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De-noising of diesel vibration signal using wavelet packet and singular value decomposition

DUAN Li-xiang, ZHANG Lai-bin, WANG Zhao-hui

《机械工程前沿（英文）》 2006年 第1卷 第4期   页码 443-447 doi: 10.1007/s11465-006-0055-6

摘要： The vibration signals of diesel include excess noise that must be eliminated before extraction of characteristic parameters. Firstly, the effects of vibration-signal de-noising among Fourier transform, wavelet decomposition and wavelet packet decomposition are compared. Secondly, singular value decomposition is applied to de-noising vibration signals. Finally, a new de-noise method integrated with wavelet packet and singular value is presented. In this method, vibration signals are decomposed by wavelet packet, and the wavelet packet coefficient is de-noised by singular value decomposition again. The results indicate that the new de-noising method is the best. The SNR (signal-to-noise ratio) of the vibration signals of a diesel cylinder lid is the highest. The diesel vibration waveforms of combustion and valve become clear and the extracted characteristic parameters become more precise.

关键词： coefficient     de-noised     cylinder     signal-to-noise     wavelet decomposition    

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Vibration testing of a steel girder bridge using cabled and wireless sensors

Dapeng ZHU, Yang WANG, James BROWNJOHN

《结构与土木工程前沿（英文）》 2011年 第5卷 第3期   页码 249-258 doi: 10.1007/s11709-011-0113-y

摘要： Being able to significantly reduce system installation time and cost, wireless sensing technology has attracted much interest in the structural health monitoring (SHM) community. This paper reports the field application of a wireless sensing system on a 4-span highway bridge located in Wayne, New Jersey in the US. Bridge vibration due to traffic and ambient excitation is measured. To enhance the signal-to-noise ratio, a low-noise high-gain signal conditioning module is developed for the wireless sensing system. Nineteen wireless and nineteen cabled accelerometers are first installed along the sidewalk of two neighboring bridge spans. The performance of the wireless sensing system is compared with the high-precision cabled sensing system. In the next series of testing, 16 wireless accelerometers are installed under the deck of another bridge span, forming a 4 × 4 array. Operating deflection analysis is successfully conducted using the wireless measurement of traffic and ambient vibrations.

关键词： wireless sensing     structural health monitoring (SHM)     signal conditioning     operating deflection analysis     ambient vibration    

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data enhancement for implementation in purification of modal frequency for extremely noisy ambient vibration

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI, Soheil MOHAMMADI

《结构与土木工程前沿（英文）》 2020年 第14卷 第2期   页码 446-472 doi: 10.1007/s11709-019-0605-8

摘要： The main purpose of the present study is to enhance high-level noisy data by a wavelet-based iterative filtering algorithm for identification of natural frequencies during ambient wind vibrational tests on a petrochemical process tower. Most of denoising methods fail to filter such noise properly. Both the signal-to-noise ratio and the peak signal-to-noise ratio are small. Multiresolution-based one-step and variational-based filtering methods fail to denoise properly with thresholds obtained by theoretical or empirical method. Due to the fact that it is impossible to completely denoise such high-level noisy data, the enhancing approach is used to improve the data quality, which is the main novelty from the application point of view here. For this iterative method, a simple computational approach is proposed to estimate the dynamic threshold values. Hence, different thresholds can be obtained for different recorded signals in one ambient test. This is in contrast to commonly used approaches recommending one global threshold estimated mainly by an empirical method. After the enhancements, modal frequencies are directly detected by the cross wavelet transform (XWT), the spectral power density and autocorrelation of wavelet coefficients. Estimated frequencies are then compared with those of an undamaged-model, simulated by the finite element method.

关键词： ambient vibration test     high level noise     iterative signal enhancement     wavelet     cross and autocorrelation of wavelets    

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Digital image correlation-based structural state detection through deep learning

《结构与土木工程前沿（英文）》 2022年 第16卷 第1期   页码 45-56 doi: 10.1007/s11709-021-0777-x

摘要： This paper presents a new approach for automatical classification of structural state through deep learning. In this work, a Convolutional Neural Network (CNN) was designed to fuse both the feature extraction and classification blocks into an intelligent and compact learning system and detect the structural state of a steel frame; the input was a series of vibration signals, and the output was a structural state. The digital image correlation (DIC) technology was utilized to collect vibration information of an actual steel frame, and subsequently, the raw signals, without further pre-processing, were directly utilized as the CNN samples. The results show that CNN can achieve 99% classification accuracy for the research model. Besides, compared with the backpropagation neural network (BPNN), the CNN had an accuracy similar to that of the BPNN, but it only consumes 19% of the training time. The outputs of the convolution and pooling layers were visually displayed and discussed as well. It is demonstrated that: 1) the CNN can extract the structural state information from the vibration signals and classify them; 2) the detection and computational performance of the CNN for the incomplete data are better than that of the BPNN; 3) the CNN has better anti-noise ability.

关键词： structural state detection     deep learning     digital image correlation     vibration signal     steel frame    

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基于钻头运动诱发套管头振动信号检测的井眼防碰监测方法

何保生,刘刚,王平双,文敏

《中国工程科学》 2011年 第13卷 第5期   页码 74-78

摘要：

针对海上加密调整井的井眼防碰问题，设计了一种井筒防碰地面监测预警系统，并进行了现场应用。系统利用加速度传感器监测通过套管传输到套管头上的钻头振动信号，利用数据采集、信号滤波放大和专门编制的监测软件记录分析传感器采集的振动信号，通过对信号的时域、频域分析，确定信号特征与井间相对距离的关系，识别钻头对风险井套管的趋近或碰撞。应用结果表明，该系统能有效感知通过地层、套管传输到套管头的钻头振动信号，并能识别出钻头对风险邻井的趋近，验证了系统在设计理论和方法上的可行性，为加密调整井的井眼防碰、保证钻井安全提供了一种有效的手段。

关键词： 调整井     防碰     风险井     振动信号     时域分析     频域分析    

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基于经验模式分解的旋转机械振动信号降噪处理

杨建文,贾民平,许飞云,胡建中

《中国工程科学》 2005年 第7卷 第8期   页码 66-69

摘要：

分析了经验模式分解的滤波性能；针对旋转机械振动信号信噪比低及非平稳特性，应用经验模式分解对振动信号进行降噪处理，突出了有用振动信号，为旋转机械在线监测和故障诊断提供了有效的依据；仿真实验及真实数据分析表明，经验模式分解在振动信号降噪处理中是有效的，为振动信号分析提供了新的方法。

关键词： 故障诊断     经验模式分解     旋转机械     滤波    

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Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0730-2

摘要： Ultrasonic vibration-assisted grinding (UVAG) is an advanced hybrid process for the precision machining of difficult-to-cut materials. The resonator is a critical part of the UVAG system. Its performance considerably influences the vibration amplitude and resonant frequency. In this work, a novel perforated ultrasonic vibration platform resonator was developed for UVAG. The holes were evenly arranged at the top and side surfaces of the vibration platform to improve the vibration characteristics. A modified apparent elasticity method (AEM) was proposed to reveal the influence of holes on the vibration mode. The performance of the vibration platform was evaluated by the vibration tests and UVAG experiments of particulate-reinforced titanium matrix composites. Results indicate that the reasonable distribution of holes helps improve the resonant frequency and vibration mode. The modified AEM, the finite element method, and the vibration tests show a high degree of consistency for developing the perforated ultrasonic vibration platform with a maximum frequency error of 3%. The employment of ultrasonic vibration reduces the grinding force by 36% at most, thereby decreasing the machined surface defects, such as voids, cracks, and burnout.

关键词： ultrasonic vibration-assisted grinding     perforated ultrasonic vibration platform     vibration characteristics     apparent elasticity method     grinding force     surface integrity    

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基于径向基函数神经网络的滚动轴承故障模式的识别

陆爽,张子达,李萌

《中国工程科学》 2004年 第6卷 第2期   页码 56-60

摘要：

径向基函数（RBF）神经网络是一种3层前馈性神经网络，它具有较强的函数逼近能力和分类能力。鉴于径向基函数神经网络的优点，在对滚动轴承振动信号特征分析的基础上，提出了采用时序方法对其建立AR模型，利用AR模型参数建立径向基函数神经网络，并用该网络对滚动轴承的故障模式进行了识别。理论和试验证明了该方法的有效性，且具有较高的识别精度。

关键词： 滚动轴承     振动信号     AR模型     RBF神经网络     模式识别    

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非平稳环境振动下桥梁的阻尼识别

Sunjoong Kim, Ho-Kyung Kim

《工程（英文）》 2017年 第3卷 第6期   页码 839-844 doi: 10.1016/j.eng.2017.11.002

摘要：
本研究着重于使用非平稳的环境振动数据来识别桥梁的阻尼比。我们通常使用基于输入信号的静态白噪声假设的运行模态分析（OMA）来识别使用中的桥梁的阻尼比。然而，大多数桥梁在使用时通常会受到非平稳激励，而违反这种基本假设会导致阻尼识别的不确定性。为了处理非平稳性，根据测量的响应来计算幅度调制函数，以消除由非平稳输入引起的整体趋势。采用自然激励技术（NExT）-特征系统实现算法（ERA）估算平稳过程中的阻尼比。为了提高基于OMA 的阻尼估计的准确性，在提取的平稳过程和非平稳数据之间进行比较分析，以评估消除非平稳性的效果。在信号平稳化后，第一竖向模态的阻尼比的平均值和标准偏差会减小。

关键词： 阻尼     运行模态分析     交通导致振动     非平稳     信号平稳化     调幅     大桥     斜拉     悬索    

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CHARACTERISTICS OF HERBIVORY/WOUND-ELICITED ELECTRICAL SIGNAL TRANSDUCTION IN TOMATO

《农业科学与工程前沿（英文）》 2021年 第8卷 第2期

摘要：

Electrical signals commonly occur in plants in response to various environmental changes and have a dominant function in plant acclimation. The transduction of wound-elicited electrical signals in the model plant species Arabidopsis has been characterized but the characteristics of electrical signal transduction in response to herbivory or wounding in crop species remain unknown. Here, the features of electrical signals elicited by insect herbivory and wounding in tomato were investigated. Unlike those in Arabidopsis, wounding tomato leaves did not cause leaf-to-leaf electrical signal transduction. In contrast, electrical signals elicited in response to petiole wounding were stronger and more strongly transduced. Leaflet wounding also activated electrical signal transduction and jasmonic acid (JA) signaling within the whole compound leaf. It was also demonstrated that tomato glutamate receptor-like 3.3 (GLR3.3) and GLR3.5 mediated leaflet-to-leaflet electrical signal transduction. Herbivory-induced JA accumulation and Helicoverpa armigera resistance were reduced in glr3.3/3.5 plants. This work reveals the nature of electrical signal transduction in tomato and emphasizes the key roles of GLR3.3 and GLR3.5 in electrical signal transduction and JA signaling activation.

 

关键词： electrical signal / glutamate receptor-like / herbivory / jasmonic acid / tomato    

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Recent development of vibration utilization engineering

WEN Bangchun

《机械工程前沿（英文）》 2008年 第3卷 第1期   页码 1-9 doi: 10.1007/s11465-008-0017-2

摘要： The utilization of vibration and wave, which was developed during the latter half of the 20th century, is one of the most valueable technology applications and has been rapidly developing recently . Because the technique is closely associated with industry and agriculture, it can create huge social and economical benefits and provide excellent services for society. Thus, due to its necessity in industry and daily life, extensive research has been devoted to vibration utillization engineering. In this paper, vibration utilization is classified into linear or non-linear vibrations, waves, and electric-magnetic oscillations. Their phenomena, patterns, and applications in nature and society are introduced. Some research results about vibration utilization engineering are described.

关键词： utilization engineering     non-linear     vibration     vibration utillization     utillization engineering    

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Acoustic fault signal extraction via the line-defect phononic crystals

《机械工程前沿（英文）》 2022年 第17卷 第1期   页码 10-10 doi: 10.1007/s11465-021-0666-y

摘要： Rotating machine fault signal extraction becomes increasingly important in practical engineering applications. However, fault signals with low signal-to-noise ratios (SNRs) are difficult to extract, especially at the early stage of fault diagnosis. In this paper, 2D line-defect phononic crystals (PCs) consisting of periodic acrylic tubes with slit are proposed for weak signal detection. The defect band, namely, the formed resonance band of line-defect PCs enables the incident acoustic wave at the resonance frequency to be trapped and enhanced at the resonance cavity. The noise can be filtered by the band gap. As a result, fault signals with high SNRs can be obtained for fault feature extraction. The effectiveness of weak harmonic and periodic impulse signal detection via line-defect PCs are investigated in numerical and experimental studies. All the numerical and experimental results indicate that line-defect PCs can be well used for extracting weak harmonic and periodic impulse signals. This work will provide potential for extracting weak signals in many practical engineering applications.

关键词： phononic crystals     line-defect     fault signal extraction     acoustic enhancement    

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The role of protein kinase C epsilon in neural signal transduction and neurogenic diseases

null

《医学前沿（英文）》 2011年 第5卷 第1期   页码 70-76 doi: 10.1007/s11684-011-0119-9

摘要：

Protein kinase C epsilon (PKC ?) is one of major isoforms in novel PKC family. Although it has been extensively characterized in the past decade, the role of PKC ? in neuron is still not well understood. Advances in molecular biology have now removed significant barriers to the direct investigation of PKC ? functions in vivo, and PKC ? has been increasingly implicated in the neural biological functions and associated neurogenic diseases. Recent studies have provided important insights into the influence of PKC ? on cortical processing at both the single cell level and network level. These studies provide compelling evidence that PKC ? could regulate distinct aspects of neural signal transduction and suggest that the coordinated actions of a number of molecular signals contribute to the specification and differentiation of PKC ? signal pathway in the developing brain.

关键词： protein kinase C ?     signal transduction     neurogenic disease    

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提高地下金属管振动波测试中冲击响应信号的信噪比

韩修廷,王洁春,焦振强,高飞,宋宇波

《中国工程科学》 2005年 第7卷 第10期   页码 64-68

摘要：

提出了在套损振动波检测过程中提高信号信噪比的方法。检测过程中，在井口敲击套管并接收、分析套管的回波，以了解介质的变化情况。由于反射波信号强度较微弱，单纯用一组接收信号无法进行正确的套损分析，采用信号增强方法，即利用多个类似信号进行叠加，增强反射波的有效信号，降低背景噪声，从而得到有用信息，进行正确的套损状况分析。开发了相应的信号处理软件，提高了信号处理速度。通过10井次的测试表明，技术原理可行，软件工作稳定、可靠，便于操作，可以进行多种方法的信号处理，极大地提高了工作效率。

关键词： 振动波     反射波     信号增强     信号叠加    

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Application of python-based Abaqus preprocess and postprocess technique in analysis of gearbox vibration

Guilian YI, Yunkang SUI, Jiazheng DU

《机械工程前沿（英文）》 2011年 第6卷 第2期   页码 229-234 doi: 10.1007/s11465-011-0128-z

摘要：

To reduce vibration and noise, a damping layer and constraint layer are usually pasted on the inner surface of a gearbox thin shell, and their thicknesses are the main parameters in the vibration and noise reduction design. The normal acceleration of the point on the gearbox surface is the main index that can reflect the vibration and noise of that point, and the normal accelerations of different points can reflect the degree of the vibration and noise of the whole structure. The K-S function is adopted to process many points’ normal accelerations as the comprehensive index of the vibration characteristics of the whole structure, and the vibration acceleration level is adopted to measure the degree of the vibration and noise. Secondary development of the Abaqus preprocess and postprocess on the basis of the Python scripting programming automatically modifies the model parameters, submits the job, and restarts the analysis totally, which avoids the tedious work of returning to the Abaqus/CAE for modifying and resubmitting and improves the speed of the preprocess and postprocess and the computational efficiency.

关键词： Abaqus secondary development     Python language     vibration and noise reduction     K-S function     vibration acceleration level    

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标题 作者 时间 类型 操作

De-noising of diesel vibration signal using wavelet packet and singular value decomposition

DUAN Li-xiang, ZHANG Lai-bin, WANG Zhao-hui

期刊论文

Vibration testing of a steel girder bridge using cabled and wireless sensors

Dapeng ZHU, Yang WANG, James BROWNJOHN

期刊论文

data enhancement for implementation in purification of modal frequency for extremely noisy ambient vibration

Hassan YOUSEFI, Alireza TAGHAVI KANI, Iradj MAHMOUDZADEH KANI, Soheil MOHAMMADI

期刊论文

Digital image correlation-based structural state detection through deep learning

期刊论文

基于钻头运动诱发套管头振动信号检测的井眼防碰监测方法

何保生,刘刚,王平双,文敏

期刊论文

基于经验模式分解的旋转机械振动信号降噪处理

杨建文,贾民平,许飞云,胡建中

期刊论文

Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform

期刊论文

基于径向基函数神经网络的滚动轴承故障模式的识别

陆爽,张子达,李萌

期刊论文

非平稳环境振动下桥梁的阻尼识别

Sunjoong Kim, Ho-Kyung Kim

期刊论文

CHARACTERISTICS OF HERBIVORY/WOUND-ELICITED ELECTRICAL SIGNAL TRANSDUCTION IN TOMATO

期刊论文

Recent development of vibration utilization engineering

WEN Bangchun

期刊论文

Acoustic fault signal extraction via the line-defect phononic crystals

期刊论文

The role of protein kinase C epsilon in neural signal transduction and neurogenic diseases

null

期刊论文

提高地下金属管振动波测试中冲击响应信号的信噪比

韩修廷,王洁春,焦振强,高飞,宋宇波

期刊论文

Application of python-based Abaqus preprocess and postprocess technique in analysis of gearbox vibration

Guilian YI, Yunkang SUI, Jiazheng DU

期刊论文