Before revision:  Our  model is a time-dependent susceptible-infected-recovered (SIR) model that tracks two time series : (i) the transmission rate at time t and (ii) the recovering rate at time t.
After revision:  Our first model is a time-dependent susceptible-infected-recovered (SIR) model that tracks two time series : (i) the transmission rate at time t and (ii) the recovering rate at time t.