基于离散微粒群算法求解背包问题研究

微粒群算法(PSO)是一种新的演化算法,主要用于求解数值优化问题.基于离散微粒群算法(DPSO)分别与处理约束问题的罚函数法和贪心变换方法相结合,提出了求解背包问题的两个算法:基于罚函数策略的离散微粒群算法(PFDPSO)和基于贪心变换策略的离散微粒群算法(GDPSO).通过将这两个算法与文献[7]中的混合微粒群算法(Hybrid_PSO)进行数值计算比较发现:对于求解大规模的背包问题,GDPSO非常优秀,其求解能力优于Hybrid_PSO和PFDPSO,是求解背包问题的一种非常有效的方法.     

基于扩散机制的双种群粒子群优化算法*

为了避免标准粒子群优化算法（PSO）过早收敛的缺点,把热力学中的扩散现象引入到PSO算法的改进当中,提出了基于扩散机制的双种群粒子群优化算法(DPSO)。DPSO算法中定义了粒子的扩散能、种群的温度和粒子的扩散概率三个概念,两个群体中的粒子在进化过程中根据粒子的扩散概率被选入到各自种群的扩散池中,从而实现两个种群之间信息的交换和共享。通过解决典型的多峰、高维函数优化问题来证实DPSO算法的有效性,实验结果表明DPSO比标准PSO具有更高的性能。     

Particle swarm optimization with justification and designed mechanisms for resource-constrained project scheduling problem

The studied resource-constrained project scheduling problem (RCPSP) is a classical well-known problem which involves resource, precedence, and temporal constraints and has been applied to many applications. However, the RCPSP is confirmed to be an NP-hard combinatorial problem. Restated, it is hard to be solved in a reasonable time. Therefore, there are many metaheuristics-based schemes for finding near optima of RCPSP were proposed. The particle swarm optimization (PSO) is one of the metaheuristics, and has been verified being an efficient nature-inspired algorithm for many optimization problems. For enhancing the PSO efficiency in solving RCPSP, an effective scheme is suggested. The justification technique is combined with PSO as the proposed justification particle swarm optimization (JPSO), which includes other designed mechanisms. The justification technique adjusts the start time of each activity of the yielded schedule to further shorten the makespan. Moreover, schedules are generated by both forward scheduling particle swarm and backward scheduling particle swarm in this work. Additionally, a mapping scheme and a modified communication mechanism among particles with a designed gbest ratio (GR) are also proposed to further improve the efficiency of the proposed JPSO. Simulation results demonstrate that the proposed JPSO provides an effective and efficient approach for solving RCPSP.     

A novel discrete particle swarm optimization algorithm for meta-task assignment in heterogeneous computing systems

Optimal assignment of a meta-task in heterogeneous computing systems is NP-complete in the general case. Therefore, heuristic approaches must be employed to find good solutions within a reasonable time. We propose a novel discrete particle swarm optimization (DPSO) algorithm for this problem. Firstly, to make particle swarm optimization algorithm more suitable for solving task assignment problems, particles are represented as integer vectors and a new position update method is developed based on discrete domain. Secondly, an effective variable neighborhood descent algorithm is applied to emphasize exploitation. In addition, migration mechanism is introduced with the hope to escape from possible local optimum and to balance the exploration and exploitation. Computational simulations and comparisons based on a set of benchmark instances indicate that the proposed DPSO algorithm is a viable approach for the task assignment problem.     

Discrete particle swarm optimization method for the large-scale discrete time–cost trade-off problem

Despite many research studies have concentrated on designing heuristic and meta-heuristic methods for the discrete time–cost trade-off problem (DTCTP), very little success has been achieved in solving large-scale instances. This paper presents a discrete particle swarm optimization (DPSO) to achieve an effective method for the large-scale DTCTP. The proposed DPSO is based on the novel principles for representation, initialization and position-updating of the particles, and brings several benefits for solving the DTCTP, such as an adequate representation of the discrete search space, and enhanced optimization capabilities due to improved quality of the initial swarm. The computational experiment results reveal that the new method outperforms the state-of-the-art methods, both in terms of the solution quality and computation time, especially for medium and large-scale problems. High quality solutions with minor deviations from the global optima are achieved within seconds, for the first time for instances including up to 630 activities. The main contribution of the proposed particle swarm optimization method is that it provides high quality solutions for the time–cost optimization of large size projects within seconds, and enables optimal planning of real-life-size projects.     

An effective hybrid particle swarm optimization algorithm for multi-objective flexible job-shop scheduling problem

Flexible job-shop scheduling problem (FJSP) is an extension of the classical job-shop scheduling problem. Although the traditional optimization algorithms could obtain preferable results in solving the mono-objective FJSP. However, they are very difficult to solve multi-objective FJSP very well. In this paper, a particle swarm optimization (PSO) algorithm and a tabu search (TS) algorithm are combined to solve the multi-objective FJSP with several conflicting and incommensurable objectives. PSO which integrates local search and global search scheme possesses high search efficiency. And, TS is a meta-heuristic which is designed for finding a near optimal solution of combinatorial optimization problems. Through reasonably hybridizing the two optimization algorithms, an effective hybrid approach for the multi-objective FJSP has been proposed. The computational results have proved that the proposed hybrid algorithm is an efficient and effective approach to solve the multi-objective FJSP, especially for the problems on a large scale.     

批量无等待调度问题的微粒群蛙跳混合优化算法*

将离散微粒群与蛙跳算法相结合解决以最大完工时间为指标的批量无等待流水线调度问题.结合微粒群算法较强的全局收敛能力和蛙跳算法较强的深度搜索能力,设计了三种混合算法,平衡了算法的全局开发能力和局部探索能力.对随机生成不同规模的实例进行了广泛的实验,仿真实验结果的比较表明了所得混合算法的有效性和高效性.     

A hybrid particle swarm optimization algorithm for the vehicle routing problem

This paper introduces a new hybrid algorithmic nature inspired approach based on particle swarm optimization, for successfully solving one of the most popular supply chain management problems, the vehicle routing problem. The vehicle routing problem is considered one of the most well studied problems in operations research. The proposed algorithm for the solution of the vehicle routing problem, the hybrid particle swarm optimization (HybPSO), combines a particle swarm optimization (PSO) algorithm, the multiple phase neighborhood search–greedy randomized adaptive search procedure (MPNS–GRASP) algorithm, the expanding neighborhood search (ENS) strategy and a path relinking (PR) strategy. The algorithm is suitable for solving very large-scale vehicle routing problems as well as other, more difficult combinatorial optimization problems, within short computational time. It is tested on a set of benchmark instances and produced very satisfactory results. The algorithm is ranked in the fifth place among the 39 most known and effective algorithms in the literature and in the first place among all nature inspired methods that have ever been used for this set of instances.     

基于QPSO算法的单阶段投资组合优化

投资组合优化问题是NP难解问题,通常的方法很难较好地接近全局最优.在经典微粒群算法(PSO)的基础上,研究了基于量子行为的微粒群算法(QPSO)的单阶段投资组合优化方法,具体介绍了依据目标函数如何利用QPSO算法去寻找最优投资组合.在具体应用中,为了提高算法的收敛性和稳定性对算法进行了改进.利用真实历史数据进行验证,结果表明在解决单阶段投资组合优化问题时,基于QPSO算法的投资组合优化的性能比PSO算法更加优越,且QPSO算法在投资组合优化领域具有很大的实际应用价值.     

二进制粒子群优化算法在化工优化问题中的应用

优化问题是化工过程的一个主要问题,而由化工问题建模所得到的优化问题大多较为复杂,此时要求的优化算法具有良好的优化性能。粒子群优化算法是新近发展起来的一种优化算法,但其对多极值函数的优化时,易陷局部极值。本文在分析粒子群优化算法的机理、考虑二进制比十进制更易于学习等的基础上,提出采用二进制表示粒子群优化算法,使每个粒子更易于从个体极值与全局极值中学习,从而使算法具有更强的搜索能力与更快的收敛速度,性能测试说明了所提出的算法是有效的．最后将算法用于求解换热网络的优化问题,取得良好效果。     

An improved cooperative quantum-behaved particle swarm optimization

Particle swarm optimization (PSO) is a population-based stochastic optimization. Its parameters are easy to control, and it operates easily. But, the particle swarm optimization is a local convergence algorithm. Quantum-behaved particle swarm optimization (QPSO) overcomes this shortcoming, and outperforms original PSO. Based on classical QPSO, cooperative quantum-behaved particle swarm optimization (CQPSO) is present. This CQPSO, a particle firstly obtaining several individuals using Monte Carlo method and these individuals cooperate between them. In the experiments, five benchmark functions and six composition functions are used to test the performance of CQPSO. The results show that CQPSO performs much better than the other improved QPSO in terms of the quality of solution and computational cost.     

A two-stage discrete particle swarm optimization for the problem of multiple multi-level redundancy allocation in series systems

Nowadays, the redundancy allocation problem (RAP) is increasingly becoming an important tool in the initial stages of or prior to planning, designing, and control of systems. The multiple multi-level redundancy allocation problem (MMRAP) is an extension of the traditional RAP such that all available items for redundancy (system, module and component) can be simultaneously chosen. In this paper, a novel particle swarm optimization algorithm (PSO) called the two-stage discrete PSO (2DPSO) is presented to solve MMRAP in series systems such that some subsystems or modules consist of different components in series. To the best of our knowledge, this is the first attempt to use a PSO to MMRAP. The proposed PSO used a totally new, very simple, effective and efficient mechanism to move to the next position without velocity. The result obtained by 2DPSO has been compared with those obtained by genetic algorithm (GA) and binary PSO (BPSO). Computational results show that the proposed 2DPSO is very competitive and performs well in the number of times it finds the best solutions, the average numbers of the earliest finding of the best solutions, and computation times.     

A hybrid meta-heuristic algorithm for optimization of crew scheduling

Crew scheduling problem is the problem of assigning crew members to the flights so that total cost is minimized while regulatory and legal restrictions are satisfied. The crew scheduling is an NP-hard constrained combinatorial optimization problem and hence, it cannot be exactly solved in a reasonable computational time. This paper presents a particle swarm optimization (PSO) algorithm synchronized with a local search heuristic for solving the crew scheduling problem. Recent studies use genetic algorithm (GA) or ant colony optimization (ACO) to solve large scale crew scheduling problems. Furthermore, two other hybrid algorithms based on GA and ACO algorithms have been developed to solve the problem. Computational results show the effectiveness and superiority of the proposed hybrid PSO algorithm over other algorithms.     

Optimal short-term hydro-thermal scheduling using quasi-oppositional teaching learning based optimization

This paper presents a new approach for solving short-term hydrothermal scheduling (HTS) using an integrated algorithm based on teaching learning based optimization (TLBO) and oppositional based learning (OBL). The practical hydrothermal system is highly complex and possesses nonlinear relationship of the problem variables, cascading nature of hydro reservoirs, water transport delay and scheduling time linkage that make the problem of optimization difficult using standard optimization methods. To overcome these problems, the proposed quasi-oppositional teaching learning based optimization (QOTLBO) is employed. To show its efficiency and robustness, the proposed QOTLBO algorithm is applied on two test systems. Numerical results of QOTLBO are compared with those obtained by two phase neural network, augmented Lagrange method, particle swarm optimization (PSO), improved self-adaptive PSO (ISAPSO), improved PSO (IPSO), differential evolution (DE), modified DE (MDE), fuzzy based evolutionary programming (Fuzzy EP), clonal selection algorithm (CSA) and TLBO approaches. The simulation results reveal that the proposed algorithm appears to be the best in terms of convergence speed, solution time and minimum cost when compared with other established methods. This method is considered to be a promising alternative approach for solving the short-term HTS problems in practical power system.     

Nonconvex dynamic spectrum allocation for cognitive radio networks via particle swarm optimization and simulated annealing

Dynamic spectrum access is a promising technique designed to meet the challenge of rapidly growing demands for broadband access in cognitive radio networks. By utilizing the allocated spectrum, cognitive radio devices can provide high throughput and low latency communications. This paper introduces an efficient dynamic spectrum allocation algorithm in cognitive radio networks based on the network utility maximization framework. The objective function in this optimization problem is always nonconvex, which makes the problem difficult to solve. Prior works on network resource optimization always transformed the nonconvex optimization problem into a convex one under some strict assumptions, which do not meet the actual networks. We solve the nonconvex optimization problem directly using an improved particle swarm optimization (PSO) method. Simulated annealing (SA), combined with PSO to form the PSOSA algorithm, overcomes the inherent defects and disadvantages of these two individual components. Simulations show that the proposed solution achieves significant throughput compared with existing approaches, and it is efficient in solving the nonconvex optimization problem.     

粒子群和人工鱼群混合优化算法

提出基于粒子群的人工鱼群混合优化算法,该算法综合利用人工鱼群算法的良好全局收敛性和粒子群算法的局部快速收敛性、易实现性等优点,克服人工鱼群算法收敛速度慢及粒子群算法后期全局收敛差的缺点,发挥了两者的优越性,并成功应用于求解具有变量边界约束的非线性的复杂函数最优化问题和求解复杂化学方程根的问题。仿真结果表明,混合粒子群算法不仅具有较好的全局收敛性能,而且具有较快的收敛速度。     

差分进化混合粒子群算法求解装配式住宅项目进度优化问题

针对装配式住宅项目进度优化问题,提出了基于差分算法(DE)和粒子群算法(PSO)的差分粒子群混合算法(DEPSO)。建立了以项目工期最优为目标的进度优化模型,通过在DE和PSO之间建立信息交流机制,避免了单一算法容易落入局部最优和精度低的缺陷。最后以某装配式住宅项目为例,通过三种算法的比较,结果表明DEPSO在求解装配式住宅项目进度优化中合理高效、鲁棒性较强,能有效地解决装配式住宅项目工期优化问题,有较大的应用价值。     

解决零空闲流水线调度问题的离散粒子群算法

研究了以最大完工时间为目标的零空闲流水线调度问题.提出一种复杂度为O(nm)的最大完工时间算法和一种快速插入邻域搜索算法;提出了解决该问题的离散粒子群调度算法,并结合简化邻域搜索算法给出了提高调度算法性能的措施.仿真实验表明了所得算法的有效性.     

Parameter selection in synchronous and asynchronous deterministic particle swarm optimization for ship hydrodynamics problems

Deterministic optimization algorithms are very attractive when the objective function is computationally expensive and therefore the statistical analysis of the optimization outcomes becomes too expensive. Among deterministic methods, deterministic particle swarm optimization (DPSO) has several attractive characteristics such as the simplicity of the heuristics, the ease of implementation, and its often fairly remarkable effectiveness. The performances of DPSO depend on four main setting parameters: the number of swarm particles, their initialization, the set of coefficients defining the swarm behavior, and (for box-constrained optimization) the method to handle the box constraints. Here, a parametric study of DPSO is presented, with application to simulation-based design in ship hydrodynamics. The objective is the identification of the most promising setup for both synchronous and asynchronous implementations of DPSO. The analysis is performed under the assumption of limited computational resources and large computational burden of the objective function evaluation. The analysis is conducted using 100 analytical test functions (with dimensionality from two to fifty) and three performance criteria, varying the swarm size, initialization, coefficients, and the method for the box constraints, resulting in more than 40,000 optimizations. The most promising setup is applied to the hull-form optimization of a high speed catamaran, for resistance reduction in calm water and at fixed speed, using a potential-flow solver.     

高维化工数据共轭粒子群算法处理

针对化工数据多为高维数据,而粒子群算法对求解高维优化问题易陷局部极值,提出将共轭方向法与粒子群算法相结合处理高维数据.当粒子群算法迭代了一定步数而陷入局部极值并得局部最优解χ*时,以χ*为初值,用共轭方向法对其求解,利用粒子群算法对低维优化问题的有效性,将得新的更优的当前最优解χ**,从而使算法跳出局部极值;在新极值的条件下,又用粒子群算法对原问题求解,如此反复直至结束.通过经典的测试函数对其测试,结果表明这一尝试是有效的.最后将算法用于SO2催化氧化反应动力学模型的非线性参数估计,获得满意效果.