The Quadratic Assignment Problem (QAP) has remained one of the great challenges in combinatorial optimization. It is still considered a computationally nontrivial task to solve modest size problems, say of size n = 20: The QAPLIB was rst published in 1991, in order to provide a uni ed testbed for QAP, accessible to the scienti c community. It consisted of virtually all QAP instances that were a...

The facility layout problem has generally been formulated as a quadratic assignment problem, where the interacting facilities are assigned to the various sites. In this paper a different approach, based on assigning distances between pairs of sites to pairs of facilities, is taken. A network formulation and analysis of this problem is provided. An algorithm, composed of three phases, is develop...

The production of commercial DNA microarrays is based on a light-directed chemical synthesis driven by a set of masks or micromirror arrays. Because of the natural properties of light and the ever shrinking feature sizes, the arrangement of the probes on the chip and the order in which their nucleotides are synthesized play an important role on the quality of the final product. We propose a new...

In this work we present a simple, but effective method of enhancing and exploiting diversity from multiple packet transmissions in systems that employ nonbinary linear modulations such as PSK and QAM. This diversity improvement results from redesigning the symbol mapping for each packet transmission. Using a general framework for evaluating the upper bound of bit error rate (BER) with multiple ...

This paper presents an improved as well as a completely new version of a mixed integer linear programming (MILP) formulation for solving the quadratic assignment problem (QAP) to global optimum. Both formulations work especially well on instances where at least one of the matrices is sparse. Modification schemes, to decrease the number of unique elements per row in symmetric instances, are pres...

Page 55 line 6: replace " among the matched " with " among the unmatched " ; 229 line 13: replace " Palubeckis [544] " with the following (missing) reference: G. Palubeckis. The use of special graphs for obtaining lower bounds in the geometric quadratic assignment problem. 289 eqn (9.27): replace " s ∈ F " with " S ∈ F " ; 308 line 14: replace " approximation algorithms which yield a feasible s...

In this work, we introduce the variance expression for quadratic assignment problem (QAP) costs. We also de;ne classes of QAP instances, described by a common linear relaxation form. The use of the variance in these classes leads to the study of isomorphism and allows for a de;nition of a new di"culty index for QAP instances. This index is then compared to a classical measure found in the liter...

This paper compares some of the most efficient heuristic methods for the quadratic assignment problem. These methods are known as strict taboo search, robust taboo search, reactive taboo search and genetic hybrids. It is shown that the efficiency of these methods strongly depends on the problem type and that no one method is better than all the others. A fast method for tuning the short term me...

An instance of the quadratic assignment problem (QAP) with cost matrix Q is said to be linearizable if there exists an instance of the linear assignment problem (LAP) with cost matrix C such that for each assignment, the QAP and LAP objective function values are identical. The QAP linearization problem can be solved in O(n) time. However, for the special cases of Koopmans-Beckmann QAP and the m...

Program libraries are one tool to make the cooperation between specialists from various elds successful: the separation of application-speci c knowledge from applicationindependent tasks ensures portability, maintenance, extensibility, and exibility. The current paper demonstrates the success in combining problem-speci c knowledge for the quadratic assignment problem (QAP) with the raw computin...