Before revision:  SUIR model adds a unique U (Undiagnosed) state of the epidemic and divides the population into four states: S (Susceptible), U (Undiagnosed), I (Infectious and Uninfectious), and R (Recovered). This approach enables us to predict the incidence of 2019-nCoV effectively and the clear advantage of the model accuracy more reliable than the traditional SIR model .
After revision:  SUIR model adds a unique U (Undiagnosed) state of the epidemic to estimate effective reproduction number, which addresses the initial susceptible population of the infectious disease model approach to the model accuracy more reliable than the traditional SIR model .