“…Multivariate statistical methods such as principal component analysis (PCA), independent component analysis (ICA) and partial least square (PLS) have been widely applied in chemical industry for fault diagnosis (Chen & Chen, 2006;Detroja, Gudi, Patwardhan, & Roy, 2006;Lee, Han, & Yoon, 2004;Lieftucht, Kruger, & Irwin, 2006;Zuo, Lin, & Fan, 2005). Among these methods, PCA is the most popular one.…”