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Modal analysis of acoustic leak signal in pipelines using time-frequency analysis

JIAO Jing-pin, FEI Ren-yuan, HE Cun-fu, WU Bin

Frontiers of Mechanical Engineering 2006, Volume 1, Issue 2,   Pages 146-150 doi: 10.1007/s11465-006-0013-3

Abstract: In this paper, the acoustic leak signal is analyzed in the time-frequency domain.Based on the relation of time-frequency distribution of the acoustic leak signal and the dispersion curves

Keywords： dispersion     selection     guided     research     time-frequency    

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Short-term prediction of influent flow rate and ammonia concentration in municipal wastewater treatment plants

Shuai MA, Siyu ZENG, Xin DONG, Jining CHEN, Gustaf OLSSON

Frontiers of Environmental Science & Engineering 2014, Volume 8, Issue 1,   Pages 128-136 doi: 10.1007/s11783-013-0598-9

Abstract: To give meaningful information for feedforward control systems, predictions in different time scalesperiodicity, the decreasing of prediction accuracy is not distinct with increasing of the prediction time

Keywords： influent load prediction     wavelet de-noising     power spectrum density     autoregressive model     time-frequency    

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Time-domain and frequency-domain approaches to identification of bridge flutter derivatives

Zhengqing CHEN

Frontiers of Structural and Civil Engineering 2009, Volume 3, Issue 2,   Pages 173-179 doi: 10.1007/s11709-009-0034-1

Abstract: method and a frequency-domain method.It was shown that all the flutter derivatives of the thin-plate model identified with the frequency-domainmethod and time-domain method, respectively, agree very well.More precisely, the frequency-domain method usually results in smooth curves of the flutter derivativesThe formulation of time-domain method makes the identification results of flutter derivatives relatively

Keywords： long-span bridges     wind-induced vibration     flutter derivatives     forced vibration test     time-domain method     frequency-domain method    

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Non-stationary signal analysis based on general parameterized time--frequency transform and its application

Peng ZHOU, Zhike PENG, Shiqian CHEN, Yang YANG, Wenming ZHANG

Frontiers of Mechanical Engineering 2018, Volume 13, Issue 2,   Pages 292-300 doi: 10.1007/s11465-017-0443-0

Abstract: Since the time-frequency (TF) pattern of the vibration signal from the rotary machine often containsarticle introduces an effective non-stationary signal analysis method based on the general parameterized time–frequency transform (GPTFT).The GPTFT is achieved by inserting a rotation operator and a shift operator in the short-time FourierA multi-component instantaneous frequency (IF) extraction method is proposed based on it.

Keywords： rotary machines     condition monitoring     fault diagnosis     GPTFT     SCI    

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Real-Time Detection of Cracks on Concrete Bridge Decks Using Deep Learning in the Frequency Domain Article

Qianyun Zhang,Kaveh Barri,Saeed K. Babanajad,Amir H. Alavi

Engineering 2021, Volume 7, Issue 12,   Pages 1786-1796 doi: 10.1016/j.eng.2020.07.026

Abstract: one-dimensional convolutional neural network (1D-CNN) and long short-term memory (LSTM) method in the image frequencyIn order to improve the training efficiency, images are first transformed into the frequency domain duringThe algorithm is then calibrated using the flattened frequency data.performance in comparison with existing deep learning methods in terms of accuracy and computation timeThe fast implementation of the 1D-CNN-LSTM algorithm makes it a promising tool for real-time crack detection

Keywords： Crack detection     Concrete bridge deck     Deep learning     Real-time    

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A frequency error estimation for isogeometric analysis of Kirchhoff–Love cylindrical shells

Frontiers of Structural and Civil Engineering doi: 10.1007/s11709-023-0006-x

Abstract: A frequency error estimation is presented for the isogeometric free vibration analysis of Kirchhoff–LoveBy analyzing the discrete isogeometric equations with the aid of harmonic wave assumption, the frequencyIn particular, the governing relationship of the continuum frequency for Kirchhoff–Love cylindrical shellsis naturally embedded into the frequency error measures without the need of explicit frequency expressionsNumerical results not only thoroughly verify the theoretical convergence rates of frequency solutions

Keywords： isogeometric analysis     Kirchhoff–Love cylindrical shell     free vibration     frequency error     convergence    

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Analysis of planetary gear transmission in non-stationary operations

Fakher CHAARI, Mohamed Slim ABBES, Fernando Viadero RUEDA, Alfonso Fernandez del RINCON, Mohamed HADDAR

Frontiers of Mechanical Engineering 2013, Volume 8, Issue 1,   Pages 88-94 doi: 10.1007/s11465-013-0361-8

Abstract: A combined amplitude and frequency modulation is observed which is well characterized using Short Time

Keywords： planetary gearbox     non-stationary conditions     variable load     dynamic response     time frequency analysis    

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Calculation of collision frequency function for aerosol particles in free molecule regime in presence

Xiaowei LUO, Yannick BENICHOU, Suyuan YU

Frontiers in Energy 2013, Volume 7, Issue 4,   Pages 506-510 doi: 10.1007/s11708-013-0275-5

Abstract: The collision frequency function for aerosol particles has already been calculated for the free moleculeforce, electric force and molecular forces, created by particles themselves, recalculated the collision frequencyAttractive forces increase naturally the collision frequency, while repulsive forces decrease it.

Keywords： aerosol particles     collision frequency function     coagulation    

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Fuel variability effect on flickering frequency of diffusion flames

Jizhao LI, Yang ZHANG

Frontiers in Energy 2009, Volume 3, Issue 2,   Pages 134-140 doi: 10.1007/s11708-009-0034-9

Abstract: Mechanisms that control the time scale of the heat release oscillations and acoustic pressure perturbationsThe intent of this study is to investigate the fuel variability on the flickering frequency of diffusionIt was found that the low frequency oscillation of flow and flame structures depended only weakly onWhen a mixture of methane/propane at a ratio of 1:1 was used the peak flickering frequency was aroundMechanisms thought to produce changes in the dynamic response and frequency harmonics were discussed.

Keywords： fuel variability     flickering frequency     diffusion flames     dynamics of combustion    

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Capacity limitation of nuclear units in grid based on analysis of frequency regulation

Yiping DAI, Pan JIANG, Lin GAO, Weimin KAN, Xiaoqing XIAO, Ge JIN

Frontiers in Energy 2012, Volume 6, Issue 2,   Pages 148-154 doi: 10.1007/s11708-012-0174-1

Abstract: Based on the analysis of frequency regulation, mathematic models for nuclear units in the grid are establishedThe relationship between different styles of frequency regulation and the allowable capacity of the nuclear

Keywords： nuclear units capacity     overspeed     primary frequency control (PFC)     second frequency control (SFC)    

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Oscillation frequency of simplified arterial tubes

Hui AN, Fan HE, Lingxia XING, Xiaoyang LI

Frontiers of Mechanical Engineering 2009, Volume 4, Issue 3,   Pages 300-304 doi: 10.1007/s11465-009-0038-5

Abstract: To construct the spatial kinetic equation of an arterial tube and obtain its radial natural frequencyThe results show that the first-order frequency is 15.8 Hz and the obtained exact analytical solutions

Keywords： spatial kinematics     natural frequency     finite element method    

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Parameter identification of interconnected power system frequency after trip-out of high voltage transmission

Xuzhan ZHOU,Shanshan LIU,Mingkun WANG,Yiping DAI,Yaohua TANG

Frontiers in Energy 2014, Volume 8, Issue 3,   Pages 386-393 doi: 10.1007/s11708-014-0323-9

Abstract: Accurate modeling and parameters of high voltage (HV) grid are critical for stability research of system frequencyIn this paper, simulation modeling of the system frequency was conducted of an interconnected power system

Keywords： high voltage (HV) grid     frequency stability parameter identification     primary frequency regulation (PFR    

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Dependence of error sensitivity of frequency on bias voltage in force-balanced micro accelerometer

Lili CHEN, Wu ZHOU

Frontiers of Mechanical Engineering 2013, Volume 8, Issue 2,   Pages 146-149 doi: 10.1007/s11465-013-0260-z

Abstract:

To predict more precisely the frequency of force-balanced micro accelerometer with different biasvoltages, the effects of bias voltages on error sensitivity of frequency is studied.The resonance frequency of accelerometer under closed loop control is derived according to its operationsensitivity with designed parameters of structure, circuit and process error can be used to predict the frequency

Keywords： Micro-Electro-Mechanical Systems (MEMS)     micro accelerometer     force-balanced micro accelerometer     frequency    

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Potential unreliability of ALK variant allele frequency in the efficacy prediction of targeted therapy

Frontiers of Medicine 2023, Volume 17, Issue 3,   Pages 493-502 doi: 10.1007/s11684-022-0946-x

Abstract: Anaplastic lymphoma kinase (ALK) is the most common fusion gene involved in non-small cell lung cancer (NSCLC), and remarkable response has been achieved with the use of ALK tyrosine kinase inhibitors (ALK-TKIs). However, the clinical efficacy is highly variable. Pre-existing intratumoral heterogeneity (ITH) has been proven to contribute to the poor treatment response and the resistance to targeted therapies. In this work, we investigated whether the variant allele frequencies (VAFs) of ALK fusions can help assess ITH and predict targeted therapy efficacy. Through the application of next-generation sequencing (NGS), 7.2% (326/4548) of patients were detected to be ALK positive. On the basis of the adjusted VAF (adjVAF, VAF normalization for tumor purity) of four different threshold values (adjVAF < 50%, 40%, 30%, or 20%), the association of ALK subclonality with crizotinib efficacy was assessed. Nonetheless, no statistical association was observed between median progression-free survival (PFS) and ALK subclonality assessed by adjVAF, and a poor correlation of adjVAF with PFS was found among the 85 patients who received first-line crizotinib. Results suggest that the ALK VAF determined by hybrid capture-based NGS is probably unreliable for ITH assessment and targeted therapy efficacy prediction in NSCLC.

Keywords： next-generation sequencing     fluorescence in situ hybridization     immunohistochemistry     variant allele frequency    

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Remote calibration system for frequency based on in-place benchmark

Xiaobin HONG, Guixiong LIU, Zhuokui WU, Xipeng DU,

Frontiers of Mechanical Engineering 2010, Volume 5, Issue 3,   Pages 316-321 doi: 10.1007/s11465-010-0021-1

Abstract: calibration mode based on material object reference, a new model of a remote calibration system for frequencytechnology of some key problems for the remote calibration system is particularly discussed, including the timeand frequency benchmark receiving module based on global positioning system (GPS), frequency comparisonbased on a phase method, frequency division based on dual high-frequency phase locked loop (PLL), andsystem possesses some characteristics, such as high precision, good versatility, and no limitation of time

Keywords： remote calibration     in-place benchmark     frequency comparison     global position system (GPS)    

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Title Author Date Type Operation

Modal analysis of acoustic leak signal in pipelines using time-frequency analysis

JIAO Jing-pin, FEI Ren-yuan, HE Cun-fu, WU Bin

Journal Article

Short-term prediction of influent flow rate and ammonia concentration in municipal wastewater treatment plants

Shuai MA, Siyu ZENG, Xin DONG, Jining CHEN, Gustaf OLSSON

Journal Article

Time-domain and frequency-domain approaches to identification of bridge flutter derivatives

Zhengqing CHEN

Journal Article

Non-stationary signal analysis based on general parameterized time--frequency transform and its application

Peng ZHOU, Zhike PENG, Shiqian CHEN, Yang YANG, Wenming ZHANG

Journal Article

Real-Time Detection of Cracks on Concrete Bridge Decks Using Deep Learning in the Frequency Domain

Qianyun Zhang,Kaveh Barri,Saeed K. Babanajad,Amir H. Alavi

Journal Article

A frequency error estimation for isogeometric analysis of Kirchhoff–Love cylindrical shells

Journal Article

Analysis of planetary gear transmission in non-stationary operations

Fakher CHAARI, Mohamed Slim ABBES, Fernando Viadero RUEDA, Alfonso Fernandez del RINCON, Mohamed HADDAR

Journal Article

Calculation of collision frequency function for aerosol particles in free molecule regime in presence

Xiaowei LUO, Yannick BENICHOU, Suyuan YU

Journal Article

Fuel variability effect on flickering frequency of diffusion flames

Jizhao LI, Yang ZHANG

Journal Article

Capacity limitation of nuclear units in grid based on analysis of frequency regulation

Yiping DAI, Pan JIANG, Lin GAO, Weimin KAN, Xiaoqing XIAO, Ge JIN

Journal Article

Oscillation frequency of simplified arterial tubes

Hui AN, Fan HE, Lingxia XING, Xiaoyang LI

Journal Article

Parameter identification of interconnected power system frequency after trip-out of high voltage transmission

Xuzhan ZHOU,Shanshan LIU,Mingkun WANG,Yiping DAI,Yaohua TANG

Journal Article

Dependence of error sensitivity of frequency on bias voltage in force-balanced micro accelerometer

Lili CHEN, Wu ZHOU

Journal Article

Potential unreliability of ALK variant allele frequency in the efficacy prediction of targeted therapy

Journal Article

Remote calibration system for frequency based on in-place benchmark

Xiaobin HONG, Guixiong LIU, Zhuokui WU, Xipeng DU,

Journal Article