A Method for Determining Intrinsic Mode Function Number in Variational Mode Decomposition and Its Application to Bearing Vibration Signal Processing

Table 5

NMI under different component frequencies.

Signal code	K	Normalized mutual information				Threshold range
S5	3	1.0000	0.1677	0.1452		(0.1426, 0.1452)
	4	1.0000	0.3034	0.2094	0.1426
S6	3	1.0000	0.2993	0.2295		(0.0956, 0.1900)
	4	1.0000	0.3003	0.1900	0.0956
S7	3	1.0000	0.1097	0.0599		No
	4	1.0000	0.2744	0.1185	0.0614
S8	3	1.0000	0.2864	0.1257		(0.0911, 0.1257)
	4	1.0000	0.2675	0.1373	0.0911