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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.
1

Self-Affine signals and weighted multiresolution processes

Malassenet, Francois Jacques 12 1900 (has links)
No description available.
2

Μελέτη ευαισθησίας σε διαταραχές ενός ψηφιακού συστήματος δειγματοληπτικών δεδομένων σε σχέση με την περίοδο δειγματοληψίας

Σιαδήμας, Βασίλειος 19 July 2012 (has links)
Η παρούσα εργασία μελετά την ευαισθησία σε διάφορες διαταραχές που μπορούν να εφαρμοστούν σε ένα ψηφιακό σύστημα δειγματοληπτικών δεδομένων σε σχέση με τη μεταβολή της περιόδου δειγματοληψίας κάθε φορά. Οι συγκρίσεις και τα αποτελέσματα γίνονται με τη χρήση συγκεκριμένων παραδειγμάτων. / This thesis studies the sensitivity of various disorders that can be applied to a digital sample data in relation to the change in the sampling period at a time. The results and comparisons made using specific examples.
3

Episode 2.7 – The Effect of Sampling Rates on Digital Signals

Tarnoff, David 01 January 2020 (has links)
Converting an analog signal to digital involves more than just digitizing some measurements. Consequences result from sampling an analog signal and care has to be taken to capture all the desired frequencies and avoid creating new ones.
4

Nonlinear Feedback Equalization of Digital Signals Transmitted Over Dispersive Channels

Taylor, Desmond Patrick 05 1900 (has links)
<p> This thesis deals with the problem of digital communication over noisy dispersive channels. The dispersion causes the overlapping of successive received pulses thus creating intersymbol interference which severely limits the performance of conventional receivers designed to combat only additive interference or noise.</p> <p> In this thesis Bayes estimation theory has been applied to obtain a new, optimum, unrealizable receiver structure for the improved reception of noisy, dispersed, pulse amplitude-modulated (PAM) signals. By making certain approximations, a realization of this structure, known as the estimate feedback receiver or equalizer, is obtained. It consists of the combination of a matched filter and a nonlinear, recursive equalizer having, in the case of binary signals, a hyperbolic tangent nonlinearity in the feedback path. The well known decision feedback equalizer is shown to be a small noise limiting case of the estimate feedback equalizer. A saturating limiter is also considered as an approximation to the hyperbolic tangent nonlinearity.</p> <p> A new adaptive algorithm for the iterative adjustment of the estimate feedback equalizer is derived. It incorporates an extrapolation process which has the purposes of accelerating convergence of the equalizer's parameters to their optimum values and of maintaining the equalizer's frame of reference. It is constrained so that the equalizers parameters always move toward their optimum values.</p> <p> Computer simulations are used to demonstrate the properties of the adaptive estimate feedback equalizer and to compare them to those of presently known equalizers. When the estimate feedback equalizer is used, without a matched filter preceding it, to equalize phase distorted channels, its performance is seen to be superior to that of existing equalizers. The performance of an equalizer using a saturating limiter in place of the optimum hyperbolic tangent nonlinearity is seen to be almost as good as that of the estimate feedback equalizer.</p> / Thesis / Doctor of Philosophy (PhD)
5

Suplementação de triptofano na atividade elétrica cerebral (EEG) e glicemia de cães da raça Pit Bull / Tryptophan supplementation on brain electrical activity and blood glucose in Pit Bulls

Elmôr, Lucas Domênico 23 January 2009 (has links)
Três cães machos adultos da raça Pit Bull foram utilizados com o intuito de avaliar o efeito da suplementação de triptofano na atividade elétrica cerebral e taxa glicêmica. Os tratamentos foram: A) Dieta base + veículo com placebo (controle); B) Dieta base + veículo com 1,11g de triptofano. Inicialmente os animais passaram por doze dias de fornecimento do tratamento A, destes, cinco dias foram destinados a colheita dos dados. Após três dias de descanso teve início o período de 12 dias de fornecimento do tratamento B, com o aumento de um dia de colheita. Para a colheita de EEG foi utilizado o registro bipolar, sendo o sinal colhido numa freqüência de amostragem de 120 Hz por um período de 20 minutos por dia de colheita. Utilizou-se um glicosímetro portátil para mensurar a glicemia nos tempos 0, 15, 30, 45 minutos, relacionados com o período destinado ao manejo de colheita de EEG. A suplementação de triptofano diminuiu a energia das bandas de freqüências beta, teta, alfa e delta, permitindo sugerir uma modificação na atividade elétrica cerebral. Não houve efeito significativo do fornecimento de triptofano suplementar sobre a glicemia dos cães utilizados neste experimento. / Three adults male Pit Bulls dogs were housed with the intention of evaluating the effects of tryptophan supplementation on brain electrical activity and glicemic curve. The treatments were: A) Basic Diet + Placebo (control); B) Basic Diet + 1,11 g of tryptophan. First the animals were kept for 12 days using the A treatment, with five days of data collecting. After three days off they were kept for 12 days using the B treatment, but with an addition of one day of data collecting. The EEG collecting was made using a bipolar register, and the signal was collected on a 120 Hz sampling frequency for 20 minutes per collecting day. The blood glucose was measured using a portable blood glucose meter on 0, 15, 30 and 45 minutes, related to the EEG collecting period. The Tryptophan supplementation decreased the energy signals of the beta, theta, alpha and delta frequencies, which suggests some modification on the brain electrical activity. There was no effect of the tryptophan supplementation on the glicemic curve.
6

Suplementação de triptofano na atividade elétrica cerebral (EEG) e glicemia de cães da raça Pit Bull / Tryptophan supplementation on brain electrical activity and blood glucose in Pit Bulls

Lucas Domênico Elmôr 23 January 2009 (has links)
Três cães machos adultos da raça Pit Bull foram utilizados com o intuito de avaliar o efeito da suplementação de triptofano na atividade elétrica cerebral e taxa glicêmica. Os tratamentos foram: A) Dieta base + veículo com placebo (controle); B) Dieta base + veículo com 1,11g de triptofano. Inicialmente os animais passaram por doze dias de fornecimento do tratamento A, destes, cinco dias foram destinados a colheita dos dados. Após três dias de descanso teve início o período de 12 dias de fornecimento do tratamento B, com o aumento de um dia de colheita. Para a colheita de EEG foi utilizado o registro bipolar, sendo o sinal colhido numa freqüência de amostragem de 120 Hz por um período de 20 minutos por dia de colheita. Utilizou-se um glicosímetro portátil para mensurar a glicemia nos tempos 0, 15, 30, 45 minutos, relacionados com o período destinado ao manejo de colheita de EEG. A suplementação de triptofano diminuiu a energia das bandas de freqüências beta, teta, alfa e delta, permitindo sugerir uma modificação na atividade elétrica cerebral. Não houve efeito significativo do fornecimento de triptofano suplementar sobre a glicemia dos cães utilizados neste experimento. / Three adults male Pit Bulls dogs were housed with the intention of evaluating the effects of tryptophan supplementation on brain electrical activity and glicemic curve. The treatments were: A) Basic Diet + Placebo (control); B) Basic Diet + 1,11 g of tryptophan. First the animals were kept for 12 days using the A treatment, with five days of data collecting. After three days off they were kept for 12 days using the B treatment, but with an addition of one day of data collecting. The EEG collecting was made using a bipolar register, and the signal was collected on a 120 Hz sampling frequency for 20 minutes per collecting day. The blood glucose was measured using a portable blood glucose meter on 0, 15, 30 and 45 minutes, related to the EEG collecting period. The Tryptophan supplementation decreased the energy signals of the beta, theta, alpha and delta frequencies, which suggests some modification on the brain electrical activity. There was no effect of the tryptophan supplementation on the glicemic curve.
7

Music Visualization Using Source Separated Stereophonic Music

Chookaszian, Hannah Eileen 01 June 2022 (has links) (PDF)
This thesis introduces a music visualization system for stereophonic source separated music. Music visualization systems are a popular way to represent information from audio signals through computer graphics. Visualization can help people better understand music and its complex and interacting elements. This music visualization system extracts pitch, panning, and loudness features from source separated audio files to create the visual. Most state-of-the art visualization systems develop their visual representation of the music from either the fully mixed final song recording, where all of the instruments and vocals are combined into one file, or from the digital audio workstation (DAW) data containing multiple independent recordings of individual audio sources. Original source recordings are not always readily available to the public so music source separation (MSS) can be used to obtain estimated versions of the audio source files. This thesis surveys different approaches to MSS and music visualization as well as introduces a new music visualization system specifically for source separated music.
8

Metodologia para implantação de redes de frequência única Single Frequency Network – SFN em televisão digital / Methodology for the implementation of Single Frequency Network - SFN in digital television

Glock, Henry Saute 28 September 2016 (has links)
Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-06-27T22:29:40Z No. of bitstreams: 1 HenrySG_DISSERT.pdf: 34025203 bytes, checksum: 2defdce123ba16681be74520906f9baf (MD5) / Rejected by Vanessa Christiane (referencia@ufersa.edu.br), reason: Corrigir referência on 2017-07-03T12:20:54Z (GMT) / Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-07-04T16:10:45Z No. of bitstreams: 1 HenrySG_DISSERT.pdf: 34025203 bytes, checksum: 2defdce123ba16681be74520906f9baf (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-04T16:56:33Z (GMT) No. of bitstreams: 1 HenrySG_DISSERT.pdf: 34025203 bytes, checksum: 2defdce123ba16681be74520906f9baf (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-04T16:59:16Z (GMT) No. of bitstreams: 1 HenrySG_DISSERT.pdf: 34025203 bytes, checksum: 2defdce123ba16681be74520906f9baf (MD5) / Made available in DSpace on 2017-07-04T17:02:35Z (GMT). No. of bitstreams: 1 HenrySG_DISSERT.pdf: 34025203 bytes, checksum: 2defdce123ba16681be74520906f9baf (MD5) Previous issue date: 2016-09-28 / This paper presents a methodology that includes the structure and the care needed to design and implement a Single Frequency Network (SFN), with the benefits of energy conservation, transmitted power, and optimization of coverage area. It shows the network synchronization options and how to adjust the converged signal coverage areas within a region, showing clearly that this technology is a good and safe technological investment option. It also contains a history of one of the greatest technological developments that has occurred, indicating their form and difficulty in analog times. In the theoretical review are evidenced the technical limitations and the actions towards building a new, modern and robust digital transmission technology / Neste trabalho é apresentada uma metodologia que contempla a estrutura e cuidados necessários para projetar e implantar uma Single Frequency Network (SFN), apresentando os benefícios da racionalização de energia, potência transmitida, e otimização das áreas de cobertura. Apresenta as opções de sincronismo de rede bem como ajustar as regiões de cobertura de sinais convergentes a uma mesma região, mostrando com clareza que a tecnologia é uma boa e segura opção de investimento tecnológico. Também contém um histórico de um dos maiores desenvolvimentos tecnológicos já ocorridos, indicando sua forma e dificuldades em épocas analógicas. Na revisão teórica são é evidenciado o porquê das limitações técnicas até então existentes bem como as ações rumo a construção de uma nova, moderna e robusta tecnologia de transmissão digital / 2017-06-27
9

Neviditelné značení digitálních signálů / Invisible watermarking of digital signals

Pacura, Dávid January 2016 (has links)
Cílem téhle práce je navrhnutí nových technik pro robustní neviditelné značení digitálních signálů. Nejdříve je prezentován současný stav tohoto odvětví a dostupné softwarové řešení. Poté následuje návrh několika algoritmů pro neviditelné značení, přičemž každý z nich je založen na jiném principu. Dále je připravena sada digitálních testovacích signálů společně s testovacím softwarem pro otestování navržených řešení a jejích porovnání s vybraným dostupným softwarem. Poté následuje srovnání naměřených výsledků, výkonu a jejích diskuze.
10

Desarrollo de técnicas avanzadas en la auscultación dinámica para la optimización del mantenimiento de vías férreas

Salvador Zuriaga, Pablo 25 July 2014 (has links)
El mantenimiento de la vía se ha convertido en los últimos años en un tema verdaderamente relevante para la ingeniería ferroviaria debido a la necesidad de conseguir mejores niveles de calidad a menores costes. Para ello, no hay más remedio que incorporar a las filosofías y procedimientos tradicionales del mantenimiento y la auscultación de la vía nuevas técnicas, que en muchos casos están ampliamente desarrolladas en otros campos de la ingeniería. Así, este trabajo profundiza en las técnicas de adquisición y procesado de datos para su aplicación a la auscultación de la vía. Para ello, se han realizado varias pruebas en la red de Metro de Valencia, registrando las aceleraciones producidas en las cajas de grasa durante la circulación de los vehículos por las vías. Dichas aceleraciones se han registrado y analizado de diferentes maneras, variando la frecuencia de muestreo, la frecuencia de filtrado, el emplazamiento de los acelerómetros y los diferentes parámetros que definen las representaciones tiempo-frecuencia. Los resultados muestran los valores óptimos de los parámetros que determinan la auscultación dinámica y el mejor emplazamiento para los acelerómetros. Además, mediante el análisis espectral y los diagramas tiempo-frecuencia es posible identificar y clasificar los diferentes defectos, puntos singulares y modos de vibración de la vía. De este modo, pueden sentarse las bases para la aplicación de técnicas de procesado digital de imágenes al mantenimiento de la vía. / Salvador Zuriaga, P. (2014). Desarrollo de técnicas avanzadas en la auscultación dinámica para la optimización del mantenimiento de vías férreas [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39003 / Alfresco

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