“…However, this impulse response function overestimates a non-causality because of the dispersion relation [26]. To obtain more accurate prediction results, the impulse response function using the dispersion relation of finitedepth water ω|ω| = k tanh k is examined [26,28]. As it is difficult to obtain a single solution valid for the whole time domain, the time domain is divided into three parts, and analytical solutions on respective time domains are obtained [26].…”