Before revision:  Our pricing problem is derived to a solving problem of inhomogeneous  Black-Scholes PDEs with different coefficients and terminal value of binary type in every subinterval between the two adjacent announcing dates.
After revision:  Our pricing problem is derived to a solving problem of inhomogeneous or homogeneous Black-Scholes PDEs with different coefficients and terminal value of binary type in every subinterval between the two adjacent announcing dates.