Study on the Water Volume of Erhai Lake in Yunnan Plateau by LI Hongyan

“…Based on the monitoring results of hydrological factors such as measured discharge,precipitation,evaporation and outflow in the Erhai Lake Basin from 1956 to 2018,this paper calculates the natural water volume of the Erhai Lake by using two related methods,namely the principle of watershed generation and convergence and the water balance,and studies the trend and periodicity of natural water volume in Erhai Lake over the years through the Manner-Kendall method and wavelet analysis method.The results show that:The natural water volume calculated by the two methods in Erhai Lake for many years is relatively close,with the relative error of 0.5%,that is 851.9 million cubic meters,among which the water production in the lake area is -93.2 million cubic meters,and the water volume of the land is 944.9 million cubic meters (north (a)>west (b)>southeast (c)>east (d),accounting for 54.9%,33.2%,6.9%,and 4.9% of the land water volume,respectively);The natural water volume in the Erhai Lake throughout the year,the flood season,and the dry season show a decreasing trend with time,especially in the flood season;There are periodic changes in the water volume around 9,12,21,and 32 a,which led to the trend of rich and dry changes in the natural water volume of Erhai Lake.…”
Get full text

Characteristic Analysis and Prediction of Rainfall and Runoff in Ankang Section of Hanjiang River Basin by LIU Yiwen, LI Jiake, DING Qiang, HAO Gairui

“…Accurate runoff simulation plays a very important role in the planning and management of water resources.However,traditional methods have some limitations in the simulation of runoff near peaks and abrupt points.This paper identifies the abrupt change components of rainfall and runoff in the basins above the controlled section of Ankang Hydrological Station in the Hanjiang River Basin through the Mann-Kendall test.analyzes the trend and cycle of the rainfall and runoff by R/S analysis and wavelet analysis,simulates the runoff series with the partial least squares regression (PLSR) and BP neural network-partial least squares regression (BP-PLSR),and analyzes the simulation effect of runoff near peaks and abrupt points.The results show that:The abrupt points of rainfall appear in 1973,1984 and 2002;and those of runoff appear in 1977 and 1985.The Hurst index of rainfall and runoff is close to 0,indicating that there will be an anti-continuous trend in the future.The simulation effect of BP-PLSR on runoff (RMSE=92.863,NSE=0.797) is better than PLSR (RMSE=152.182,NSE=0.456),and preprocessing the original data by BP can better avoid the over-fitting and local optimization near the abrupt points.…”
Get full text

MODELING AND SIMULATION OF COAL-ROCK RECOGNITION SYSTEM OF SHEARER BASED ON CYBER-PHYSICAL SYSTEM (MT) by ZHAO LiJuan, SI HuanHuan, SHI Lei, JIN Xin, ZHANG MeiChen

“…The overall simulation of the system was carried out, the experimental data was extracted from the physical prototype system, and the information processing system model was constructed based on the wavelet packet feature extraction and the PSO-BP neural network algorithm. …”
Get full text

Quantitative Nondestructive Testing of Wire Ropes Based on Features Fusion of Magnetic Image and Infrared Image by Shiliang Lu, Juwei Zhang

“…A denoising algorithm based on Hilbert vibration decomposition (HVD) and wavelet transform is proposed to denoise the MFL signal, and the modulus maxima method is used to locate and segment the defect. …”
Get full text

Analysis and Modeling of Time-Correlated Characteristics of Rainfall-Runoff Similarity in the Upstream Red River Basin by Xiuli Sang, Jianxin Xu, Kun Zhang, Hua Wang

“…Both noised and denoised time series by thresholding the wavelet coefficients were applied to verify the accuracy of model. …”
Get full text

Research on Spatiotemporal Evolution and Driving Factors of Extreme Climate in Guangdong-Hong Kong-Macao Greater Bay Area by GUO Shan, ZHANG Dawei, WANG Yadi

“…In recent years,frequent extreme climate events have become the focus of attention of the world.Studying the spatiotemporal evolution of extreme climate in the Guangdong-Hong Kong-Macao Greater Bay Area is of great significance for timely and accurate disaster prevention and mitigation forecasts and early warnings.On the basis of the precipitation and temperature data from 1961 to 2016,this paper uses the heuristic segmentation method,Mann-Kendall trend test,and cross wavelet method to analyze the spatiotemporal evolution of extreme climate in the Guangdong-Hong Kong-Macao Greater Bay Area and its relationship with driving factors.The results reveal that extreme precipitation and temperature changes are potentially related to sunspots and large-scale circulation factors including the multivariate ENSO index (MEI) and interdecadal Pacific oscillation (IPO),but their effects on extreme climate are different.Climate change will continue to profoundly affect urban construction and development.For future studies on the climate change in the Guangdong-Hong Kong-Macao Greater Bay Area,attention should be paid to the impact assessment of climate change in the Pearl River Basin and typical regions,and the research on the occurrence mechanism,risk assessment,countermeasures of extreme weather in the basin should be strengthened to reduce the damage of extreme climate events.…”
Get full text

Analysis of Variation Characteristics of Precipitation Series from 1970 to 2019 in Qingyuan City by LIU Xuanxuan

“…In order to understand the variation characteristics of precipitation in Qingyuan City in recent decades,and realize the scientific management and utilization of water resources,based on the measured precipitation data of six representative hydrologic stations in Qingyuan from 1970 to 2019,this paper analyzes and studies the trend change,sudden change and periodic characteristics of annual precipitation in Qingyuan by moving average method,Mann-Kendall test method and Morlet wavelet analysis method.The results show that:The annual precipitation of Qingyuan Station and Zhukeng Station showed a decreasing trend,while that of Damiaoxia Station,Yingde Station,Yangshan Station and Lianxian Station showed an increasing trend,but the change was not significant.The sudden drop occurred around 1975 for Qingyuan Station and Yingde Station,around 2015 for Damiaoxia Station and Lianxian Station,around 1982 for Zhukeng Station.and around 1973 and 2015 for Yangshan Station.The precipitation series of each station has obvious alternation of wet and dry seasons.There are 3 to 4 main periods of precipitation at each station.The first and second main periods are generally 22 or 15 years,and the third and fourth main periods are generally 7 or 3 years.After 2015,the annual precipitation at each station turned into a decreasing trend.Currently,Qingyuan is in a period of low precipitation.…”
Get full text

A secure and robust color image watermarking method using SVD and GAT in the multiresolution DCHWT domain by Boubakeur Latreche, Hilal Naimi, Slami Saadi

“…The method operates within the domain of SVD-based multiresolution discrete cosine harmonic wavelet transforms. In this approach, the pre-processing phase employs successive generalized Arnold transforms to encrypt the RGB watermark layers, significantly enhancing the security of the watermarking algorithm. …”
Get full text

Technology for the Quantitative Identification of Dairy Products Based on Raman Spectroscopy, Chemometrics, and Machine Learning by Zheng-Yong Zhang, Jian-Sheng Su, Huan-Ming Xiong

“…In terms of spectral preprocessing, there are various methods, such as normalization, wavelet denoising, and feature extraction. A combination of these methods with appropriate quantitative techniques is beneficial to reveal the differences between samples or improve predictive performance. …”
Get full text

Comprehensive Analysis of Fault Diagnosis Methods for Aluminum Electrolytic Control System by Jie-jia Li, Xiao-yan Han, Peng Zhou, Xiao-yu Sun, Na Chang

“…EMD algorithm is used for data preprocessing of current signal in stator of the fault subsystem. Wavelet decomposition is used to extract feature on current signal in the stator; then, the system inputs the feature to the rough neural network for fault diagnosis and fault classification. …”
Get full text

An Empirical Analysis of the Role of Piano Performance in Alleviating Psychological Trauma in People with Psychological Isolation Disorder by Xia Cao

“…For the EEG signals in the DEAP emotion database, a Butterworth bandpass filter is used to denoise the signals, and then, a wavelet packet decomposition reconstruction is used to remove the artifacts and complete the preprocessing of the signals. …”
Get full text

Detection of Lungs Status Using Morphological Complexities of Respiratory Sounds by Ashok Mondal, Parthasarathi Bhattacharya, Goutam Saha

“…The performance of the proposed method is compared with a wavelet analysis based method. The developed algorithm gives a better accuracy of 92.86% and sensitivity of 86.30% and specificity of 86.90% for a composite feature vector of four morphological indices.…”
Get full text

Computer Aided Diagnostic System for Blood Cells in Smear Images Using Texture Features and Supervised Machine Learning by Shakhawan Hares Wady

“…The framework combines the features extracted by Center Symmetric Local Binary Pattern (CSLBP), Gabor Wavelet Transform (GWT), and Local Gradient Increasing Pattern (LGIP), the data was then fed into machine learning classifiers including Decision Tree (DT), Ensemble, K-Nearest Neighbor (KNN), Naïve Bayes (NB), and Random Forest (RF)).  …”
Get full text

Consistency Analysis of Precipitation Characteristics of Mu Us Sandy Land Based on Daily Precipitation Data by MA Lan, LIU Dengfeng, BAI Bing, REN Mengzhi, HUANG Qiang, LIN Mu

“…Mu Us Sandy Land is located in Yulin city of Shaanxi province and Ordos city of Inner Mongolia Autonomous Region,where the ecological and hydrological system is relatively fragile.However,precipitation is an important controlling factor to the evolution of the ecology and hydrology.Meanwhile,the intensity and process of precipitation also have a crucial influence on ecosystem.Therefore,it is necessary to evaluate the consistency of precipitation characteristic value sequences in Mu Us Sandy Land.Based on daily precipitation data from 1957 to 2019 at 10 meteorological stations in Mu Us Sand Land,this paper selects four precipitation characteristic value sequences namely annual precipitation,annual maximum daily precipitation,annual longest continuous precipitation and annual longest continuous precipitation days,and analyzes the trend by Mann-Kendall method,the abrupt change by sliding t test,and the period by continuous wavelet analysis for evaluating the consistency of precipitation characteristic value sequences.The results indicate that:On the whole,the precipitation characteristic value sequences show a decreasing trend;The significant abrupt change points occur in 1970—1990 and after 2000;The main period of the precipitation characteristic value is about 35 years.…”
Get full text

Bearing Feature Extraction Method Based on the Time Subsequence by Wang Dexue, Nie Fei, Zheng Zhifei, Yu Yongsheng

“…The experiments show that the features extracted by BOTS+ wavelet packet energy method have higher recognition.…”
Get full text

Instantaneous Modal Parameter Identification of Linear Time-Varying Systems Based on Chirplet Adaptive Decomposition by Jie Zhang, Zhiyu Shi

“…Then, the method is demonstrated by comparing with the traditional wavelet and time-domain peak method. The identified results illustrate that the proposed method can obtain more accurate modal parameters in low signal-to-noise ratio (SNR) scenarios.…”
Get full text

An Approach to Fault Diagnosis for Gearbox Based on Image Processing by Yang Wang, Yujie Cheng

“…The image-processing-based diagnostic flow consists of the following steps: first, the vibration signal after noise reduction by wavelet denoising and signal demodulation by Hilbert transform is transformed into an image by bispectrum analysis. …”
Get full text

Estimation of the Defect Width on the Outer Race of a Rolling Element Bearing under Time-Varying Speed Conditions by Guang-Quan Hou, Chang-Myung Lee

“…The entry and exit points when the roller passes over the defect width on the outer race were identified by further processing the extracted signal with time-frequency analysis based on the continuous wavelet transform. The defect size can be calculated with the angle duration, which is measured from the identified entry and exit points. …”
Get full text

Landslide Displacement Prediction Model Based on Time Series and CNN-GRU by FU Zhentao, LI Limin, WANG Lianxia, REN Ruibin, CUI Chengtao, FENG Qingqing

“…Landslide displacement prediction is an important basis for early landslide warning.This paper proposes a prediction model of landslide moving states based on time series and convolutional gated recurrent unit (CNN-GRU) to deal with the shortcomings of previous prediction models.Firstly,after employing wavelet analysis to determine the displacement of the trend term,the exponential smoothing method is adopted to decompose the cumulative displacement to obtain two displacement types of the trend term and the periodic term,and the trend term is fitted by a five-order polynomial.Then,the autocorrelation function is utilized to test the periodic displacement characteristics,and the gray correlation method is applied to determine the correlation degree between each factor and the periodic term.Meanwhile,the periodic term and the influencing factor are input into the CNN-GRU model for prediction,and finally the predicted cumulative displacement value is obtained by superposition.By taking the Baishui River landslide in the Three Gorges Reservoir area as an example,this paper selects the data from January 2004 to December 2012 for study,and the average absolute error percentage of the final prediction results is only 0.525%,with RMSE of 9.614 and R² of 0.993.Experimental results show that CNN-GRU has higher prediction accuracy.…”
Get full text

Rigid-flexible Coupling Dynamics and Fatigue Life Evaluation of Wheel Reducers Based on the Load Spectrum by Yang Siyuan, Wan Yipin, Zhang Lei, Song Xuding

“…The peak-valley extraction and wavelet removal are carried out for the stress-time history. …”
Get full text