| Abstract: | It has been widely accepted that physical stimulation—such as illumination, music, and environmental variables—that has a 1/f fluctuation power spectrum produces relaxation. There should, however, exist a number of stimulation waveforms that have 1/f power spectral characteristics, and thus the parameters of the waveform in the time domain that cause comfortable biostimulation remain unknown. As a first step in elucidating what kinds of biostimulation waveforms produce relaxation, this paper theoretically derives the CRD (crossing rate distribution: the number of times per second that the amplitude crosses various levels in the positive direction) and APD (amplitude probability distribution) for a Gaussian fluctuation waveform with a 1/f-like power spectrum. Flame fluctuation of candles, which is said to produce a sedative effect, is statistically measured. The findings obtained here show that the flame has a peak crossing rate between 0.08 and 0.4 Hz, fluctuating with a rhythm close to that of blood pressure (0.1 Hz) or breathing (0.25 to 0.33 Hz). © 1998 Scripta Technica. Electr Eng Jpn, 121(4): 48–55, 1997 |
