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Fault feature extraction of planet gear in wind turbine gearbox based on spectral kurtosis and time waveletenergy spectrum

Yun KONG, Tianyang WANG, Zheng LI, Fulei CHU

《机械工程前沿（英文）》 2017年 第12卷 第3期   页码 406-419 doi: 10.1007/s11465-017-0419-0

摘要：

Planetary transmission plays a vital role in wind turbine drivetrains, and its fault diagnosis has been an important and challenging issue. Owing to the complicated and coupled vibration source, time-variant vibration transfer path, and heavy background noise masking effect, the vibration signal of planet gear in wind turbine gearboxes exhibits several unique characteristics: Complex frequency components, low signal-to-noise ratio, and weak fault feature. In this sense, the periodic impulsive components induced by a localized defect are hard to extract, and the fault detection of planet gear in wind turbines remains to be a challenging research work. Aiming to extract the fault feature of planet gear effectively, we propose a novel feature extraction method based on spectral kurtosis and time wavelet energy spectrum (SK-TWES) in the paper. Firstly, the spectral kurtosis (SK) and kurtogram of raw vibration signals are computed and exploited to select the optimal filtering parameter for the subsequent band-pass filtering. Then, the band-pass filtering is applied to extrude periodic transient impulses using the optimal frequency band in which the corresponding SK value is maximal. Finally, the time wavelet energy spectrum analysis is performed on the filtered signal, selecting Morlet wavelet as the mother wavelet which possesses a high similarity to the impulsive components. The experimental signals collected from the wind turbine gearbox test rig demonstrate that the proposed method is effective at the feature extraction and fault diagnosis for the planet gear with a localized defect.

关键词： wind turbine     planet gear fault     feature extraction     spectral kurtosis     time wavelet energy spectrum    

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五滚柱式定向离合器故障诊断的小波包变换方法

胡斌梁,罗一新,谢明

《中国工程科学》 2005年 第7卷 第6期   页码 66-68

摘要：

论述了小波包分解及其能量谱处理五滚柱式定向离合器故障的原理与方法。应用小波包分解及其能量谱直观地识别出故障的特征频带，并进行了量化分析。结果表明，小波包及小波包分解能量谱比传统的傅立叶分析方法具有更大的优越性和价值。

关键词： 故障诊断     小波包     能量谱     离合器    

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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

《环境科学与工程前沿（英文）》 2014年 第8卷 第1期   页码 128-136 doi: 10.1007/s11783-013-0598-9

摘要： The prediction of the influent load is of great importance for the improvement of the control system to a large wastewater treatment plant. A systematic data analysis method is presented in this paper in order to estimate and predict the periodicity of the influent flow rate and ammonia (NH ) concentrations: 1) data filtering using wavelet decomposition and reconstruction; 2) typical cycle identification using power spectrum density analysis; 3) fitting and prediction model establishment based on an autoregressive model. To give meaningful information for feedforward control systems, predictions in different time scales are tested to compare the corresponding predicting accuracy. Considering the influence of the rainfalls, a linear fitting model is derived to estimate the relationship between flow rate trend and rain events. Measurements used to support coefficient fitting and model testing are acquired from two municipal wastewater treatment plants in China. The results show that 1) for both of the two plants, the periodicity affects the flow rate and NH concentrations in different cycles (especially cycles longer than 1 day); 2) when the flow rate and NH concentrations present an obvious periodicity, the decreasing of prediction accuracy is not distinct with increasing of the prediction time scales; 3) the periodicity influence is larger than rainfalls; 4) the rainfalls will make the periodicity of flow rate less obvious in intensive rainy periods.

关键词： influent load prediction     wavelet de-noising     power spectrum density     autoregressive model     time-frequency analysis     wastewater treatment    

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Causality between energy consumption and GDP in the U.S.: evidence from wavelet analysis

Alper ASLAN, Nicholas APERGIS, Selim YILDIRIM

《能源前沿（英文）》 2014年 第8卷 第1期   页码 1-8 doi: 10.1007/s11708-013-0290-6

摘要： This study investigates the dynamic causal relationship between energy consumption and economic growth in the U.S. at different time scales. The main novelty of the study is that this paper complements the existing studies on the nexus between energy consumption and economic growth by employing the wavelet transformation to obtain different time scales in order to investigate causality between energy consumption and economic growth. This method is first developed by Ramsey and Lampart. Their approach consists of first decomposing the series into time scales by wavelet filters and testing causality of each time scale with the pertinent time scale of the other series separately. The data span from 1973q1 to 2012q1 on a quarterly basis. The main empirical insight is that the causal relationship is stronger at finer time scales, whereas the relationship is less and less apparent at longer time horizons. The results indicate that energy consumption causes economic growth, while the reverse is not true at the original frequency of the data. At the very finest scale the same result arises. However, at coarser scales feedback is observed. In particular, at intermediate time scales the evidence indicates that energy consumption causes economic growth, while the reverse is also true. These empirical findings are expected to be of high importance in terms of the effective design and implementation of energy and environmental policies, especially when a number of countries in the pursuit of high economic growth targets do not pay any serious attention on environmental issues.

关键词： energy consumption     economic growth     wavelet analysis     granger causality    

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难加工材料高速切削力非线性特征规律的最大熵谱分析与小波分析

龙震海,王西彬,王好臣

《中国工程科学》 2004年 第6卷 第10期   页码 28-31

摘要：

在切削速度范围157～1000 m/min内，综合应用析因试验与速度单因素试验，对航空用难加工材料2Cr13马氏体不锈钢进行了高速干式铣削试验。在分析其切削力显著性影响因素的基础上，对切削力随机信号进行了现代谱分析与小波分析。研究结果表明，高速切削马氏体不锈钢材料时，切削速度和每齿进给量之间的交互作用对切削力有显著影响；铣削深度和每齿进给量之间的交互作用在切削力响应信号中表现为低频周期信号；低频周期信号与高频信号叠加后，其波形的振幅将会增大。

关键词： 难加工材料     高速切削     析因设计     Meyer小波变换     Mallat算法    

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Combustion instability detection using the wavelet detail of pressure fluctuations

JI Junjie, LUO Yonghao

《能源前沿（英文）》 2008年 第2卷 第1期   页码 116-120 doi: 10.1007/s11708-008-0019-0

摘要： A combustion instability detection method that uses the wavelet detail of combustion pressure fluctuations is put forward. To confirm this method, combustion pressure fluctuations in a stoker boiler are recorded at stable and unstable combustion with a pressure transducer. Daubechies one-order wavelet is chosen to obtain the wavelet details for comparison. It shows that the wavelet approximation indicates the general pressure change in the furnace, and the wavelet detail magnitude is consistent with the intensity of turbulence and combustion noise. The magnitude of the wavelet detail is nearly constant when the combustion is stable, however, it will fluctuate much when the combustion is unstable.

关键词： comparison     wavelet approximation     pressure transducer     general pressure     consistent    

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Robust energy-efficient train speed profile optimization in a scenario-based position–time–speed network

《工程管理前沿（英文）》 2021年 第8卷 第4期   页码 595-614 doi: 10.1007/s42524-021-0173-1

摘要： Train speed profile optimization is an efficient approach to reducing energy consumption in urban rail transit systems. Different from most existing studies that assume deterministic parameters as model inputs, this paper proposes a robust energy-efficient train speed profile optimization approach by considering the uncertainty of train modeling parameters. Specifically, we first construct a scenario-based position–time–speed (PTS) network by considering resistance parameters as discrete scenario-based random variables. Then, a percentile reliability model is proposed to generate a robust train speed profile, by which the scenario-based energy consumption is less than the model objective value at α confidence level. To solve the model efficiently, we present several algorithms to eliminate the infeasible nodes and arcs in the PTS network and propose a model reformulation strategy to transform the original model into an equivalent linear programming model. Lastly, on the basis of our field test data collected in Beijing metro Yizhuang line, a series of experiments are conducted to verify the effectiveness of the model and analyze the influences of parameter uncertainties on the generated train speed profile.

关键词： robust train speed profile     percentile reliability model     scenario-based position–time–speed network     mixed-integer programming    

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Identification of faults through wavelet transform vis-à-vis fast Fourier transform of noisy vibration

null

《机械工程前沿（英文）》 2014年 第9卷 第2期   页码 130-141 doi: 10.1007/s11465-014-0298-6

摘要：

Fault diagnosis of rolling element bearings requires efficient signal processing techniques. For this purpose, the performances of envelope detection with fast Fourier transform (FFT) and continuous wavelet transform (CWT) of vibration signals produced from a bearing with defects on inner race and rolling element, have been examined at low signal to noise ratio. Both simulated and experimental signals from identical bearings have been considered for the purpose of analysis. The bearings have been modeled as spring-mass-dashpot systems and the simulated signals have been obtained considering transfer functions for the bearing systems subjected to impulsive loads due to the defects. Frequency B spline wavelets have been applied for CWT and a discussion on wavelet selection has been presented for better effectiveness. Results show that use of CWT with the proposed wavelets overcomes the short coming of FFT while processing a noisy vibration signals for defect detection of bearings.

关键词： Fault detection     spline wavelet     continuous wavelet transform     fast Fourier transform    

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Mirror system based therapy for autism spectrum disorders

CHEN Wei, ZHANG Jing, DING Jun

《医学前沿（英文）》 2008年 第2卷 第4期   页码 344-347 doi: 10.1007/s11684-008-0065-3

摘要： This paper reviews the present theories and empirical research of autisms’ cognitive research and mirror systems and introduces a new hypothesis about the causes of autism spectrum disorders (ASD): autistic mirror neuron dysfunction hypothesis. ASD subjects show obvious lack of the activation of the mirror system during the task of observation or emotional cognition. It is significant to investigate the mirror system for revealing the causes of autism and it is also helpful for developing new ways to diagnose or treat this disorder.

关键词： emotional cognition     observation     activation     spectrum     empirical research    

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Influence of envelope insulation materials on building energy consumption

Junlan YANG, Jiabao TANG

《能源前沿（英文）》 2017年 第11卷 第4期   页码 575-581 doi: 10.1007/s11708-017-0473-7

摘要： In this paper, the influence of different external wall insulation materials on the energy consumption of a newly built apartment in Germany is investigated. Three types of insulation materials commonly used in Germany including mineral fiber, polyurethane, and vacuum insulation panel are chosen for the case studies. An energy analysis model is established to clarify the primary energy use for production of the insulation materials and for building space heating. The calculation results show that the energy consumption for insulation material production increases with the insulation thickness, whereas the energy use for space heating decreases with the insulation thickness. Thus, there exists an optimum thickness to get the lowest total energy consumption for each kind of insulation material. The ascending order of the total energy consumption of the three materials is mineral fiber, polyurethane, and vacuum insulation panel. However, the optimum insulation thicknesses for the three insulation materials show a verse order at a certain heat transfer coefficient of the base envelope. The energy payback time (EPT) is proposed to calculate the payback time of the primary energy use for insulation material production. Mineral fiber has the shortest time, followed by polyurethane and vacuum insulation panel. The EPTS is 10, 19 and 21 years, respectively when the heat transfer coefficient of the base envelope is 0.2 W/(m ·K). In addition, the simulated results show that the theoretical value and the simulated value are basically identical.

关键词： building envelope     insulation materials     energy consumption     payback time    

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自适应小波阈值去噪在重力仪信号处理中的应用

赵立业,周百令,李坤宇

《中国工程科学》 2006年 第8卷 第3期   页码 49-52

摘要：

为了有效地消除各种外界干扰噪声对高精度海洋重力仪测量值的影响，提高重力异常测量值的精度，在分析了小波阈值及自适应小波阈值去噪算法的基础上，将其应用到高精度海洋重力仪系统数据处理中，并与自适应卡尔曼滤波做了对比，以处理后信号的信噪比作为衡量3种数据处理方法优劣的依据。理论分析和仿真实验表明，自适应小波阈值去噪方法、传统的小波阈值去噪方法和自适应卡尔曼滤波都能在一定程度上消除噪声信号对重力仪测量信号的影响，但在相同情况下，自适应小波阈值去噪方法具有明显的优越性。

关键词： 重力仪     信号处理     小波变换     自适应阈值去噪     自适应卡尔曼滤波    

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Solar fuel from photo-thermal catalytic reactions with spectrum-selectivity: a review

Sanli TANG, Jie SUN, Hui HONG, Qibin LIU

《能源前沿（英文）》 2017年 第11卷 第4期   页码 437-451 doi: 10.1007/s11708-017-0509-z

摘要： Solar fuel is one of the ideal energy sources in the future. The synergy of photo and thermal effects leads to a new approach to higher solar fuel production under relatively mild conditions. This paper reviews different approaches for solar fuel production from spectrum-selective photo-thermal synergetic catalysis. The review begins with the meaning of synergetic effects, and the mechanisms of spectrum-selectivity and photo-thermal catalysis. Then, from a technical perspective, a number of experimental or theoretical works are sorted by the chemical reactions and the sacrificial reagents applied. In addition, these works are summarized and tabulated based on the operating conditions, spectrum-selectivity, materials, and productivity. A discussion is finally presented concerning future development of photo-thermal catalytic reactions with spectrum-selectivity.

关键词： photo-thermal catalysis     spectrum-selectivity     solar fuel     full-spectrum    

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Minimization of total energy consumption in an m-machine flow shop with an exponential time-dependent

Lingxuan LIU, Zhongshun SHI, Leyuan SHI

《工程管理前沿（英文）》 2018年 第5卷 第4期   页码 487-498 doi: 10.15302/J-FEM-2018042

摘要：

This study investigates an energy-aware flow shop scheduling problem with a time-dependent learning effect. The relationship between the traditional and the proposed scheduling problem is shown and objective is to determine a job sequence in which the total energy consumption is minimized. To provide an efficient solution framework, composite lower bounds are proposed to be used in a solution approach with the name of Bounds-based Nested Partition (BBNP). A worst-case analysis on shortest process time heuristic is conducted for theoretical measurement. Computational experiments are performed on randomly generated test instances to evaluate the proposed algorithms. Results show that BBNP has better performance than conventional heuristics and provides considerable computational advantage.

关键词： flow shop     energy-aware scheduling     learning effect     nested partition     worst-case error bound    

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Detection of geosmin and 2-methylisoborneol by liquid-liquid extraction-gas chromatograph mass spectrum(LLE-GCMS) and solid phase extraction-gas chromatograph mass spectrum (SPE-GCMS)

MA Xiaoyan, CHEN Beibei, LI Qingsong, ZHANG Qiaoli, GU Guofen

《环境科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 286-291 doi: 10.1007/s11783-007-0048-7

摘要： Two sample preparation methods were introduced and compared in this paper to establish a simple, quick and exact analysis of geosmin and 2-methylisoborneol. LC-18 column was employed in solid phase extraction (SPE), 1.0 mL of hexane was adopted in liquid-liquid extraction (LLE), and the extracts were analyzed by gas chromatograph mass spectrum (GCMS) in selected ion mode. Mean recoveries of SPE were low for 2-methylisoborneol (2-MIB) and geosmin (GSM) with values below 50%. For LLE, the recoveries were satisfyingly above 50% for 2-MIB and 80% for GSM. Detection limits of the LLE method were as low as 1.0 ng/L for GSM and 5.0 ng/L for 2-MIB. A year-long investigation on odor chemicals of drinking water in Shanghai demonstrated that in the summer, there was a serious odor problem induced by a high concentration of 2-MIB. The highest concentration of 152.82 ng/L appeared in July in raw water, while GSM flocculation was minimal with concentrations below odor threshold.

关键词： summer     flocculation     simple     Shanghai     spectrum    

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基于子带瞬时能量谱的铝电解槽电压槽况敏感频域分段方法 Article

曾朝晖, 桂卫华, 陈晓方, 谢永芳, 张红亮, 孙玉波

《工程（英文）》 2021年 第7卷 第9期   页码 1282-1292 doi: 10.1016/j.eng.2020.11.012

摘要： 在对槽电压定性分析的基础上，本文提出子带瞬时能量谱（sub-band Instantaneous energy spectrum, SIEP），并用其对多种槽况下槽电压的频域特性进行定量表示，最终给出了槽电压槽况敏感频域分段方法

关键词： 子带瞬时能量谱     槽况敏感频段     频域分段     铝液异常波动     铝电解    

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标题 作者 时间 类型 操作

Fault feature extraction of planet gear in wind turbine gearbox based on spectral kurtosis and time waveletenergy spectrum

Yun KONG, Tianyang WANG, Zheng LI, Fulei CHU

期刊论文

五滚柱式定向离合器故障诊断的小波包变换方法

胡斌梁,罗一新,谢明

期刊论文

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

期刊论文

Causality between energy consumption and GDP in the U.S.: evidence from wavelet analysis

Alper ASLAN, Nicholas APERGIS, Selim YILDIRIM

期刊论文

难加工材料高速切削力非线性特征规律的最大熵谱分析与小波分析

龙震海,王西彬,王好臣

期刊论文

Combustion instability detection using the wavelet detail of pressure fluctuations

JI Junjie, LUO Yonghao

期刊论文

Robust energy-efficient train speed profile optimization in a scenario-based position–time–speed network

期刊论文

Identification of faults through wavelet transform vis-à-vis fast Fourier transform of noisy vibration

null

期刊论文

Mirror system based therapy for autism spectrum disorders

CHEN Wei, ZHANG Jing, DING Jun

期刊论文

Influence of envelope insulation materials on building energy consumption

Junlan YANG, Jiabao TANG

期刊论文

自适应小波阈值去噪在重力仪信号处理中的应用

赵立业,周百令,李坤宇

期刊论文

Solar fuel from photo-thermal catalytic reactions with spectrum-selectivity: a review

Sanli TANG, Jie SUN, Hui HONG, Qibin LIU

期刊论文

Minimization of total energy consumption in an m-machine flow shop with an exponential time-dependent

Lingxuan LIU, Zhongshun SHI, Leyuan SHI

期刊论文

Detection of geosmin and 2-methylisoborneol by liquid-liquid extraction-gas chromatograph mass spectrum(LLE-GCMS) and solid phase extraction-gas chromatograph mass spectrum (SPE-GCMS)

MA Xiaoyan, CHEN Beibei, LI Qingsong, ZHANG Qiaoli, GU Guofen

期刊论文

基于子带瞬时能量谱的铝电解槽电压槽况敏感频域分段方法

曾朝晖, 桂卫华, 陈晓方, 谢永芳, 张红亮, 孙玉波

期刊论文