Figure 1.

Cumulative confirmed cases divided into two segments using the segmentation algorithm. Japan is the typical country with two waves (red: first segment and green: second segment). (A) Epidemic segmented growth curve of COVID-19 fitted by the logistic model. Estimated parameters were $({\alpha }_1, {\beta }_1, {\gamma }_1, {\alpha }_2, {\beta }_2, {\gamma }_2$) = (16549.7588, 7.8244, 0.1231, 58877.8030, 6.7353, and 0.0859, respectively). (B) Epidemic segmented growth curve of COVID-19 fitted by the Gompertz model. Estimated parameters were $({\alpha }_1, {\beta }_1, {\gamma }_1, {\alpha }_2, {\beta }_2, {\gamma }_2$) = (17,531.5024, 89.4251, 0.0760, 98,622.3568, 15.6933, and 0.0325, respectively).