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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Ordered Frechet spaces.

January 1977 (has links)
Cheng Hon-wing. / Thesis (M.Phil.)--Chinese University of Hong Kong. / Bibliography: leaf 29.
112

Split Non-Linear Cyclic Analog-to-Digital Converter

Orchanian, Shant 26 April 2010 (has links)
Analog-to-Digital Converters (ADC's) are inherently optimized for linearity in order to produce an accurate digital representation of an analog voltage. The Cyclic ADC's linearity is limited by one of its components, the residue amplifier. The residue amplifier is used to amplify the error between the analog voltage and the digital decision by a gain of two in each cycle of a conversion. In previous designs, this was accomplished by using a compound op-amp with a large open loop gain for linearity, and negative feedback to achieve the gain of two. This thesis explores the use of a resistively loaded differential pair to achieve this gain. The design reduces die size, power usage, and analog complexity. To correct for this inherent non- linearity, a Split ADC concept is employed to enable digital background calibration and a correction algorithm to account for this non- linearity. The Integrated circuit is designed, laid out, and simulated using the Cadence Integrated Circuit Front to Back design suite (ICFB) in the 0.18um Jazz CMOS process.
113

Um modelo em programação estocástica para produção de serviços previdenciários

Bastos, Roselita Cavalcante 07 December 2001 (has links)
Made available in DSpace on 2019-03-30T00:34:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2001-12-07 / This work develops a stochastic linear programming model for production of services welfare, whose purpose is to improve the attendance welfare. The proposed model possesses planning apprenticeship for the execution of its objectives, could involve n counters of different attendance, and it obtains a great strategy for the production of services, learning in an optimization approach, where there is not knowledge of the times of installment of the services. A comparison with the experimental productivity was accomplished through a resource logical-probabilistic to validate it and to check its precision. The results obtained with the experimental procedure corroborate with the values foreseen stochastic. / Este trabalho desenvolve um modelo em programação linear estocástica para produção de serviços previdenciários, cujo propósito é aperfeiçoar o atendimento na previdência social. O modelo proposto possui estágio de planejamento para a execução de seus objetivos, podendo envolver n balcões de atendimento distintos, e obtêm uma estratégia ótima para a produção de serviços, apoiando-se em um critério de otimização, quando não há conhecimento dos tempos de prestação dos serviços. Uma comparação com a produtividade experimental foi realizada através de um recurso lógicoprobabilístico para validá-lo e comparar sua precisão. Os resultados obtidos através da execução do experimento corroboram com os resultados previstos estocasticamente.
114

Otimização do processo de fabricação do biscoito tipo cracker

Melo, Micheline Elga Pessoa 27 June 2002 (has links)
Made available in DSpace on 2019-03-30T00:34:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-06-27 / The purpose of this work is to construct a Mathematical Programming model aim to optimizer the biscuit cracker s fabrication process, applying Linear and Nonlinear programming. Through the knowledge of the stages of cracker s production a model was built in Linear Programming that minimizes the losses production and the cost involved in its production process. Was developed a model in Nonlinear Programming to control the factors time and pH in the sponge fermentation. Through the Linear Programming model was determinate a detailed interpretation of the cost in the cracker s production process and the Nonlinear model was reduced the time of sponge fermentation, resulting increase in the productivity. / O objetivo deste trabalho é construir modelos em Programação Matemática visando otimizar o processo de fabricação do biscoito cracker, aplicando Programação Linear e Não Linear. Através do conhecimento das etapas de produção do biscoito cracker, construiu-se um modelo em Programação Linear que minimiza as perdas de produção e o custo envolvido em seu processo de produção. Desenvolveu-se um modelo em Programação Não Linear para controlar os fatores tempo e pH na fermentação da esponja. Com a utilização do modelo em Programação Linear determinou-se a interpretação detalhada do custo no processo de produção do cracker e com o modelo Não Linear reduziu-se o tempo de fermentação da esponja, resultando em aumento na produtividade.
115

The use of general linear models for failure data and categorical data

Sauter, Roger Mark January 2010 (has links)
Typescript (photocopy) / Digitized by Kansas Correctional Industries
116

Linear operators in Hilbert space

Best, George January 1966 (has links)
Thesis (M.A.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The purpose of this paper is to present a modified version of Riesz's proof of the spectral theorem for bounded linear operators. The modifications employed are those suggested by S. K. Berberian (5, page 1049). The basic properties of Hilbert space are presented in Chapter I. Chapter II is a discussion of linear operators which includes consideration of functionals, self-adjoint operators, and the spectrum of an operator. The spectral decomposition of a bounded self-adjoint operator is presented in Chapter III. The material in the paper is based primarily on the references in the bibliography. Most of the nontrival proofs have been carried out in detail. / 2031-01-01
117

Construção de tabela de horário escolar na WEB

Oliveira, José Auriço 11 April 2003 (has links)
Made available in DSpace on 2019-04-05T23:00:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-04-11 / The objective of this research is to present a support environment to the construction of school timetabling using the WEB. This environment is characterized by the configuration, generation and resolution of a computacional model structured in a problem of interger linear programming in the WEB to the schools of medium teaching. The implemented architecture offers flexibility to be used in other problems in the public service that can be solved through varied techniques of operational research. The results of this implementation in Ceará s State will allow the the state s schools to optimize it s construction of school timetabling. / O objetivo deste trabalho é apresentar um ambiente de apoio a construção de tabela de horário escolar utilizando a WEB. Este ambiente caracteriza-se pela configuração, geração e resolução de um modelo computacional estruturado em um problema de programação linear inteira disponibilizado na WEB para as escolas de ensino médio. A arquitetura implementada oferece flexibilidade na aplicação em outros problemas no serviço público que possam ser solucionados através de variadas técnicas de pesquisa operacional. Os resultados obtidos desta implementação no Estado do Ceará permitirão otimizar o processo de construção das tabelas de horários nas escolas estaduais.
118

Complex quadratic optimization via semidefinite programming: models and applications. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Finally, as combinatorial applications of complex quadratic optimization; we consider Max 3-Cut with fixed nodes constraints, Max 3-Dicut with weight constraints, Max 3-XOR, and so on, and present corresponding bounds on the approximation ratios. / Quadratic optimization problems with complex-valued decision variables, in short called complex quadratic optimization problems, find many applications in engineering. In this dissertation, we study several instructive models of complex quadratic optimization, as well as its applications in combinatorial optimization. The tool that we use is a combination of semidefinite programming (SDP) relaxation and randomization technique, which has been well exploited in the last decade. Since most of the optimization models are NP-hard in nature, we shall design polynomial time approximation algorithms for a general model, or polynomial time exact algorithms for some restricted instances of a general model. / To enable the analysis, we first develop two basic theoretical results: one is the probability formula for a bivariate complex normal distribution vector to be in a prescribed angular region, and the other one is the rank-one decomposition theorem for complex positive semidefinite matrices. The probability formula enables us to compute the expected value of a randomized (with a specific rounding rule) solution based on an optimal solution of the SDP relaxation problem, while the rank-one decomposition theorem provides a new proof of the complex S -lemma and leads to novel deterministic rounding procedures. / With the above results in hand, we then investigate the models and applications of complex quadratic optimization via semidefinite programming in detail. We present an approximation algorithm for a convex quadratic maximization problem with discrete complex decision variables, where the approximation analysis is based on the probability formula. Besides, an approximation algorithm is proposed for a non-convex quadratic maximization problem with discrete complex decision variables. Then we study a limit of the model, i.e., a quadratic maximization problem with continuous unit module decision variables. The problem is shown to be strongly NP-hard. Approximation algorithms are described for the problem, including both convex case and non-convex case. Furthermore, if the objective matrix has a sign structure, then a stronger approximation result is shown to hold. In addition, we use the complex matrix decomposition theorem to solve complex quadratically constrained complex quadratic programming. We consider several interesting cases for which the corresponding SDP relaxation admits no gap with the true optimal value, and consequently, this yields polynomial time procedures for solving those special cases of complex quadratic optimization. / Huang Yongwei. / "August 2005." / Adviser: Shuzhong Zhang. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 4033. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 142-155). / 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, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
119

Planejamento agropecuário através de um modelo de programação linear não determinista / Agricultural planning through a nondeterministic linear programming model

Luiz Carlos Estraviz Rodriguez 10 August 1987 (has links)
O planejamento de uma empresa agrícola se faz sob condições de risco. Ao se utilizar a programação linear como instrumento auxiliar no processo de decisão rural, o fator risco deve ser considerado com o objetivo de melhor representar a realidade enfrentada pelo agricultor. O trabalho avalia a viabilidade de se utilizar a simulação Monte Carlo como forma de incorporação da aleatoriedade dos coeficientes nos modelos de programação linear. Os resultados mostram que o método proposto é capaz de fornecer informações não apresentadas por outros modelos e, para alguns casos, poderá se apresentar como único método adequado de análise. / Farm planning is done under risky conditions. When using linear programming as an auxiliary tool in the rural decision process, risk factor must be considered in order to better represent the reality faced by the farmer. The work evaluates the feasibility of using a Monte Carlo simulation approach to incorporate the randomness of the coefficients in the linear programming models. The results show that the proposed method is able to provide information not presented by other models and, in some cases, may become the only appropriate method of analysis.
120

Contribution au développement d'un moteur Stirling : de la cogénération dans le bâtiment à l'autonomie énergétique / Contribution to the development of a stirling engine : from combined heat and power in the building to energy independence

Lanciaux, Nicolas 13 January 2015 (has links)
Après avoir fait un bilan bibliographique des réalisations, des modèles analytiques et numériques dumoteur Stirling, on fait un point sur les applications possibles de ce moteur ce qui permet de décrire lecontexte de cette thèse : la cogénération.Les éléments historiques de la bibliographie montrent que le régénérateur est un des éléments essentielssur lequel on peut travailler pour améliorer les performances d’un moteur Stirling.Suite à cela on fait une proposition d’architecture moteur potentiellement capable d’apporter desaméliorations sur 3 difficultés essentielles dans la conception d’un tel moteur.Parmi ces 3 éléments, l’un d’eux concerne le régénérateur qui est alors re-baptisé « partageur »poursignifier sa particularité.La suite des travaux évalue le bénéfice que pourrait apporter le partageur sur le rendement du moteur.On réalise alors une double évaluation de l’effet du partageur au moyen d’un modèle analytique et d’unmodèle numérique. On aura au préalable décrit les bases de ces modèles et les modifications apportées.La conclusion n’est pas qu’un bilan des résultats et propose des perspectives originales qui vont bienau-delà de ce qui peut être fait actuellement en mécanique / After a state-of-the art presentation on achievements, analytical and numerical models of the Stirlingengine, we analyze the possible applications of this engine which allows describing the context of thisthesis : the cogeneration.Historical elements of the bibliography show that the regenerator is a key element on which we canwork to improve the performance of a Stirling engine.After that we make a proposal for engine design that is potentially able to make improvements on threekey challenges in designing such an engine.One of the three elements is the regenerator, named here sharer.Further work shows the potential benefit that the sharer could bring on the engine performance.A double assessment of the effect of the sharer using an analytical model and a numerical model isthen carried out. We precisely describe the basics of these models and propose modifications.The conclusion is not only an assessment of results but it offers original insights that could go beyondwhat can be done now in mechanical engineering.

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