随机选择最优个体的量子粒子群优化算法

在分析量子行为粒子群优化算法的基础上,针对算法后期粒子群体容易聚集到一个狭小搜索区域,群体多样性降低的问题,提出了在算法中引入随机选择最优个体的改进方法,提高算法搜索过程中粒子群体的多样性。将改进后的量子粒子群算法与量子粒子群算法、粒子群算法通过benchmark测试函数进行了比较,仿真结果表明改进后的算法更适合解决多峰类的优化问题。     

一种求解典型JSP的改进离散粒子群优化算法

针对NP-hard性质的作业车间调度问题, 设计了一种改进的离散粒子群优化算法。引入遗传算法交叉算子和变异算子来实现粒子的更新, 并将变异思想和模拟退火算法思想融入该算法中对全局最优粒子的邻域进行局部搜索, 很好地防止了算法出现早熟收敛。通过将该算法和标准粒子群优化算法用于求解典型JSP, 计算结果对比表明, 改进的算法具有很强的全局寻优能力; 就综合解的质量和计算效率而言, 改进算法优于标准粒子群优化算法。同时, 将该算法结果与文献中其他相关算法结果进行比较, 验证了该改进算法的有效性。该算法能够有效地、高质量地解决作业车间调度问题。     

杂交粒子群算法在列车运行调整中的应用研究

针对列车运行调整存在约束条件多、求解难度大等问题, 结合城市轨道交通列车运行特点, 建立了优化的列车运行调整模型。在此基础上, 引入遗传算法中的杂交思想, 采用改进后的粒子群算法对此模型进行求解, 给出了求解算法的具体步骤, 并采用西安地铁2号线数据进行仿真验证。结果表明, 采用杂交粒子群算法解决列车运行调整问题是一种有效的方法, 并且其优化能力优于标准粒子群算法。     

一种新的混合粒子群优化算法

针对标准粒子群算法在优化过程中受初始值影响较大且容易陷入局部极值的缺陷,将鱼群算法中聚群行为的基本思想引入粒子群算法中,据此建立了粒子中心的基本概念,并利用粒子的聚群特性调整粒子的飞行方向与目标位置,从而提出了一种新的混合粒子群算法,旨在改进原粒子群算法的全局收敛能力。为了检验混合粒子群算法的优化特性,采用三种典型的标准函数对五种现行智能算法进行了多方面的测试和比较。实验结果表明,新算法具有良好的搜索精度与速度,有效弥补了标准粒子群算法局部收敛和鱼群算法精度不高的双重缺陷,适用于解决复杂函数优化问题。     

改进粒子群算法在DOA估计中的应用

针对均匀线性阵列的相干信号波达方向（DOA）估计问题,提出了一种结合粒子群优化（PSO）算法和最大似然函数的解相干算法。算法充分利用了PSO算法解决优化问题的优势和最大似然测向的优点,对独立信号、相干信号或二者的混合信号的DOA都能进行有效的估计。为了提高估计性能,对标准PSO算法的惯性权重、最大速度和搜索机制进行了改进。仿真结果证明了改进算法的有效性。     

多策略融合的改进粒子群优化算法

为解决传统粒子群算法收敛精度低、收敛速度慢和易陷入局部最优的问题,提出了一种多策略融合的改进粒子群算法。首先,设计了一种基于中垂线算法的游离粒子位置更新方法,加快了游离粒子的收敛速度;其次,设计了一种在最优粒子附近生成爆炸粒子的策略,以增强算法的寻优精度和寻优速度,为适应前两个策略,还设计了一种仅依靠全局最优粒子位置的粒子速度更新策略;最后,将基于概率分层的简化粒子群优化算法的惯性权重和粒子位置更新方法用于本算法。与其他五种改进粒子群算法进行了对比实验,结果表明提出的改进算法无论是处理低维问题还是高维问题表现均具有较大优势,性能更优越。     

改进的二阶振荡粒子群算法

针对粒子群算法易陷入局部最优等问题,分析了粒子群算法的进化方程,提出了一种改进的粒子群优化算法。算法在振荡环节采用互不相同的参数取值来调节粒子群算法的全局和局部搜索能力,并通过对测试函数和机器人路径规划问题仿真模拟,与标准PSO、标准二阶PSO、二阶振荡PSO算法的实验结果进行对比分析,验证了所提出算法的有效性和可行性。     

一种深度扩展记忆的仿人粒子群算法仿真分析

从仿生学和心理学角度出发,提出一种深度扩展记忆的仿人粒子群算法,以解决标准粒子群及其主流改进算法易陷入局部最优等问题.算法对粒子认知进行群体共享,并采用深度扩展记忆积累粒子认知,通过仿人遗忘函数配置不同时期认知对当前决策的影响权重.仿真分析表明,所提出算法对遗忘函数和遗忘因子高度敏感,算法寻优多维多极值函数时,在收敛精度、成功率和优化成本等方面较标准粒子群及其改进算法有显著提升.     

基于自调节粒子群算法的盲检测

以往基于粒子群优化的盲算法能成功实现信号盲检测,但具有算法收敛速度慢、容易陷入局部最小的缺点。文中通过分析粒子群算法的机能及参数的设置,提出一种改进的基于自调节粒子群优化的盲检测算法。算法构成思想是:基于MIMO系统的盲检测系统模型将盲检测问题转化为二次优化问题,利用改进的自调节粒子群优化算法对此优化问题进行寻优。仿真表明,改进算法具有全局收敛性好、收敛速度快、误码率低的优点,能够更好地解决盲检测问题。     

基于自调节粒子群算法的盲检测

以往基于粒子群优化的盲算法能成功实现信号盲检测,但具有算法收敛速度慢、容易陷入局部最小的缺点。文中通过分析粒子群算法的机能及参数的设置,提出一种改进的基于自调节粒子群优化的盲检测算法。算法构成思想是：基于MIMO系统的盲检测系统模型将盲检测问题转化为二次优化问题,利用改进的自调节粒子群优化算法对此优化问题进行寻优。仿真表明,改进算法具有全局收敛性好、收敛速度快、误码率低的优点,能够更好地解决盲检测问题。     

An application of particle swarm optimization algorithm to clustering analysis

Particle swarm optimization algorithm (PSOA), which maintains a population of particles, where each particle represents a potential solution to an optimization problem, is a population-based stochastic search process. This study intends to integrate PSOA with K-means to cluster data. It is shown that PSOA can be employed to find the centroids of a user-specified number of clusters. The proposed PSOA is evaluated using four data sets, and compared to the performance of some other PSOA-based methods and K-means method. Computational results show that the proposed method has much potential. A real-world problem for order clustering also illustrates that the proposed method is quite promising.     

The particle swarm optimization algorithm in size and shape optimization

Shape and size optimization problems instructural design are addressed using the particle swarm optimization algorithm (PSOA). In our implementation of the PSOA, the social behaviour of birds is mimicked. Individual birds exchange information about their position, velocity and fitness, and the behaviour of the flock is then influenced to increase the probability of migration to regions of high fitness. New operators in the PSOA, namely the elite velocity and the elite particle, are introduced. Standard size and shape design problems selected from literature are used to evaluate the performance of the PSOA. The performance of the PSOA is compared with that of three gradient based methods, as well as the genetic algorithm (GA). In attaining the approximate region of the optimum, our implementation suggests that the PSOA is superior to the GA, and comparable to gradient based algorithms. Received December 18, 2000     

Multidisciplinary design of a small satellite launch vehicle using particle swarm optimization

In the present paper, particle swarm optimization, a relatively new population based optimization technique, is applied to optimize the multidisciplinary design of a solid propellant launch vehicle. Propulsion, structure, aerodynamic (geometry) and three-degree of freedom trajectory simulation disciplines are used in an appropriate combination and minimum launch weight is considered as an objective function. In order to reduce the high computational cost and improve the performance of particle swarm optimization, an enhancement technique called fitness inheritance is proposed. Firstly, the conducted experiments over a set of benchmark functions demonstrate that the proposed method can preserve the quality of solutions while decreasing the computational cost considerably. Then, a comparison of the proposed algorithm against the original version of particle swarm optimization, sequential quadratic programming, and method of centers carried out over multidisciplinary design optimization of the design problem. The obtained results show a very good performance of the enhancement technique to find the global optimum with considerable decrease in number of function evaluations.     

Topology optimization of planar cross-sections

Topology optimization provides a rigorous method for the conceptual design of structural components. In this note, a practical approach for solving topology optimization problems of planar cross-sections is discussed. A problem formulation involving the use of continuous design variables is presented, and a standard nonlinear programming algorithm is used to solve the optimization problem. Results of the technique for two examples are presented and compared to similar results in the literature.     

基于黄金分割双种群遗传算法的区域交通信号控制

针对非均匀交通流的城市区域信号配时优化问题,以区域总通行能力和总延误为优化目标,构建基于目标相对占优策略的城市区域交通信号优化模型;在采用遗传算法求解优化模型时,由于遗传算法易早熟收敛会导致寻优效果不佳,因此引入黄金分割法对双种群遗传算法进行改进,两个种群同时且独立地进行寻优操作,并进行个体交换,避免算法陷入局部最优的陷阱,利用4个常用的测试函数验证算法有效性,实验结果表明改进的算法能够快速搜索到全局最优解;最后对所提的模型和算法进行有效性评价,结果表明,所建模型符合实际交通控制目标并且计算简单,验证了模型的有效性;所改进的算法在城市区域路网中能够有效地获得良好的信号配时方案。     

Improving convergence of Iterative Feedback Tuning

Iterative Feedback Tuning constitutes an attractive control loop tuning method for processes in the absence of an accurate process model. It is a purely data driven approach aiming at optimizing the closed loop performance. The standard formulation ensures an unbiased estimate of the loop performance cost function gradient with respect to the control parameters. This gradient is important in a search algorithm. The extension presented in this paper further ensures informative data to improve the convergence properties of the method and hence reduce the total number of required plant experiments especially when tuning for disturbance rejection. Informative data is achieved through application of an external probing signal in the tuning algorithm. The probing signal is designed based on a constrained optimization which utilizes an approximate black box model of the process. This model estimate is further used to guarantee nominal stability and to improve the parameter update using a line search algorithm for determining the iteration step size. The proposed algorithm is compared to the classical formulation in a simulation study of a disturbance rejection problem. This type of problem is notoriously difficult for Iterative Feedback Tuning due to the lack of excitation from the reference.     

用填充函数改进的智能控制系统全局优化算法

为了提高全局优化算法的速度,提出了智能控制系统全局优化算法。该算法应用了闭环控制系统的反馈的思想,使得在寻优迭代过程中被优化函数的值不断接近设定值,直至达到其全局最优值。该算法的关键在于控制策略的设计和策略中的参数值的设定。为了降低参数初值设定的难度同时提高算法的寻优精度,利用填充函数法对智能控制系统全局优化算法进行改进。经12个标准的测试函数的验证,改进后的算法的速度较填充函数法快,算法的精度比智能控制系统全局优化算法高。     

A new multi-objective programming scheme for topology optimization of compliant mechanisms

This paper presents an alternative method in implementing multi-objective optimization of compliant mechanisms in the field of continuum-type topology optimization. The method is designated as “SIMP-PP” and it achieves multi-objective topology optimization by merging what is already a mature topology optimization method—solid isotropic material with penalization (SIMP) with a variation of the robust multi-objective optimization method—physical programming (PP). By taking advantages of both sides, the combination causes minimal variation in computation algorithm and numerical scheme, yet yields improvements in the multi-objective handling capability of topology optimization. The SIMP-PP multi-objective scheme is introduced into the systematic design of compliant mechanisms. The final optimization problem is formulated mathematically using the aggregate objective function which is derived from the original individual design objectives with PP, subjected to the specified constraints. A sequential convex programming method, the method of moving asymptotes (MMA) is then utilized to process the optimization evolvement based on the design sensitivity analysis. The main findings in this study include distinct advantages of the SIMP-PP method in various aspects such as computation efficiency, adaptability in convex and non-convex multi-criteria environment, and flexibility in problem formulation. Observations are made regarding its performance and the effect of multi-objective optimization on the final topologies. In general, the proposed SIMP-PP method is an appealing multi-objective topology optimization scheme suitable for “real world” problems, and it bridges the gap between standard topological design and multi-criteria optimization. The feasibility of the proposed topology optimization method is exhibited by benchmark examples.     

协方差斜格法的LPC参数提取及其FPGA实现

分析语音信号声道特征参数提取问题,针对自相关法的缺陷,提出声道特征参数提取的改进算法。介绍其运算步骤和流程,考虑FPGA适于短期开发及高速性的优点,设计Finite State Machine来控制复杂运算操作及对寄存器的频繁访问。利用Cyclone EP1C6 FPGA实现语音信号声道特征参数提取算法。     

求解车间作业调度问题的一种改进遗传算法

针对标准遗传算法收敛速度慢和易陷入局部最优的问题,在总结已有经验的基础上对标准遗传算法提出改进:采用基于工序的编码、解码方式,每一次遗传操作后对种群采用循环选择并保留最优个体,对交叉操作和变异概率的计算提出了一系列改进方法,避免遗传算法产生无用解或陷入局部优化,以提高效率。通过实验验证,改进后的算法具有可行性,并且可以得到十分满意的结果。