\"Ver o corpo humano por dentro\" sem a necessidade de intervenção cirurgica é objetivo que motivou a criação de diversos instrumentos como eletrocardiogramas, eletroencefalogramas, equipamentos de ressonância magnética e raio-X. Através daavaliação de imagens ou resultados numéricos, pode-se detectar patologias nos primeiros estágios, permitindo uma ação decisiva de especialistas médicos na cura destas. Especialistas da fala normalmente empregam instrumentos comovideolaringoscopia e videoestroboscopia para avaliar qualitativamente o comportamento da laringe e pregas vocais. Comprendendo que a voz transmite informações sobre alterações orgânicas ou funcionais nas estruturas de vocalização, este trabalhoapresenta um conjunto de medidas acústicas neste sinal que evidenciam alterações na periodicidade do movimento das cordas vocais e quantidade de ruído turbulento que atravessa a glote. A partir de avaliação estatística da capacidadedescriminatória destes índices acústicos e empregando-se redes neurais artificiais, define-se um método automático para identificação probabilística das patologias que afetam as estruturas da laringe. / \"To see the inside of the human body\" without the necessity of surgical intervention is the objective that motivates the conception of several instruments like electrocardiogram, electroencephalongram, magnetic resonance and X-ray equipments. Through the image analysis or numerical results, it is possible to identify pathologies, allowing a decisive action of physician specialists in cure of these. Voice specialists, normally, use instruments as videolaryngoscopy and videostroboscopy to assess the vocal folds and larynx comportment, qualitatively. Understanding that the voice transmits information upon functional or organic alterations in vocalization structures, this work presents a set of acoustic measurements, based on this signal, that evidences alterations on vocal folds movement periodicity and quantify of turbulent noise throught the glottis. From the statistic evaluation of discriminatory capacity of these acoustic indexes and using artificial neural networks, it defines an automatic method for the probabilistic identification of pathologies that affect the laryngeal structures.

Um tópico importante na análise de seqüências biológicas é a busca de genes, ou seja, a identificação de regiões codificantes de proteínas. Esta identificação permite a posterior procura de significado, descrição ou categorização biológica do organismo analisado. Atualmente, vários métodos combinam reconhecimento de padrões com conhecimento coletado de conjuntos de treinamento ou de comparações com banco de dados genômicos. Entretanto, a acurácia desses métodos está ainda longe do satisfatório. Novos métodos de processamento de seqüências de DNA e de identificação de genes podem ser criados através da busca por conteúdo (search-by-content). O padrão periódico de DNA em regiões codificantes de proteína, denominada periodicidade de três bases, vem sendo considerado uma propriedade dessas regiões. As técnicas de processamento digital de sinais fornecem uma base robusta para a identificação de regiões com periodicidade de três bases. Nesta dissertação, são apresentados um \\pipeline, os conceitos básicos da identificação genômica, e métodos de processamento digital de sinais utilizados para a identificação de regiões codificantes de proteínas. Introduzimos um novo método para a identificação dessas regiões, baseado na transformada proposta, denominada Transformada Modificada de Morlet. Apresentamos vários resultados experimentais obtidos a partir de seqüências de DNA sintéticas e reais. As principais contribuições do trabalho consistem no desenvolvimento de um pipeline para projetos genoma e na criação de um método de identificação de regiões codificantes onde a periodicidade de três bases seja latente. O método apresenta desempenho superior e vantagens importantes em comparação ao método tradicional baseado na transformada de Fourier de tempo reduzido. / An important topic in biological sequences analysis is gene finding, i.e. the identification of protein coding regions. This identification allows the posterior research for meaning, description or biological categorization of the analyzed organism. Currently, several methods combine pattern recognition with knowledge collected from training datasets or from comparison with genomic databases. Nonetheless, the accuracy of these methods is still far from satisfactory. New methods of DNA sequences processing and genes identification can be created through search-by-content such sequences. The periodic pattern of DNA in protein coding regions, called three-base periodicity, has been considered proper of coding regions. Digital signal processing techniques supply a strong basis for regions identification with three-base periodicity. In this work, we present a bioinformatics pipeline, basic concepts of the genomic identification and digital signal processing methods used for protein coding regions identification. We introduce a new method for identification of these regions, based on a newly proposed transform, called Modified Morlet Transform. We present some obtained experimental results from synthetic and real DNA sequences. The main contributions consist of the bioinformatics pipeline development for genoma projects and the creation of a method for protein coding regions identification where the three-base periodicity is latent. The method presents superior performance and important advantages in comparison to traditional method based on the short time Fourier transform.

As elevadas perdas existentes no setor elétrico tem causado preocupação nas empresas de distribuição, aliadas ainda a necessidade crescente de um desenvolvimento econômico sustentável. Neste cenário a calibração periódica dos instrumentos destinados a medição (entre eles os transformadores de instrumentos) tornam-se essenciais e tais procedimentos encontram-se previstos no novo modelo de operação do setor elétrico. Porém, as dificuldades logísticas e operacionais de transporte a laboratórios metrológicos credenciados dificultam a execução de tais serviços. As técnicas e métodos desenvolvidos nesse trabalho visam a implementação de uma unidade eletrônica capaz de aquisitar e processar dados provenientes de transformadores de instrumentos, de natureza indutiva (denominado de convencional) e ópticos, bem como seus subsistemas de apoio, como ferramentas de medição e calibração portátil, móvel, para execução dos serviços metrológicos in situ nos ambientes das subestações e cabines primárias. Estes serviços, apesar de estarem em estágio incipiente, são de extremo interesse para empresas de energia elétrica. Este projeto está baseado no estado da arte de componentes da eletrônica analógica e digital, onde destacam-se conversores analógico/digital (A/D), microprocessadores, osciladores, FPGA e técnicas computacionais para processamento digital de sinais. São apresentadas as formas de implementação tanto em hardware como em software para esta unidade eletrônica de forma a atender aos requisitos funcionais especificados e às normas do INMETRO e normas internacionais equivalentes para aplicações metrológicas. A validação é baseada em testes comparativos dos fasores na frequência fundamental dos sinais obtidos, analisando os valores de amplitude (para cálculo de erro de relação) e de fase ( para cálculo de erro de fase) entre transformadores ópticos e convencionais, sendo que estes últimos podem ser de referência ou não. / The high losses in the electricity sector have caused concern in distribution companies, together with the growing need for sustainable economic development. In this scenario the periodic calibration of instruments intended for measurement (including instrument transformers) become essential and such procedures are provided for in the new model of operation of the electric sector. However, the logistical and operational difficulties of transportation to accredited metrological laboratories make it difficult to perform such services. The techniques and methods developed in this work are aimed at the implementation of an electronic unit capable of acquiring and processing data from instrument transformers of an inductive (conventional) and optical nature, as well as its supporting subsystems, such as portable and mobile measuring and calibration tools for the execution of on-site metrological services in the substations and primary cabins. These services, although in an incipient stage, are of extreme interest to electric energy companies. This project is based on the state-of-the-art components of analog and digital electronics, including analog/digital (A/D) converters, microprocessors, oscillators, FPGA and computational techniques for digital signal processing. The forms of implementation in both hardware and software for this electronic unit are presented in order to meet the functional requirements specified and the standards of the Instituto Nacional de Metrologia (INMETRO) and equivalent international standards for metrological applications. The validation is based on comparative tests of the phasors at the fundamental frequency of the obtained signals, analyzing the amplitude (for ratio error calculation) and phase (for phase error calculation) between optical and conventional transformers, the last one can be reference or not.

Este trabalho tem a finalidade de analisar algumas técnicas de processamento do sinal mioelétrico, de forma a possibilitar uma posterior implementação de um circuito, que reconheça este sinal e apresente como saída um sinal de controle a ser utilizado em sistemas de reabilitação. Foram simuladas e avaliadas três técnicas de filtragem para o sinal mioelétrico, a fim de atenuar a interferência dos principais ruídos que corrompem este sinal. As técnicas avaliadas foram: filtragem digital clássica; cancelamento de ruído adaptativo e reconstrução do sinal por meio das componentes obtidas pela transformada wavelet. Também foi implementado e analisado um sistema simplificado de reconhecimento dos padrões para este sinal, realizado por meio de uma rede neural artificial, em que foi aplicado em sua entrada o próprio sinal mioelétrico e não suas características obtidas por processamentos matemáticos. Diante dos resultados obtidos os canceladores de ruído adaptativos apresentaram melhores resultados com relação às outras técnicas de filtragem. Apesar de não ter sido adequada para a filtragem, a transformada wavelet mostrou-se uma poderosa ferramenta de análise de sinais, em virtude da sua característica multiresolução. A técnica utilizada para reconhecer os padrões do sinal mostrou bons resultados com os sinais analisados. / This work has the purpose to analyze some techniques for myoelectric signal processing, towards a subsequent implementation of a circuit which can recognize this signal and present as output a control signal to be used in rehabilitation systems. Simulation and evaluation of three filtering techniques for the myoelectric signal were done in order to attenuate the main interferences of noises which corrupt this signal. The evaluated techniques were: classic digital filtering; adaptive noise cancelling and the signal reconstruction through the obtained components by the wavelet transform. A simplified system of pattern recognition for this signal also was implemented and analyzed, accomplished through an artificial neural network. The myoelectric signal itself was applied to the input instead of its characteristics obtained by mathematical processing. According to the results obtained the adaptive noise cancelling presented better results in comparison to the other filtering techniques. Despite not being adequate for filtering, the wavelet transform proved to be a powerful tool for signal analysis, by virtue of its multiresolution characteristics. The technique used to recognize the signal patterns has shown good results with the analyzed signals.

The Brigham Young University (BYU) Radio Astronomy Systems group, in collaboration with the National Radio Astronomy Observatory (NRAO), the Center for Astrophysics at West Virginia University (WVU), and the Green Bank Observatory (GBO) have developed, and commissioned, a broadband real-time digital back end processing system for a 38-element phased array feed (PAF) with 150 MHz of instantaneous bandwidth. This system is capable of producing coarse and fine channel correlations, and implements a real-time beamformer that forms 7 simultaneous dual-polarized beams. This thesis outlines the hardware and software development for the digital back end and presents on-telescope commissioning results. This system has been measured to provide an unprecedented low Tsys/η noise level of 28 K and can perform maps of galactic hydrogen observations in a fraction of the time of a conventional single horn feed. The National Radio Astronomy Observatory (NRAO) has recently announced the concept and development of the next generation Very Large Array (ngVLA), a large interferometric array consisting of 300 radio telescopes and longest baseline (distance between a pair of antennas) of 300 km. Large interferometric arrays have been shown to attenuate radio frequency interference (RFI) because it is decorrelated as it propagates across long baselines. This is not always sufficient, especially with dense core array geometries and with the ever-increasing amount of strong RFI sources. Conventional RFI projection-based mitigation techniques have performed poorly on large interferometers because of covariance matrix estimation error due to decorrelation when identifying interference subspace parameters. This thesis presents an algorithm that overcomes the challenge of decorrelation by applying subspace projection via subarray processing (SP-SAP). Each subarray is designed to have a set of elements with high mutual correlation in the interferer for better estimation of subspace parameters. In simulation, compared to the former approach of applying subspace projection on the full array, SP-SAP improves mitigation of the RFI on the order of 9 dB. A signal of interest is shown then to be observable through the RFI in a full synthetic image.

This dissertation studies the effects of radiation-induced single-event upsets (SEUs) on digital signal processing (DSP) systems designed for field-programmable gate arrays (FPGAs). It presents a novel method for evaluating the effects of radiation on DSP and digital communication systems. By using an application-specific measurement of performance in the presence of SEUs, this dissertation demonstrates that only 5-15% of SEUs affecting a communications receiver (i.e. 5-15% of sensitive SEUs) cause critical performance loss. It also reports that the most critical SEUs are those that affect the clock, global reset, and most significant bits (MSBs) of computation. This dissertation also demonstrates reduced-precision redundancy (RPR) as an effective and efficient alternative to the popular triple modular redundancy (TMR) for FPGA-based communications systems. Fault injection experiments show that RPR can improve the failure rate of a communications system by over 20 times over the unmitigated system at a cost less than half that of TMR by focusing on the critical SEUs. This dissertation contrasts the cost and performance of three different variations of RPR, one of which is a novel variation developed here, and concludes that the variation referred to as "Threshold RPR" is superior to the others for FPGA systems. Finally, this dissertation presents several methods for applying Threshold RPR to a system with the goal of reducing mitigation cost and increasing the system performance in the presence of SEUs. Additional fault injection experiments show that optimizing the application of RPR can result in a decrease in critical SEUs by as much 65% at no additional hardware cost.

<p>The most important aspects of nuclear medicine imaging systems such as Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) are the spatial resolution and the sensitivity (detector efficiency in combination with the geometric efficiency). Considerable efforts have been spent during the last two decades in improving the resolution and the efficiency by developing new detectors. Our proposed improvement technique is focused on the readout and electronics. Instead of using traditional pulse height analysis techniques we propose using free running digital sampling by replacing the analog readout and acquisition electronics with fully digital programmable systems.</p><p>This thesis describes a fully digital data acquisition system for KS/SU SPECT, new algorithms for high resolution timing for PET, and modular FPGA based decentralized data acquisition system with optimal timing and energy. The necessary signal processing algorithms for energy assessment and high resolution timing are developed and evaluated. The implementation of the algorithms in field programmable gate arrays (FPGAs) and digital signal processors (DSP) is also covered. Finally, modular decentralized digital data acquisition systems based on FPGAs and Ethernet are described.</p>

The most important aspects of nuclear medicine imaging systems such as Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) are the spatial resolution and the sensitivity (detector efficiency in combination with the geometric efficiency). Considerable efforts have been spent during the last two decades in improving the resolution and the efficiency by developing new detectors. Our proposed improvement technique is focused on the readout and electronics. Instead of using traditional pulse height analysis techniques we propose using free running digital sampling by replacing the analog readout and acquisition electronics with fully digital programmable systems. This thesis describes a fully digital data acquisition system for KS/SU SPECT, new algorithms for high resolution timing for PET, and modular FPGA based decentralized data acquisition system with optimal timing and energy. The necessary signal processing algorithms for energy assessment and high resolution timing are developed and evaluated. The implementation of the algorithms in field programmable gate arrays (FPGAs) and digital signal processors (DSP) is also covered. Finally, modular decentralized digital data acquisition systems based on FPGAs and Ethernet are described.

Recently, smart dust or wireless sensor networks are gaining more attention.These autonomous, ultra-low power sensor-based electronic devices sense and process burst-type environmental variations and pass the data from one node (mote) to another in an ad-hoc network. Subsystems for smart dust are typically the analog interface (AI), analog-to-digital converter (ADC), digital signal processor (DSP), digital-to-analog converter (DAC), power management, and transceiver for communication. This thesis project describes an event-driven (ED) digital signal processing system (ADC, DSP and DAC) operating in continuous-time (CT) with smart dust as the target application. The benefits of the CT system compared to its conventional counterpart are lower in-band quantization noise and no requirement of a clock generator and anti-aliasing filter, which makes it suitable for processing burst-type data signals. A clockless EDADC system based on a CT delta modulation (DM) technique is presented. The ADC output is digital data, continuous in time, known as “data token”. The ADC employs an unbuffered, area efficient, segmented resistor-string (R-string) feedback DAC. A study of different segmented R-string DAC architectures is presented. A comparison in component reduction with prior art shows nearly 87.5% reduction of resistors and switches in the DAC and the D flip-flops in the bidirectional shift registers for an 8-bit ADC, utilizing the proposed segmented DAC architecture. The obtained SNDR for the 3-bit, 4-bit and 8-bit ADC system is 22.696 dB, 30.435 dB and 55.73 dB, respectively, with the band of interest as 220.5 kHz. The CTDSP operates asynchronously and process the data token obtained from the EDADC. A clockless transversal direct-form finite impulse response (FIR) low-pass filter (LPF) is designed. Systematic top-down test-driven methodology is employed through out the project. Initially, MATLAB models are used to compare the CT systems with the sampled systems. The complete CTDSP system is implemented in Cadence design environment. The thesis has resulted in two conference contributions. One for the 20th European Conference on Circuit Theory and Design, ECCTD’11 and the other for the 19th IFIP/IEEE International Conference on Very Large Scale Integration, VLSI-SoC’11. We obtained the second-best student paper award at the ECCTD.

In the present work, the magnetotransport measurement technique was developed and various materials, exhibiting resistances from 1 mOhm up to several tens of kOhm, were investigated in pulsed magnetic fields of up to 60 T. Phase diagrams of irreversibility and upper critical fields for pure and Zn-doped YBa2Cu3O_7-x high-temperature superconductors were measured. A high-field study of the electronic properties of the two semimetals LaBiPt and CeBiPt were presented. Magnetoresistance of La0.7Sr0.3MnO3 and La0.7Ca0.3MnO3 thin films were investigated.