一种求解多峰函数优化问题的量子行为粒子群算法

介绍了一种利用量子行为粒子群算法（QPSO）求解多峰函数优化问题的方法。为此,在QPSO中引进一种物种形成策略,该方法根据群体微粒的相似度并行地分成子群体。每个子群体是围绕一个群体种子而建立的。对每个子群体通过QPSO算法进行最优搜索,从而保证每个峰值都有同等机会被找到,因此该方法具有良好的局部寻优特性。将基于物种形成的QPSO算法与粒子群算法(PSO)对多峰优化问题的结果进行比较。对几个重要的测试函数进行仿真实验结果证明,基于物种形成的QPSO算法可以尽可能多地找到峰值点,峰值收敛性能优于PSO。     

基于混沌序列的多峰函数微粒群寻优算法

基于混沌序列的多峰函数微粒群寻优算法的目标就是找到多峰函数的所有局部优化峰值。在分析微粒群优化算法中各个参数对微粒运动影响的基础上,对微粒群算法进行改造,让微粒运动从初始位置沿优化函数曲线向优化峰值方向爬行,直至找到所在区域的局部优化峰值;要想求得尽可能多的局部优化峰值,就要求微粒群中微粒的初始位置分布具有随机性和遍历性,为此采用混沌序列设置微粒初始位置;为使每一个局部最优值点都可能有微粒群中的微粒经过,采用变步长的迭代计算;为防止优化函数曲线的某些局部峰附近没有微粒分布,从而漏掉该局部峰值,对计算进行重复,直至两轮求得的优化函数的局部峰值之差小于给定阈值。仿真结果表明,该算法具有很好的局部寻优特性,计算过程简捷,寻优效果良好,可有效地应用于多峰函数的局部寻优并求取全局最优值。     

粒子群Memetic算法求解多峰函数优化

针对目前多峰函数优化问题较难找到全部局部最优解的情况,提出了一种粒子群Memetic算法。算法结合了粒子群优化的全局搜索能力和爬山法的局部搜索能力,增强了算法搜索最优解的能力。实验结果表明,该算法求解精度较高,且收敛速度较快。     

一种速度改进型粒子群优化算法及应用

针对一般粒子群算法收敛速度慢易发散的缺点,提出一种速度改进型粒子群优化算法。该算法对速度的最大值进行动态改变．可以使粒子群算法在前期保持快速而又全局范围的探测搜索,而在后期,也可以将粒子限定在局部的重点区域的探测搜索。采用速度改进型粒子群优化算法对典型的多峰函数进行优化,仿真结果表明方法的有效性,并通过与一般粒子群算法进行比较,表明方法能够加快粒子群算法的收敛速度,具有更好的优化性能。     

一种速度改进型粒子群优化算法及应用

针对一般粒子群算法收敛速度慢易发散的缺点,提出一种速度改进型粒子群优化算法。该算法对速度的最大值进行动态改变,可以使粒子群算法在前期保持快速而又全局范围的探测搜索,而在后期,也可以将粒子限定在局部的重点区域的探测搜索。采用速度改进型粒子群优化算法对典型的多峰函数进行优化,仿真结果表明方法的有效性,并通过与一般粒子群算法进行比较,表明方法能够加快粒子群算法的收敛速度,具有更好的优化性能。     

多目标优化的粒子群算法研究

本文介绍了粒子群优化算法PSO中的多目标优化的粒子群算法及其应用,并将其运用在防守对方多个前锋球员的进攻威胁,以粒子群算法随机性来适应不断变化的形势。     

小生境人工免疫算法用于多峰函数优化

基于自然免疫系统的原理,提出了小生境人工免疫算法,为了解决多峰优化问题,可使每个抗体适度得到修改.利用小生境的共享函数法更好地维持了群体的多样性.同时小生境淘汰算法和免疫系统的记忆及变异特性促使群体中优良个体持续向问题的优化解逼近.算法对三个典型的多峰问题题进行了优化,给出了具体的实现步骤和较好的优化结果.     

多峰搜索的动态微粒群算法

对多峰搜索问题提出了一类动态微粒群算法。该算法通过变换函数将多峰问题中的所有峰变为等高峰,从而保证每个峰都有同等机会被找到;在搜索过程中采用群体规模动态可调的进化方式,使得初始群体可以任意指定,从而克服了标准微粒群算法由于无法事先知道多峰函数峰值点个数而很难确定合适群体大小的困难。实验表明了该算法可以尽可能多地找到峰值点。     

一种改进快速稳定的多目标优化算法

多目标优化问题属于高维的搜索空间,用一些传统方法来优化这些问题会导致较高的时间复杂性.为了解决该问题,使用了粒子群优化算法(PSO),同时将ε-dominance的概念应用到PSO中.该方法在实验过程中取得了良好的效果.其运算速度快,而且最终优化的点数可以得到控制.     

一种求解复杂多峰问题的新型粒子群优化算法研究

为提升标准粒子群算法在求解多峰复杂问题时收敛速度慢和极易陷入局部最优解等缺点, 提出一种基于球形坐标的分类学习策略粒子群算法(CLPSO-HC)。该算法给出种群运行较差粒子的确定方法, 将运行较差的粒子进行分类, 并对每类粒子给出相应的学习策略, 保证种群跳出局部最优解的能力。为减少外界扰动, 将粒子速度和位置的更新在球形坐标中进行, 提升了种群向最优解飞行的概率。对三个典型测试函数进行仿真实验, 所得结果表明CLPSO-HC相比其他几种算法有较好的收敛性。因此, CLPSO-HC可以作为求解复杂多峰问题的有效算法。     

多峰搜索的自适应遗传算法

对多峰函数问题提出了基于峰值转换和优育子群相结合的遗传搜索策略.主要是:通过变换函数将多峰问题中的所有峰变成“等高”峰,从而保证每个峰都有同等机会被找到;在种群中实施各种遗传操作及近亲排斥策略,以保证种群的多样性;将种群中适应值超过阈值的个体迁徙形成一个子群,在子群中实施“梯度操作”,对个体进行精细进化.该方法不仅可保证较快地找到所有峰,而且无需对多峰函数做峰的个数已知、峰均匀健分布等任何先验假设.最后与Spears的简单子群法进行了对比实验.     

A fast projection algorithm for sequence data searching

In real life, data often appear in the form of sequences and this form of data is called sequence data. In this paper, a new definition on sequence similarity and a novel algorithm, Projection Algorithm, for sequence data searching are proposed. This algorithm is not required to access every datum in a sequence database. However, it guarantees that no qualified subsequence is falsely rejected. Moreover, the projection algorithm can be extended to match subsequences with different scales. With careful selection of parameters, most of the similar subsequences with different scales can be retrieved. We also show by experiments that the proposed algorithm can outperform the traditional sequential searching algorithm up to 96 times in terms of speed up.     

Practical fast searching in strings

The problem of searching through text to find a specified substring is considered in a practical setting. It is discovered that a method developed by Boyer and Moore can outperform even special-purpose search instructions that may be built into the computer hardware. For very short substrings however, these special purpose instructions are fastest—provided that they are used in an optimal way.     

动态格点搜索的改进算法用于团簇结构快速优化

结合高效的动态格点搜索(DLS)算法与扰动操作(Perturbation Operation)提出一种新的改进方法(DLS-PO),用于确定团簇的最低能量结构。针对一个特定构型,DLS算法总能给出其对应搜索空间的最规则结构。然而,一次失败的DLS优化将消耗大量的运算资源。为此,采取原子移动和结构旋转的扰动操作成功地改变了构型,再结合后续的DLS操作,提高了优化效率。将该算法用于原子数高达309的Lennard-Jones团簇及100原子NP-B函数铝团簇的结构优化。优化结果显示相比于DLS算法,DLS-PO算法更为高效。     

基于形态学的快速图像搜索与识别算法

介绍了一个无人直升机实时机器视觉系统的设计和实现,重点是图像的动态处理技术.以自适应门限值提取前景区域,通过扩展的连通分量提取算法实现了目标的快速搜索,最后基于几何特征对目标加以识别.通过在大量飞行中对目标的成功搜索和识别,证明了该算法的有效性.     

An improved PSO-based approach with dynamic parameter tuning for cooperative multi-robot target searching in complex unknown environments

Target searching in complex unknown environments is a challenging aspect of multi-robot cooperation. In this paper, an improved particle swarm optimisation (PSO) based approach is proposed for a team of mobile robots to cooperatively search for targets in complex unknown environments. The improved cooperation rules for a multi-robot system are applied in the potential field function, which acts as the fitness function of the PSO. The main improvements are the district-difference degree and dynamic parameter tuning. In the simulation studies, various complex situations are investigated and compared to the previous research results. The results demonstrate that the proposed approach can enable the multi-robot system to accomplish the target searching tasks in complex unknown environments.     

Improved string searching

We show that it is possible to improve the average time of the Boyer-Moore string matching algorithm using more space. This is accomplished by applying a transformation that virtually increases the size of the alphabet in use. The improvement is such that for long patterns it is possible to obtain an algorithm more than 50 per cent faster than the original one. We include experimental results on random and English text. Some improvements for searching on English text are also discussed.     

Connected searching of weighted trees

In this paper we consider the problem of connected edge searching of weighted trees. Barrière et al. claim in [L. Barrière, P. Flocchini, P. Fraigniaud, N. Santoro, Capture of an intruder by mobile agents, in: SPAA’02: Proceedings of the Fourteenth Annual ACM Symposium on Parallel Algorithms and Architectures, ACM, New York, NY, USA, 2002, pp. 200-209] that there exists a polynomial-time algorithm for finding an optimal search strategy, that is, a strategy that minimizes the number of used searchers. However, due to some flaws in their algorithm, the problem turns out to be open. It is proven in this paper that the considered problem is strongly NP-complete even for node-weighted trees (the weight of each edge is 1) with one vertex of degree greater than 2. It is also shown that there exists a polynomial-time algorithm for finding an optimal connected search strategy for a given bounded degree tree with arbitrary weights on the edges and on the vertices. This is an FPT algorithm with respect to the maximum degree of a tree.