Broadband
Mostrando 13-24 de 143 artigos, teses e dissertações.
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13. ESTIMATING THE DEMAND FOR BROADBAND SERVICES IN BRAZIL: ANALYSIS BY A DISCRETE-CHOICE MODEL
RESUMO A análise empírica estima a demanda por banda larga fixa residencial no Brasil por meio do modelo de escolha discreta Nested Logit. Os resultados indicam que a demanda é elástica. A elasticidade preço da demanda é maior para os municípios que contam com mais de um grupo econômico ofertando banda larga. Esse resultado é intuitivo na medida que
Rev. econ. contemp.. Publicado em: 29/07/2019
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14. Compact Broadband High-Directivity Microstrip Directional Coupler
Abstract The difference between phase velocities of the odd and even modes in inhomogeneous microstrip coupled lines makes the microstrip directional coupler a poor device regarding directivity. In this work, this issue is successfully compensated by the addition of a matching network at the ports of coupled lines. Furthermore, the proposed matching network,
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 19/06/2019
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15. Wideband Pattern Reconfigurable Printed-Yagi Antenna Array Based on Feed Structure
Abstract A pattern reconfigurable antenna array with two elements is designed in this paper. The antenna element is made up of a printed Yagi and feed structure with variable phase. By changing the states of diodes in the feed structure of these two elements, the far-field radiation phase of both elements can be changed. That is, the pattern reconfigurable f
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 19/06/2019
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16. Effect of Boundary Layer and Rotor Speed on Broadband Noise from Wind Turbines
ABSTRACT: Trailing edge surface of aerofoil is an important source of broadband aerodynamic noise production. In this paper, three aerofoil self-noise mechanisms from turbulent boundary layer near trailing edge surface are studied. Numerical computations were performed for a three bladed 2 MW horizontal axis upwind turbine of blade length 37 m and source hei
J. Aerosp. Technol. Manag.. Publicado em: 03/06/2019
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17. Translation and cross-cultural adaptation of the Motor Behavior Checklist (MBC) into Brazilian Portuguese
Resumo Introdução Existem poucos instrumentos disponíveis para avaliar problemas de comportamento em crianças em idade escolar com base no relato de professores de educação física. O Motor Behavior Checklist (MBC) foi criado para ser usado por este profissional observando a criança em uma situação de brincadeira livre ou nas aulas de educação f
Trends Psychiatry Psychother.. Publicado em: 30/05/2019
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18. Dumbbell Shaped Microstrip Broadband Antenna
Abstract In this article, a dumbbell shaped microstrip broadband microstrip antenna with partial ground plane is presented, The overall dimension of the proposed antenna is 20 × 15 × 1.5 mm3 and is fabricated on FR4 substrate which has electrical permittivity of 4.3 and loss tangent of 0.025. FR4 is a low cost and easily available. The thickness of the sub
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2019-03
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19. Investigation of Thermal Effects in Coaxial Probe Method and Dielectric Characterization of Glycerol up to 140°C
Abstract Dielectric properties of a material are of paramount importance in many areas of knowledge. All scientific fields that deal with the interaction of electromagnetic radiation with matter demand this information. Consequently, suitable methods for obtaining accurate dielectric data are required. In the microwave community, the dielectric metrology wit
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2019-03
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20. Millimeter Wave Antenna for Intelligent Transportation Systems Application
Abstract A compact broadband millimeter wave antenna for intelligent transportation (ITS) application is proposed in this paper. This antenna uses coplanar wave guide feeding technique for broad bandwidth. The proposed antenna works at 79 GHz resonant frequency having a large bandwidth of 78.2 GHz. The measured gain of the antenna is 17.5 dBi. The proposed a
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-03
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21. Design of Waveguide Structures Using Improved Neural Networks
Abstract In this paper, an improved neural networks (INN) strategy is proposed to design two waveguide filters (Pseudo-elliptic waveguide filter and Broad-band e-plane filters with improved stop-band). INN is trained by an efficient optimization algorithm called teaching–learning-based optimization (TLBO). To validate the effective of this proposed strateg
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-12
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22. Operational Measurements for Infrared Camera Characterization
ABSTRACT: The detection, location, identification and recognition are very important activities for the air forces. Imaging systems are tools used for those functions, so it is mandatory to characterize those systems to really know their actual operational limits. This paper presents a set of measurements for spectral, radiometric and spatial camera characte
J. Aerosp. Technol. Manag.. Publicado em: 2017-12
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23. Quantum Particle Swarm Optimization for Synthesis of Non-uniformly Spaced Linear Arrays with Broadband Frequency Invariant Pattern
Abstract This paper describes a method using Quantum Particle Swarm Optimization to obtain a broadband frequency invariant pattern for synthesis of nonuniformly spaced linear array of isotropic antennas. Two cases related to this work using QPSO have been studied, namely, in the first case, the generated frequency invariant far-field pattern is broadside in
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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24. A simple strategy to design broadband low power consumption distributed Raman amplifier
Abstract In this work, a simple strategy to design wideband low power consumption Raman amplifiers is demonstrated for a three-pump configuration using a low water peak optical fiber. The approach is based on the introduction of a novel numerical measure, which quantifies and isolates pump-pump interaction contribution to gain profile and analyzes its correl
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09