The left and right panels of Figure shows the recovered impedances and DRTs for the PWC model using the hyper-opt, hyper-GCV, and hyper-mGCV methods. For the hyper-opt, hyper-GCV, and hyper-mGCV methods, the recovered impedances and DRTs closely matched the corresponding exact, and the positions of the discontinuities were excellently captured compared to the optimal, GCV, and mGCV methods (see panels (b), (d), and (f) of Figure , respectively).