... concept of logtransformation of sample variance, Chang and Gan (1995) suggest a CUSUM scheme based on ln (S 2 ),which performs as well as the corresponding EWMA. Performances of Chang and ... Interna-tional Journal of Production Research, 30(7), 1655-1669.Ho, E. S. and Chang, S. I. (1999) An integrated neural network approach for simultaneous monitoring of process mean and variance shifts — ... sure the performance of the joined chart is satisfactory, we can adjust the parameters (Cm1, Cm2) of M-NN and (Cv1, Cv2) of V-NN for the two-in-a-row decision rule. The performance criterion...