Figure 3: Monthly morbidity sequence and transformation of brucellosis in Jinzhou from 2004 to 2013. (a) Original time sequence. The original time sequence took up a upward or downward trend with a seasonal cycle rule, which was not smooth and had unequal variances. (b) Transformed time sequence. The original sequence was transformed into a random one by square-root transformation, once common difference, and once seasonal difference successively. ADF test: t = −8.66 and ; the trend of time sequence turned random and stationary.