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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.
21

Průzkum úrovně českého managementu z hlediska řízení firem / The survey of the level of Czech management from the firm's leading point of view

Kalábová, Lucie January 2008 (has links)
Purpose of work is analysis efficiency and character Czech managers. Further finding of optimal managerial operation style, appreciation levels of service culture and determination aspects that affect on this . The research was made on the sample of 100 questionaire which was put in firms in different branches.
22

On numerical studies of explosion and implosion in air.

January 2006 (has links)
Fu Sau-chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 68-71). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background of Explosion and Implosion Problems --- p.1 / Chapter 1.2 --- Background of the Development of Numerical Schemes --- p.2 / Chapter 1.3 --- Organization of the Thesis --- p.5 / Chapter 2 --- Governing Equations and Numerical Schemes --- p.6 / Chapter 2.1 --- Governing Equations --- p.6 / Chapter 2.2 --- Numerical Schemes --- p.8 / Chapter 2.2.1 --- Splitting Scheme for Partial Differential Equations with Source Terms --- p.8 / Chapter 2.2.2 --- Boundary Conditions --- p.9 / Chapter 2.2.3 --- "Numerical Solvers for the ODEs - The Second-Order, Two-Stage Runge-Kutta Method" --- p.10 / Chapter 2.2.4 --- Numerical Solvers for the Pure Advection Hyperbolic Problem - The Second-Order Relaxed Scheme --- p.11 / Chapter 3 --- Numerical Results --- p.29 / Chapter 3.1 --- Spherical Explosion Problem --- p.30 / Chapter 3.1.1 --- Physical Description --- p.32 / Chapter 3.1.2 --- Comparison with Previous Analytical and Experimental Results --- p.33 / Chapter 3.2 --- Cylindrical Explosion Problem --- p.46 / Chapter 3.2.1 --- Physical Description --- p.46 / Chapter 3.2.2 --- Two-Dimensional Model --- p.49 / Chapter 3.3 --- Spherical Implosion Problem --- p.52 / Chapter 3.3.1 --- Physical Description --- p.52 / Chapter 3.4 --- Cylindrical Implosion Problem --- p.53 / Chapter 3.4.1 --- Physical Description --- p.53 / Chapter 3.4.2 --- Two-Dimensional Model --- p.53 / Chapter 4 --- Conclusion --- p.65 / Bibliography --- p.68
23

Planejamento e gerenciamento de recursos para redes IEEE 802.16 baseadas em rádio sobre fibra / Resource planning and management for IEEE 802.16 networks based on radio over fiber

Silva, Pedro Henrique Gomes da, 1984- 19 August 2018 (has links)
Orientador: Nelson Luis Saldanha da Fonseca / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-19T00:15:10Z (GMT). No. of bitstreams: 1 Silva_PedroHenriqueGomesda_M.pdf: 2438089 bytes, checksum: 1531b4c3213529b3d7064cb49b95e0c8 (MD5) Previous issue date: 2011 / Resumo: A tecnologia de Rádio sobre Fibra (Radio over Fiber - RoF) possibilita o barateamento da instalação e manutenção de redes de acesso sem fio, dado que a distribuição da utilização dos sinais de radiofrequência (RF) pode ser otimizada, bem como emprega-se, nessas redes, antenas mais simples e baratas. Dentre as tecnologias de redes sem fio de acesso banda larga (Broadband Wireless Access - BWA), o padrão IEEE 802.16, conhecido como WiMAX, vem sendo apresentado como uma solução de baixo custo para o acesso última milha à Internet ou como meio de distribuição backhaul. Suas características, muito semelhantes às das redes celulares, tornam interessante o emprego da tecnologia de RoF para a instalação e expansão das redes WiMAX a um baixo custo. Nesta dissertação, apresenta-se um estudo sobre o dimensionamento da tecnologia RoF para redes WiMAX. Apresentam-se medidas de desempenho que levam em consideração os ajustes dos parâmetros de sincronização das camadas física e de controle de acesso ao meio. O objetivo desse estudo é servir de base para o planejamento e instalação dessas redes, levando em consideração restrições devido à degradação de desempenho que a introdução da fibra óptica impõe. Esta dissertação estuda, adicionalmente, o problema de otimização do uso dos recursos de rádio da rede, mais especificamente do posicionamento e alocação das estações base. A proposta considera uma arquitetura de rede sem fio com diversas camadas de antenas, cada camada com células de diferentes raios de cobertura. As células são implantadas através de associações entre as antenas e as estações base disponíveis. Para a otimização da rede, propõe-se um modelo baseado em programação linear inteira que distribui, de maneira ótima, os recursos e encontra a melhor configuração de células para minimizar o número de BSs usadas na rede, para maximizar a receita, ou para obter esses dois critérios simultaneamente. O custo computacional do problema de otimização proposto é bastante alto, o que inviabiliza o seu emprego em redes móveis. Para contornar esse problema, são apresentados também algoritmos rápidos baseados em relaxação linear da programação linear inteira que possibilitam a obtenção de soluções de boa qualidade em tempo reduzido / Abstract: The Radio over Fiber technology allows the reduction of the cost of installation and maintenance of wireless access networks, since it can allow an optimized use of radio frequency (RF). Moreover, it employs simplified and inexpensive antennas. The IEEE 802.16 wireless networks, known as WiMAX, are low cost solutions for the last mile access to the Internet. Its characteristics are very similar to those of cellular networks, which makes attractive the use of RoF technology for the installation and expansion of WiMAX networks at low cost. This dissertation studies the use of RoF technology for WiMAX networks, which considers the parameters of physical layer and medium access synchronization. Results can be used as guideline for planning of these networks. This dissertation also studies the optimization of the use of radio resources of the network, specifically the problem of positioning base stations. The proposed architecture considers a wireless network with several layers of antennas, each layer with cells of different radii of coverage. The cells are deployed dynamically by the association between antennas and the available base stations. It is proposed a network optimization model based on integer linear programming that optimally distributes the radio resources and finds the best configuration to either minimize the number of Base Stations used in the network, or to maximize the operator revenue, as well as ato try to achieve both criteria simultaneously. The computational cost of the proposed optimization problem is quite high, which prevents its use in mobile networks. To circumvent this problem, it is also presented fast algorithms based on linear relaxation of the integer linear programming model, which enable the obtainment of good solutions in short time frames / Mestrado / Ciência da Computação / Mestre em Ciência da Computação

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