共查询到19条相似文献,搜索用时 62 毫秒
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基于Fisher判别理论提出了一种新的设备运行模式监测方法.该方法能自动对设备各运行模式的特征信息进行提取,并建立运行模式判别规则,能有效处理设备监测系统采集到的测量信息,进行设备运行模式辨识. 相似文献
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《实验室研究与探索》2019,(9):10-13
图像的频谱反映了图像能量在频域的分布情况,频谱的高低频成分比例反映了图像中边缘信息与平滑信息的分布情况。通过统计分析清晰与模糊图像的频谱分布,提出了一种基于子带频谱信息的图像清晰与模糊判别方法。首先统计各频率半径以外的频谱能量,获得频谱剩余能量变化特性曲线。其次根据剩余能量变化曲线,获得归一化模糊判断参数。当模糊参数小于某个门限值时,判断图像为模糊图像。实验结果表明,提出的参数可定量地对图像的模糊程度进行度量,具有判断过程快速、简便,分类区分度高等优点。 相似文献
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特定信源符号在整个通信过程中起到关键作用,针对信息论中描述的这些信源符号信息量的不足,采用自信息量与信源符号先验概率相结合的基本思想提出符号信息量概念.利用符号信息量来衡量特定信源符号在整个通信过程中所提供的信息量大小,同时给出了符号信息量的数学特征和物理意义,理论证明有效刻画了通信过程中特定信源的信息量. 相似文献
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Acoustic signals from diesel engines contain useful information but also include considerable noise components.To extract information for condition monitoring purposes, continuous wavelet transform (CWT) is used for the characterization of engine acoustics. This paper first reviews CWT characteristics represented by short duration transient signals.Wavelet selection and CWT are then implemented and wavelet transform is used to analyze the major sources of the engine front's exterior radiation sound. The research provides a reliable basis for engineering practice to reduce vehicle sound level.Comparison of the identification results of the measured acoustic signals with the identification results of the measured surface vibration showed good agreement. 相似文献
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Acoustic signals from diesel engines contain useful information but also include considerable noise components. To extract information for condition monitoring purposes, continuous wavelet transform (CWT) is used for the characterization of engine acoustics. This paper first reviews CWT characteristics represented by short duration transient signals. Wavelet selection and CWT are then implemented and wavelet transform is used to analyze the major sources of the engine front's exterior radiation sound. The research provides a reliable basis for engineering practice to reduce vehicle sound level. Comparison of the identification results of the measured acoustic signals with the identification results of the measured surface vibration showed good agreement. 相似文献
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基于偏离-份额分析法的产业结构分析 总被引:3,自引:0,他引:3
运用偏离-份额分析法对宁波产业结构及经济增长的影响进行了定量分析,并结合宁波三次产业比重变化指出了宁波产业结构目前存在的问题,从产业结构高度化的角度提出了产业结构优化的建议。 相似文献
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A three-step damage identification method based on dynamic characteristics is proposed to improve the structure reliability and security and avoid serious accident. In the proposed method, the frequency and difference of modal curvature (DMC) are used as damage indexes. Firstly, the detection of the occurrence of damage is addressed by the frequency or the square of frequency change. Then the damage location inside the structure is measured by the DMC. Finally, with the stiffness reduction rate as a damage factor, the amount of damage is estimated by the optimization algorithm. The three-step damage identification method has been validated by conducting the simulation on a cantilever beam and the shaking table test on a submerged bridge. The results show that the method proposed in this paper can effectively solve the damage identification problem in theory and engineering practice. 相似文献