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瞬频特征的谐波小波域提取与应用 被引量:4
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作者 柏林 董鹏飞 刘小峰 《振动与冲击》 EI CSCD 北大核心 2010年第8期131-135,149,共6页
为了能精确提取出复杂信号中特征分量的瞬频特征,提出了谐波小波域内的分量瞬频估计方法。该方法首先在分析谐波小波变换的基本原理及其优良特性的基础上,对谐波小波进行加窗光滑处理,改善了谐波小波的时域衰减特性。然后,针对在传统瞬... 为了能精确提取出复杂信号中特征分量的瞬频特征,提出了谐波小波域内的分量瞬频估计方法。该方法首先在分析谐波小波变换的基本原理及其优良特性的基础上,对谐波小波进行加窗光滑处理,改善了谐波小波的时域衰减特性。然后,针对在传统瞬频估计方法的不足之处,将线性回归、自适应滤波、曲线平滑、重采样等方法应用到瞬时相位函数的处理中,提高了瞬时频率特征的提取精度。最后,通过仿真实验与工程实践验证了该方法在信号分量瞬频特征提取中的可行性与有效性。 展开更多
关键词 瞬频特征 谐波小波包 相位估计 故障诊断
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The motion analysis of fire video images based on moment features and flicker frequency 被引量:9
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作者 LIJin FONG +3 位作者 N.K.,CHOW W.K.,WONG L.T.,LUPuyi XUDian-guo 《Journal of Marine Science and Application》 2004年第1期81-86,共6页
In this paper, motion analysis methods based on the moment features and flicker frequency features for early fire flame from ordinary CCD video camera were proposed, and in order to describe the changing of flame and ... In this paper, motion analysis methods based on the moment features and flicker frequency features for early fire flame from ordinary CCD video camera were proposed, and in order to describe the changing of flame and disturbance of non-flame phenomena further more, the average changing pixel number of the first-order moments of consecutive flames has been defined in the moment analysis as well. The first-order moments of all kinds of flames used in our experiments present irregularly flickering, and their average changing pixel numbers of first-order moments are greater than fire-like disturbances. For the analysis of flicker frequency of flame, which is extracted and calculated in spatial domain, and therefore it is computational simple and fast. The method of extracting flicker frequency from video images is not affected by the catalogues of combustion material and distance. In experiments, we adopted two kinds of flames, i. e. , fixed flame and movable flame. Many comparing and disturbing experiments were done and verified that the methods can be used as criteria for early fire detection. 展开更多
关键词 fire video images moment features flicker frequency
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