“…Consequently, an iterative procedure, which provides the selection of the optimal regularization parameter, occurs within each step of the iterative algorithm of Kozlov et al [12] and hence the computational cost of the iterative MFS-based algorithm is increased. To overcome this inconvenience and encouraged by the recent findings of Johansson and Marin [32], as well as similar results obtained for the Cauchy problem associated with the Poisson equation [55], the Laplace equation [56,57], and the Cauchy-Navier system of elasticity [58,59], we decided to employ the two relaxation procedures, as proposed and investigated using the BEM in [32], for the iterative MFS-based algorithm implemented by Marin [52] and study the influence of the relaxation parameter upon the rate of convergence of the modified method. The efficiency of these relaxation procedures is tested for Cauchy problems associated with the two-dimensional modified Helmholtz operator in simply and doubly connected domains with smooth or piecewise smooth boundaries.…”