Hilbert
Mostrando 1-12 de 203 artigos, teses e dissertações.
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1. Microstrip 3-Bit Fractal-based Phase Shifter
Abstract This paper presents the implementation of a 3-bit microstrip fractal-based phase shifter operating in the 430 MHz to 470 MHz frequency range. The fractal structure is used to confine different delay line lengths in the same area due to the space-filling properties of the used Hilbert fractal curve. The proposed design has three bits corresponding to
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Wheel-flat detection on trams using envelope analysis with Hilbert transform
Abstract The wheel-flat defect is one of the many issues decreasing the level of and comfort in light rail vehicles. The two main causes of wheel-flats are temporary or complete wheel blocking. The negative effect is the increase of the dynamic phenomenons in the wheel-rail interaction, which are impulsive in their nature. It could prove to be dangerous for
Lat. Am. j. solids struct.. Publicado em: 18/02/2019
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3. A simple way to obtain average occupation on quantum systems
Abstract In this work, we present a simple method to obtain time average occupation of quantum systems with time-independent Hamiltonian. Our method is fast and can be used for system with large Hilbert space. The average occupation can give insights and help finding the best parameter to be used in experiments or for a more complex simulation using time-dep
Rev. Bras. Ensino Fís.. Publicado em: 14/11/2018
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4. Feynman e as Integrais de Trajetória
Resumo O método de integrais de trajetória, desenvolvido por Feynman no artigo “Space-Time Approach to Non-Relativistic Quantum Mechanics” de 1948, é uma das formulações da teoria quântica que se junta, considerando a época do artigo, a duas anteriores: (i) a formulação, de certa forma o padrão apresentado em livros-textos, desenvolvida na déc
Rev. Bras. Ensino Fís.. Publicado em: 02/07/2018
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5. C*-Álgebras e a Descrição da Mecânica Quântica
Neste artigo apresentamos a Teoria das C *-Álgebras. Demonstramos dois importantes resultados que são: o Teorema de Gelfand, que associa toda C *-Álgebra Abeliana às funções contínuas sobre um espaço Hausdorff compacto, e o Teorema de Gelfand-Neumark, que relaciona toda C *-Álgebra não Abeliana aos operadores lineares sobre um espaço de
Rev. Bras. Ensino Fís.. Publicado em: 22/01/2018
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6. Modeling and FPGA-based implementation of an efficient and simple envelope detector using a Hilbert Transform FIR filter for ultrasound imaging applications
Abstract Introduction Although the envelope detection is a widely used method in medical ultrasound (US) imaging to demodulate the amplitude of the received echo signal before any back-end processing, novel hardware-based approaches have been proposed for reducing its computational cost and complexity. In this paper, we present the modeling and FPGA impleme
Res. Biomed. Eng.. Publicado em: 15/01/2018
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7. Potencial energético da biomassa residual do milho em diferentes espaçamentos e doses de nitrogênio
RESUMO A biomassa residual agrícola é uma importante fonte de energia e sua produção e qualidade varia com o manejo das lavouras. O objetivo deste estudo foi avaliar o efeito da distribuição de plantas e da adubação nitrogenada sobre o potencial de produção de energia da biomassa do milho cultivado sob sistema de plantio direto. O experimento de ca
Ciênc. agrotec.. Publicado em: 2017-12
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8. Formación de Profesores de Matemáticas desde la Etnomatemática: estado de desarrollo
Abstract The goal of this study is to contribute to our understanding of the state of research development about math professors’ training from an ethnomathematics perspective. The empirical material was selected from articles published between 1995 and 2015. The analysis was oriented around four questions: What characteristics should a school curriculum b
Bolema. Publicado em: 2017-08
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9. A note on the introduction of Hilbert’s Grundlagen der Geometrie
ABSTRACT We present and discuss a change in the introduction of Hilbert’s Grundlagen der Geometrie between the first and the subsequent editions: the disappearance of the reference to the independence of the axioms. We briefly outline the theoretical relevance of the notion of independence in Hilbert’s work and we suggest that a possible reason for this
Manuscrito. Publicado em: 2017-06
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10. Litterfall and Nutrient Dynamics in a Mature Atlantic Rainforest in Brazil
ABSTRACT We assessed litterfall and nutrient cycling in an old-growth Atlantic rainforest in southern Brazil. Plant litter collected monthly was separated into: leaves, twigs, reproductive organs, and fragments, and dried, weighed, and ground. Determination of carbon, nitrogen, phosphorus, potassium, calcium, magnesium, and sodium contents of different litte
Floresta Ambient.. Publicado em: 15/05/2017
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11. Comparação da acurácia de predições genômicas através de gerações usando métodos paramétricos e semi paramétricos
RESUMO. A acurácia da predição genômica foi comparada através de três métodos paramétricos e semi-paramétricos, que incluíram BayesA, LASSO Bayesiano e regressão RKHS (Reproducing Kernel Hilbert Spaces) sob vários níveis de hereditariedade (0,15; 0,3 e 0,45), números diferentes de marcadores (500, 750 e 1000) e intervalos de geração de conjun
Acta Sci., Anim. Sci.. Publicado em: 2016-12
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12. A QUÍMICA DOS POVOS INDÍGENAS DA AMÉRICA DO SUL
The contribution of non-European cultures to science and technology, primarily to chemistry, has gained very little attentions until now. Especially the high technological intelligence and inventiveness of South American native populations shall be put into a different light by our contribution. The purpose of this essay is to show that mainly in the area of
Quím. Nova. Publicado em: 2016-11