%0 Journal Article %T Effect of Population Structures on Quantum-Inspired Evolutionary Algorithm %A Nija Mani %A Gursaran Srivastava %A A. K. Sinha %A Ashish Mani %J Applied Computational Intelligence and Soft Computing %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/976202 %X Quantum-inspired evolutionary algorithm (QEA) has been designed by integrating some quantum mechanical principles in the framework of evolutionary algorithms. They have been successfully employed as a computational technique in solving difficult optimization problems. It is well known that QEAs provide better balance between exploration and exploitation as compared to the conventional evolutionary algorithms. The population in QEA is evolved by variation operators, which move the Q-bit towards an attractor. A modification for improving the performance of QEA was proposed by changing the selection of attractors, namely, versatile QEA. The improvement attained by versatile QEA over QEA indicates the impact of population structure on the performance of QEA and motivates further investigation into employing fine-grained model. The QEA with fine-grained population model (FQEA) is similar to QEA with the exception that every individual is located in a unique position on a two-dimensional toroidal grid and has four neighbors amongst which it selects its attractor. Further, FQEA does not use migrations, which is employed by QEAs. This paper empirically investigates the effect of the three different population structures on the performance of QEA by solving well-known discrete benchmark optimization problems. 1. Introduction Evolutionary algorithms (EAs) represent a class of computational techniques, which draw inspiration from nature [1] and are loosely based on the Darwinian principle of ˇ°survival of the fittestˇ± [2¨C4]. EAs have been successfully applied in solving wide variety of real life difficult optimization problems (i.e., problems which do not have efficient deterministic algorithms for solving them, yet known) and where near optimal solutions are acceptable (as EAs do not guarantee finding optimal solutions). Moreover, EAs are not limited by the requirements of domain specific information as in the case of traditional calculus based optimization techniques [5]. EAs, typically, maintain a population of candidate solutions, which compete for survival from one generation to the next, and, with the generation of new solutions by employing the variation operators like crossover, mutation, rotation gate, and so forth, the population gradually evolves to contain the optimal or near optimal solutions. EAs are popular due to their simplicity and ease of implementation. However, EAs suffer from convergence issues like stagnation, slow convergence, and premature convergence [6]. Efforts have been made by researchers to overcome the convergence issues by %U http://www.hindawi.com/journals/acisc/2014/976202/