Grey Relation Evaluation and Truth Value Fusion of Rolling Bearing Multisource Residual Stress

Table 1

Selection of the number of groups.

Sample size	Number of groups
50∼60	6∼8
60∼100	7∼10
100∼200	9∼12
200∼500	12∼17
500	20
Computer simulation	1.87 (B − 1)^2.5