A grouped double link data structure corresponding to element inserting coefficient (EIC) is presented to eliminate the search for the maximum EIC element in the point-by-point center insertion algorithm.

The algorithm of computerized tomography(CT) inversion method is used to reconstruct a 1-D image of shear wave velocity around a borehole The adopted geologic model of node velocity interpolation element is superior to the conventional methods for calculating s_wave velocity An engineering example is given in the pape