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Novel hybrid approaches based on evolutionary strategy for streamfow forecasting in the Chellif River, Algeria

Zakhrouf Mousaab, Bouchelkia Hamid, Stamboul Madani, Kim Sungwon

Acta Geophysica

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2020

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Vol. 68, no. 1

167--180

EN

In this study, the feedforward neural networks (FFNNs) were proposed to forecast the multi-day-ahead streamfow. The parameters of FFNNs model were optimized utilizing genetic algorithm (GA). Moreover, discrete wavelet transform was utilized to enhance the accuracy of FFNNs model’s forecasting. Therefore, the wavelet-based feedforward neural networks (WFFNNs-GA) model was developed for the multi-day-ahead streamfow forecasting based on three evolutionary strategies [i.e., multi-input multi-output (MIMO), multi-input single-output (MISO), and multi-input several multi-output (MISMO)]. In addition, the developed models were evaluated utilizing fve diferent statistical indices including root mean squared error, signal-to-noise ratio, correlation coefcient, Nash–Sutclife efciency, and peak fow criteria. Results provided that the statistical values of WFFNNs-GA model based on MISMO evolutionary strategy were superior to those of WFFNNs-GA model based on MISO and MIMO evolutionary strategies for the multi-day-ahead streamfow forecasting. Results indicated that the performance of WFFNNs-GA model based on MISMO evolutionary strategy provided the best accuracy. Results also explained that the hybrid model suggested better performance compared with stand-alone model based on the corresponding evolutionary strategies. Therefore, the hybrid model can be an efcient and robust implement to forecast the multi-day-ahead streamfow in the Chellif River, Algeria.

2

The configuration of current-mode single-input multi-output, multi-input single-output biquad filter and quadrature oscillator based-on BiCMOS CCCTAs

Jantakun A.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 7

102--107

EN

The current-mode single-input multi-output, multi-input single-output biquad filter and quadrature oscillator for the same configuration has been studied in this paper. It is configured with two BiCMOS CCCTAs and two grounded capacitors. The performing of proposed configuration can function as the single-input multi-output and multi-input single-output filter. It serves to be all standard functions; lowpass, highpass, bandpass, bandreject and allpass response. The pole frequency and the quality factor can be electronically/independently tuned with the DC bias currents of the BiCMOS CCCTAs. Furthermore, the proposed configuration can be operates in the quadrature oscillator. It has been featured as the condition of oscillation and the frequency of oscillation are freely adjusted with the DC bias currents of the BiCMOS CCCTAs. The performances for proposed configuration is simulated with PSPICE program that accordance to the theoretical analysis.

PL

W pracy przedstawiono układ umożliwiający realizację prądowego filtru czwartego stopnia z jednym wejściem i wieloma wyjściami oraz z jednym wyjściem i wieloma wejściami. Ten sam układ umożliwia realizację układu generatora. Układ wykporzystuje dwa obwpody BiCMOS CCCTAs i dwa uziemione kondensatory.

3

Current-mode multi-input single-output filter based on CCCDTAs

Kinnaree P., Sa-Ngiamvibool W.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 3

201--206

EN

This paper presents three current-mode multi-input single-output filters based on the current controlled current differencing transconductance amplifier (CCCDTA). They can be set to serve as standard filter functions. The pole frequency and quality factor parameters are such that filters can be electronically controlled and independently tuned via input bias current of the CCCDTAs. All output filters have highimpedances in current-mode configuration. Their performances were simulated by using PSPICE which resulted in a correlation with the theoretical prediction.

PL

W artykule zaprezentowano trzy filtry bazujące na current controlled current differencing transconductance amplifier CCCDTA. Filtry mogą być strojone za pośrednictwem wejścuowego prądu bias układu CCCDTA.