Propagation Prediction
Mostrando 1-12 de 57 artigos, teses e dissertações.
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1. Channel Characteristics for Fixed and Portable DTV Reception in a Single Frequency Network
Abstract This paper presents the propagation channel characteristics of a digital TV single-frequency network (SFN) obtained by carrying out field measurements using two synchronized transmitters. The measurements are performed at 31 reception points using both a directive reception antenna, which is typical of fixed reception scenarios, and an omnidirection
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 12/09/2019
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2. Preliminary investigation of Terahertz spectroscopy to predict pork freshness non-destructively
Abstract Freshness, a very important criterion for pork quality control, is normally assessed by the index of K value. In this paper, Terahertz (THz) spectroscopy was employed to predict K value of pork nondestructively. The THz spectra (0.2~2.0THz) of 80 pork samples with different freshness in the attenuated total reflectance (ATR) mode were acquired. Simu
Food Sci. Technol. Publicado em: 22/07/2019
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3. Ray Tracing and Applications to an Evaporation Duct Model Based on Data from Oceanographic Buoy Sensors
Abstract The two-dimensional ray tracing method allows an easy and fast modeling of tropospheric propagation in the microwave frequency range. A version of this method that determines ray trajectories, amplitudes and delays of the electromagnetic field, as well as the propagation loss in a two-dimensional inhomogeneous environment will be described. The impl
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2019-03
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4. Propagation of bichromatic-bidirectional waves
RESUMO Este trabalho tem por objetivo investigar as transformações sobre o nível médio da água e o tensor de tensão de radiação durante a propagação de ondas Bicromáticas e Bidirecionais (Bi-Bi) em um talude 1:22 e profundidades variando de 55 cm a 26 cm, simulando uma bacia de ondas em laboratório. Um modelo matemático escrito em Python foi ut
RBRH. Publicado em: 14/02/2019
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5. Vegetation Image as Bayesian Predictor for Radio Propagation in Complex Environments Using Unscented Transform
Abstract Vegetation is considered a complex environment for analysis of scattering and attenuation in radio propagation phenomena. Satellite image processing can improve planning of radio systems with a vegetation attenuation predictor. In this research, the prediction is based on the correlation of more than 56% between RGB pixel values and vegetation atten
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-06
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6. Comparing blast-induced ground vibration models using ANN and empirical geomechanical relationships
Abstract Blasting remains as an economical and reliable excavation technique, but there are some environmental shortcomings such as the control of blast-induced vibration. The impacts of vibration over surrounding communities in a blast area have been investigated for decades and researchers have been using a myriad of empirical predictive attenuation equati
REM, Int. Eng. J.. Publicado em: 2018-03
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7. A Hybrid Path Loss Prediction Model based on Artificial Neural Networks using Empirical Models for LTE And LTE-A at 800 MHz and 2600 MHz
Abstract This article presents the analysis of a hybrid, error correction-based, neural network model to predict the path loss for suburban areas at 800 MHz and 2600 MHz, obtained by combining empirical propagation models, ECC-33, Ericsson 9999, Okumura Hata, and 3GPP's TR 36.942, with a feedforward Artificial Neural Network (ANN). The performance of the hyb
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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8. Numerical Modelling of Crack Propagation in Cement PMMA: Comparison of Different Criteria
Modelling of a crack propagating through a finite element mesh under mixed mode conditions is of prime importance in fracture mechanics. In this paper, three different crack growth criteria and the respective crack paths prediction in the cement mantle of the reconstructed acetabulum are compared. The maximum tangential stress (MTS) criterion, the minimum st
Mat. Res.. Publicado em: 04/07/2016
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9. Modelling the Hot Flow Behaviors of AZ80 Alloy by BP-ANN and the Applications in Accuracy Improvement of Computations
Hot compressions of as-cast AZ80 magnesium alloy in a wide temperature range of 523-673 K and strain rate range of 0.01-10 s–1 with a height reduction of 60% were conducted by a Gleeble-1500 thermo-mechanical test simulator. The hot flow behaviors show highly non-linear intrinsic relationships with temperature, strain and strain rate. In order to model the
Mat. Res.. Publicado em: 03/11/2015
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10. The Prediction of the Man-Hour in Aircraft Assembly Based on Support Vector Machine Particle Swarm Optimization
ABSTRACT: As the representative of manufacturing industry, aircraft assembly lacks of effective method to forecast man-hour. The forecasting accuracy of existing methods is universally pretty low. On the basis of full analysis of aircraft assembly's feature, this study proposes a forecasting model based on support vector machine (SVM), which is optimized by
J. Aerosp. Technol. Manag.. Publicado em: 2015-03
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11. Neural networks for predicting breeding values and genetic gains
Analysis using Artificial Neural Networks has been described as an approach in the decision-making process that, although incipient, has been reported as presenting high potential for use in animal and plant breeding. In this study, we introduce the procedure of using the expanded data set for training the network. Wealso proposed using statistical parameter
Sci. agric. (Piracicaba, Braz.). Publicado em: 2014-12
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12. A characterization for the constitutive relationships of 42CrMo high strength steel by Artificial Neural Network and its application in isothermal deformation
In hot working process, the prediction of material constitutive relationship can improve the optimization design process. Recently, the artificial neural network models are considered as a powerful tool to describe the elevated temperature deformation behavior of materials. Based on the experimental data from the isothermal compressions of 42CrMo high streng
Mat. Res.. Publicado em: 05/08/2014