“…It is well known that if there exists a ðv; G; Þ-GD, then v ! n vðv À 1Þ 0 ðmod 2eÞ ðv À 1Þ 0 ðmod dÞ : where n ¼ jVðGÞj; e ¼ jEðGÞj; and d is the greatest common divisor of all the degrees of the vertices in G. For some simple graphs, such as path, star, cycle, k-cube, and the graphs with at most five vertices, the existence of their graph designs has been solved (see [1][2][3][4][5][6][7][8], [10][11]). Especially, for the path P k of k vertices, we have the following result.…”