“…The bounds u j of variables x j are integers such that u j ≤ ( c j 2d j ) because of the concavity of each f j , x * j ≤ ( c j 2d j ), where x * j is the optimal solution of the program max x j ≥0 f j (x j ). Problem (QMKP ) has wide applications, including financial models [4] (Djerdjour et al, 1988), [5] (Faaland, 1974) production and inventory management [2] (Bretthauer and Shetty, 2002). However, most of the knapsack problems literature has addressed attention to specialized versions.…”