“…Furthermore, since there exist reasons and motivations to present the correct solutions to readers, the main purpose of this paper is to adopt the rigorous methods of mathematical analysis in order to develop the complete solution procedures with a view to locating the optimal solution by appropriately removing the shortcomings in the work of Ouyang et al [17]. Several other interesting developments on the subject of our present investigation can be found in a number of related recent works (see, for example, [2], [3], [6][7][8], [10], [14], [15], [18], [19], [21] and [24]). …”