面向应用的快速多峰寻优算法

工程应用中的多峰寻优问题要求搜索目标函数的多个极值点,现有的多峰优化方法难以直接利用应用问题的先验知识引导算法过程,多峰寻优效率较低。基于粒子群优化算法设计一种面向应用的多峰寻优算法,能有效利用易于获得的先验参数,如峰间分辨率、峰位置精度、峰值个数等实现快速多峰搜索。该算法保持了粒子群算法的简单性并改善了搜索多样性,使其可控地收敛到多个峰值上。将该算法与几种典型的多峰寻优方法进行了对比测试和分析,结果表明,对复杂多峰函数,该算法能以最快的收敛速度实现多峰搜索。     

融合振幅随机补偿与步长演变机制的改进原子搜索优化算法

针对原子优化算法寻优精度弱且易陷入局部极值的问题,本文从种群多样性、参数适应性和位置动态性角度提出一种融合混沌优化、振幅随机补偿和步长演变机制改进的原子搜索优化算法(improved atom search optimization, IASO),并将其成功应用于分类任务。首先,引入帐篷映射(Tent混沌)增强原子种群在搜索空间中的分布均匀性;其次,通过构建振幅函数对算法参数进行随机扰动并加入步长演变因子更新原子位置,以增强算法全局性和收敛性;最后,再将改进算法应用于误差反馈神经网络(BP神经网络)参数优化。通过与6种元启发式算法在20个基准测试函数下的数值实验对比表明:IASO不仅在求解多维基准函数上具有好的寻优性能,且在对BP神经网络参数进行优化时相较于2种对比算法具有更高的分类精度。     

一种基于抗体网络的免疫算法

阐述了免疫系统抗体网络的机理和特点,深入分析了抗体网络与常用的免疫算法和Hopfield神经网络异同.通过不断更新输入模式(抗原)和采用最优保存策略,将基于克隆选择的竞争学习算子、自动生成网络结构、剪枝算子和低频变异用于进化操作,提出一种新的基于抗体网络的免疫算法,用于函数优化问题.实验结果表明新算法可行有效.与常用的免疫算法、Hopfield神经网络优化算法比较,新算法具有较好的全局搜索能力和较快收敛速度.     

一种混沌Hopfiele网络及其在优化计算中的应用

文章讨论了神经网络算法在约束优化问题中的应用,提出了一种混沌神经网络模型。在Hopfield网络中引入混沌机制,首先在混沌动态下搜索,然后利用HNN梯度优化搜索。对非线性函数的优化问题仿真表明算法具有很强的克服陷入局部极小能力。     

一种混沌Hopfield网络及其在优化计算中的应用

文章讨论了神经网络算法在约束优化问题中的应用,提出了一种混沌神经网络模型。在Hopfield网络中引入混沌机制,首先在混沌动态下搜索,然后利用HNN梯度优化搜索。对非线性函数的优化问题仿真表明算法具有很强的克服陷入局部极小能力。     

一种求解动态优化问题的免疫文化基因算法

针对传统免疫网络动态优化算法局部寻优能力弱、寻优精度低及易早熟收敛的缺点,提出一种求解动态优化问题的免疫文化基因算法。基于文化基因算法基本框架,将人工免疫网络算法作为全局搜索算法,采用禁忌搜索算法作为局部搜索算子;同时引入柯西变异加强算法的全局搜索能力,并有效防止早熟收敛。通过对经典动态优化函数测试集在相同条件下的实验表明,该免疫文化基因算法相较于其他同类算法具有较好的搜索精度和收敛速度。     

基于均匀设计的免疫克隆多峰函数优化

为了尽可能多地求得多峰函数的全部最优解,提出了基于均匀设计的免疫克隆多峰函数优化。算法采用均匀设计初始化种群,保证初始抗体群体分布的均匀性和多样性。采用Larmark学习策略对群体进行局部搜索,以增强算法的收敛速度和搜索精度。在免疫克隆参数设置上,将参数设定问题描述成多因素多水平的均匀设计问题,减少设置参数所需的实验次数。实验结果表明,该算法寻优能力较强。     

动态扩散粒子群算法及其应用

针对粒子群算法搜索精度不高特别是对高维函数优化性能不佳问题,提出了一种动态扩散粒子群算法,并将其应用于移动机器人路径规划中。该算法通过引进动态调节数,动态地选择粒子的运行轨迹,阻止种群在演化过程中搜索效率降低的缺陷,提高算法的寻优性能。实验结果表明,该算法在处理高维函数优化及移动机器人路径规划方面具有更强的寻优能力及更高的搜索精度。     

用改进的竞争Hopfield神经网络求解多边形近似问题

多边形近似是提取曲线特征点和简化曲线描述的一种重要方法.提出一种改进的Hopfield神经网络多边形近似算法,该算法利用选择拐点策略减少了搜索空间,重新定义了神经网络的能量函数,使其更能反映优化目标;引?入合并拆分搜索策略,有效帮助神经网络脱离局部最小值.实验结果表明,提出的改进算法是有效的,比其它算法如关键点检测法、竞争Hopfield神经网络、混沌Hopfield神经网络、遗传算法等具有更优的性能.     

粒子群优化算法的改进

针对粒子群优化算法搜索精度不高、对高维函数优化性能不佳的问题,提出一种改进的粒子群优化算法。以递增方式对粒子进行释放增强可利用的种群信息,通过释放粒子引导极值变化加强算法的运算效率。实验结果表明,与其他算法相比,改进算法具有更强的寻优能力和搜索精度,且适于高维复杂函数的优化。     

Mutation Hopfield neural network and its applications

In this paper, a new operator is proposed to optimize the traditional Hopfield neural network (HNN). The key idea is to incorporate the global search capability of the Estimation of Distribution Algorithms (EDAs) into the HNN, which typically has a powerful local search capability and fast operation. On account of this property of the EDA, our proposed algorithm also exhibits a powerful global search capability. In addition, the possible infeasible solutions generated during the re-sampling period of the EDA are eliminated by the HNN. Therefore, the merits of both these methods are combined in a unified framework. The proposed model is tested on a numerical example, the max-cut problem. The new and optimized model yielded a better performance than certain traditional intelligent optimization methods, such as HNN, genetic algorithm (GA). The proposed mutation Hopfield neural network (MHNN) is also used to solve a practical problem, aircraft landing scheduling (ALS). Compared with first-come-first-served sequence, MHNN sequence reduces both total landing time and total delay.     

An integrated multi-objective immune algorithm for optimizing the wire bonding process of integrated circuits

Optimization of the wire bonding process of an integrated circuit (IC) is a multi-objective optimization problem (MOOP). In this research, an integrated multi-objective immune algorithm (MOIA) that combines an artificial immune algorithm (IA) with an artificial neural network (ANN) and a generalized Pareto-based scale-independent fitness function (GPSIFF) is developed to find the optimal process parameters for the first bond of an IC wire bonding. The back-propagation ANN is used to establish the nonlinear multivariate relationships between the wire boning parameters and the multi-responses, and is applied to generate the multiple response values for each antibody generated by the IA. The GPSIFF is then used to evaluate the affinity for each antibody and to find the non-dominated solutions. The “Error Ratio” is then applied to measure the convergence of the integrated approach. The “Spread Metric” is used to measure the diversity of the proposed approach. Implementation results show that the integrated MOIA approach does generate the Pareto-optimal solutions for the decision maker, and the Pareto-optimal solutions have good convergence and diversity performance.     

基于混沌粒子群算法和Hopfield网络求解TSP问题

针对Hopfield网络求解TSP问题经常出现局部最优解,该文将混沌粒子群算法(PSO)与之结合,提出一种基于混沌粒子群的Hopfield神经网络方法。通过实验将其与文献[5,8]以及"PSO+HNN"策略比较,验证了该文算法不仅能够以更大概率收敛到全局最优,而且耗时更少。     

基于混沌粒子群算法和Hopfield网络求解TSP问题

针对Hopfield网络求解TSP问题经常出现局部最优解,该文将混沌粒子群算法（PSO）与之结合,提出一种基于混沌粒子群的Hopfield神经网络方法。通过实验将其与文献[5,8]以及“PSO＋HNN”策略比较,验证了该文算法不仅能够以更大概率收敛到全局最优,而且耗时更少。     

TSP及其基于Hopfield网络优化的研究

Ｈｏｐｆｉｅｌｄ网络（ＨＮＮ）是一种有效的优化模型,但存在易收敛到非法解或局部极小以及对模型参数与初值依赖性强的缺点。旅行商问题（ＴＳＰ）是研究算法性能的典型算例,通过对其进行计算机仿真优化,分析归纳了ＨＮＮ模型存在缺点的原因,总结并提出若干改进方法与思想。同时,针对ＴＳＰ问题的工程背景提出了若干发展性研究内容与方法。     

基于阈值自适应忆阻器Hopfield神经网络的关联规则挖掘算法

针对基于Hopfield神经网络的最大频繁项集挖掘（HNNMFI）算法存在的挖掘结果不准确的问题,提出基于电流阈值自适应忆阻器（TEAM）模型的Hopfield神经网络的改进关联规则挖掘算法。首先,使用TEAM模型设计实现突触,利用阈值忆阻器的忆阻值随方波电压连续变化的能力来设定和更新突触权值,自适应关联规则挖掘算法的输入。其次,改进原算法的能量函数以对齐标准能量函数,并用忆阻值表示权值,放大权值和偏置。最后,设计由最大频繁项集生成关联规则的算法。使用10组大小在30以内的随机事务集进行1000次仿真实验,实验结果表明,与HNNMFI算法相比,所提算法在关联挖掘结果准确率上提高33.9个百分点以上,说明忆阻器能够有效提高Hopfield神经网络在关联规则挖掘中的结果准确率。     

基于神经网络量子算法的多用户检测器

利用遗传量子算法和Hopfield神经网络，提出了一种融合两种算法优点的神经网络量子算法，并将其应用到CDMA通信系统的多用户检测问题中。所提算法把神经网络嵌入到遗传量子算法的每一代中，可进一步提高量子种群的适应度函数值。通过混合神经网络到GQA中，还可加快GQA的收敛速度进而减少算法的计算复杂度。另外，GQA所提供的良好初值改善了HNN的性能，嵌入的HNN也提高了GQA的性能。仿真结果证明了该方法的抗多址干扰能力和抗远近效应能力都优于传统检测器和一些应用智能算法的多用户检测器。     

基于ATM交换结构的Hopfield神经网络调度算法

针对ATM交换结构，采用输入缓冲和每条入线在同一个时隙内可传送多于一个信元的策略，利用神经网络具有的实时性、高度并行处理能力和易于电路或光电技术实现等特点，提出了一种Hopfield神经网络调度算法。实验仿真比较表明，该方法不但大大提高了吞吐率，消除了队头阻塞造成的性能恶化，而且降低了信元丢失率和较大程度地降低了平均信元时延，提高了ATM交换结构的性能，实现了信元的优化调度。     

A hybrid approach based on stochastic competitive Hopfield neural network and efficient genetic algorithm for frequency assignment problem

This paper presents a hybrid efficient genetic algorithm (EGA) for the stochastic competitive Hopfield (SCH) neural network, which is named SCH–EGA. This approach aims to tackle the frequency assignment problem (FAP). The objective of the FAP in satellite communication system is to minimize the co-channel interference between satellite communication systems by rearranging the frequency assignment so that they can accommodate increasing demands. Our hybrid algorithm involves a stochastic competitive Hopfield neural network (SCHNN) which manages the problem constraints, when a genetic algorithm searches for high quality solutions with the minimum possible cost. Our hybrid algorithm, reflecting a special type of algorithm hybrid thought, owns good adaptability which cannot only deal with the FAP, but also cope with other problems including the clustering, classification, and the maximum clique problem, etc. In this paper, we first propose five optimal strategies to build an efficient genetic algorithm. Then we explore three hybridizations between SCHNN and EGA to discover the best hybrid algorithm. We believe that the comparison can also be helpful for hybridizations between neural networks and other evolutionary algorithms such as the particle swarm optimization algorithm, the artificial bee colony algorithm, etc. In the experiments, our hybrid algorithm obtains better or comparable performance than other algorithms on 5 benchmark problems and 12 large problems randomly generated. Finally, we show that our hybrid algorithm can obtain good results with a small size population.     

Hopfield neural network implementation of the optimal CDMAmultiuser detector

We investigate the application of Hopfield neural networks (HNN's) to the problem of multiuser detection in spread spectrum/CDMA (code division multiple access) communication systems. It is shown that the NP-complete problem of minimizing the objective function of the optimal multiuser detector (OMD) can be translated into minimizing an HNN “energy” function, thus allowing to take advantage of the ability of HNN's to perform very fast gradient descent algorithms in analog hardware and produce in real-time suboptimal solutions to hard combinatorial optimization problems. The performance of the proposed HNN receiver is evaluated via computer simulations and compared to that of other suboptimal schemes as well as to that of the OMD for both the synchronous and the asynchronous CDMA transmission cases. It is shown that the HNN detector exhibits a number of attractive properties and that it provides a powerful generalization of a well-known and extensively studied suboptimal scheme, namely the multistage detector