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1

Effects of sampling rate on multiscale entropy of electroencephalogram time series

Zheng Jinlin, Li Yan, Zhai Yawen, Zhang Nan, Yu Haoyang, Tang Chi, Yan Zheng, Luo Erping, Xie Kangning

Biocybernetics and Biomedical Engineering

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2023

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Vol. 43, no. 1

233--245

EN

A physiological system encompasses numerous components that function at various time scales. To characterize the scale-dependent feature, the multiscale entropy (MSE) analysis has been proposed to describe the complex processes on multiple time scales. However, MSE analysis uses the relative scale factors to reveal the time-related dynamics, which may cause in-comparability of results from diverse studies with inconsistent sampling rates. In this study, in addition to the conventional MSE with relative scale factors, we also expressed MSE with absolute time scales (MaSE). We compared the effects of sampling rates on MSE and MaSE of simulated and real EEG time series. The results show that the previously found phenomenon (down-sampling can increase sample entropy) is just the projection of the compressing effect of down-sampling on MSE. And we have also shown the compressing effect of down-sampling on MSE does not change MaSE’s profile, despite some minor right-sliding. In addition, by analyzing a public EEG dataset of emotional states, we have demonstrated improved classification rate after choosing appropriate sampling rate. We have finally proposed a working strategy to choose an appropriate sampling rate, and suggested using MaSE to avoid confusion caused by sampling rate inconsistency. This novel study may apply to a broad range of studies that would traditionally utilize sample entropy and MSE to analyze the complexity of an underlying dynamic process.

2

Sampling Rate Impact on the Tuning of PID Controller Parameters

Laskawski M., Wcislik M.

International Journal of Electronics and Telecommunications

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2016

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Vol. 62, No. 1

43--48

EN

The paper deals with an analysis of automatic control system with continuous and discrete PID controllers. A method of tuning the parameters of the continuous controller is presented, which is optimal according to the ITAE criterion. The behavior of control systems with discrete controllers whose parameters were tuned using the mentioned method are described. The impact of changes in the sampling period of controlled signal on the control quality is shown. Changes of the values of optimal parameters of discrete PID controllers in relation to changes of the sampling rate of controlled signal are characterized.

3

Improved Electrical Measurement Method for Junction Temperature of Light Emitting Diodes

Shen H., Han K., Liu M., Fan S.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 3b

180-184

EN

The electrical test method (ETM) is used to measure the junction temperature Tj of high brightness LEDs. NI 5922 digitizer and Keithley S2400 source meter were used to build the measurement system. Various measurement currents were used under 1MHz sampling rate. Results of different measurement currents are found to be the same under the same sampling rate and measurement error can be found under low sampling rates. When sampling rate is down to 0.2kHz, measurement error is up to 13.7%.

PL

Zaproponowano metodę pomiaru temperatury złącza diody LED. Określono błąd metody dla różnych częstotliwości próbkowania.

4

Analysis of 2-Chloroacetophenone in air by multi-fiber solid-phase microextraction and fast gas chromatography-mass spectrometry

Pacenti M, Dugheri S, Gagliano-Candela R., Strisciullo G, Franchi E, Degli Esposti F, Perchiazzi N., Boccalon P, Arcangeli G, Cupelli V.

Acta Chromatographica

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2009

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Vol. 21, no. 3

379--397

EN

2-Chloroacetophenone (CA) is widely used as tear gas by law-enforcement agents, and by civilians for personal protection. Crimes involving robbery and rape using tear gas sprays have recently increased. Experimental and in-field evaluations have been performed to validate use of solid-phase microextraction (SPME) with a porous fiber for sampling and analysis of CA in air before analysis by fast gas chromatography-mass spectrometry equipped with a new device called a multi-fiber system. CA vapor was generated by use of a syringe pump in a dynamic system in which temperature, relative humidity, and air velocity were monitored. The theoretical sampling rate for time-weighted average and rapid-SPME were, furthermore, estimated by use of the Fuller-Schettler-Giddings diffusion coefficient and the theory of heat transfer, respectively, and were in accordance with experimental values. Concentrations of CA were analyzed in a military store containing tear gas canisters, to evaluate the risk. The results obtained in this field study showed values ranging from 0.206 to 2.46 mg m −3.