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1.
This paper presents the results of an experimental study that evaluated the ability of quantum neural networks (QNNs) to capture and quantify uncertainty in data and compared their performance with that of conventional feedforward neural networks (FFNNs). In this work, QNNs and FFNNs were trained to classify short segments of epileptic seizures in neonatal EEG. The experiments revealed significant differences between the internal representations created by trained QNNs and FFNNs from sample information provided by the training data. The results of this experimental study also confirmed that the responses of trained QNNs are more reliable indicators of uncertainty in the input data compared with the responses of trained FFNNs.  相似文献   

2.
Quantum neural networks (QNNs): inherently fuzzy feedforward neuralnetworks   总被引:7,自引:0,他引:7  
This paper introduces quantum neural networks (QNNs), a class of feedforward neural networks (FFNNs) inherently capable of estimating the structure of a feature space in the form of fuzzy sets. The hidden units of these networks develop quantized representations of the sample information provided by the training data set in various graded levels of certainty. Unlike other approaches attempting to merge fuzzy logic and neural networks, QNNs can be used in pattern classification problems without any restricting assumptions such as the availability of a priori knowledge or desired membership profile, convexity of classes, a limited number of classes, etc. Experimental results presented here show that QNNs are capable of recognizing structures in data, a property that conventional FFNNs with sigmoidal hidden units lack.  相似文献   

3.
This paper introduces a learning algorithm that can be used for training reformulated radial basis function neural networks (RBFNNs) capable of identifying uncertainty in data classification. This learning algorithm trains a special class of reformulated RBFNNs, known as cosine RBFNNs, by updating selected adjustable parameters to minimize the class-conditional variances at the outputs of their radial basis functions (RBFs). The experiments verify that quantum neural networks (QNNs) and cosine RBFNNs trained by the proposed learning algorithm are capable of identifying uncertainty in data classification, a property that is not shared by cosine RBFNNs trained by the original learning algorithm and conventional feed-forward neural networks (FFNNs). Finally, this study leads to a simple classification strategy that can be used to improve the classification accuracy of QNNs and cosine RBFNNs by rejecting ambiguous feature vectors based on their responses.  相似文献   

4.
The purpose of this article is to demonstrate the use of feedforward neural networks (FFNNs), adaptive neural fuzzy inference systems (ANFIS), and probabilistic neural networks (PNNs) to discriminate between earthquakes and quarry blasts in Istanbul and vicinity (the Marmara region). The tectonically active Marmara region is affected by the Thrace-Eski?ehir fault zone and especially the North Anatolian fault zone (NAFZ). Local MARNET stations, which were established in 1976 and are operated by the Kandilli Observatory and Earthquake Research Institute (KOERI), record not only earthquakes that occur in the region, but also quarry blasts. There are a few quarry-blasting areas in the Gaziosmanpa?a, Çatalca, Ömerli, and Hereke regions. Analytical methods were applied to a set of 175 seismic events (2001-2004) recorded by the stations of the local seismic network (ISK, HRT, and CTT stations) operated by the KOERI National Earthquake Monitoring Center (NEMC). Out of a total of 175 records, 148 are related to quarry blasts and 27 to earthquakes. The data sets were divided into training and testing sets for each region. In all the models developed, the input vectors consist of the peak amplitude ratio (S/P ratio) and the complexity value, and the output is a determination of either earthquake or quarry blast. The success of the developed models on regional test data varies between 97.67% and 100%.  相似文献   

5.
This article presents the results of a study aimed at the development of a system for short‐term electric power load forecasting. This was attempted by training feedforward neural networks (FFNNs) and cosine radial basis function (RBF) neural networks to predict future power demand based on past power load data and weather conditions. This study indicates that both neural network models exhibit comparable performance when tested on the training data but cosine RBF neural networks generalize better since they outperform considerably FFNNs when tested on the testing data. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 591–605, 2005.  相似文献   

6.
认识风廓线雷达数据在不同天气条件下的普适性特征对于改善预报服务质量具有重要意义.本文基于数据挖掘中的聚类技术,以天津静海风廓线雷达逐时观测数据为研究对象,构建了风廓线雷达数据特征聚类分析模型,并在此基础上挖掘出了静海风廓线雷达的最大探测高度、最大垂直速度在晴天、多云、降水发生前、降水期间和降水结束后等天气条件下的不同特征,为天气预报服务提供了新参考依据,为风廓线雷达数据特征分析提供了新思路.  相似文献   

7.
Quantized neural networks (QNNs), which use low bitwidth numbers for representing parameters and performing computations, have been proposed to reduce the computation complexity, storage size and memory usage. In QNNs, parameters and activations are uniformly quantized, such that the multiplications and additions can be accelerated by bitwise operations. However, distributions of parameters in neural networks are often imbalanced, such that the uniform quantization determined from extremal values may underutilize available bitwidth. In this paper, we propose a novel quantization method that can ensure the balance of distributions of quantized values. Our method first recursively partitions the parameters by percentiles into balanced bins, and then applies uniform quantization. We also introduce computationally cheaper approximations of percentiles to reduce the computation overhead introduced. Overall, our method improves the prediction accuracies of QNNs without introducing extra computation during inference, has negligible impact on training speed, and is applicable to both convolutional neural networks and recurrent neural networks. Experiments on standard datasets including ImageNet and Penn Treebank confirm the effectiveness of our method. On ImageNet, the top-5 error rate of our 4-bit quantized GoogLeNet model is 12.7%, which is superior to the state-of-the-arts of QNNs.  相似文献   

8.
Feed-forward neural networks (FFNNs) are among the most important neural networks that can be applied to a wide range of forecasting problems with a high degree of accuracy. Several large-scale forecasting competitions with a large number of commonly used time series forecasting models conclude that combining forecasts from more than one model often leads to improved performance, especially when the models in the ensemble are quite different. In the literature, several hybrid models have been proposed by combining different time series models together. In this paper, in contrast of the traditional hybrid models, a novel hybridization of the feed-forward neural networks (FFNNs) is proposed using the probabilistic neural networks (PNNs) in order to yield more accurate results than traditional feed-forward neural networks. In the proposed model, the estimated values of the FFNN models are modified based on the distinguished trend of their residuals and optimum step length, which are respectively yield from a probabilistic neural network and a mathematical programming model. Empirical results with three well-known real data sets indicate that the proposed model can be an effective way in order to construct a more accurate hybrid model than FFNN models. Therefore, it can be applied as an appropriate alternative model for forecasting tasks, especially when higher forecasting accuracy is needed.  相似文献   

9.
Remote sensors of various types have contributed increasingly over the past decade to studies of meteorological processes affecting air quality over mesoscale domains. Doppler sodars and lidars as well as newly emerging 915-MHz radar wind profiler technology are shown to describe well mean wind and temperature profiles. A number of air quality field research programmes have now deployed these instruments in various combinations in mesoscale experiments. Three studies provide examples for discussion of mean wind and temperature profiles. Unfortunately, many remote sensing instruments have not realized their full potential for measurement of turbulent momentum and heat fluxes as well as mixed-layer depth. A simple four-beam Doppler acoustic system provides a preliminary example of such potential applications. Furthermore, pattern-recognition methods, although subjective in nature, can be applied to time-height cross sections of reflectivity with the data of use in the interpretation of dispersion process in the atmoshpheric boundary layer  相似文献   

10.
In this paper, we present the feed-forward neural network (FFNN) and recurrent neural network (RNN) models for predicting Boolean function complexity (BFC). In order to acquire the training data for the neural networks (NNs), we conducted experiments for a large number of randomly generated single output Boolean functions (BFs) and derived the simulated graphs for number of min-terms against the BFC for different number of variables. For NN model (NNM) development, we looked at three data transformation techniques for pre-processing the NN-training and validation data. The trained NNMs are used for complexity estimation for the Boolean logic expressions with a given number of variables and sum of products (SOP) terms. Both FFNNs and RNNs were evaluated against the ISCAS benchmark results. Our FFNNs and RNNs were able to predict the BFC with correlations of 0.811 and 0.629 with the benchmark results, respectively.  相似文献   

11.
An online clustering task is considered for machine state monitoring purpose. In the previous authors’ researches a classical ART-2 network was tested for online classification of operational states in the context of a wind turbine monitoring. Some drawbacks, however, were found when a data stream size had been increased. This case is investigated in this paper. Classical ART-2 network can cluster data incorrectly when data points are compared by using Euclidean distance. Furthermore, ART-2 network can lose accuracy when data stream is processed for long time. The way of improving the ART-2 network is considered and two main steps of that are taken. At first, the stereographic projection is implemented. At the second step, a new type of hybrid neural system which consists of ART-2 and RBF networks with data processed by using the stereographic projection is introduced. Tests contained elementary scenarios for low-dimensional cases as well as higher dimensional real data from wind turbine monitoring. All the tests implied that an efficient system for online clustering had been found.  相似文献   

12.
雷达目标检测近年来一直是雷达信号处理中的重要任务,在探测监控等安全领域中有非常重要的作用;针对传统恒虚警目标检测方法存在的环境适应能力较弱、复杂地形环境下雷达虚警数量急剧上升等问题,提出一种基于卷积神经网络的雷达目标检测方法;以雷达回波信号数据处理后得到的距离-多普勒图像作为模型的训练集和测试集,设计基于FasterR-CNN结构的雷达目标检测模型,训练模型并将测试结果与传统恒虚警目标检测算法结果相比较,所设计的模型提升了雷达目标检测正确率并较大地减少了虚警数量,这表明将卷积神经网络应用于雷达回波信号的处理任务中是可行的。  相似文献   

13.
量子神经网络由于结合了量子计算和神经网络的优点, 近年来受到了广泛的关注. 然而由于目前量子计算 资源受限(如量子比特数、量子逻辑门的保真度等)以及贫瘠高原现象(量子神经网络优化过程中解空间变得平坦时 出现的训练困难)的存在, 量子神经网络当前还难以大规模训练. 针对上述问题, 本文面向量子–经典混合神经网络 模型提出了一种基于无监督学习的特征提取方法. 所采用的无监督学习方法结合了量子自编码器和K-medoids聚类 方法, 可用于多层次结构的特征学习. 该方法创新地利用了K-mediods方法对训练得到的量子自编码器进行聚类, 以 最大化量子自编码器性质的差异. 进一步, 本文在轴承异常检测问题上, 通过实验验证了所提出的无监督特征提取 方法的有效性和实用性, 测试集准确率在二分类、四分类和十分类分别达到100%, 89.6%和81.6%.  相似文献   

14.
基于灰色关联度神经网络的雷达型号识别模型   总被引:1,自引:1,他引:0  
针对现代电子战对雷达目标信号的复杂性和残缺性以及实用雷达目标识别系统的健壮性和扩展性等要求,提出一种基于灰色关联度和BP神经网络的灰色神经网络识别模型.首先采用比较成熟的BP神经网络对侦察雷达目标信号进行粗分,识别出雷达的体制;然后把模板数据库中该体制的雷达标准数据作为比较序列,建立差异信息空间,再把观测的数据和比较序列进行灰关联度分析,得出其对应的关联度,从而识别出雷达的具体型号.仿真结果表明在对参数残缺或畸变以及新体制的雷达辐射源进行识别时,取得良好的效果.表明综合灰色神经网络对辐射源进行识别是完全可行的,并且可以提高识别率、可靠性.  相似文献   

15.
基于神经网络的飞控系统传感器故障诊断的研究   总被引:4,自引:0,他引:4  
在标准逆传播神经网络的基础上,提出了一种改进的逆传播神经网络,用来消除标准逆传播神经网络的缺陷,并且设计了一个主神经网络和三个分布神经网络的结构,通过神经网络的在线学习,得到需要的参数估计。用它与传感器实际测得的实际值比较,可判断出阶跃故障,并且给出了仿真实例。  相似文献   

16.
曹茂俊  李盼池  肖红 《计算机工程》2011,37(12):182-184
提出一种基于量子神经网络(QNNs)的比例积分微分(PID)参数在线调整方法.通过构造受控量子旋转门,给出一个量子神经元模型,其中包括输入量子比特相位的旋转角度和控制量2种设计参数.在此基础上提出一个量子神经网络模型,利用梯度下降法设计该模型的学习算法,并将其用于PID参数的在线调整,实验结果表明,QNNs的调整能力及...  相似文献   

17.
短期风电功率预测对电力系统的安全稳定运行和能源的优化配置具有重要意义。鉴于卷积神经网络(CNN)高效的数据特征提取能力,以及长短期记忆网络(LSTM)描述时间序列长期依赖关系的能力。为了提高短期风电功率预测的精度,设计了一种基于CNN和LSTM的风电功率预测模型。该模型利用卷积神经网络对风电功率、风速、风向数据进行多层卷积和池化堆叠计算,提取风电功率相关数据的特征图谱。为了描述风电功率序列的时序依从关系,将图谱特征信息作为长短期记忆网络的输入信息,计算得到风电功率的预测结果。采用西班牙某风电场的实测数据进行模型预测精度验证。结果表明,该模型较LSTM、Elman模型具有更好的预测性能。  相似文献   

18.
An expert system for fault diagnosis in internal combustion engines using adaptive order tracking technique and artificial neural networks is presented in this paper. The proposed system can be divided into two parts. In the first stage, the engine sound emission signals are recorded and treated as the tracking of frequency-varying bandpass signals. Ordered amplitudes can be calculated with a high-resolution adaptive filter algorithm. The vital features of signals with various fault conditions are obtained and displayed clearly by order figures. Then the sound energy diagram is utilized to normalize the features and reduce computation quantity. In the second stage, the artificial neural network is used to train the signal features and engine fault conditions. In order to verify the effect of the proposed probability neural network (PNN) in fault diagnosis, two conventional neural networks that included the back-propagation (BP) network and radial-basic function (RBF) network are compared with the proposed PNN network. The experimental results indicated that the proposed PNN network achieved the best performance in the present fault diagnosis system.  相似文献   

19.
提出了一种基于神经网络与专家系统,具有一定自学习能力的铸造质量控制方法,具体描述了其工作原理.该系统由工艺参数优化模块和缺陷诊断模块组成.工艺参数优化模块以神经网络为推理机,以过去生产数据和有限元数值模拟数据作为训练样本,建立工艺参数与铸件性能之间的非线性关系.缺陷诊断模块以基于产生式规则的推理方式,诊断缺陷类型、产生原因及防治措施,且诊断结果反馈到工艺参数优化模块,用于神经网络再学习.试验结果表明,该系统提高了工艺参数准确率,增强了缺陷诊断能力,减少了铸件次品率.  相似文献   

20.
Pattern recognition has a long history within electrical engineering but has recently become much more widespread as the automated capture of signal and images has been cheaper. Very many of the application of neural networks are to classification, and so are within the field of pattern recognition and classification. In this paper, we explore how probabilistic neural networks fit into the earlier framework of pattern recognition of partial discharge patterns since the PD patterns are an important tool for diagnosis of HV insulation systems. Skilled humans can identify the possible insulation defects in various representations of partial discharge (PD) data. One of the most widely used representation is phase resolved PD (PRPD) patterns. Also this paper describes a method for the automated recognition of PRPD patterns using a novel complex probabilistic neural network system for the actual classification task. The efficacy of composite neural network developed using probabilistic neural network is examined.  相似文献   

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