This paper reports on a new algorithm for the Generalized Quadratic Assignment problem (GQAP). The GQAP describes a broad class of quadratic integer programming problems, wherein M pairwise related entities are assigned to N destinations constrained by the destinations’ ability to accommodate them. This new algorithm is based on a Reformulation Linearization Technique (RLT) dual ascent procedur...

In this paper we discuss two particular layout problems, namely the Single-Row Equidistant Facility Layout Problem (SREFLP) and the Single-Row Facility Layout Problem (SRFLP). Our aim is to consolidate the two respective branches in the layout literature. We show that the (SREFLP) is not only a special case of the Quadratic Assignment Problem but also a special case of the (SRFLP). This new con...

Reducing manufacturing lead times and minimizing work-in-process (WIP) inventories are the cornerstones of popular manufacturing strategies such as Lean, Quick Response, and Just-inTime Manufacturing. In this paper, we present a model that captures the relationship between facility layout and congestion-related measures of performance. We use the model to introduce a formulation of the facility...

In this paper, we discuss analog neural approaches to the quadratic assignment problem (QAP). These approaches employ a hard constraints scheme to restrict the domain space, and are able to obtain much improved solutions over conventional neural approaches. Since only a few strong heuristics for QAP have been known to date, our approaches are good alternatives, capable of obtaining fairly good ...

The Max-Profit Generalized Assignment Problem (Max-GAP) is: given sets J of bins and I of items, where each j ∈ J has capacity c(j) and each i ∈ I has in bin j size `(i, j) and profit p(i, j), find a maximum profit feasible assignment. The problem admits a 1/2-approximation algorithm. Our main result is a (1− 1/e)-approximation algorithm for Max-GAP with fixed profits when each i ∈ I has a fixe...

Let A = {a1, a2, . . . , as} and {b1, b2, . . . , bt} be two sets of objects with s + r = n, the generalized assignment problem assigns each element ai ∈ A to at least αi and at most α ′ i elements in B, and each element bj ∈ B to at least βj and at most β ′ j elements in A for all 1 ≤ i ≤ s and 1 ≤ j ≤ t. In this paper, we present an O(n) time and O(n) space algorithm for this problem using th...

Using the recently proposed model of combinatorial landscapes: local optima networks, we study the distribution of local optima in two classes of instances of the quadratic assignment problem. Our results indicate that the two problem instance classes give rise to very different configuration spaces. For the so-called real-like class, the optima networks possess a clear modular structure, while...

This paper is concerned with automated tuning of parameters of algorithms to handle heterogeneous and large instances. We propose an automated parameter tuning framework with the capability to provide instance-specific parameter configurations. We report preliminary results on the Quadratic Assignment Problem (QAP) and show that our framework provides a significant improvement on solutions qual...