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<p> This thesis defends the use of genetic algorithms (GA) to solve the maximum number of repetitions in a binary string. Repetitions in strings have significant uses in many different fields, whether it is data-mining, pattern-matching, data compression or computational biology 14]. Main extended the definition of repetition, he realized that in some cases output could be reduced because of overlapping repetitions, that are simply rotations of one another [10]. As a result, he designed the notion of a run to capture the maximal leftmost repetition that is extended to the right as much as possible. Franek and Smyth independently computed the same number of maximum repetition for strings of length five to 35 using an exhaustive search method. Values greater than 35 were not computed because of the exponential increase in time required. Using GAs we are able to generate string with very large, if not the maximum, number of runs for any string length. The ability to generate strings with large runs is an advantage for learning more about the characteristics of these strings. </p> / Thesis / Master of Science (MSc)

<p> For 30 years the Lempel-Ziv factorization LZx of a string x = x[1..n] has been a fundamental data structure of string processing, especially valuable for string compression and for computing all the repetitions (runs) in x. When the Internet came in, a huge need for Lempel-Ziv factorization was created. Nowadays it has become a basic efficient data transmission format on the Internet.</p> <p> Traditionally the standard method for computing LZx was based on O(n)-time processing of the suffix tree STx of x. Ukkonen's algorithm constructs suffix tree online and so permits LZ to be built from subtrees of ST; this gives it an advantage, at least in terms of space, over the fast and compact version of McCreight's STCA [37] due to Kurtz [24]. In 2000 Abouelhoda, Kurtz & Ohlebusch proposed a O(n)-time Lempel-Ziv factorization algorithm based on an "enhanced" suffix array - that is, a suffix array SAx together with other supporting data structures.</p> <p> In this thesis we first examine some previous algorithms for computing Lempel-Ziv factorization. We then analyze the rationale of development and introduce a collection of new algorithms for computing LZ-factorization. By theoretical proof and experimental comparison based on running time and storage usage, we show that our new algorithms appear either in their theoretical behavior or in practice or both to be superior to those previously proposed. In the last chapter the conclusion of our new algorithms are given, and some open problems are pointed out for our future research.</p> / Thesis / Master of Science (MSc)

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As a growth industry, tremendous cost pressures are pushing the LED lighting market away from traditional power electronics converters and towards solutions that are more unconventional. Lower quality LED lights use simple low-cost converters, whereas high end product may add complexity in order to achieve a more dramatic energy savings. SIMO technology represents an opportunity in LED lighting to combine the low cost of single-stage converters with the energy saving capability of a two-stage, multiple string solution. This paper describes the modeling, analysis, design, and testing of a Multiple Independently Regulated Output Flyback (MIROF) converter, used in LED lighting for the purpose of multiple string control. This converter is based upon SIMO technology applied to a PFC Flyback converter. The result was the development of a novel control method and an operational demonstration unit. A cost comparison of the MIROF and a conventional two-stage driver shows a promising cost reduction benefit for the former, and comparative testing shows favorable performance of the MIROF converter compared to the two-stage approach. / Master of Science

This thesis is devoted to a discussion of various aspects of supersymmetric quantum field theories in four and two dimensions. In four dimensions, 𝒩 = 1 supersymmetric quantum gauge theories on various four-manifolds are constructed. Many of their properties, some of which are distinct to the theories on flat spacetime, are analyzed. In two dimensions, general 𝒩 = (2, 2) nonlinear sigma models on S² are constructed, both for chiral multiplets and twisted chiral multiplets. The explicit curvature coupling terms and their effects are discussed. Finally, 𝒩 = (0, 2) gauged linear sigma models with nonabelian gauge groups are analyzed. In particular, various dualities between these nonabelian gauge theories are discussed in a geometric content, based on their Higgs branch structure. / Ph. D.

Thesis (M.A.)--Boston University

A thesis about the String Septet. The author explains that it deals with problems concerned in the reconciliation of contemporary aesthetics with extensions of romantic harmony, classical and pre-classical form, classical figuration and ornamentation, and contrapuntal organization.