Results 51 to 60 of about 480 (135)

结合KPCA的阴性选择变压器故障诊断

open access: yesGaoya dianqi, 2015
为解决常规阴性选择方法在故障诊断领域存在漏诊和故障难以有效细分检测的缺陷,文中提出一种结合核主成分分析(KPCA)的实值阴性选择自适应分类算法,采用实值编码,以欧氏距离衡量被检样本与检测器的亲和度,具备学习和分类的能力,实现了故障的细分类。针对电力变压器油中溶解气体数据(DGA),应用核主成分分析技术提取样本特征量,经归一化处理后对所提出的算法进行训练,测试结果证明了该方法的有效性,与BP神经网络、最小二乘支持向量机相比,获得了更高的故障检出率,对电力变压器典型的4类故障检出率达到了90%以上。
陈鹏
doaj  

Information monitor method of RFID system based on logarithm spectrum RF fingerprint identification [PDF]

open access: yes, 2014
To make up for the shortcomings of the information control in RFID systems, an information monitor method of passive RFID systems based on emitter identification was proposed.
Hong-lin YUAN, Yan YAN, Zhi-hua BAO
core   +1 more source

悬式复合绝缘子电晕放电紫外图像光斑面积

open access: yesGaoya dianqi, 2013
笔者采用数字图像处理算法提取了紫外图像中的放电光斑区域并定义了"光斑面积"参数,试验研究了10、35、110 kV复合绝缘子高压侧电晕放电时的紫外图像和放电量的变化特性,得到了光斑面积与视在放电量之间的关系曲线。获得了光斑面积随仪器增益和观测距离变化时的试验数据并利用MATLAB的CFTOOL工具箱函数进行了拟合分析,研究表明光斑面积与增益之间近似满足于指数变化规律,光斑面积与距离之间近似满足于幂函数变化规律。在此基础上论文给出了50%、60%、70%、80%4种增益 ...
陈磊   +4 more
doaj  

Comparative research on multiple estimation models of magnesium content in honey pummelo leaves based on spectral indices [PDF]

open access: yes
[Objectives] Guanxi honey pummelo [Citrus grandis (L.) Osbeck] has a large planting area in Pinghe County, Fujian Province, China. For a long time, honey pummelo farmers have often only focused on the application of fertilizers containing large amounts ...
KONG Qingbo, LI Fangliang, ZHANG Qing
core   +1 more source

The performance analysis of power spectrum in a regulating valve′s fault diagnosis [PDF]

open access: yes, 2011
利用小波包分别提取调速阀振动时的正常信号和故障信号的Ar功率谱的特征值,之后利用提取的特征值作为lSSVM的输入,对调速阀的故障进行诊断,取得了良好效果,并与原始信号的效果进行了对比,并阐明了原因。By means of wavelet packet, this paper first extracts features from the AR power spectrum of signals in normal and fault state respectively, then the ...
吴文兵, 黄宜坚
core  

Long-term intuitionistic fuzzy time series forecasting model based on DTW [PDF]

open access: yes, 2016
In existing fuzzy time series forecasting models,the intuitionistic fuzzy relationship groups and deterministic transition rules excessively relied on scale of the training data.A long-term intuitionistic fuzzy time series (IFTS) fore-casting model based
Xiao-shi FAN   +3 more
core   +1 more source

Research and application of integrated grey support vector machine model [PDF]

open access: yes, 2009
对灰色预测gM(1,1)模型进行了分析,提出了集成灰色支持向量机的预测模型。分别对影响灰色预测gM(1,1)模型精度的背景值的计算、初值的选取以及数据序列的光滑度进行改进,提出了背景gM模型、初值gM模型、光滑度gM模型,并结合支持向量机的特点,将一维原始数据序列通过三个灰色模型得到的三组值作为支持向量机的输入,原始序列作为支持向量机的输出,训练得到最佳支持向量回归机模型。仿真结果表明了该模型的有效性。Based on grey prediction GM (1,1) model,an ...
吴顺祥, 周忠眉, 林耀进
core  

Research on Emotion Recognition Model Based on Hybrid Feature Extraction of EEG [PDF]

open access: yes, 2017
随着计算机技术尤其是人工智能的快速发展,拥有情感、具备表达情感和理解情感的能力已经成为人类与机器之间的重要区别。为了加强人机之间的交流和互动,尤其是发展人机之间带有情感交流的感性沟通,情感计算变得越来越重要,而作为其研究过程中不可或缺的重要环节,情绪识别也逐渐发展成为一大热门的研究领域。情绪识别主要是通过人类用户脸上的表情、说话的语气和语调、身体的姿势和行为以及生理信号等特征,来识别和判断人类用户的情绪状态,而基于生理信号的识别由于难以伪装和隐藏显得更加可靠和真实。 本文以人类脑电图 ...
张仕婧
core  

The Effect of Bispectrum Coupling Property on Fault Diagnosis [PDF]

open access: yes, 2013
为了对双谱的耦合性质进行分析,同时利用三阶累积量和双谱对溢流阀进行故障诊断。由于双谱与三阶累积量相比,可以用来描述二次相位耦合,对比实验结果表明,故障的种类不同,其耦合信息对于这些故障判断的影响也不一样。实验中还通过二维小波在不同的方向上对故障信号和正常信号进行特征提取,然后将这些特征值输入支持向量机进行故障判别,实验结果表明,无论考虑耦合因素与否,这些故障信号在不同的频率部分与其正常状态的区分程度都不一样。In order to analyze the coupling properties of ...
吴文兵, 陈文芗, 黄宜坚
core  

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