No abstract

Nature-inspired metaheuristic algorithms, especially those based on swarm intelligence, have attracted much attention in the last ten years. Firefly algorithm appeared in about five years ago, its literature has expanded dramatically with diverse applications. In this paper, we will briefly review the fundamentals of firefly algorithm together with a selection of recent publications. Then, we discuss the optimality associated with balancing exploration and exploitation, which is essential for all metaheuristic algorithms. By comparing with intermittent search strategy, we conclude that metaheuristics such as firefly algorithm are better than the optimal intermittent search strategy. We also analyse algorithms and their implications for higher-dimensional optimization problems.

No abstract

No abstract

Bat algorithm is a population metaheuristic proposed in 2010 which is based on the echolocation or bio-sonar characteristics of microbats. Since its first implementation, the bat algorithm has been used in a wide range of fields. In this paper, we present a discrete version of the bat algorithm to solve the well-known symmetric and asymmetric traveling salesman problems. In addition, we propose an improvement in the basic structure of the classic bat algorithm. To prove that our proposal is a promising approximation method, we have compared its performance in 37 instances with the results obtained by five different techniques: evolutionary simulated annealing, genetic algorithm, an island based distributed genetic algorithm, a discrete firefly algorithm and an imperialist competitive algorithm. In order to obtain fair and rigorous comparisons, we have conducted three different statistical tests along the paper: the Student's ttest, the Holm's test, and the Friedman test. We have also compared the convergence behaviour shown by our proposal with the ones shown by the evolutionary simulated annealing, and the discrete firefly algorithm. The experimentation carried out in this study has shown that the presented improved bat algorithm outperforms significantly all the other alternatives in most of the cases.

No abstract

This paper introduces a new variant of the popukir 'i-dimensional hypercube network Q^. known as the K-dimensional locally twisted cube LTQ,,, which has ihe same number of nodes and ihe same number of connections per node as Q,,, Kurlhcrmoro. LTQ,, is similar lo Q,, in the sense Ihat the nodes can be one-to-one labeled with i)-\ binary sequences of length n, so ihal the lalwls of any two adjacent nodes differ in at most two successive hits. One advantage of LTQ,, is that the diameter is only about half of ihe diameter ot C?n • We develop a simple routing algorithm tor LTQ,,. which creates a shoiiest path from the source to the destination in 0[n) time. We find Ihat LTy,, consists of two disjoint copies of Q,,-j by adding a matching between their nodes. On this basis, we show that LTQn has a connectivity of n.

No abstract