用蛙跳算法优化RBF神经网络参数的研究

针对径向基函数（Radial Basis Functions,RBF）神经网络结构参数确定问题,提出了一种基于蛙跳算法优化RBF神经网络参数的新方法。将RBF神经网络参数组成一个多维向量,作为蛙跳算法中的参数进行优化。以适应度函数为标准,在可行解空间中搜索最优解,并对蛙跳算法进行了改进。非线性函数逼近实验结果表明,该优化算法相对标准遗传优化算法、粒子群优化算法有较小的均方误差,具有更好的逼近能力。     

Evolutionary Generalized Radial Basis Function neural networks for improving prediction accuracy in gene classification using feature selection

Radial Basis Function Neural Networks (RBFNNs) have been successfully employed in several function approximation and pattern recognition problems. The use of different RBFs in RBFNN has been reported in the literature and here the study centres on the use of the Generalized Radial Basis Function Neural Networks (GRBFNNs). An interesting property of the GRBF is that it can continuously and smoothly reproduce different RBFs by changing a real parameter τ. In addition, the mixed use of different RBF shapes in only one RBFNN is allowed. Generalized Radial Basis Function (GRBF) is based on Generalized Gaussian Distribution (GGD), which adds a shape parameter, τ, to standard Gaussian Distribution. Moreover, this paper describes a hybrid approach, Hybrid Algorithm (HA), which combines evolutionary and gradient-based learning methods to estimate the architecture, weights and node topology of GRBFNN classifiers. The feasibility and benefits of the approach are demonstrated by means of six gene microarray classification problems taken from bioinformatic and biomedical domains. Three filters were applied: Fast Correlation-Based Filter (FCBF), Best Incremental Ranked Subset (BIRS), and Best Agglomerative Ranked Subset (BARS); this was done in order to identify salient expression genes from among the thousands of genes in microarray data that can directly contribute to determining the class membership of each pattern. After different gene subsets were obtained, the proposed methodology was performed using the selected gene subsets as new input variables. The results confirm that the GRBFNN classifier leads to a promising improvement in accuracy.     

基于遗传优化径向基概率神经网络的岩性识别应用

岩性识别是测井数据解释中最关键的一环,但传统的岩性识别方法解释效率慢,精度低,受人为因素影响大。为此,提出一种遗传优化径向基概率神经网络(RBPNN)的岩性识别方法。该方法融合概率神经网络(PNN)和径向基函数神经网络(RBFNN)的优势来构造RBPNN,采用遗传算法搜索使得RBPNN训练法误差最小的最优隐中心矢量和相匹配的核函数控制参数,优化网络结构,提高收敛速度与精度,形成全结构遗传优化的RBPNN模型。实例应用表明,基于遗传优化RBPNN的岩性识别能够达到工程实际应用的规范标准,且是可行有效的,能够为油田地质勘探领域的岩性识别提供科学的理论支持与依靠。     

基于正则化RBF神经网络的钢包精炼炉电极系统智能建模

通过RBF神经网络和模糊推理系统的比较，得出正则化RBF神经网络的输出特性，在此基础上利用改进的最近邻聚类算法确定网络的隐层节点个数和高斯函数中心，并估计输出层权值。仿真结果表明了所提方案的有效性。     

基于AHP-RBF的Swift云存储负载预测

通过对Swift云存储中Proxy Node的负载因素研究,提出结合层次分析法（AHP）和混合递阶遗传训练的RBF神经网络实现对Swift云存储负载情况的预测,其中使用AHP构造对云存储系统的负载层次化模式,提高负载预测的综合精度,设计了RBF神经网络预测模型,用混合递阶遗传算法（HHGA）确定RBF神经网络的参数和结构。仿真实验结果表明,对Swift云存储负载的预测具有可行性,能为系统动态负载均衡决策提供依据。     

Parameter estimation of q-Gaussian Radial Basis Functions Neural Networks with a Hybrid Algorithm for binary classification

A classification problem is a decision-making task that many researchers have studied. A number of techniques have been proposed to perform binary classification. Neural networks are one of the artificial intelligence techniques that has had the most successful results when applied to this problem. Our proposal is the use of q-Gaussian Radial Basis Function Neural Networks (q-Gaussian RBFNNs). This basis function includes a supplementary degree of freedom in order to adapt the model to the distribution of data. A Hybrid Algorithm (HA) is used to search for a suitable architecture for the q-Gaussian RBFNN. The use of this type of more flexible kernel could greatly improve the discriminative power of RBFNNs. In order to test performance, the RBFNN with the q-Gaussian basis functions is compared to RBFNNs with Gaussian, Cauchy and Inverse Multiquadratic RBFs, and to other recent neural networks approaches. An experimental study is presented on 11 binary-classification datasets taken from the UCI repository. Moreover, aerial imagery taken in mid-May, mid-June and mid-July was used to evaluate the potential of the methodology proposed for discriminating Ridolfia segetum patches (one of the most dominant and harmful weeds in sunflower crops) in two naturally infested fields in southern Spain.     

一种基于模糊径向基神经网络的图像融合方法

传统的基于区域特征图像融合方法的一个难点是各源图像最佳权值的分配问题。该文利用径向基神经网络与T-S模糊推理模型具有函数等价性的特点,设计了一种模糊推理神经网络实现基于区域特征的图像融合,并用遗传算法优化网络参数。该网络能够自适应地动态获取优化的图像融合权值参数。仿真实验表明该算法有效可行,通过与传统的基于区域特征的图像融合算法相比,融合性能得到明显改善。     

径向基神经网络的汇率预测模型研究

针对BP网络存在着收敛速度慢和局部极小的问题,提出了一种基于径向基神经网络的汇率预测研究方法。将经济变量数据归一化处理,然后送入径向基神经网络（RBF）中训练,得出相应参数,再对汇率进行预测。详细的仿真实验以及与BP神经网络的比较表明,该方法不仅运算速度较快,且预测精度明显要高于传统BP神经网络所能达到的效果。     

基于RBF神经网络的传感器静态误差综合校正方法

以一受环境温度和电源波动影响的压力传感器为例,说明了具体实现方法和校正效果.并与采用BP神经网络进行误差校正的方法进行了比较.实验结果表明,采用RBF神经网络可以明显提高网络收敛速度,大大减小传感器静态误差,校正效果优于BP神经网络.     

Output value-based initialization for radial basis function neural networks

The use of Radial Basis Function Neural Networks (RBFNNs) to solve functional approximation problems has been addressed many times in the literature. When designing an RBFNN to approximate a function, the first step consists of the initialization of the centers of the RBFs. This initialization task is very important because the rest of the steps are based on the positions of the centers. Many clustering techniques have been applied for this purpose achieving good results although they were constrained to the clustering problem. The next step of the design of an RBFNN, which is also very important, is the initialization of the radii for each RBF. There are few heuristics that are used for this problem and none of them use the information provided by the output of the function, but only the centers or the input vectors positions are considered. In this paper, a new algorithm to initialize the centers and the radii of an RBFNN is proposed. This algorithm uses the perspective of activation grades for each neuron, placing the centers according to the output of the target function. The radii are initialized using the center’s positions and their activation grades so the calculation of the radii also uses the information provided by the output of the target function. As the experiments show, the performance of the new algorithm outperforms other algorithms previously used for this problem.     

Improving project-profit prediction using a two-stage forecasting system

Accurate project-profit prediction is a crucial issue because it can provide an early feasibility estimate for the project. In order to achieve accurate project-profit prediction, this study developed a novel two-stage forecasting system. In stage one, the proposed forecasting system adopts fuzzy clustering technology, fuzzy c-means (FCM) and kernel fuzzy c-means (KFCM), for the correct grouping of different projects. In stage two, least-squares support vector regression (LSSVR) technology is employed for forecasting the project-profit in different project groups, respectively. Moreover, genetic algorithms (GA) were simultaneously used to select the parameters of the LSSVR. The project data come from a real enterprise in Taiwan. In this study, some forecasting methodologies are also compared, for instance Generalized Regression Neural Network (GRNN), Radial Basis Function Neural Networks (RBFNN), and Back Propagation Neural Network (BPNN), to predict project-profit in this real case. Empirical results indicate that the two-stage forecasting system (FCM+LSSVR and KFCM+LSSVR) has superior performance in terms of forecasting accuracy, compared to other methods. Furthermore, in observing the results of the two-stage forecasting system, it can be seen that FCM+LSSVR can achieve superior performance, and KFCM+LSSVR can achieve consistently good performance. Therefore, based on the empirical results, the two-stage forecasting system was verified to efficiently provide credible predictions for project-profit forecasting.     

A local linear radial basis function neural network for financial time-series forecasting

In this paper a Local Linear Radial Basis Function Neural Network (LLRBFN) is presented. The difference between the proposed neural network and the conventional Radial Basis Function Neural Network (RBFN) is connection weights between the hidden layer and the output layer which are replaced by a local linear model in the LLRBFN. A modified Particle Swarm Optimization (PSO) with hunter particles is introduced for training the LLRBFN. The proposed methods have been applied for prediction of financial time-series and the result shows the feasibility and effectiveness.     

基于GA-NN的碳通量预测因素选择

研究和选择碳循环的影响因素是预测碳通量的重要环节,也是研究碳循环机理的重要步骤。然而从众多的影响因素中选择重要的因素,依然存在着困难。提出利用相关分析、遗传算法和神经网络进行碳通量预测的主要因素选择的方法,首先用相关分析去处冗余的因素;然后利用遗传算法,以选择最小数目的因素时,最大碳通量的观测值和用神经网络预测值的相关系数为准则,来搜寻最优的影响因素。实验证明该方法能在不影响（或尽量小地影响）预测精度的前提下,有效地选择出碳通量预测的重要因素。     

基于双决策子空间和神经网络的人脸表情识别

提出了一种新的基于双决策子空间和径向基函数（RBF）神经网络的人脸表情识别方法。该方法首先采用KPCA+ FLD算法在双决策子空间（核空间和值域空间）中进行决策分析,提取两类判决特征信息：非常规信息和常规信息,并按一定的规则融合这两类判决信息;再运用RBF神经网络分类器和融合特征信息进行人脸表情的分类识别。基于日本女性表情数据库JAFFE的实验结果表明,它是一种有效的人脸表情识别方法。     

基于概率神经网络的垃圾邮件分类

概率神经网络是由Specht博士在1989年提出的一种径向基神经网络的重要变形。本文提出了把概率神经网络用于垃圾邮件分类,并通过Matlab仿真试验与贝叶斯分类器进行比较,得到了比较理想的结果。     

Power transformer differential protection using neural network Principal Component Analysis and Radial Basis Function Neural Network

Many methods have been used to discriminate magnetizing inrush from internal faults in power transformers. Most of them follow a deterministic approach, i.e. they rely on an index and fixed threshold. This article proposes two approaches (i.e. NNPCA and RBFNN) for power transformer differential protection and address the challenging task of detecting magnetizing inrush from internal fault. These approaches based on the pattern recognition technique. In the proposed algorithm, the Neural Network Principal Component Analysis (NNPCA) and Radial Basis Function Neural Network (RBFNN) are used as a classifier. The principal component analysis is used to preprocess the data from power system in order to eliminate redundant information and enhance hidden pattern of differential current to discriminate between internal faults from inrush and over-excitation condition. The presented algorithm also makes use of ratio of voltage-to-frequency and amplitude of differential current for detection transformer operating condition. For both proposed cases, optimal number of neurons has been considered in the neural network architectures and the effect of hidden layer neurons on the classification accuracy is analyzed. A comparison among the performance of the FFBPNN (Feed Forward Back Propagation Neural Network), NNPCA, RBFNN based classifiers and with the conventional harmonic restraint method based on Discrete Fourier Transform (DFT) method is presented in distinguishing between magnetizing inrush and internal fault condition of power transformer. The algorithm is evaluated using simulation performed with PSCAD/EMTDC and MATLAB. The results confirm that the RBFNN is faster, stable and more reliable recognition of transformer inrush and internal fault condition.     

基于集成RBF神经网络的小类别手写体汉字识别系统

该文介绍了RBF神经网络的模型,讨论了RBF网络分类器的机理和特点,提出了一种集成RBF神经网络并应用于小类别手写体汉字识别系统的设计,采用了组合重心分解网格特征方法来提取汉字特征,设计了遗传进化隐层节点自生成算法用于RBF的训练。实验表明该小类别手写体汉字识别系统有很高的识别率,具有一定的实用推广价值。     

A gradient-based sequential radial basis function neural network modeling method

Radial basis function neural network (RBFNN) is widely used in nonlinear function approximation. One of the key issues in RBFNN modeling is to improve the approximation ability with samples as few as possible, so as to limit the network’s complexity. To solve this problem, a gradient-based sequential RBFNN modeling method is proposed. This method can utilize the gradient information of the present model to expand the sample set and refine the model sequentially, so as to improve the approximation accuracy effectively. Two mathematical examples and one practical problem are tested to verify the efficiency of this method. This article was originally presented in the fifth International Symposium on Neural Networks.     

A clustering algorithm for radial basis function neural network initialization

In this paper, we propose an Output-Constricted Clustering (OCC) algorithm for Radial Basis Function Neural Network (RBFNN) initialization. OCC first roughly partitions the output based on the required precision and then refinedly clusters data based on the input complexity within each output partition. The main contribution of the proposed clustering algorithm is that we introduce the concept of separability, which is a criterion to judge the suitability of the number of sub-clusters in each output partition. As a result, OCC is able to determine the proper number of sub-clusters with appropriate locations within each output partition by considering both input and output information. The resulting clusters from OCC are used to initialize RBFNN, with proper number and initial locations of for hidden neurons. As a result, RBFNN starting it's learning from a good point, is able to achieve better approximation performance than existing clustering methods for RBFNN initialization. This better performance is illustrated by a number of examples.     

云计算环境中基于混合蛙跳算法的资源调度

提出云计算环境中基于改进混合蛙跳算法（Shuffled Frog Leaping Algorithm,SFLA）的保证QoS（Quality of Service）资源调度方案。根据任务和资源的特点提出SFLA两种编码结构及其对应更新方程;对调度方案的QoS给出定义;提出根据QoS值进行个体优劣选择的改进SFLA;在CloudSim平台对算法进行了仿真实验。实验结果证明所提出的计算方案有效。