Global Prediction System of the COVID-19 Pandemic
The second version of Global prediction system for COVID-19 pandemic (GPCP) use a more complex modified SEIR model. The modified SEIR model defines six states of the crowd: susceptible cases (S), insusceptible cases (P), potentially infected cases (E, infected cases in a latent period), infectious cases (I, infected cases that have not been quarantined), quarantined cases (Q, confirmed and quarantined cases), recovered cases and death cases (R). The sum of the six categories is equal to the total population (N) at any time :
The model is consisted of the following equations:
In the second version of the model we have introduced the timing of community reopening. Indicated by the daily new cases on the day of reopening (dQc), the local government can start to lift the blockade when the number of newly confirmed cases on a given day is lower than dQc. The consideration of factors such as community reopening and citizen self-quarantine in the model makes the prediction more accurate.
