Internet traffic classification plays an important role in network management, and many approaches have been proposed to classify different kinds of internet traffics. A novel approach was proposed to classify network...Internet traffic classification plays an important role in network management, and many approaches have been proposed to classify different kinds of internet traffics. A novel approach was proposed to classify network applications by optimized back-propagation (BP) neural network. Particle swarm optimization (PSO) algorithm was used to optimize the BP neural network. And in order to increase the identification performance, wavelet packet decomposition (WPD) was used to extract several hidden features from the time-frequency information of network traffic. The experimental results show that the average classification accuracy of various network applications can reach 97%. Moreover, this approach optimized by BP neural network takes 50% of the training time compared with the traditional neural network.展开更多
针对当前风机轴承故障诊断准确率较低、诊断难度较大、耗时较长等问题,提出改进的灰狼优化(Improved Grey Wolf Optimization,IGWO)算法与支持向量机(Support Vector Machine,SVM)故障诊断方法。为了能够精准地提取故障特征,采用时频域...针对当前风机轴承故障诊断准确率较低、诊断难度较大、耗时较长等问题,提出改进的灰狼优化(Improved Grey Wolf Optimization,IGWO)算法与支持向量机(Support Vector Machine,SVM)故障诊断方法。为了能够精准地提取故障特征,采用时频域分析中的小波包分解法对故障振动信号进行特征提取,将小波包分解后的8个频带能量作为故障特征并构建特征向量;建立SVM故障模型并利用IGWO算法对SVM模型进行参数寻优,避免了灰狼优化(Grey Wolf Optimization,GWO)算法后期易陷入局部最优、收敛速度过慢等。实验结果表明,IGWO算法平均故障识别率高达99.3%,能够更加快速、高效、准确地识别故障的类型,为故障诊断的发展提供了良好的技术支撑。展开更多
基金Project(2007CB311106) supported by National Key Basic Research Program of ChinaProject(NEUL20090101) supported by the Foundation of National Information Control Laboratory of China
文摘Internet traffic classification plays an important role in network management, and many approaches have been proposed to classify different kinds of internet traffics. A novel approach was proposed to classify network applications by optimized back-propagation (BP) neural network. Particle swarm optimization (PSO) algorithm was used to optimize the BP neural network. And in order to increase the identification performance, wavelet packet decomposition (WPD) was used to extract several hidden features from the time-frequency information of network traffic. The experimental results show that the average classification accuracy of various network applications can reach 97%. Moreover, this approach optimized by BP neural network takes 50% of the training time compared with the traditional neural network.
文摘针对当前风机轴承故障诊断准确率较低、诊断难度较大、耗时较长等问题,提出改进的灰狼优化(Improved Grey Wolf Optimization,IGWO)算法与支持向量机(Support Vector Machine,SVM)故障诊断方法。为了能够精准地提取故障特征,采用时频域分析中的小波包分解法对故障振动信号进行特征提取,将小波包分解后的8个频带能量作为故障特征并构建特征向量;建立SVM故障模型并利用IGWO算法对SVM模型进行参数寻优,避免了灰狼优化(Grey Wolf Optimization,GWO)算法后期易陷入局部最优、收敛速度过慢等。实验结果表明,IGWO算法平均故障识别率高达99.3%,能够更加快速、高效、准确地识别故障的类型,为故障诊断的发展提供了良好的技术支撑。
