微粒群神经网络在绩效评价系统中的应用

绩效评价系统是人力资源系统3P模型中的重要一环,是定期考察和评价个人或小组工作业绩的一种正式制度。利用微粒群算法对神经网络进行训练,再将此网络模型应用到人力资源管理系统中的绩效评价系统。最后通过在各级评价标准内按随机均匀分布方式生成的训练样本和测试样本来检测该微粒群神经网络。结果表明微粒群神经网络具有较强的泛化能力,应用在绩效评价系统中具有很高的评价准确率。     

基于改进型PSO的模糊神经网络PM2.5浓度预测

为科学合理地预测大气污染物PM2.5颗粒物浓度变化规律,分析PM2.5颗粒物浓度变化历史数据,综合判断外部条件(温度、风速、天气状况)和内部条件(其它污染物的浓度)对PM2.5颗粒物浓度变化的影响.采用一种改进型PSO优化的模糊神经网络,将粒子群算法与模糊神经网络进行融合,发挥PSO算法全局寻优的特点,预测PM2.5颗粒物浓度的变化规律.对某市2013年PM2.5颗粒物浓度进行预测和验证,验证结果表明,该算法具备良好的预测精度.     

模糊神经网络模型混沌混合优化学习算法及应用

基于混沌优化的思想,提出一种新的模糊模型的优化学习算法．将模糊推理规则转化为模糊RBF网络模型,用模糊C均值(FCM)聚类算法和分区效验熵得到模型结构。用混沌变换序列寻优得到优化的中心初值群,用FCM获得最优聚类中心,最后获得模糊神经网络模型．将该方法应用于转炉终点磷含量预报模型。取得了较好的结果．     

基于神经网络和模糊逻辑的工业过程故障诊断与报警系统

用单一理论和方法对复杂系统进行故障诊断效果不太好.文章讨论了基于神经网络和模糊系统的故障诊断以及它们之间结合方式的特点,提出了一种保障工业生产安全可靠运行的有效方法:分级故障诊断算法 过程监控与报警,仿真并设计了基于工控网络的工业过程故障诊断与报警系统.研究表明基于径向基函数神经网络 模糊逻辑的算法具有较快的训练速度和较好的泛化能力,可识别多回路故障.     

Position control of electro-hydraulic actuator system using fuzzy logic controller optimized by particle swarm optimization

The position control system of an electro-hydraulic actuator system (EHAS) is investigated in this paper. The EHAS is developed by taking into consideration the nonlinearities of the system: the friction and the internal leakage. A variable load that simulates a realistic load in robotic excavator is taken as the trajectory reference. A method of control strategy that is implemented by employing a fuzzy logic controller (FLC) whose parameters are optimized using particle swarm optimization (PSO) is proposed. The scaling factors of the fuzzy inference system are tuned to obtain the optimal values which yield the best system performance. The simulation results show that the FLC is able to track the trajectory reference accurately for a range of values of orifice opening. Beyond that range, the orifice opening may introduce chattering, which the FLC alone is not sufficient to overcome. The PSO optimized FLC can reduce the chattering significantly. This result justifies the implementation of the proposed method in position control of EHAS.     

Control-affine fuzzy neural network approach for nonlinear process control

An internal model control strategy employing a fuzzy neural network is proposed for SISO nonlinear process. The control-affine model is identified from both steady state and transient data using back-propagation. The inverse of the process is obtained through algebraic inversion of the process model. The resulting model is easier to interpret than models obtained from the standard neural network approaches. The proposed approach is applied to the tasks of modelling and control of a continuous stirred tank reactor and a pH neutralization process which are not inherently control-affine. The results show a significant performance improvement over a conventional PID controller. In addition, an additional neural network which models the discrepancy between a control-affine model and real process dynamics is added, and is shown to lead to further improvement in the closed-loop performance.     

改进量子粒子群算法的模糊神经网络水质评价

传统的粒子群算法训练神经网络的水质评价模型有学习速度慢,容易陷入局部最优和精确性不高的缺点。为了克服模型的缺点,提出了利用改进的自适应量子粒子群算法训练T-S模糊神经网络的新模型,新的自适应量子粒子群算法通过在算法中引入聚集度的概念,使得算法可以在迭代中自适应地调整收缩扩张系数,让算法更具动态自适应性。新的模型结合了量子粒子群算法和T-S模糊神经网络的优点,提高了模型的泛化能力。通过对东江湖流域站点2002到2013年的水文数据进行实验,结果显示,该模型比其他神经网络模型的评价结果具有更高的效率,适合被用于日常水质评价工作。     

模糊神经网络的混沌优化算法设计

提出了一种基于混沌变量的多层模糊神经网络优化算法设计.离线优化部分采用混沌算法,将混沌变量引入到模糊神经网络结构和参数的优化搜索中,使整个网络处于动态混沌状态,根据性能指标在动态模糊神经网络中寻找较优的网络结构和参数.在线优化部分采用梯度下降法,把混沌搜索后得到的参数全局次优值作为梯度下降搜索的初始值,进一步调整模糊神经网络的参数,实现混沌粗搜索和梯度下降细搜索相结合的优化目的,能较快地找到全局最优解.最后对二阶延迟系统进行仿真,结果表明混沌优化方法控制精度高、超调小、响应快和鲁棒性强.     

非线性系统模糊神经网络控制的改进策略

针对以模糊神经网络自适应方法为核心的不确定非线性系统控制问题, 以常规静态模糊神经网络控制结构为基础, 分别就控制器、辨识器及优化算法3个方面展开改进研究. 以一种改进结构的动态PID型模糊神经网络为控制器, 最小二乘支持向量机为辨识器构成控制系统. 利用带混沌搜索的量子粒子群算法离线优化结合在线误差反传微调的寻优策略优化控制器参数, 带混沌扰动的粒子群离线优化支持向量机的核参数, 并通过对系统稳定性的讨 论将改进的控制系统逐步完善. 对某热交换对象模型的数值仿真验证了该改进方法的可行性和有效性.     

A reinforcement learning approach based on the fuzzy min-max neural network

The fuzzy min-max neural network constitutes a neural architecture that is based on hyperbox fuzzy sets and can be incrementally trained by appropriately adjusting the number of hyperboxes and their corresponding volumes. Two versions have been proposed: for supervised and unsupervised learning. In this paper a modified approach is presented that is appropriate for reinforcement learning problems with discrete action space and is applied to the difficult task of autonomous vehicle navigation when no a priori knowledge of the enivronment is available. Experimental results indicate that the proposed reinforcement learning network exhibits superior learning behavior compared to conventional reinforcement schemes.     

改进协同微粒群优化的模糊神经网络控制系统设计

针对协同微粒群算法不能保证收敛到局部或全局最优值的问题,提出一种改进协同微粒群算法(ICPSO),并证明了该算法能以概率1收敛干全局最优解.应用ICPSO建立一类非线性对象的神经网络辨识模型,并对系统的模糊神经网络自适应控制器的参数进行了离线和在线优化.仿真结果表明,ICPSO能提高系统的建模精度,增强模型的泛化能力,而且由ICPSO训练的控制器可以达到良好的控制效果.     

综合改进的粒子群神经网络算法

粒子群优化算法是一种解决非线性、不可微和多峰值复杂优化问题的优秀算法,但该算法在进化后期容易出现速度变慢以及早熟的现象;BP神经网络的学习算法是基于梯度下降这一本质的,因此存在着容易陷于局部极小值,收敛速度慢,训练时间长等问题.针对上述现象,对粒子群优化算法进行了增强粒子多样性和避免种群陷入早熟两个方面的改进,并提出了一种基于改进算法的粒子群神经网络算法,最后通过在IRIS数据集上进行的仿真实验验证了改进的有效性.     

基于自适应模糊神经网络的功放预失真新方法

针对无线通信系统中记忆非线性功率放大器预失真结构不足和精度不高等问题,提出了一种基于模糊神经网络模型识别的双环学习结构自适应预失真方法。该方法以实数延时模糊神经网络模型为基础,采用改进的简化粒子群优化（Simplified Particle Swarm Optimization,SPSO）算法进行间接学习结构离线训练模糊神经网络来确定模型参数,作为预失真器的初值,再利用最小均方（Least Mean Square,LMS）算法进行直接学习结构在线微调整预失真器参数,拟合功放的非线性和记忆效应。该方法结构简单,收敛速度快且精度高,避免了局部最优。实验结果表明,该方案邻信道功率比经典的双环结构预失真方法约改善7 dB,功放的线性化性能明显提高,由此验证了其可行性。     

一种改进的RBF神经网络参数优化方法

提出了一种改进的RBF神经网络参数优化算法。通过资源分配网络算法确定隐含层节点个数,引入剪枝策略删除对网络贡献不大的节点,用改进的粒子群算法对RBF网络的中心、宽度、权值进行优化,使RBF网络不仅可以得到合适的结构,同时也可以得到合适的控制参数。将此算法用于连续搅拌釜反应器模型的预测,结果表明,此算法优化后的RBF网络结构小,并且具有较高的泛化能力。     

Matlab与C混合编程实现Type-2模糊系统

Type-2模糊系统的理论有着广泛的应用,但是Type-2模糊系统结构较Type-1模糊系统复杂,且编程实现难度和计算强度都较大.Matlab平台下,运用M语言调试算法,在实现Type-2模糊系统的基础上,利用C语言的高效性优化算法,改进程序,克服了Matlab计算瓶颈的问题.给出的Matlab C混合编程实现Type-2模糊系统的程序,编译后可以函数的形式调用,既保留了Matlab平台处理数据的便捷性,又具有很高的执行效率.仿真结果表明该方法的有效性.     

神经网络泛化性能优化算法

基于提高神经网络泛化性能的目标提出了神经网络泛化损失率的概念,解析了与前一周期相比当前网络误差的变化趋势,在此基础上导出了基于泛化损失率的神经网络训练目标函数.利用新的目标函数和基于量子化粒子群算法的神经网络训练方法,得到了一种新的网络泛化性能优化算法.实验结果表明,将该算法与没有引入泛化损失率的算法相比,网络的收敛性能和泛化性能都有明显提高.     

Meta-modeling using generalized regression neural network and particle swarm optimization

Swarm intelligence (SI) and evolutionary computation (EC) algorithms are often used to solve various optimization problems. SI and EC algorithms generally require a large number of fitness function evaluations (i.e., higher computational requirements) to obtain quality solutions. This requirement becomes more challenging when optimization problems are associated with computationally expensive analyses and/or simulation tasks. To tackle this issue, meta-modeling has shown successful results in improving computational efficiency by approximating the fitness or constraint functions of these complex optimization problems. Meta-modeling approaches typically use polynomial regression, kriging, radial basis function network, and support vector machines. Less attention has been given to the generalized regression neural network approach, and yet, it offers several advantages. Specifically, the model construction process does not require iterations. Its only one parameter is known to be less sensitive and usually requires less effort in selecting an optimal parameter. We use generalized regression neural network in this paper to construct meta-models and to approximate the fitness function in particle swarm optimization. To assess the performance and quality of these solutions, the proposed meta-modeling approach is tested on ten benchmark functions. The results are promising in terms of the solution quality and computational efficiency, especially when compared against the results of particle swarm optimization without meta-modeling and several other meta-modeling methods in previously published literature.     

Using B-spline neural network to extract fuzzy rules for a centrifugal pump monitoring

In mechanical equipment monitoring tasks, fuzzy logic theory has been applied to situations where accurate mathematical models are unavailable or too complex to be established, but there may exist some obscure, subjective and empirical knowledge about the problem under investigation. Such kind of knowledge is usually formalized as a set of fuzzy relationships (rules) on which the entire fuzzy system is based upon. Sometimes, the fuzzy rules provided by human experts are only partial and rarely complete, while a set of system input/output data are available. Under such situations, it is desirable to extract fuzzy relationships from system data and combine human knowledge and experience to form a complete and relevant set of fuzzy rules. This paper describes application of B-spline neural network to monitor centrifugal pumps. A neuro-fuzzy approach has been established for extracting a set of fuzzy relationships from observation data, where B-spline neural network is employed to learn the internal mapping relations from a set of features/conditions of the pump. A general procedure has been setup using the basic structure and learning mechanism of the network and finally, the network performance and results have been discussed.     

模糊粒子群神经网络算法及应用

针对流程工业神经网络建模时,BP算法的局部收敛问题,采用模糊粒子群算法改进神经网络学习问题。该算法将模糊粒子群引入神经网络学习算法,使得粒子群的权重自适应更新,同时模糊粒子群自适应调整神经网络权重参数,改进网络收敛性。将算法用于建立乙烯裂解炉出口温度(COT)、裂解产品收率软测量模型,取得了较好的应用效果。     

Application of artificial neural network and fuzzy logic in a case-based system for initial process parameter setting of injection molding

Determination of initial process meters for injection molding is a highly skilled job and based on skilled operators know-how and intuitive sense acquired through long-term experience rather than a theoretical and analytical approach. Facing with the global competition, the current trial-and-error practice becomes inadequate. In this paper, application of artificial neural network and fuzzy logic in a case-based system for initial process meter setting of injection molding is described. Artificial neural network was introduced in the case adaptation while fuzzy logic was employed in the case indexing and similarity analysis. A computer-aided system for the determination of initial process meter setting for injection molding based on the proposed techniques was developed and validated in a simulation environment. The preliminary validation tests of the system have indicated that the system can determine a set of initial process meters for injection molding quickly without relying on experienced molding personnel, from which good quality molded parts can be produced.