054234c7d697e11a2f453534 282583 application/pdf ANSARI_LAZIMA_MSC_2017.pdf URL http://localhost:4000/bitstreams/916a2c2d-118a-42bb-9752-4d86191ec147/download File MD5 811fa6e633cfb48805506b422023e4f6 124748 text/plain ANSARI_LAZIMA_MSC_2017.pdf.txt