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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.
141

On Newton-Okounkov bodies, linear series and positivity

Merz, Georg 08 March 2018 (has links)
No description available.
142

Newton e a metafisica : uma proposta de ensino de fisica para o segundo grau a partir do resgate das origens do concreto de força a distancia

Barreto, Márcio, 1961- 08 February 1995 (has links)
Orientador: Laymert Garcia dos Santos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação / Made available in DSpace on 2018-07-19T22:21:05Z (GMT). No. of bitstreams: 1 Barreto_Marcio_M.pdf: 7934407 bytes, checksum: 6d6c3f1c0671dbb67b0310e07d4d964b (MD5) Previous issue date: 1995 / Resumo: Nesta dissertação de mestrado o leitor encontrará os principais aspectos da obra de Newton,. vistos a partir das relações entre ciência e religião em seus escritos.o foco da análise é a lei da atração gravitacional, aqui utilizada como uma metáfora valiosa para o ensino de Segundo Grau, mais especificamente o ensino de Física. O resgate das origens do conceito de força à distância, baseado em autores como B. Dobbs, R. Westfall, A. Koyré e outros, mostra que no ceme do pensamento científico moderno é possível encontrar respostas para questões essenciais da Educação do nosso tempo / Mestrado / Mestre em Educação
143

[en] A HEURISTIC METHOD FOR MULTIOBJECTIVE SCHEDULING PROBLEM IN VARIOUS MACHINE ENVIRONMENTS / [pt] UM MÉTODO HEURÍSTICO PARA O PROBLEMA DE ESCALONAMENTO MULTIOBJETIVO EM VÁRIOS AMBIENTES DE MÁQUINAS

MIGUEL ANGEL FERNANDEZ PEREZ 04 June 2012 (has links)
[pt] Um problema de programação ou escalonamento de produção tem como finalidade determinar uma seqüência factível de processamento de um conjunto de operações e de um conjunto de recursos ao longo de um intervalo de tempo, visando otimizar uma ou mais medidas de desempenho, geralmente associadas ao fator tempo ou ao balanceamento de uso dos recursos. Nesse problema, podem existir ainda restrições de precedência entre as operações e de disponibilidade de recursos por operação. Tais operações formam parte das tarefas ou pedidos de clientes por bens ou serviços. Problemas de escalonamento podem ser difíceis, particularmente, porque o tempo é um limitante para se buscar a melhor seqüência entre as seqüências factíveis possíveis. Porém, encontrar boas soluções para problemas complexos de otimização em um intervalo de tempo aceitável é crucial em sistemas produtivos competitivos, onde os problemas de escalonamento são comumente encontrados. A dissertação tem como foco o desenvolvimento de um novo método computacional para resolver problemas de escalonamento nos ambientes de operações: flow shop, flexible job shop, integrated resource selection and operation sequences e advanced planning and scheduling. Inspirado no método de Newton para problemas de otimização contínua multiobjetivo de Fliege et al. (2008), o método proposto é adaptado a cada ambiente de operação. Exemplos e experimentos numéricos com o método proposto são apresentados para cada ambiente de operações, assim como são realizadas comparações com algoritmos existentes. / [en] The production scheduling problem aims to determine a feasible sequence operation processes and resources over a period of time to optimize one or more measures of performance, usually associated with the time factor or balancing the use of resources. In this problem, precedence constraints between operations and availability of resources per operation may exist. Such operations are part of the tasks or customer orders for products or services. Scheduling problems can be difficult, particularly because time is a limiting factor to get the best sequence among possible feasible sequences. However, finding good solutions for complex optimization problems in an acceptable amount time is crucial in competitive production systems, where the scheduling problems are usually found. The dissertation is focused on the development of a new computational method for solving scheduling problems in the operations environments: flow shop, flexible job shop, integrated resource selection and operation sequences and advanced planning and scheduling. Inspired by Newton s method for continuous multiobjective optimization problems of Fliege et al. (2008), the proposed method is adapted to each operating environment. Examples and numerical experiments with the proposed method are presented for each operating environment, showing some comparisons with existing algorithms, as well.
144

Física mecánica. Nivelacion para estudiantes universitarios [Capítulo 1]

Arrascue Cordova, Lily January 1900 (has links)
Física Mecánica. Nivelación para estudiantes universitarios es un libro que presenta los conocimientos de física de forma muy sencilla y los relaciona con situaciones reales y cotidianas para los estudiantes. Esta obra fue escrita inicialmente para enseñar la física en un nivel introductorio a los estudiantes de carreras como ingeniería y arquitectura. Sin embargo, su lenguaje y metodología facilitan su uso a nivel de educación secundaria también. Para ello, la autora repasa los temas de física clásica en cuatro unidades: Magnitudes y medida, Cinemática, Dinámica, y Trabajo y Energía mecánica y su conservación. Cada unidad consta de capítulos que presentan una introducción conceptual con ejemplos resueltos, preguntas y problemas, actividades y ejercicios de autoevaluación. Cabe señalar que en todo el texto se toma en cuenta el Sistema Legal de Unidades y Medidas del Perú y que el nivel matemático requerido para enfrentar los problemas y ejercicios propuestos es básico, de modo que no es necesario que el estudiante cuente con conocimientos de cálculo. Este libro constituye, en suma, una alternativa para la enseñanza de conceptos de mecánica en física que se adapta muy bien a la forma de aprendizaje que desarrollan los estudiantes de hoy.
145

Communication-efficient Distributed Inference: Distributions, Approximation, and Improvement

Yin, Ziyan January 2022 (has links)
In modern data science, it is common that large-scale data are stored and processed parallelly across a great number of locations. For reasons including confidentiality concerns, only limited data information from each parallel center is eligible to be transferred. To solve these problems more efficiently, a group of communication-efficient methods are being actively developed. The first part of our investigation is the distributions of the distributed M-estimators that require a one-step update, combining data information collected from all parallel centers. We reveal that the number of centers plays a critical role. When it is not small compared with the total sample size, a non-negligible impact occurs to the limiting distributions, which turn out to be mixtures involving products of normal random variables. Based on our analysis, we propose a multiplier-bootstrap method for approximating the distributions of these one-step updated estimators. Our second contribution is that we propose two communication-efficient Newton-type algorithms, combining the M-estimator and the gradient collected from each data center. They are created by constructing two Fisher information estimators globally with those communication-efficient statistics. Enjoying a higher rate of convergence, this framework improves upon existing Newton-like methods. Moreover, we present two bias-adjusted one-step distributed estimators. When the square of the center-wise sample size is of a greater magnitude than the total number of centers, they are as efficient as the global M-estimator asymptotically. The advantages of our methods are illustrated by extensive theoretical and empirical evidences. / Statistics
146

A study of semantic flexibility as a predictor of teacher communication patterns

McInnis, Irene Margaret January 1970 (has links)
Dissertation (Ed.D.)--Boston University, 1970. / The purpose of this study was to determine whether or not semantic flexibility as a language characteristic of teachers in training could be used as a predictor of the teacher's ability to receive and transmit information. The Guilford Word Association Test, designed by J. P. Guilford to measure convergent and divergent thinking, was selected as the instrument for measuring semantic flexibility and was administered to 201 students enrolled in the block methods course at Boston University. The students were all juniors, scheduled to student teach the following semester. The Guilford Word Association Test was also administered to 154 sixth grade children enrolled in the Boston Public Schools in the South End and Roxbury and to 182 sixth grade children enrolled in the Newton Public Schools. The two groups of children were designated as the urban and suburban samples, respectively. From the populations tested four high Guilford teachers and four low Guilford teachers were selected. From each of the urban and suburban classes four high Guilford and four low Guilford children were selected. Each teacher had eight pupils assigned to her and for the purposes of data analysis, the children were categorized first as high and low Guilford scorers and then as urban or suburban children. In total there were eight teachers and sixty-four children in this experiment. [truncated]
147

[en] ADVANCES IN IMPLICIT INTEGRATION ALGORITHMS FOR MULTISURFACE PLASTICITY / [pt] AVANÇOS EM ALGORITMOS DE INTEGRAÇÃO IMPLÍCITA PARA PLASTICIDADE COM MÚLTIPLAS SUPERFÍCIES

RAFAEL OTAVIO ALVES ABREU 04 December 2023 (has links)
[pt] A representação matemática de comportamentos complexos em materiais exige formulações constitutivas sofisticada, como é o caso de modelos com múltiplas superfícies de plastificação. Assim, um modelo elastoplástico complexo demanda um procedimento robusto de integração das equações de evolução plástica. O desenvolvimento de esquemas de integração para modelos de plasticidade é um tópico de pesquisa importante, já que estes estão diretamente ligados à acurácia e eficiência de simulações numéricas de materiais como metais, concretos, solos e rochas. O desempenho da solução de elementos finitos é diretamente afetado pelas características de convergência do procedimento de atualização de estados. Dessa forma, este trabalho explora a implementação de modelos constitutivos complexos, focando em modelos genéricos com múltiplas superfícies de plastificação. Este estudo formula e avalia algoritmos de atualização de estado que formam uma estrutura robusta para a simulação de materiais regidos por múltiplas superfícies de plastificação. Algoritmos de integração implícita são desenvolvidos com ênfase na obtenção de robustez, abrangência e flexibilidade para lidar eficazmente com aplicações complexas de plasticidade. Os algoritmos de atualização de estado, baseados no método de Euler implícito e nos métodos de Newton-Raphson e Newton-Krylov, são formulados utilizando estratégias de busca unidimensional para melhorar suas características de convergência. Além disso, é implementado um esquema de subincrementação para proporcionar mais robustez ao procedimento de atualização de estado. A flexibilidade dos algoritmos é explorada, considerando várias condições de tensão, como os estados plano de tensões e plano de deformações, num esquema de integração único e versátil. Neste cenário, a robustez e o desempenho dos algoritmos são avaliados através de aplicações clássicas de elementos finitos. Além disso, o cenário desenvolvido no contexto de modelos com múltiplas superfícies de plastificação é aplicado para formular um modelo elastoplástico com dano acoplado, que é avaliado através de ensaios experimentais em estruturas de concreto. Os resultados obtidos evidenciam a eficácia dos algoritmos de atualização de estado propostos na integração de equações de modelos com múltiplas superfícies de plastificação e a sua capacidade para lidar com problemas desafiadores de elementos finitos. / [en] The mathematical representation of complex material behavior requires a sophisticated constitutive formulation, as it is the case of multisurface plasticity. Hence, a complex elastoplastic model demands a robust integration procedure for the plastic evolution equations. Developing integration schemes for plasticity models is an important research topic because these schemes are directly related to the accuracy and efficiency of numerical simulations for materials such as metals, concrete, soils and rocks. The performance of the finite element solution is directly influenced by the convergence characteristics of the state-update procedure. Therefore, this work explores the implementation of complex constitutive models, focusing on generic multisurface plasticity models. This study formulates and evaluates state-update algorithms that form a robust framework for simulating materials governed by multisurface plasticity. Implicit integration algorithms are developed with an emphasis on achieving robustness, comprehensiveness and flexibility to handle cumbersome plasticity applications effectively. The state-update algorithms, based on the backward Euler method and the Newton-Raphson and Newton-Krylov methods, are formulated using line search strategies to improve their convergence characteristics. Additionally, a substepping scheme is implemented to provide further robustness to the state-update procedure. The flexibility of the algorithms is explored, considering various stress conditions such as plane stress and plane strain states, within a single, versatile integration scheme. In this scenario, the robustness and performance of the algorithms are assessed through classical finite element applications. Furthermore, the developed multisurface plasticity background is applied to formulate a coupled elastoplastic-damage model, which is evaluated using experimental tests in concrete structures. The achieved results highlight the effectiveness of the proposed state-update algorithms in integrating multisurface plasticity equations and their ability to handle challenging finite element problems.
148

Kant's Theory of Simultaneity

Al-Fadli, Ageel 23 October 2023 (has links)
In this thesis, I examine Kant's conception of simultaneity in relation to the idea of the empirical determinacy of time. I begin by introducing the concepts of time and simultaneity in Newton and Leibniz, and demonstrate how these two modern conceptions of time contributed to Kant's understanding of simultaneity and cosmological unity. It will be argued that Kant's conception of simultaneity was intended to account for the possibility of the rational determination of time, and that for this purpose, Kant sought to reinterpret the Principle of Sufficient Reason in his early writings by linking it to the simultaneity-relation between substances in reciprocal interaction, thus arguing for the possibility of coexistence between substances. This provides a way to understand how the unity of the world is fundamental to Kant's understanding of the rational determination of time and space. In Kant's critical period the relation of simultaneity is analysed as empirically realized through mutual interaction, but the pure manifold of time is thought to be intuitional, which requires the implementation of relational categories in order to be reproduced in experience. In the Third Analogy of the First Critique, the concept of mutual interaction is analysed in terms of balanced forces, which provides a means of describing the evolution of a dynamical system over time. It provides the process by which the connection between different dynamical systems is possible, and also for the synchronization of different clocks.
149

An Evaluation of Transfer Capability Limitations and Solutions for South Mississippi Electric Power Association

Brown, Nathan L 11 May 2002 (has links)
Historically, transmission transfer capability between transmission systems was typically assumed based on the thermal limits of specific transmission paths. Because electric transmission systems are becoming more and more heavily loaded, accurately evaluating transfer capability between transmission systems and maintaining minimum levels of transfer capability has become increasingly important. This Thesis evaluates the transfer capability needs and limitations of a specific small electric utility. Identified are various analysis tools and evaluation methods used to determine transfer capability. Two specific evaluation methods are analyzed and compared to determine the best method of determining transfer capability. Various solutions, including upgrading existing or installing new transmission interconnections, are identified and evaluated to determine the best overall solution to achieve and maintain the utility?s desired transfer capability level.
150

STUDENT MISCONCEPTIONS IN NEWTONIAN MECHANICS

Lark, Adam Christopher 27 March 2007 (has links)
No description available.

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