INDEX high-frequency performance

NATIONAL INSTRUMENTS, Texas, USA), and were stored on the hard disk of a personal computer. With recorded EGG signal, R-R intervals (RRI) were calculated using a cross-correlation fimetion to detect R waves. And analysis of time series of RRI to estimate heart rate variability (HRV) was performed with STFT as well as analysis of EGG. Indexes of HRV were defined as below. The component of low frequency (LF) and high frequency (HE) were given as area of frequency spectrum from 0.05 to 0.15 Hz and 0.15 to 0.4 Hz respectively, and then ratio of LF to HE (LF/HF) reflects the activity of sympathetic nervous system and HE reflects the activity of parasympathetic nervous system. Obtained time series of HE and LF/HF were divided for sub-periods as well as DP and DF. 

In addition to the above prescriptions, many other quantities such as solution phase ionization potentials (IPs) [15], nuclear magnetic resonance (NMR) chemical shifts and IR absorption frequencies [16-18], charge decompositions [19], lowest unoccupied molecular orbital (LUMO) energies [20-23], IPs [24], redox potentials [25], high-performance liquid chromatography (HPLC) [26], solid-state syntheses [27], Ke values [28], isoelectrophilic windows [29], and the harmonic oscillator models of the aromaticity (HOMA) index [30], have been proposed in the literature to understand the electrophilic and nucleophilic characteristics of chemical systems. 

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