TABU SEARCH TECHNIQUES FOR THE

Summary Assigning items to sets such that a quadratic function is minimized may be referred to as the quadra­ tic semi-assignment problem. This problem indeed is a relaxed versioo of the well known quadratic assignment problem. Applications may be found in floor layout planning, in certain median problems with mutual communicatioo, and in the problem of schedule synchrooization in public transit networks. The same problem also arises in certain scheduling problems where the deviation from due dates is penalized by a quadratic function. In this paper we compare different improvement procedures for the quadratic semi-assignment problem. The main contribution will be to explore detailed tabu search techniques with respect to this specific problem and, in addition, to compare them with simulated annealing.