共查询到20条相似文献,搜索用时 78 毫秒
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异常数据检测是保障无线传感器网络节点数据准确性和可靠性的重要步骤。针对无线传感器网络节点异常数据检测问题,提出一种基于卷积神经网络的异常数据检测方法。该方法是对正常数据和注入故障后生成的异常数据进行归一化处理后映射成的灰度图片作为卷积神经网络的输入数据,并且基于LeNet-5卷积神经网络设计了合适的卷积层特征面及全连接层的参数,构造了3种新的卷积神经网络模型。该模型通过卷积层自主学习数据特征,解决了传统检测算法的性能容易受到相关阈值影响的问题。通过网络公开数据集进行模型测试,结果表明该方法具有很好的检测性能和较高的可靠性 相似文献
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RUDY SETIONO HUAN LIU 《连接科学》1998,10(1):21-42
The hidden layer of backpropagation neural networks (NNs) holds the key to the networks' success in solving pattern classification problems. The units in the hidden layer encapsulate the network's internal representations of the outside world described by the input data. this paper, the hidden representations of trained networks are investigated by means simple greedy clustering algorithm. This clustering algorithm is applied to networks have been trained to solve well-known problems: the monks problems, the 5-bit problem and the contiguity problem. The results from applying the algorithm to problems with known concepts provide us with a better understanding of NN learning. These also explain why NNs achieve higher predictive accuracy than that of decision-tree methods. The results of this study can be readily applied to rule extraction from Production rules are extracted for the parity and the monks problems, as well as benchmark data set: Pima Indian diabetes diagnosis. The extracted rules from the Indian diabetes data set compare favorably with rules extracted from ARTMAP NNs terms of predictive accuracy and simplicity. 相似文献
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Neural network solution of the inverse vibration problem 总被引:1,自引:0,他引:1
The feasibility of using general regression neural networks (GRNN) to solve the inverse vibration problem of cracked structures was investigated. The case study used in the investigation was a steel cantilever beam with a single edge crack. The first six natural frequencies were used as network inputs, and crack size and crack location were the outputs. The effect of the number of frequency inputs to the network on prediction accuracy was quantitatively evaluated. The results show that GRNN is a powerful instrument for predicting crack size and location over a wide range, and that the prediction accuracy increases with larger number of vibration modes. 相似文献
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This paper introduces a new method called Dynamic Node Creation (DNC) which automatically grows BP networks until the target problem is solved. DNC sequentially adds nodes one at a time to the hidden layer(s) of the network until the desired approximation accuracy is achieved. Simulation results for parity, symmetry, binary addition, and the encoder problem are presented. The procedure was capable of finding known minimal topologies in many cases, and was always within three nodes of the minimum. Computational expense for finding the solutions was comparable to training normal BP networks with the same final topologies. Starting out with fewer nodes than needed to solve the problem actually seems to help find a solution. The method yielded a solution for every problem tried. 相似文献
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Charles R. Day James C. Austin John B. Butcher Peter W. Haycock Anthony T. Kearon 《NDT & E International》2009,42(5):446-451
In this article, we report on the application of neural networks to the problem of making an element-specific determination of unknown metal targets based on the characteristics of their transmitted X-ray signatures. Our method was applied to two groups of metal targets that we characterised as light elements (atomic numbers between 40 and 50) and heavy elements (atomic numbers between 73 and 83). In all cases their X-ray signatures were pre-processed; randomly allocated into training and testing datasets; and then presented to a self-organising map neural network in order to perform the element-specific determination. The technique was able to make a correct determination of unknown metal targets with an accuracy of 95% for the heavy elements and 99% for the light elements. 相似文献
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RUDY SETIONO 《连接科学》1995,7(2):147-166
A new method for constructing a feedforward neural network is proposed. The method starts with a single hidden unit and more units are added to the hidden layer one at a time until a network that completely recognizes all its input patterns is constructed. The novel idea about this method is that the network is trained to maximize a certain likelihood function and not to minimize the more widely used mean squared error function. We show that when a new hidden unit is added to the network, this likelihood function is guaranteed to increase and this increase ensures the finite termination of the method. We also provide a wide range of numerical results. The method was tested on the n -bit parity problems and the spiral problem. It was able to construct networks having less than n hidden units that solve the n -bit parity problems for n = 4, 5, 6, 7 and 8. The method was also tested on some real-world data and the networks it constructed were shown to be able to predict patterns not in the training set with more than 95% accuracy. 相似文献
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为解决柴油机故障诊断这一复杂问题,提出了一种基于智能互补融合的智能诊断方法.采用蚁群算法(ACA)对反映运行工况的特征参数进行属性约简,剔除不必要的属性.根据约简结果,建立了基于径向基函数(RBF)神经网络的故障诊断系统.网络的训练对比结果表明,基于蚁群算法的约简处理简化了输入神经网络的数据维数,提高了网络的训练效率和故障分类准确性. 相似文献
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Anapproachofartificialneuralnetworktoroboticweldingprocessmodelling¥LiYan(HarbinResearchInstituteofWeldingJohnNorrishandT.E.B... 相似文献
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Anthony Robins 《连接科学》1996,8(2):259-276
In this paper we explore the topic of the consolidation of information in neural network learning. One problem in particular has limited the ability of a broad range of neural networks to perform ongoing learning and consolidation. This is 'catastrophic forgetting', the tendency for new information, when it is learned, to disrupt old information. We will review and slightly extend the rehearsal and pseudorehearsal solutions to the catastrophic forgetting problem presented in Robins (1995). The main focus of this paper is to then relate these mechanisms to the consolidation processes which have been proposed in the psychological literature regarding sleep. We suggest that the catastrophic forgetting problem in artificial neural networks (ANNs) is a problem that has actually occurred in the evolution of the mammalian brain, and that the pseudorehearsal solution to the problem in ANNs is functionally equivalent to the sleep consolidation solution adopted by the brain. Finally, we review related work by McClelland et al. (1995) and propose a tentative model of learning and sleep that emphasizes consolidation mechanisms and the role of the hippocampus. 相似文献
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In this paper, a neural network approach is employed to deal with the blending problem with surface construction based on digitized points, and some related computational cases are presented. Compared with the NURBS method, this neural network based approach does not need the derivation of complex equation provided that a limited number of offset points are obtained, and its accuracy can meet general engineering needs. 相似文献
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由于机械手逆运动学问题的求解存在多解且非常复杂,以往解决机械手的逆运动学求解问题主要是通过神经网络逆模型来建立机械手的逆运动学模型然后通过遗传或改进的BP算法来训练神经网络的权(阀)值矩阵从而达到问题的求解,然而这种方法在建立神经网络的逆模型时要对训练数据进行限制或筛选使其成为单解问题(即满足逆映射关系存在的要求),这对于那些对数据事先进行处理很困难或根本无法进行的复杂系统是不可行,为此提出了一种采用小脑神经网络和约束条件相结合的方法来解决逆运动学问题.研究结果表明此方法可以很好的解决机械手的逆运动学控制问题,同时该方法可以推广应用到那些通过数学模型求解困难或者数学模型不确知的复杂系统反求问题. 相似文献
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SHERIF HASHEM 《连接科学》1996,8(3-4):315-336
Collinearity or linear dependency among a number of estimators may pose a serious problem when combining these estimators. The corresponding outputs of a number of neural networks NNs , which are trained to approximate the same quantity or quantities , may be highly correlated. Thus, the estimation of the optimal weights for combining such networks may be subjected to the harmful effects of collinearity, which results in a final model with inferior generalizations ability compared with the individual networks. In this paper, we investigate the harmful effects of collinearity on the estimation of the optimal weights for combining a number on NNs. We discuss an approach for selecting the component networks in order to improve the generalization ability of the combined model. Our experimental results demonstrate significant improvements in the generalization ability of a combined model as a result of the proper selection of the component networks. The approximation accuracy of the combined model is compared with two common alternatives: the apparent best network or the simple average of the corresponding outputs of the networks. 相似文献
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This paper analyses a three-layer connectionist network that solves a translation-invariance problem, offering a novel explanation for transposed letter effects in word reading. Analysis of the hidden unit encodings provides insight into two central issues in cognitive science: (1) What is the novelty of claims of “modality-specific” encodings? and (2) How can a learning system establish a complex internal structure needed to solve a problem? Although these topics (embodied cognition and learnability) are often treated separately, we find a close relationship between them: modality-specific features help the network discover an abstract encoding by causing it to break the initial symmetries of the hidden units in an effective way. While this neural model is extremely simple compared to the human brain, our results suggest that neural networks need not be black boxes and that carefully examining their encoding behaviours may reveal how they differ from classical ideas about the mind-world relationship. 相似文献