The aim of this paper is to solve a free boundary problem arising in pricing Americanput options.It is known that the fr......

在时域内对弹性波动方程退化的非均匀介质声波方程，引入背景场参数与扰动参数，并化为积分方程形式；针对脉冲源情况，根据射线理论中的传......