What's the function of eduction ?

The elementary concept of numerical simulation of wave motion in the time domain is discussed systematically by analyzing the one-dimensional seismic response of a soil layer. The relationship between the accurate radiation condition of the simulating bedrock underlying soil layers and a multi-transmitting formula is clarified, and a simplified method of simulating accurate radiation condition is presented. By connecting the boundary condition and finite element equations of motion, an uncoupling finite element algorithm, which is used to calculate seismic response of semi-infinite soil layers, is presented. The numerical simulation of the algorithm is...