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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.
41

Study on a second-order bandpass Σ∆-modulator for flexible AD-conversion

Svensson, Hanna January 2008 (has links)
<p>An important component in many communication system is the digital to analog converter. The component is needed in order to convert real world analog quantities to digital quantities which are easier to process. As the market for hand held devices with wireless communication with the outer world has increased new approaches for sharing the frequency spectrum are needed. Therefore it would be interesting to look at the possibility to design an analog to digital converter that, in runtime, can change the frequency band converted, and hence the used standard. This thesis study one of the possibilities to design such an ADC, as a Σ∆ modulator, and more precise the structure called Cascade of resonators with distributed feedback and input (CRFB). The order of the modulator in this study is two.</p>
42

Study on a second-order bandpass Σ∆-modulator for flexible AD-conversion

Svensson, Hanna January 2008 (has links)
An important component in many communication system is the digital to analog converter. The component is needed in order to convert real world analog quantities to digital quantities which are easier to process. As the market for hand held devices with wireless communication with the outer world has increased new approaches for sharing the frequency spectrum are needed. Therefore it would be interesting to look at the possibility to design an analog to digital converter that, in runtime, can change the frequency band converted, and hence the used standard. This thesis study one of the possibilities to design such an ADC, as a Σ∆ modulator, and more precise the structure called Cascade of resonators with distributed feedback and input (CRFB). The order of the modulator in this study is two.
43

THEORETICAL INVESTIGATION AND PERFORMANCE ASSESSMENT OF REVERSED HYSTERESIS DELTA SIGMA MODULATOR DESIGN

Althomali, Raed 01 May 2014 (has links)
This dissertation studies a unique delta sigma modulator (DSM), known as reversed hysteresis delta sigma modulator (R-HDSM). This modulator is appropriate for ultra-high speed analog-to-digital converters, which can be used for communications and signal processing systems and their applications. Furthermore, the procedure to design the binary delta sigma modulator (BDSM) with a delay is developed and then parameters deltaOFF and deltaON ; are calculated for the system. In addition, analysis of the BDSM with a delay is achieved and the theoretical and simulated values compared. The reversed hysteresis delta sigma modulators are also analyzed, and the theoretical and the simulated values compared. The dissertation evaluates the performance measure for the suggested systems with continuous DSM and BDSM in terms of the spurious free dynamic range (SFDR), the signal to noise ratio (SNR), and the root mean square error (RMS). It studies the second-order R-HDSM. Finally, it compares the first-order R- HDSM and the second-order R-HDSM in terms of the signal to noise ratio (SNR).
44

Os termos sigma do núcleon e da delta / Nucleon and Delta sigma-terms

Gabriel Rocha de Santana Zarnauskas 02 June 2006 (has links)
O termo sigma do núcleon, $sigma_N$, pode ser extraído dos dados experimentais e permite testar teorias e modelos que buscam descrever os efeitos da quebra explícita de simetria quiral sobre o núcleon. A teoria de perturbação quiral é considerada atualmente a teoria efetiva da cromodinâmica quântica, sendo destinada a descrever o regime de baixas energias das interações fortes. Neste contexto, a expansão do termo sigma do núcleon em função da massa do píon depende das chamadas constantes de baixa energia, que devem ser extraídas da experiência. Neste trabalho apresentamos um modelo em que se elimina este tipo de dependência e fornece valores para $sigma_N$ e o termo sigma da delta, $sigma_Delta$, a partir de parâmetros conhecidos. No caso deste último, este procedimento é particularmente importante, porque não é possível extrair $sigma_Delta$ a partir da experiência, apesar desta grandeza ser fundamental para a obtenção de amplitudes na teoria de perturbação quiral, quando a delta aparece como grau de liberdade explícito. Variando as constantes de acoplamento entre os bárions e o píon, obtivemos resultados nos intervalos 43~MeV~$leq sigma_N leq$~49~MeV e 28~MeV~$leq sigma^R_Delta leq$~32~MeV, compatíveis com resultados de outros grupos. Pela possibilidade da delta decair, o seu termo sigma possui uma parte imaginária, a qual usamos para testar a consistência dos nossos resultados. Analisamos também a contagem de potências e o limite quiral, que mostraram o acordo entre a nossa expansão e a tirada da teoria de perturbação quiral. / The nucleon sigma term, $sigma_N$, may be extracted from experimental data and allows theories and models aimed at describing chiral symmetry breaking effects to be tested. At present, chiral perturbation theory is considered the effective theory of quantum chromodynamics at low energies. With this theory, one can obtain an expansion of $sigma_N$ in terms of the pion mass, involving low energy constants, which must be obtained from experiment. In this work we present a model that yields values for both $sigma_N$ and the delta sigma term, $sigma_Delta$, as functions of known parameters only. In the case of $sigma_Delta$, this procedure is particularly relevant, because $sigma_Delta$ is an important quantity in the evaluation of theoretical amplitudes and it is impossible to take it from experimental data. Several choices for pion-baryon coupling constants were used and our results lie in the intervals 43~MeV~$leq sigma_N leq$~49~MeV e 28~MeV~$leq sigma^R_Delta leq$~32~MeV, which are compatible with values produced by other groups. As the delta can decay, its sigma term has an imaginary part that we used to test the consistency of our calculations. The power counting in the chiral limit of our results is consistent with chiral perturbation theory.
45

Aplicação da metodologia \'Design for Six Sigma\' (DFSS) em projetos automotivos. / Application of the \'Design for Six Sigma\' (DFSS) methodology in automotive projects.

Alexandre Fioravanti 17 June 2005 (has links)
Este presente trabalho visa avaliar a aplicação da metodologia Design for Six Sigma (DFSS) ao processo de desenvolvimento de veículos (PDV) visando atingir níveis de qualidade Seis Sigma quando do início do processo de fabricação. Na verdade, quando se fala em fabricar produtos que já nasçam com níveis de qualidade Seis Sigma, não significa que seja mandatório que se obtenha a honrosa relação de 3,4 defeitos por milhão de oportunidades, mas sim que proporcionem resultados positivos em relação à melhoria da qualidade, otimização de custos, redução do tempo de desenvolvimento, vislumbrando o mais importante de todos os aspectos: o total entusiasmo do cliente. Para tanto, quando se fala da aplicação do DFSS no âmbito do desenvolvimento de veículos, o panorama deste contexto torna-se relativamente mais amplo e complexo, face ao nível de desenvolvimento tecnológico deste setor. O assunto é introduzido descrevendo-se o processo de desenvolvimento de veículos em sua abordagem atualmente difundida, alicerçada por um processo bem definido e estruturado, para se poder introduzir o DFSS neste processo. Antes, porém, introduz-se toda a metodologia referente ao Seis Sigma, por ser o fundamento base para a criação do DFSS. Por fim, a colocação de um estudo de caso procura relatar a aplicação da metodologia DFSS aplicada especificamente para a GM, procurando relatar a estratégia da aplicação, bem como seus principais ganhos alcançados. / This present work aims to evaluate the application of the Design for Six Sigma (DFSS) methodology to the vehicle development process (VDP) seeking to reach Six Sigma quality levels when the beginning of the production process. Actually, when it is spoken in manufacturing products that are already born with Six Sigma quality levels, it doesn\'t mean that it is mandatory that must be obtained the honorable relationship of 3,4 defects per millions of opportunities, but that provide positive results in relation to the quality improvement, costs optimization, reduction of the development timing, glimpsing the most important of all of the aspects: the customer\'s total enthusiasm. For that, when it is spoken about the application of DFSS in the extent of the vehicles development, the scenery of this context becomes relatively wider and complex, face at the level of technological development of this section. The subject is introduced being described the vehicles development process in its approach currently spread, found by a very defined and structured process, to allow introducing DFSS in this process. Before, however, the whole methodology regarding Six Sigma is introduced, for being the foundation base for the creation of DFSS. Finally, the placement of a case study tries to demonstrate the application of the DFSS methodology applied specifically for GM, trying to report the strategy of the application, as well as their main reached benefits.
46

Metoda Six Sigma v podnikové praxi / Method Six Sigma in Business Use

Nová, Marie January 2007 (has links)
In the first part, author is describing theoretical concept of rasing economic performance by using method Six Sigma (basic terms, tools, DMAIC). Then she describes current phenomenon outsourcing. The final part of the master thesis deals with practical implementatin of Six Sigma on a project called Reduction of manually allocated remittances in company Capgemini.
47

Aplicação da estratégia Seis Sigma ao Fundo de Saúde do Exército da Guarnição de Caçapava / Application of Six Sigma Strategy to the Fund for Health of the Army of the Lining Caçapava

Heliton Eleandro de Moura Damasceno 21 December 2009 (has links)
No atual contexto, a metodologia Seis Sigma passou a ser enfocada como uma nova estratégia voltada para o melhoramento contínuo dos processos com foco evidenciado na satisfação dos clientes e, em conseqüência, uma importante ferramenta para as Instituições Públicas, de caráter militar, aprimorarem seus serviços. O objetivo deste estudo é diagnosticar e implementar a metodologia Seis Sigma no Fundo de Saúde do Exército da Guarnição de Caçapava visando a melhoria no atendimento ao usuário. Para isso, com base no referencial teórico disponível, o trabalho inicialmente apresentou um breve relato sobre a gestão da qualidade, desde a evolução da qualidade até a sua abordagem nos serviços, procurando enfatizar a importância da qualidade nos serviços de saúde, seguido de uma abordagem sobre a metodologia Seis Sigma e suas principais características. A partir do estudo desenvolvido, implantou-se o modelo proposto para se analisar os resultados alcançados. Os resultados obtidos evidenciaram ganhos significativos com a implantação da metodologia Seis Sigma, principalmente no que se refere ao aumento da satisfação dos usuários com o Fundo de Saúde do Exército, em função do aumento da produtividade e da racionalização do tempo de processamento e atendimento. / In the current context, the Six Sigma methodology is now focused as a new strategy to the continuous improvement of processes with an evidenced focus in customer satisfaction, and consequently an important tool for public institutions of military nature to improve their services. The aim of this study is to diagnose and implement the Six Sigma methodology in the Health Fund Army Garrison Caçapava aimed at improving the service User. For that, based on the available theoretical framework, the work originally presented a brief report on the quality management, from the evolution of quality to its approach to services, trying to emphasize the importance of quality in health services, followed by an approach to the Six Sigma methodology and its main characteristics. Based on the study that had been developed, the proposed model was implemented in order to analyze the results. The results showed significant gains with the implementation of Six Sigma methodology, particularly with regard to increased user satisfaction with the Health Fund of the Army, with increasing productivity and streamlining the processing time and attendance.
48

Zlepšení zákaznického servisu / Customer service improvement

Deml, Kamil January 2008 (has links)
Diploma thesis put mind to improve of a customer service in a company that offers some financial service. Service means international money transfer in this case. To analyze the whole processes in the company, methods Six Sigma is used together with knowledge of other modern methods of quality and of operation management. The Six Sigma method is only used for the analyses of the procedures and not for an implementation it in the company.
49

A continuous-time asynchronous Sigma Delta analog to digital converter for broadband wireless receiver with adaptive digital calibration technique

Ng, Sheung Yan 29 September 2009 (has links)
No description available.
50

Application of DMAIC to integrate Lean Manufacturing and Six Sigma

Stephen, Philip 29 June 2004 (has links)
The slow rate of corporate improvement is not due to lack of knowledge of six sigma or lean. Rather, the fault lies in making the transition from theory to implementation. Managers need a step-by-step, unambiguous roadmap of improvement that leads to predictable results. This roadmap provides the self-confidence, punch, and power necessary for action and is the principal subject of this research. Unique to this research is the way the integration of lean and six sigma is achieved; by way of an integration matrix formed by lean implementation protocols and six sigma project phases. This integration matrix is made more prescriptive by an integrated leanness assessment tool, which will guide the user given their existing level of implementation and integration. Further guidance in each of the cells formed by the integration matrix is provided by way of phase methodologies and statistical/non-statistical tools. The output of this research is a software tool that could be used in facilities at any stage of lean implementation, including facilities with no existing lean implementation. The developed software tool has the capability to communicate among current and former project teams within any group, division, or facility in the organization. The developed software tool has also the capability to do data analysis (Example: Design of Experiments, Value Stream Mapping, Multi-Vari Analysis etc.). By way of the integration matrix, leanness assessment and the data analysis capability, the developed software tool will give managers a powerful tool that will help in their quest to achieve lean six sigma. / Master of Science

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