“…Since it was first introduced in [12], the empirical mode decomposition (EMD) has been found useful applications in many engineering areas. Recently, EMD related mathematical problems attracted much attention from the mathematical community (cf., [7,16,22,23,24,25,26,29,31,32,33,34,36,37,39]). These studies aim at better understanding the mathematical insight of the algorithm, building a reasonable mathematical foundation for the method and improving upon it.…”