共查询到17条相似文献,搜索用时 234 毫秒
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首先基于一种扩展原理和模糊算术得到一类前向模糊神经网络--折线模糊神经网络.当模糊神经网络的输入为一般模糊数,激励函数为单调连续型Sigmoidal函数时,分析网络的拓扑结构及相关性质.然后证明该折线模糊神经网络能作为模糊连续函数的通用逼近器,其等价条件是模糊函数的递增性.因此关于输入为一般模糊数的折线模糊网络是否为通用逼近器的问题得到解决,且折线模糊神经网络的应用范围将进一步扩大. 相似文献
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一类模糊神经网络的函数逼近能力 总被引:6,自引:0,他引:6
根据多元Fourier变换理论提出一种多元函数的积分变换方法.据此讨论一类模糊神经网络作为函数逼近器时的逼近误差与其结构关系,得到模糊神经网络的逼近误差与其隐含层的节点数成反比的结论.并论证了模糊神经网络的函数逼近精度与输入变量数无关. 相似文献
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首先, 引入后件直联型分层方法及其推理规则, 以对广义混合模糊系统的输入变量实施分层, 获得分层广义混合模糊系统的输入输出表达式和推理规则数的计算公式; 然后, 基于??- 积分模(度量) 和分片线性函数证明分层后广义混合模糊系统对一类可积函数具有逼近性; 最后, 通过模拟实例给出后件直联型分层广义混合模糊系统对可积函数的逼近过程. 模拟结果表明, 所提出的方法不仅能使原系统模糊规则总数大大减少, 而且能使分层后系统仍具有逼近性.
相似文献6.
通过分析多元模糊值Bernstein多项式的近似特性,证明了4层前向正则模糊神经网络(FNN)的逼近性能,该类网络构成了模糊值函数的一类泛逼近器,即在欧氏空间的任何紧集上,任意连续模糊值函数能被这类FNN逼近到任意精度,最后通过实例给出了实现这种近似的具体步骤。 相似文献
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引入折线模糊数及其扩张运算,针对折线模糊神经网络,定义折线模糊数的最大摄动误差、训练模式对的γ摄动等概念,并基于纠错规则设计该网络连接权的学习算法。其次,当转移函数满足Lipschitz条件和训练模式对发生γ摄动时,在定义折线模糊神经网络对训练模式对摄动的全局稳定性的基础上,应用归纳法证明三层折线模糊神经网络的连接权具有稳定性,进而获得该网络关于训练模式对的γ摄动也具有全局稳定性。最后,通过模拟实例说明训练模式对的摄动对该网络稳定性的影响。 相似文献
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广义分层混合模糊系统及其泛逼近性 总被引:1,自引:0,他引:1
为避免广义模糊系统出现规则爆炸现象, 引进实参数将Mamdani模糊系统和T--S模糊系统统一起来建立广义分层混合模糊系统, 进而给出了广义分层混合模糊系统的数学表示. 此外, 应用方形分片线性函数的优良性质获得该广义分层混合模糊系统在积分模意义下仍具有泛逼近性, 并通过实例及仿真说明该分层混合模糊系统能够避免模糊规则爆炸问题. 相似文献
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基于核的非凸数据模糊K-均值聚类研究 总被引:4,自引:4,他引:0
将模糊K-均值聚类算法与核函数相结合,采用基于核的模糊K-均值聚类算法来进行聚类。核函数隐含地定义了一个非线性变换,将数据非线性映射到高维特征空间来增加数据的可分性。该算法能够解决模糊K-均值聚类算法对于非凸形状数据不能正确聚类的问题。 相似文献
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运用一种基于K-聚类算法的模糊径向基函数(RBF)神经网络对污水处理中的溶解氧质量浓度进行控制,该方法结合了模糊控制的推理能力强与神经网络学习能力强的特点,将模糊控制、RBF神经网络以及K-聚类学习算法相结合以在线调整隶属函数,优化控制规则。通过对阶跃输入仿真分析,其结果表明基于RBF的模糊神经网络控制器具有良好的动态性能、较强的鲁棒性和抗干扰能力,使其快速、准确地达到期望水平。 相似文献
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A novel fuzzy neural network and its approximation capability 总被引:1,自引:0,他引:1
刘普寅 《中国科学F辑(英文版)》2001,44(3):184-194
The polygonal fuzzy numbers are employed to define a new fuzzy arithmetic. A novel ex-tension principle is also introduced for the increasing function σ:R→R. Thus it is convenient to con-struct a fuzzy neural network model with succinct learning algorithms. Such a system possesses some universal approximation capabilities, that is, the corresponding three layer feedforward fuzzy neural networks can be universal approximators to the continuously increasing fuzzy functions. 相似文献
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Approximation capabilities of multilayer fuzzy neural networks on the set of fuzzy-valued functions 总被引:1,自引:0,他引:1
This paper first introduces a piecewise linear interpolation method for fuzzy-valued functions. Based on this, we present a concrete approximation procedure to show the capability of four-layer regular fuzzy neural networks to perform approximation on the set of all dp continuous fuzzy-valued functions. This approach can also be used to approximate d∞ continuous fuzzy-valued functions. An example is given to illustrate the approximation procedure. 相似文献
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Huan Huang Congxin Wu 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2014,18(12):2525-2540
In this paper, it is shown that four-layer regular fuzzy neural networks can serve as universal approximators for the sendograph-metric-continuous fuzzy-valued functions. The proof is constructive. We propose a principled method to design four-layer regular fuzzy neural neural network to approximate the target functions. In the previous work, a step function is used as the activation function. To improve the approximation accuracy, in the present work, we also consider using a semi-linear sigmoidal function as the activation function. Then it shows how to design the regular fuzzy neural networks (RFNNs) when the activation functions are the semi-linear sigmoidal function and the step function, respectively. After analyze the approximation accuracy of these two classes of RFNNs, it is found that the former has a much better performance than the latter in approximation accuracy. This conclusion also holds when the target functions satisfy other types of continuity. So the results in this paper can also be used to improve the related work. At last, we give a simulation example to validate the theoretical results. 相似文献
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Design of fuzzy systems using neurofuzzy networks 总被引:5,自引:0,他引:5
Introduces a systematic approach for fuzzy system design based on a class of neural fuzzy networks built upon a general neuron model. The network structure is such that it encodes the knowledge learned in the form of if-then fuzzy rules and processes data following fuzzy reasoning principles. The technique provides a mechanism to obtain rules covering the whole input/output space as well as the membership functions (including their shapes) for each input variable. Such characteristics are of utmost importance in fuzzy systems design and application. In addition, after learning, it is very simple to extract fuzzy rules in the linguistic form. The network has universal approximation capability, a property very useful in, e.g., modeling and control applications. Here we focus on function approximation problems as a vehicle to illustrate its usefulness and to evaluate its performance. Comparisons with alternative approaches are also included. Both, non-noisy and noisy data have been studied and considered in the computational experiments. The neural fuzzy network developed here and, consequently, the underlying approach, has shown to provide good results from the accuracy, complexity, and system design points of view. 相似文献
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The shapes of if-part fuzzy sets affect the approximating capability of fuzzy systems. In this paper, the fuzzy systems with the kernel-shaped if-part fuzzy sets are built directly from the training data. It is proved that these fuzzy systems are universal approximators and their uniform approximation rates can be estimated in the single-input-single-output (SISO) case. On the basis of these rates, the relationships between the approximating capability and the shapes of if-part fuzzy sets are developed for the fuzzy systems. Furthermore, the sinc functions that serve as input membership functions are proved to have the almost best approximation property in a particular class of membership functions. The theoretical results are confirmed from the simulation data. In addition, the estimations of the uniform approximation rates are extended to the multi-input-single-output (MISO) case. 相似文献