283 research outputs found

    Exploiting Group Symmetry in Semidefinite Programming Relaxations of the Quadratic Assignment Problem

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    We consider semidefinite programming relaxations of the quadratic assignment problem, and show how to exploit group symmetry in the problem data. Thus we are able to compute the best known lower bounds for several instances of quadratic assignment problems from the problem library: [R.E. Burkard, S.E. Karisch, F. Rendl. QAPLIB ā€” a quadratic assignment problem library. Journal on Global Optimization, 10: 291ā€“403, 1997]. AMS classification: 90C22, 20Cxx, 70-08.quadratic assignment problem;semidefinite programming;group sym- metry

    A hybrid Tabu search-simulated annealing method to solve quadratic assignment problem

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    Quadratic assignment problem (QAP) has been considered as one of the most complicated problems. The problem is NP-Hard and the optimal solutions are not available for large-scale problems. This paper presents a hybrid method using tabu search and simulated annealing technique to solve QAP called TABUSA. Using some well-known problems from QAPLIB generated by Burkard et al. (1997) [Burkard, R. E., Karisch, S. E., & Rendl, F. (1997). QAPLIBā€“a quadratic assignment problem library. Journal of Global Optimization, 10(4), 391-403.], two methods of TABUSA and TS are both coded on MATLAB and they are compared in terms of relative percentage deviation (RPD) for all instances. The performance of the proposed method is examined against Tabu search and the preliminary results indicate that the hybrid method is capable of solving real-world problems, efficiently

    Problema de asignaciĆ³n quadrĆ”tica (pac) sobre gpu a travĆ©s de una pga maestro-esclavo

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    This document describes the implementation of a Masterā€“Slave Parallel Genetic AlgorithmĀ (PGA) on Graphic Processing Units (GPU) to find solutions or solutions close to optimalĀ solutions to particular instances of the Quadratic Assignment Problem (QAP). The efficiencyĀ of the algorithm is tested on a set of QAPLIB standard library problems.Este documento describe la implementaciĆ³n de un algoritmo genĆ©tico paralelo maestroesclavo (AGP) en unidades de procesamiento grĆ”fico (UPG) para encontrar soluciones oĀ soluciones cercanas a soluciones Ć³ptimas para casos particulares del Problema deĀ asignaciĆ³n CuadrĆ”tica (PAC). La eficiencia del algoritmo se prueba en un conjunto deĀ problemas de la biblioteca estĆ”ndar QAPLIB

    Applications of Bee Colony Optimization

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    Many computationally difficult problems are attacked using non-exact algorithms, such as approximation algorithms and heuristics. This thesis investigates an ex- ample of the latter, Bee Colony Optimization, on both an established optimization problem in the form of the Quadratic Assignment Problem and the FireFighting problem, which has not been studied before as an optimization problem. Bee Colony Optimization is a swarm intelligence algorithm, a paradigm that has increased in popularity in recent years, and many of these algorithms are based on natural pro- cesses. We tested the Bee Colony Optimization algorithm on the QAPLIB library of Quadratic Assignment Problem instances, which have either optimal or best known solutions readily available, and enabled us to compare the quality of solutions found by the algorithm. In addition, we implemented a couple of other well known algorithms for the Quadratic Assignment Problem and consequently we could analyse the runtime of our algorithm. We introduce the Bee Colony Optimization algorithm for the FireFighting problem. We also implement some greedy algorithms and an Ant Colony Optimization al- gorithm for the FireFighting problem, and compare the results obtained on some randomly generated instances. We conclude that Bee Colony Optimization finds good solutions for the Quadratic Assignment Problem, however further investigation on speedup methods is needed to improve its performance to that of other algorithms. In addition, Bee Colony Optimization is effective on small instances of the FireFighting problem, however as instance size increases the results worsen in comparison to the greedy algorithms, and more work is needed to improve the decisions made on these instances

    Comparative Performance of Tabu Search and Simulated Annealing Heuristics for the Quadratic Assignment Problem

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    For almost two decades the question of whether tabu search (TS) or simulated annealing (SA) performs better for the quadratic assignment problem has been unresolved. To answer this question satisfactorily, we compare performance at various values of targeted solution quality, running each heuristic at its optimal number of iterations for each target. We find that for a number of varied problem instances, SA performs better for higher quality targets while TS performs better for lower quality targets
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