Calibration procedures for microwave vector comparators

Vieira, Juner M.; Fabiani, B. M.; Silveira, E. S.; Sakomura, Eduardo S.; Oliveira, Fúlvio F.; Nascimento, Daniel C.; Ferreira, Daniel B.; Bianchi, I.

doi:10.1016/j.sna.2021.112955

Cited by 3 publications

(1 citation statement)

References 16 publications

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“…To investigate the sensitivity of the 4 input variables to the UCS of CPB in this paper, the cosine amplitude method is used to perform sensitivity analysis [69][70][71][72]. The sensitivity is calculated in Eq.…”

Section: Sensitivity Analysismentioning

confidence: 99%

A Modeling Method for Predicting the Strength of Cemented Paste Backfill Based on a Combination of Aggregate Gradation Optimization and LSTM

Zhang¹,

Li²,

Zhang³

et al. 2022

Journal of Renewable Materials

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Cemented paste backfill (CPB) is a sustainable mining technology that is widely used in mines and helps to improve the mine environment. To investigate the relationship between aggregate grading and different affecting factors and the uniaxial compressive strength (UCS) of the cemented paste backfill (CPB), Talbol gradation theory and neural networks is used to evaluate aggregate gradation to determine the optimum aggregate ratio. The mixed aggregate ratio with the least amount of cement (waste stone content river sand content = 7:3) is obtained by using Talbol grading theory and pile compactness function and combined with experiments. In addition, the response surface method is used to design strength-specific ratio experiments. The UCS prediction model which uses the LSTM and considers the aggregates gradation have high accuracy. The root mean square error (RMSE) of the prediction results is 0.0914, the coefficient of determination (R 2 ) is 0.9973 and the variance account for (VAF) is 99.73. Compared with back propagation neural network (BP-ANN), extreme learning machine (ELM) and radial basis function neural network (RBF-ANN), LSTM can effectively characterize the nonlinear relationship between UCS and individual affecting factors and predict UCS with high accuracy. The sensitivity analysis of different affecting factors on UCS shows that all 4 factors have significant effect on UCS and sensitivity is in the following ranking: cement content (0.9264) > slurry concentration (0.9179) > aggregate gradation (waste rock content) (0.9031) > curing time (0.9031).

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Section: Sensitivity Analysismentioning

confidence: 99%

A Modeling Method for Predicting the Strength of Cemented Paste Backfill Based on a Combination of Aggregate Gradation Optimization and LSTM

Zhang¹,

Li²,

Zhang³

et al. 2022

Journal of Renewable Materials

View full text Add to dashboard Cite

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Design of High-precision Optical Heterodyne Interferometer Phase Demodulation System

Chen

Xie

Wang

et al. 2022

2022 IEEE International Conference on High Voltage Engineering and Applications (ICHVE)

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Alternative Formulation of Antenna Arrays for DF Systems Considering Active-Element Patterns and Scattering Matrices

Fabiani

Sakomura

Silveira

et al. 2021

Sensors

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Direction finding (DF) systems are used to determine the direction-of-arrival (DoA) of electromagnetic waves, thus allowing for the tracking of RF sources. In this paper, we present an alternative formulation of antenna arrays for modeling DF systems. To improve the accuracy of the data provided by the DF systems, the effects of mutual coupling in the array, polarization of the received waves, and impedance mismatches in the RF front-end receiver are all taken into account in the steering vectors of the DoA algorithms. A closed-form expression, which uses scattering parameter data and active-element patterns, is derived to compute the receiver output voltages. Special attention is given to the analysis of wave polarization relative to the DF system orientation. Applying the formulation introduced here, a complete characterization of the received waves is accomplished without the need for system calibration techniques. The validation of the proposed model is carried out by measurements of a 2.2 GHz DF system running a MUSIC algorithm. Tests are performed with a linear array of printed monopoles and with a planar microstrip antenna array having polarization diversity. The experimental results show DoA estimation errors below 6° and correct classification of the polarization of incoming waves, confirming the good performance of the developed formulation.

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Calibration procedures for microwave vector comparators

Cited by 3 publications

References 16 publications

A Modeling Method for Predicting the Strength of Cemented Paste Backfill Based on a Combination of Aggregate Gradation Optimization and LSTM

A Modeling Method for Predicting the Strength of Cemented Paste Backfill Based on a Combination of Aggregate Gradation Optimization and LSTM

Design of High-precision Optical Heterodyne Interferometer Phase Demodulation System

Alternative Formulation of Antenna Arrays for DF Systems Considering Active-Element Patterns and Scattering Matrices

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