心电信号的分割方法可以有效地反映运动员的心脏功能和身体机能状况.通过人工对心电信号的手动分割往往耗费大量的时间和精力.为了实现自动化的心电信号分割,本文提出了一种改进的两层双向长短期记忆网络(bi-directional long short-ter...心电信号的分割方法可以有效地反映运动员的心脏功能和身体机能状况.通过人工对心电信号的手动分割往往耗费大量的时间和精力.为了实现自动化的心电信号分割,本文提出了一种改进的两层双向长短期记忆网络(bi-directional long short-term memory,BiLSTM)的心电图分割算法,可以前向和后向分析时间序列,以检测和定位重要波段,如P波、QRS波群和T波.实验使用公开QT数据集进行验证,以模拟运动员在赛前的心电数据.在与LSTM,BiLSTM以及两层BiLSTM的对比实验中,本方法的所有评价指标均有所提升.其准确率达95.68%,召回率为91.62%,精确度为91.05%,特异性为96.64%,F1分数为91.41%.结果表明该方法对心电信号进行分割具有较好的效果.展开更多
Since the multicomponent signal with nonlinear time-frequency structures occupies a wide frequency band, and the spectral contents may alias, it is therefore difficult to separate the signal components and to separate...Since the multicomponent signal with nonlinear time-frequency structures occupies a wide frequency band, and the spectral contents may alias, it is therefore difficult to separate the signal components and to separate the signal from Ijackground noise. In this paper, a new signal separation method using FMmlet transform is proposed by taking the advantage that the atoms of FMm let transform can match both the linear and nonlinear time-varying structures. Theoretical predictions and numerical experiments show the feasibility of the methodology advocated.展开更多
针对深孔加工质量检测难、效率低和成本高等问题,提出一种基于振动监测信号分割的改进动态时间规整算法,实现深孔加工质量一致性快速无损检测。首先,以啄钻间歇进给式加工采集的振动信号为研究对象,利用抗噪性能优良的双窗双谱算法对其...针对深孔加工质量检测难、效率低和成本高等问题,提出一种基于振动监测信号分割的改进动态时间规整算法,实现深孔加工质量一致性快速无损检测。首先,以啄钻间歇进给式加工采集的振动信号为研究对象,利用抗噪性能优良的双窗双谱算法对其进行分割;其次,对分割信号在时域和频域内进行特征降维;然后,针对信号长度不等引起的特征不等情况,采用改进的动态时间规整算法(dynamic time warping,简称DTW)进行规整对齐,同时达到减小时间复杂度和防止病态规整的目的;最后,利用求得的累积最短距离评估啄钻阶段振动信号的相似性程度,从而判别啄钻加工质量的一致性。仿真和试验结果表明,该方法能快速有效完成对深孔加工质量一致性无损检测,振动信号分析结果与实际物理检测结果相吻合。展开更多
This paper proposes a new method for ship recognition and classification using sound produced and radiated underwater. To do so, a three-step procedure is proposed. First, the preprocessing operations are utilized to ...This paper proposes a new method for ship recognition and classification using sound produced and radiated underwater. To do so, a three-step procedure is proposed. First, the preprocessing operations are utilized to reduce noise effects and provide signal for feature extraction. Second, a binary image, made from frequency spectrum of signal segmentation, is formed to extract effective features. Third, a neural classifier is designed to classify the signals. Two approaches, the proposed method and the fractal-based method are compared and tested on real data. The comparative results indicated better recognition ability and more robust performance of the proposed method than the fractal-based method. Therefore, the proposed method could improve the recognition accuracy of underwater acoustic targets.展开更多
[ 篇名 ] Automated tuning of an engine management unit for an automotive engine，[ 篇名 ] Automotive Signal Fault Diagnostics-Part I: Signal Fault Analysis, Signal Segmentation, Feature Extraction and Quasi-Optimal Fe...[ 篇名 ] Automated tuning of an engine management unit for an automotive engine，[ 篇名 ] Automotive Signal Fault Diagnostics-Part I: Signal Fault Analysis, Signal Segmentation, Feature Extraction and Quasi-Optimal Feature Selection，[ 篇名 ] Automotive tribology overview of current advances and challenges for the future，[ 篇名 ] Camshaft roller chain drive With reduced meshing impact noise levels，[ 篇名] Combating Automotive Engine Valve Recession，[ 篇名 ] Comparison of reliability enhancement tests for electronic equipment，[ 篇名 ] Competitive surface interactions of critical additives with piston ring/cylinder linear components under lubricated breaking-in conditions，[ 篇名 ] Component-based distributed control systems for automotive manufacturing machinery developed under the foresight vehicle program，[ 篇名 ] Compression ratio influence on maximum load of a natural gas-fueled HCCI engine，[ 篇名 ] Computerized analysis of fuel systems performance dynamics，[ 篇名 ] Concepts for the control of boost pressure and EGR-rate for a heavy duty engine，[ 篇名 ] Condition monitoring for a car engine using higher order time frequency method，[ 篇名 ] Design and evaluation of the ELEVATE two-stroke automotive engine，[ 篇名 ] Development of a cheep creep resistant Mg-Al-Zn-Si-base alloy，[ 篇名 ] Development of a nozzle-fouling test for additive rating in heavy-duty DI diesel engines。展开更多
文摘心电信号的分割方法可以有效地反映运动员的心脏功能和身体机能状况.通过人工对心电信号的手动分割往往耗费大量的时间和精力.为了实现自动化的心电信号分割,本文提出了一种改进的两层双向长短期记忆网络(bi-directional long short-term memory,BiLSTM)的心电图分割算法,可以前向和后向分析时间序列,以检测和定位重要波段,如P波、QRS波群和T波.实验使用公开QT数据集进行验证,以模拟运动员在赛前的心电数据.在与LSTM,BiLSTM以及两层BiLSTM的对比实验中,本方法的所有评价指标均有所提升.其准确率达95.68%,召回率为91.62%,精确度为91.05%,特异性为96.64%,F1分数为91.41%.结果表明该方法对心电信号进行分割具有较好的效果.
基金Supported in part by the National Natural Science Foundation of China under Grant No.60172026
文摘Since the multicomponent signal with nonlinear time-frequency structures occupies a wide frequency band, and the spectral contents may alias, it is therefore difficult to separate the signal components and to separate the signal from Ijackground noise. In this paper, a new signal separation method using FMmlet transform is proposed by taking the advantage that the atoms of FMm let transform can match both the linear and nonlinear time-varying structures. Theoretical predictions and numerical experiments show the feasibility of the methodology advocated.
文摘针对深孔加工质量检测难、效率低和成本高等问题,提出一种基于振动监测信号分割的改进动态时间规整算法,实现深孔加工质量一致性快速无损检测。首先,以啄钻间歇进给式加工采集的振动信号为研究对象,利用抗噪性能优良的双窗双谱算法对其进行分割;其次,对分割信号在时域和频域内进行特征降维;然后,针对信号长度不等引起的特征不等情况,采用改进的动态时间规整算法(dynamic time warping,简称DTW)进行规整对齐,同时达到减小时间复杂度和防止病态规整的目的;最后,利用求得的累积最短距离评估啄钻阶段振动信号的相似性程度,从而判别啄钻加工质量的一致性。仿真和试验结果表明,该方法能快速有效完成对深孔加工质量一致性无损检测,振动信号分析结果与实际物理检测结果相吻合。
文摘This paper proposes a new method for ship recognition and classification using sound produced and radiated underwater. To do so, a three-step procedure is proposed. First, the preprocessing operations are utilized to reduce noise effects and provide signal for feature extraction. Second, a binary image, made from frequency spectrum of signal segmentation, is formed to extract effective features. Third, a neural classifier is designed to classify the signals. Two approaches, the proposed method and the fractal-based method are compared and tested on real data. The comparative results indicated better recognition ability and more robust performance of the proposed method than the fractal-based method. Therefore, the proposed method could improve the recognition accuracy of underwater acoustic targets.
文摘[ 篇名 ] Automated tuning of an engine management unit for an automotive engine，[ 篇名 ] Automotive Signal Fault Diagnostics-Part I: Signal Fault Analysis, Signal Segmentation, Feature Extraction and Quasi-Optimal Feature Selection，[ 篇名 ] Automotive tribology overview of current advances and challenges for the future，[ 篇名 ] Camshaft roller chain drive With reduced meshing impact noise levels，[ 篇名] Combating Automotive Engine Valve Recession，[ 篇名 ] Comparison of reliability enhancement tests for electronic equipment，[ 篇名 ] Competitive surface interactions of critical additives with piston ring/cylinder linear components under lubricated breaking-in conditions，[ 篇名 ] Component-based distributed control systems for automotive manufacturing machinery developed under the foresight vehicle program，[ 篇名 ] Compression ratio influence on maximum load of a natural gas-fueled HCCI engine，[ 篇名 ] Computerized analysis of fuel systems performance dynamics，[ 篇名 ] Concepts for the control of boost pressure and EGR-rate for a heavy duty engine，[ 篇名 ] Condition monitoring for a car engine using higher order time frequency method，[ 篇名 ] Design and evaluation of the ELEVATE two-stroke automotive engine，[ 篇名 ] Development of a cheep creep resistant Mg-Al-Zn-Si-base alloy，[ 篇名 ] Development of a nozzle-fouling test for additive rating in heavy-duty DI diesel engines。
