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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

A resampling theory for non-bandlimited signals and its applications : a thesis presented for the partial fulfillment of the requirements for the degree of Doctor of Philosophy in Engineering at Massey University, Wellington, New Zealand

Huang, Beilei January 2008 (has links)
Currently, digital signal processing systems typically assume that the signals are bandlimited. This is due to our knowledge based on the uniform sampling theorem for bandlimited signals which was established over 50 years ago by the works of Whittaker, Kotel'nikov and Shannon. However, in practice the digital signals are mostly of finite length. This kind of signals are not strictly bandlimited. Furthermore, advances in electronics have led to the use of very wide bandwidth signals and systems, such as Ultra-Wide Band (UWB) communication systems with signal bandwidths of several giga-hertz. This kind of signals can effectively be viewed as having infinite bandwidth. Thus there is a need to extend existing theory and techniques for signals of finite bandwidths to that for non-bandlimited signals. Two recent approaches to a more general sampling theory for non-bandlimited signals have been published. One is for signals with finite rate of innovation. The other introduced the concept of consistent sampling. It views sampling and reconstruction as projections of signals onto subspaces spanned by the sampling (acquisition) and reconstruction (synthesis) functions. Consistent sampling is achieved if the same discrete signal is obtained when the reconstructed continuous signal is sampled. However, it has been shown that when this generalized theory is applied to the de-interlacing of video signals, incorrect results are obtained. This is because de-interlacing is essentially a resampling problem rather than a sampling problem because both the input and output are discrete. While the theory for the resampling for bandlimited signals is well established, the problem of resampling without bandlimited constraints is largely unexplored. The aim of this thesis is to develop a resampling theory for non-bandlimited discrete signals and explore some of its potential applications. The first major contribution is the the theory and techniques for designing an optimal resampling system for signals in the general Hilbert Space when noise is not present. The system is optimal in the sense that the input of the system can always be obtained from the output. The theory is based on the concept of consistent resampling which means that the same continuous signal will be obtained when either the original or the resampled discrete signal is presented to the reconstruction filter. While comparing the input and output of a sampling/reconstruction system is relatively simple since both are continuous signals, comparing the discrete input and output of a resampling system is not. The second major contribution of this thesis is the proposal of a metric that allows us to evaluate the performance of a resampling system. The performance is analyzed in the Fourier domain as well. This performance metric also provides a way by which different resampling algorithms can be compared effectively. It therefore facilitates the process of choosing proper resampling schemes for a particular purpose. Unfortunately consistent resampling cannot always be achieved if noise is present in the signal or the system. Based on the performance metric proposed, the third major contribution of this thesis is the development of procedures for designing resampling systems in the presence of noise which is optimal in the mean squared error (MSE) sense. Both discrete and continuous noise are considered. The problem is formulated as a semi-definite program which can be solved effciently by existing techniques. The usefulness and correctness of the consistent resampling theory is demonstrated by its application to the video de-interlacing problem, image processing, the demodulation of ultra-wideband communication signals and mobile channel detection. The results show that the proposed resampling system has many advantages over existing approaches, including lower computational and time complexities, more accurate prediction of system performances, as well as robustness against noise.
22

Quantikov um analisador microestrutural para o ambiente windows sup (TM)

PINTO, LUCIO C.M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:40:53Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:17Z (GMT). No. of bitstreams: 1 02953.pdf: 10337836 bytes, checksum: 9de56156c1135dba861ce367dcc48691 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
23

Estudo de arquitetura de hardware para aplicacao em sistemas digitais de protecao de reatores nucleares. Metodos de analise de confiabilidade e seguranca

BENKO, PEDRO L. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:42:57Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:02Z (GMT). No. of bitstreams: 1 05358.pdf: 6193324 bytes, checksum: c9b68865b6cec7bb9c83ee65a4e97865 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
24

Processamento e análise digital de imagens em estudos da cinética de recristalização de ligas Al-Mg-X / Processing and analysis of digital images in studies of recrystallization kinectics of Al-Mg-X alloys

IGNACIO, JULIANO da S. 21 January 2015 (has links)
Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-01-21T10:14:57Z No. of bitstreams: 0 / Made available in DSpace on 2015-01-21T10:14:57Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
25

Desenvolvimento de uma arquitetura reconfigurável para o processamento de modelos no ambiente ABACUS /

Lima, Verônica Aparecida Lopes. January 2007 (has links)
Orientador: Norian Marranghello / Banca: Nobuo Oki / Banca: Wang Jiang Chau / Resumo: O objetivo deste trabalho é o desenvolvimento de uma arquitetura reconfigurável estaticamente, de um elemento de processamento (MPH) para o ambiente de simulação de circuitos ABACUS. Este elemento de processamento consiste de um conjunto de unidades funcionais que podem ser relacionadas por meio de algumas palavras de controle armazenadas na ROM, e cuja interconexão pode ser alterada para que o hardware de processamento se adapte ao modelo do elemento de circuito a ser simulado. O projeto foi descrito em linguagem VHDL e simulado com o auxílio do software QUARTUS II. / Abstract: The aim of this work is the development of a statically reconfigurable architecture, of a processing element (MPH) for the ABACUS circuit simulation environment. This processing element consists of a set of functional units that can be related by means of some control words stored in the ROM, and whose interconnection can be modified so that the processing hardware be adapted to the model of the circuit element to be simulated. The project was described in VHDL, and simulated with the aid of Quartus II software. / Mestre
26

IVM: uma metodologia de verificação funcional interoperável, iterativa e incremental

Prado, Bruno Otávio Piedade 03 1900 (has links)
A crescente demanda por produtos eletrônicos e a capacidade cada vez maior de integração criaram sistemas extremamente complexos em chips, conhecidos como Systemon-Chip ou SoC. Seguindo em sentido oposto a esta tendência, os prazos (time-to-market) para que estes sistemas sejam construídos vem continuamente sendo reduzidos, obrigando que muito mais funcionalidades sejam implementadas em períodos cada vez menores de tempo. A necessidade de um maior controle de qualidade do produto final demanda a atividade de Verificação Funcional que consiste em utilizar um conjuntos de técnicas para estimular o sistema em busca de falhas. Esta atividade é a extremamente dispendiosa e necessária, consumindo até cerca de 80% do custo final do produto. É neste contexto que se insere este trabalho, propondo uma metodologia de Verificação Funcional chamada IVM que irá fornecer todos os subsídios para garantir a entrega de sistemas de alta qualidade, e ainda atingindo as rígidas restrições temporais impostas pelo mercado. Sendo baseado em metodologias já bastante difundidas e acreditadas, como o OVM e o VeriSC, o IVM definiu uma organização arquitetural e um fluxo de atividades que incorporou as principais características de ambas as abordagens que antes estavam disjuntas. Esta integração de técnicas e conceitos resulta em um fluxo de verificação mais eficiente, permitindo que sistemas atinjam o custo, prazo e qualidade esperados._________________________________________________________________________________________ ABSTRACT: The growing demand for electronic devices and its even higher integration capability created extremely complex systems in chips, known as System-on-Chip or SoC. In a opposite way to this tendency, the time-to-market for these systems be built have been continually reduced, forcing much more functionalities be implemented in even shorten time periods. The final product quality control is assured by the Functional Verification activity that consists in a set of techniques to stimulate a system in order to find bugs. This activity is extremely expensive and necessary, responding to around 80% of final product cost. In this context this work is inserted on, proposing a Functional Verification methodology called IVM that will provide all conditions to deliver high quality systems, while keeping the hard time restrictions imposed by the market. Based in well known and trusted methodologies, as OVM and VeriSC, the IVM defined an architectural organization and an activity flow that incorporates features of both approaches that were separated from each other. This techniques and concepts integration resulted in a more efficient verification flow, allowing systems to meet the desired budget, schedule and quality.
27

Quantikov um analisador microestrutural para o ambiente windows sup (TM)

PINTO, LUCIO C.M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:40:53Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:17Z (GMT). No. of bitstreams: 1 02953.pdf: 10337836 bytes, checksum: 9de56156c1135dba861ce367dcc48691 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
28

Estudo de arquitetura de hardware para aplicacao em sistemas digitais de protecao de reatores nucleares. Metodos de analise de confiabilidade e seguranca

BENKO, PEDRO L. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:42:57Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:02Z (GMT). No. of bitstreams: 1 05358.pdf: 6193324 bytes, checksum: c9b68865b6cec7bb9c83ee65a4e97865 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
29

Processamento e análise digital de imagens em estudos da cinética de recristalização de ligas Al-Mg-X / Processing and analysis of digital images in studies of recrystallization kinectics of Al-Mg-X alloys

IGNACIO, JULIANO da S. 21 January 2015 (has links)
Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-01-21T10:14:57Z No. of bitstreams: 0 / Made available in DSpace on 2015-01-21T10:14:57Z (GMT). No. of bitstreams: 0 / O Processamento e Análise Digital de Imagens é utilizado cada vez mais para agilizar processos, aumentar a precisão, segurança e confiabilidade de dados extraídos de imagens nas mais diversas áreas de pesquisa. No entanto, muitas vezes é necessário que o pesquisador faça, ele próprio, o pré-processamento das imagens, mesmo não sendo um especialista nesta área. Isto coloca em risco o próprio objetivo do uso do Processamento e Análise Digital de Imagens. Este trabalho analisa a relação dos dados extraídos de uma imagem (micrografia) através do software livre ImageJ com relação ao seu processamento final desejado, avaliando assim, a necessidade ou não, de uma ou mais sequencias de pré-processamento para adequar a imagem para o processamento final, indicando ainda quais fatores de influência apresentam informações irrelevantes ou incompletas para o processamento final utilizando ferramentas da Lógica Paraconsistente Anotada. Os resultados obtidos mostram que esta abordagem carece de informações diversificadas sobre a imagem original capturada que possam subsidiar a tomada de decisão quanto aos procedimentos necessários e, para o pré-processamento adequado ao objetivo desejado. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
30

Adoption and Implementation of Hospital IT Systems in Ambulatory Surgical Care

Lundgren, Tina January 2022 (has links)
Purpose - The purpose of this study is to receive an understanding for how to enable higher rates of adoption implementation success of hospital IT (HIT) systems in ambulatory surgical care settings.   Method - The study is an explorative deductive multiple case-study, incorporating 15 ambulatory surgical centers situated in Sweden, Germany, and the United States. In total, 24 interviews were conducted with managers and users at the selected ASCs in three waves and analyzed through thematic analysis.   Findings - The study resulted in the identification of six barriers and eight enablers in the adoption- and implementation phase of HIT systems. In addition, an implementation framework was developed based on the findings from RQ1 and RQ2, with critical activities to execute to facilitate adoption- and implementation success of HIT systems in ASCs.   Theoretical contribution - This study adds to the literature by identifying new barriers and enablers in HIT adoption and implementation characterizing ambulatory surgical centers. Furthermore, the findings extend on previous literature by presenting an new all-encompassing implementation framework, showing the necessity to approach the implementation process as a whole process-improvement project for successful HIT adoption and implementation.  Managerial implications - This study emphasizes the important role managers in ambulatory surgical centers hold in facilitating successful HIT implementation and provides managers with a practical implementation framework to serve as a roadmap to guide them in achieving a successful implementation of HIT systems.   Limitations and future research - The study is limited to investigating adoption- and implementation of HIT systems (EHR, EMR, HIS) in the context of ambulatory surgical centers. Future studies can explore the identified barriers and enablers in more ambulatory surgical settings and extend upon the developed implementation framework.

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