Table 5.

Several performance indexes of three methods on the testing set.

Methods	RMSE	R2	Number of Selected Parameters	Number of Sensor Channels Involved
The PCC-based method	98.339	−0.198	33	5
The PCA-based method	94.665	−0.5768	175	7
The mRMR-based method	53.268	0.598	19	5
The proposed method	24.711	0.988	11	2