Research on Recognition of Quiet Period of Sandstone Acoustic Emission Based on Four Machine Learning Algorithms

Table 1

(a) Data before processing

Time	Amplitude value	Average frequency	RMS	ASL	Inverse calculation frequency	Initial frequency	Center frequency	Peak frequency
1927.6154	46	333	0.0024	30	0	500	224	244
1927.6155	43	30	0.0024	31	1000	22	224	264
1928.6247	50	208	0.0018	28	190	333	217	244
1928.6247	44	429	0.0024	30	400	500	261	295

(b) Preprocessed data

Time	Amplitude value	Average frequency	RMS	ASL	Inverse calculation frequency	Initial frequency	Center frequency	Peak frequency
1927.6154	0.12	0.333	0.037	0.45283	0	0.49750	0.7320	0.6893
1927.6155	0.06	0.03	0.037	0.4717	1	0.01710	0.7320	0.7457
1928.6247	0.2	0.208	0.027	0.4151	0.19	0.3296	0.7091	0.6893
1928.6219	0.08	0.429	0.037	0.4528	0.4	0.49750	0.85294	0.8333