Wenbo Xu

Quantum-behaved particle swarm optimization with mutation operator

The mutation mechanism is introduced into quantum-behaved particle swarm optimization to increase its global search ability and escape from local minima. Based on the characteristic of QPSO algorithm, the variable of gbest and mbest is mutated with Cauchy distribution respectively. The experimental results on test functions show that QPSO with gbest and mbest mutation both performs better than PSO and QPSO without mutation

Parameter selection of quantum-behaved particle swarm optimization

Particle Swarm Optimization (PSO) is a population-based evolutionary search technique, which has comparable performance with Genetic algorithm. The existing PSOs, however, are not global-convergence-guaranteed algorithms, because the evolution equation of PSO, make the particle only search in a finite sampling space. In [10,11], a Quantum-behaved Particle Swarm Optimization algorithm is proposed that outperforms traditional PSOs in search ability as well as having less parameter. This paper focuses on discussing how to select parameter when QPSO is practically applied. After the QPSO algorithm is described, the experiment results of stochastic simulation are given to show how the selection of the parameter value influences the convergence of the particle in QPSO. Finally, two parameter control methods are presented and experiment results on the benchmark functions testify their efficiency.

Quantum-Behaved particle swarm optimization with adaptive mutation operator

In this paper, the mutation mechanism is introduced into Quantum-behaved Particle Swarm Optimization (QPSO) to increase the diversity of the swarm and then effectively escape from local minima to increase its global search ability. Based on the characteristic of QPSO algorithm, the two variables, global best position (gbest) and mean best position (mbest), are mutated with Cauchy distribution respectively. Moreover, the amend strategy based on annealing is adopted by the scale parameter of mutation operator to increase the self-adaptive capability of the improved algorithm. The experimental results on test functions showed that QPSO with gbest and mbest mutation both performs better than PSO and QPSO without mutation.

Using quantum-behaved particle swarm optimization algorithm to solve non-linear programming problems

In this paper, we focus on solving non-linear programming (NLP) problems using quantum-behaved particle swarm optimization (QPSO). After a brief introduction to the original particle swarm optimization (PSO), we describe the origin and development of QPSO, and the penalty function method for constrained NLP problems. The performance of QPSO is tested on some unconstrained and constrained benchmark functions and compared with PSO with inertia weight (PSO-In) and PSO with constriction factor (PSO-Co). The experimental results show that QPSO outperforms the traditional PSOs and is a promising optimization algorithm.

Quantum-Behaved Particle Swarm Optimization with Binary Encoding

The purpose of this paper is to generalize Quantum-behaved Particle Swarm Optimization (QPSO) Algorithm to discrete binary search space. To design Binary QPSO (BQPSO), we redefine the position vector and the distance between two positions, and adjust the iterative equations of QPSO to binary search space. The operations designed for BQPSO are far different from those in BPSO, but somewhat like those in Genetic Algorithms (GAs). Therefore, BQPSO integrates strongpoint of GA with the features of PSO, which make it able to find out the global optimum of the problem more efficiently than BPSO, as shown by the experiment results of BQPSO and BPSO on De Jongs five test functions.

Quantum-Behaved particle swarm optimization algorithm with controlled diversity

Premature convergence, the major problem that confronts evolutionary algorithms, is also encountered with the Particle Swarm Optimization (PSO) algorithm. In the previous work [11], [12], [13], the Quantum-behaved Particle Swarm (QPSO) is proposed. This novel algorithm is a global-convergence-guaranteed and has a better search ability than the original PSO. But like other evolutionary optimization technique, premature in the QPSO is also inevitable. In this paper, we propose a method of controlling the diversity to enable particles to escape the sub-optima more easily. Before describing the new method, we first introduce the origin and development of the PSO and QPSO. The Diversity-Controlled QPSO, along with the PSO and QPSO is tested on several benchmark functions for performance comparison. The experiment results testify that the DCQPSO outperforms the PSO and QPSO.

A Novel and More Efficient Search Strategy of Quantum-Behaved Particle Swarm Optimization

Based on the previous proposed Quantum-behaved Particle Swarm Optimization (QPSO), in this paper, a novel and more efficient search strategy with a selection operation is introduced into QPSO to improve the search ability of QPSO. While the center of position distribution of each particle in QPSO is determined by global best position and personal best position, in the Modified QPSO (MQPSO), the global best position is substituted by a personal best position of a randomly selected particle. The MQPSO also maintains the mean best position of the swarm as in the previous QPSO to make the swarm more efficient in global search. The experiment results on benchmark functions show that MQPSO has stronger global search ability than QPSO and PSO.

Improving quantum-behaved particle swarm optimization by simulated annealing

Quantum-behaved Particle Swarm Optimization (QPSO) is a global convergence guaranteed search method, which introduced quantum theory into original Particle Swarm Optimization (PSO). While Simulated Annealing (SA) is another important stochastic optimization with the ability of probabilistic hill-climbing. In this paper, the mechanism of Simulated Annealing is introduced into the weak selection implicit in our QPSO algorithm, which effectively employs both the ability to jump out of the local minima in Simulated Annealing and the capacity of searching the global optimum in QPSO algorithm. The experimental results show that the proposed hybrid algorithm increases the diversity of the population in the search process and improves its precision in the latter period of the search.

Analysis of Adaptive IIR Filter Design Based on Quantum-behaved Particle Swarm Optimization

Adaptive infinite impulse response (IIR) filters have a wide range of applications such as channel equation, echo canceling and system identification. As the error surface of IIR filters is usually multi-modal, it is necessary to use global optimization techniques to avoid local minima. In this paper, we applied our previously proposed global optimization algorithm, called quantum-behaved particle swarm optimization (QPSO), to design IIR filters. The quantum behaving in physics and particle swarm optimization had combined to form the new method. The method has some typical characteristic, such as fast convergence rate, global convergence ability, simple coding and easily programming etc, which is proved by simulation experiments at last

Design IIR digital filters using quantum-behaved particle swarm optimization

Design IIR digital filters with arbitrary specified frequency is a multi-parameter optimization problem. In this paper, we employ our proposed method, Quantum-behaved Particle Swarm Optimization (QPSO), to solve the IIR digital filters design problem. QPSO, which is inspired by the fundamental theory of Particle Swarm Optimization and quantum mechanics, is a global convergent stochastic searching technique. The merits of the proposed method such as global convergent, robustness and rapid convergence are demonstrated by the experiment results on the low-pass and band-pass IIR filters.