Abstract
In the time-domain BEM with Haar wavelets for 2-D diffusion problems, the relation between the number of non-zero entries of the coefficient matrices and the degree of freedom(DOF) N is theoretically investigated using the information on the size and the arrangement of the support of the basis functions. The coefficient matrices are compressed using the Beylkin-type level-independent truncation scheme with a DOF-independent prescribed threshold value A. The number of non-zero entries of the matrix G^<(L,p)> and H^<(L,p)> (1 ≤ p ≤ L, L: current time step), N(G^<(L,p)>) and N(H^<(L,p)>), increases in proportion to the factors log N, N^<1/2>, N and N log N, except for the behavior in the smaller DOF range where N(G^<(L,p)>) and N^(H<(L,p)>) 〜 O(N^2).
