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A Deep Learning Approach for Fault Diagnosis in Centrifugal Pumps through Wavelet Coherent Analysis and S-Transform Scalograms with CNN-KAN
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作者 Muhammad Farooq Siddique Saif Ullah Jong-Myon Kim 《Computers, Materials & Continua》 2025年第8期3577-3603,共27页
Centrifugal Pumps(CPs)are critical machine components in many industries,and their efficient operation and reliable Fault Diagnosis(FD)are essential for minimizing downtime and maintenance costs.This paper introduces ... Centrifugal Pumps(CPs)are critical machine components in many industries,and their efficient operation and reliable Fault Diagnosis(FD)are essential for minimizing downtime and maintenance costs.This paper introduces a novel FD method to improve both the accuracy and reliability of detecting potential faults in such pumps.Theproposed method combinesWaveletCoherent Analysis(WCA)and Stockwell Transform(S-transform)scalograms with Sobel and non-local means filters,effectively capturing complex fault signatures from vibration signals.Using Convolutional Neural Network(CNN)for feature extraction,the method transforms these scalograms into image inputs,enabling the recognition of patterns that span both time and frequency domains.The CNN extracts essential discriminative features,which are then merged and passed into a Kolmogorov-Arnold Network(KAN)classifier,ensuring precise fault identification.The proposed approach was experimentally validated on diverse datasets collected under varying conditions,demonstrating its robustness and generalizability.Achieving classification accuracy of 100%,99.86%,and 99.92%across the datasets,this method significantly outperforms traditional fault detection approaches.These results underscore the potential to enhance CP FD,providing an effective solution for predictive maintenance and improving overall system reliability. 展开更多
关键词 Fault diagnosis centrifugal pump wavelet coherent analysis stockwell transform convolutional neural network Kolmogorov-Arnold network
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Transformers for Multi-Modal Image Analysis in Healthcare
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作者 Sameera V Mohd Sagheer Meghana K H +2 位作者 P M Ameer Muneer Parayangat Mohamed Abbas 《Computers, Materials & Continua》 2025年第9期4259-4297,共39页
Integrating multiple medical imaging techniques,including Magnetic Resonance Imaging(MRI),Computed Tomography,Positron Emission Tomography(PET),and ultrasound,provides a comprehensive view of the patient health status... Integrating multiple medical imaging techniques,including Magnetic Resonance Imaging(MRI),Computed Tomography,Positron Emission Tomography(PET),and ultrasound,provides a comprehensive view of the patient health status.Each of these methods contributes unique diagnostic insights,enhancing the overall assessment of patient condition.Nevertheless,the amalgamation of data from multiple modalities presents difficulties due to disparities in resolution,data collection methods,and noise levels.While traditional models like Convolutional Neural Networks(CNNs)excel in single-modality tasks,they struggle to handle multi-modal complexities,lacking the capacity to model global relationships.This research presents a novel approach for examining multi-modal medical imagery using a transformer-based system.The framework employs self-attention and cross-attention mechanisms to synchronize and integrate features across various modalities.Additionally,it shows resilience to variations in noise and image quality,making it adaptable for real-time clinical use.To address the computational hurdles linked to transformer models,particularly in real-time clinical applications in resource-constrained environments,several optimization techniques have been integrated to boost scalability and efficiency.Initially,a streamlined transformer architecture was adopted to minimize the computational load while maintaining model effectiveness.Methods such as model pruning,quantization,and knowledge distillation have been applied to reduce the parameter count and enhance the inference speed.Furthermore,efficient attention mechanisms such as linear or sparse attention were employed to alleviate the substantial memory and processing requirements of traditional self-attention operations.For further deployment optimization,researchers have implemented hardware-aware acceleration strategies,including the use of TensorRT and ONNX-based model compression,to ensure efficient execution on edge devices.These optimizations allow the approach to function effectively in real-time clinical settings,ensuring viability even in environments with limited resources.Future research directions include integrating non-imaging data to facilitate personalized treatment and enhancing computational efficiency for implementation in resource-limited environments.This study highlights the transformative potential of transformer models in multi-modal medical imaging,offering improvements in diagnostic accuracy and patient care outcomes. 展开更多
关键词 Multi-modal image analysis medical imaging deep learning image segmentation disease detection multi-modal fusion Vision transformers(ViTs) precision medicine clinical decision support
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A Hybrid CNN-Transformer Framework for Normal Blood Cell Classification:Towards Automated Hematological Analysis
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作者 Osama M.Alshehri Ahmad Shaf +7 位作者 Muhammad Irfan Mohammed M.Jalal Malik A.Altayar Mohammed H.Abu-Alghayth Humood Al Shmrany Tariq Ali Toufique A.Soomro Ali G.Alkhathami 《Computer Modeling in Engineering & Sciences》 2025年第7期1165-1196,共32页
Background:Accurate classification of normal blood cells is a critical foundation for automated hematological analysis,including the detection of pathological conditions like leukemia.While convolutional neural networ... Background:Accurate classification of normal blood cells is a critical foundation for automated hematological analysis,including the detection of pathological conditions like leukemia.While convolutional neural networks(CNNs)excel in local feature extraction,their ability to capture global contextual relationships in complex cellular morphologies is limited.This study introduces a hybrid CNN-Transformer framework to enhance normal blood cell classification,laying the groundwork for future leukemia diagnostics.Methods:The proposed architecture integrates pre-trained CNNs(ResNet50,EfficientNetB3,InceptionV3,CustomCNN)with Vision Transformer(ViT)layers to combine local and global feature modeling.Four hybrid models were evaluated on the publicly available Blood Cell Images dataset from Kaggle,comprising 17,092 annotated normal blood cell images across eight classes.The models were trained using transfer learning,fine-tuning,and computational optimizations,including cross-model parameter sharing to reduce redundancy by reusing weights across CNN backbones and attention-guided layer pruning to eliminate low-contribution layers based on attention scores,improving efficiency without sacrificing accuracy.Results:The InceptionV3-ViT model achieved a weighted accuracy of 97.66%(accounting for class imbalance by weighting each class’s contribution),a macro F1-score of 0.98,and a ROC-AUC of 0.998.The framework excelled in distinguishing morphologically similar cell types demonstrating robustness and reliable calibration(ECE of 0.019).The framework addresses generalization challenges,including class imbalance and morphological similarities,ensuring robust performance across diverse cell types.Conclusion:The hybrid CNN-Transformer framework significantly improves normal blood cell classification by capturing multi-scale features and long-range dependencies.Its high accuracy,efficiency,and generalization position it as a strong baseline for automated hematological analysis,with potential for extension to leukemia subtype classification through future validation on pathological samples. 展开更多
关键词 Acute leukemia automated diagnosis blood cell classification convolution neural networks deep learning fine-tuning hematologic malignancy hybrid deep learning architecture leukemia subtype classification medical image analysis transfer learning vision transformers
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Study on Rhizome Crops by Fourier Transform Infrared Spectroscopy Combined with Wavelet Analysis
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作者 任静 刘刚 +4 位作者 赵兴祥 赵帅群 欧全宏 徐娟 胡见飞 《Agricultural Science & Technology》 CAS 2015年第7期1522-1526,共5页
In order to distinguish 8 kinds of rhizome crops, the 40 samples were studied by Fourier transform infrared spectroscopy (FTIR) combined with wavelet transform (WT), principal component analysis (PCA) and hieram... In order to distinguish 8 kinds of rhizome crops, the 40 samples were studied by Fourier transform infrared spectroscopy (FTIR) combined with wavelet transform (WT), principal component analysis (PCA) and hieramhical cluster analysis (HCA). The results showed that the infrared spectra were similar on the whole, but there were differences in peak position, peak shape and peak absorption intensity in the range of 1 800-700 cm-1. The infrared spectra in the range of 1 800-700 cm-1 were selected to perform continuous wavelet transform (CWT) and discrete wavelet transform (DWT). The 15th-Ievel decomposition coefficients of CWT and the 5=-level detail coefficients of DWT were classified by PCA and HCA. The cumulative contri- bution rates of the first three principal components of CWT and DWT were 93.12% and 89.78%, respectively. The accurate recognition rates of PCA and HCA were all 100%. It is proved that FTIR combined with WT can be used to distinguish different kinds of rhizome crops. 展开更多
关键词 FTIR Rhizome crop Wavelet transform Principal component analysis Hierarchical cluster analysis
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ELECTROCHEMICAL NOISE ANALYSIS OF PURE ALUMINUM IN SODIUM CHLORIDE SOLUTION WITH WAVELET TRANSFORM TECHNIQUE 被引量:9
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作者 Z. Zhang, Q.D. Zhong, J.Q. Zhang, Y.L. Cheng, F.H. Cao, J.M. and C.N. CaoDepartment of Chemistry, Zhejiang University, Hangzhou 310027, ChinaElectrochemical Research Group, Shanghai University of Electric Power, Shanghai 200090, ChinaState Key Laboratory 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2002年第3期272-278,共7页
Wavelet transforms (WT) are proposed as an alternative tool to overcome the limitations of Fourier transforms (FFT) in the analysis of electrochemical noise (EN) data. The most relevant feature of this method of analy... Wavelet transforms (WT) are proposed as an alternative tool to overcome the limitations of Fourier transforms (FFT) in the analysis of electrochemical noise (EN) data. The most relevant feature of this method of analysis is its capability of decomposing electrochemical noise records into different sets of wavelet coefficients, which contain information about the time scale characteristic of the associated corrosion event. In this context, the potential noise fluctuations during the free corrosion of pure aluminum in sodium chloride solution was recorded and analyzed with wavelet transform technique. The typical results showed that the EN signal is composed of distinct type of events, which can be classified according to their scales, i.e. their time constants. Meanwhile, the energy distribution plot (EDP) can be used as 'fingerprints' of EN signals and can be very useful for analyzing EN data in the future. 展开更多
关键词 electrochemical noise wavelet analysis Fourier transforms CORROSION pure aluminum
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NYFR output pulse radar signal TOA analysis using extended Fourier transform and its TOA estimation 被引量:7
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作者 Zhaoyang Qiu Pei Wang +1 位作者 Jun Zhu Bin Tang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第2期212-223,共12页
Nyquist folding receiver (NYFR) is a typical wideband analog-to-information architecture. Focusing on the non-cooperative receiving, the pulse radar signal intercepted by the NYFR in time domain is analyzed. The NYFR ... Nyquist folding receiver (NYFR) is a typical wideband analog-to-information architecture. Focusing on the non-cooperative receiving, the pulse radar signal intercepted by the NYFR in time domain is analyzed. The NYFR outputs under different input conditions are investigated based on the extended Fourier transform (EFT) and the sampling theorem. Combining with the characteristic of the NYFR output in time domain, a new time of arrival (TOA) estimation method based on the energy envelope and the wavelet transform is proposed. The proposed estimation method can be adapted for the non-cooperative situation. It has no requirement for prior information to determine the threshold and is not necessary to transform the signal into baseband. Simulation results prove the correctness of the NYFR output expressions and show the efficacy of the proposed estimation method. © 2017 Beijing Institute of Aerospace Information. 展开更多
关键词 Fourier transforms RADAR Time domain analysis Wavelet transforms
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SIGNAL FEATURE EXTRACTION BASED UPON INDEPENDENT COMPONENT ANALYSIS AND WAVELET TRANSFORM 被引量:7
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作者 JiZhong JinTao QinShuren 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第1期123-126,共4页
It is an important precondition for machine fault diagnosis that vibrationsignal can be extracted effectively. Based on the characteristic of noise interfused during thecourse of sampling vibration signal, independent... It is an important precondition for machine fault diagnosis that vibrationsignal can be extracted effectively. Based on the characteristic of noise interfused during thecourse of sampling vibration signal, independent component analysis (ICA) method is combined withwavelet to de-noise. Firstly, The sampled signal can be separated with ICA, then the function offrequency band chosen with multi-resolution wavelet transform can be used to judge whether thestochastic disturbance singular signal is interfused. By these ways, the vibration signals can beextracted effectively, which provides favorable condition for subsequent feature detection ofvibration signal and fault diagnosis. 展开更多
关键词 Independent component analysis (ICA) Wavelet transform DE-NOISING FAULTDIAGNOSIS Feature extraction
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Carbonization mechanism of bamboo(phyllostachys)by means of Fourier Transform Infrared and elemental analysis 被引量:14
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作者 ZUO Song-lin GAO Shang-yu +1 位作者 YUAN Xi-gen XU Bo-sen 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第1期75-79,共5页
Bamboo was carbonized at different temperatures ranging from 200℃to 600℃.The dependence of the change of hemicellulose,cellulose,and lignin on the temperature was investigated by means of elemental analysis and Four... Bamboo was carbonized at different temperatures ranging from 200℃to 600℃.The dependence of the change of hemicellulose,cellulose,and lignin on the temperature was investigated by means of elemental analysis and Fourier Transform Infrared(FTIR)spectra of the residual solid products.The results showed:(1)Below 200℃,hemicellulose in bamboo was de-composed and a large amount of hydroxyl groups are dislocated from hemicellulose and cellulose,accompanied by the evolu-tion of water to escape.(2)200℃-250℃,cellulose in bamboo was drastically decomposed whereas the net structure of lignin keep stable,with the except of the dislocation of methoxyl groups from lignin.(3)250℃~400℃,the net structure of lignin col-lapse,up to 400’℃,followed by that the more position in aryl groups are substituted.(4)For bamboo carbonization,the aroma-tization of residual carbon has approximately completed at the temperature as high as 600℃.But the fusion of aromatic rings possibly does not occur. 展开更多
关键词 BAMBOO CARBONIZATION Fourier transform infrared Elemental analysis
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New homotopy analysis transform method for solving the discontinued problems arising in nanotechnology 被引量:4
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作者 M.M.Khader Sunil Kumar S.Abbasbandy 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第11期135-139,共5页
We present a new reliable analytical study for solving the discontinued problems arising in nanotechnology. Such problems are presented as nonlinear differential-difference equations. The proposed method is based on t... We present a new reliable analytical study for solving the discontinued problems arising in nanotechnology. Such problems are presented as nonlinear differential-difference equations. The proposed method is based on the Laplace trans- form with the homotopy analysis method (HAM). This method is a powerful tool for solving a large amount of problems. This technique provides a series of functions which may converge to the exact solution of the problem. A good agreement between the obtained solution and some well-known results is obtained. 展开更多
关键词 discretized mKdV lattice equation nonlinear differential-difference equations Laplace transform homotopy analysis transform method
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Mathematic Models for Analysis of Quality Components in Sugarcane Juice with Fourier Transform Near Infrared Spectroscopy 被引量:4
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作者 CAOGan TANZhong-wen 《Agricultural Sciences in China》 CAS CSCD 2003年第2期190-194,共5页
With the technique of Fourier transform near infrared (FT-NIR) spectroscopy, the calibration models for quantitative analysis of sucrose and polarization in sugarcane juice were developed by using transmission mode an... With the technique of Fourier transform near infrared (FT-NIR) spectroscopy, the calibration models for quantitative analysis of sucrose and polarization in sugarcane juice were developed by using transmission mode and calibrating with partial least square (PLS) algorithm. The determination coefficients (R2) of the predicted models for sucrose and polarization in juice were 0. 9980 and 0. 9979 respectively; the root mean square errors of cross validation (RMSECV) were 0. 143 and 0. 155% for sucrose and polarization in juice respectively. The predictive errors measured by FT-NIR were close to those by routine laboratory methods. The results demonstrated that the FT-NIR methods had high accuracy and they were able to replace the routine laboratory analysis. It was also demonstrated that as a rapid and accurate measurement, the FT-NIR technique had potential applications in quality control of mill sugarcane, establishment of payment system based on sugarcane quality, and selection of clones in sugarcane breeding. 展开更多
关键词 Fourier transform near infrared spectroscopy Quantitative analysis SUGARCANE SUCROSE
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RESEARCH OF WAVELET TRANSFORM INSTRUMENT SYSTEM FOR SIGNAL ANALYSIS 被引量:12
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作者 Qin Shuren Chen Zhikui +3 位作者 Tang Baoping Yang Changqi Xu Mingtao He Hui (Test Center, Chongqing University) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2000年第2期114-121,共8页
After brief describing the Principle of wavelet transform (WT) of signals, a new signals analysis system based on wavelet transform is introduced. The design and development of the instryment of wavelet transform are ... After brief describing the Principle of wavelet transform (WT) of signals, a new signals analysis system based on wavelet transform is introduced. The design and development of the instryment of wavelet transform are described. A number of practical uses of this system demonstrate that wavelet transform system is specially functional in identifying and processing impulse, singular and non-smooth signals, so that it should be evaluated the most advanced signal analyzing system. 展开更多
关键词 Wavelet transform Signal analysis Instrument
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Spectroscopic Analysis of Structural Transformation in Biodiesel Oxidation 被引量:4
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作者 Wu Jiang Chen Boshui +1 位作者 Fang Jianhua Wang Jiu 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2013年第3期28-32,共5页
The oxidation behavior of three biodiesels of different origins,viz.rapeseed oil derived biodiesel,soybean oil derived biodiesel and waste oil based biodiesel,were tested on an oxidation tester.The chemical compositio... The oxidation behavior of three biodiesels of different origins,viz.rapeseed oil derived biodiesel,soybean oil derived biodiesel and waste oil based biodiesel,were tested on an oxidation tester.The chemical compositions of the biodiesels were characterized by gas chromatography.Thereafter,the structural transformation of fatty acid methyl ester(FAME)of the biodiesels was analyzed by an infrared spectrometer and an ultraviolet absorption spectrometer.The results demonstrated that the oxidation behavior of biodiesels of different origins was closely related to the composition and distribution of FAMEs.Higher concentration of unsaturated FAME with multi-double bonds exhibited poorer oxidation resistance.Furthermore,cis-trans isomerization transformation occurred in the unsaturated FAME molecules and conjugated double-bond produced during the oxidation process of biodiesel.Greater cis-trans variations corresponded to deeper oxidation degree.The higher the content of unsaturated FAME with multi-double bonds in a biodiesel,the more the conjugated double bonds was formed. 展开更多
关键词 BIODIESEL OXIDATION structural transformation spectroscopic analysis
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Blind Separation of Speech Signals Based on Wavelet Transform and Independent Component Analysis 被引量:4
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作者 吴晓 何静菁 +2 位作者 靳世久 徐安桃 王伟魁 《Transactions of Tianjin University》 EI CAS 2010年第2期123-128,共6页
Speech signals in frequency domain were separated based on discrete wavelet transform (DWT) and independent component analysis (ICA). First, mixed speech signals were decomposed into different frequency domains by DWT... Speech signals in frequency domain were separated based on discrete wavelet transform (DWT) and independent component analysis (ICA). First, mixed speech signals were decomposed into different frequency domains by DWT and the subbands of speech signals were separated using ICA in each wavelet domain; then, the permutation and scaling problems of frequency domain blind source separation (BSS) were solved by utilizing the correlation between adjacent bins in speech signals; at last, source signals were reconstructed from single branches. Experiments were carried out with 2 sources and 6 microphones using speech signals at sampling rate of 40 kHz. The microphones were aligned with 2 sources in front of them, on the left and right. The separation of one male and one female speeches lasted 2.5 s. It is proved that the new method is better than single ICA method and the signal to noise ratio is improved by 1 dB approximately. 展开更多
关键词 wavelet transform independent component analysis blind source separation
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Transformative learning in nursing education: A concept analysis 被引量:2
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作者 Tebogo A Tsimane Charlene Downing 《International Journal of Nursing Sciences》 CSCD 2020年第1期91-98,共8页
Objective:There is vast literature on transformative learning,which is an important aspect of nursing education,but its meaning remains unclear.It is therefore important to clarify the meaning of transformative learni... Objective:There is vast literature on transformative learning,which is an important aspect of nursing education,but its meaning remains unclear.It is therefore important to clarify the meaning of transformative learning,identify its attributes,antecedents and consequences to increase its use in nursing education,practice and research.Methods:Walker and Avant's method was used,and the process provided a structured way to analyse the concept of'transfonnative leaming'.Nursing education dictionaries,encyclopaedias,conference papers,research articles,dissertations,theses,journal articles,thesauri and relevant books through the database library and intemet searches were reviewed.One hundred and two literature sources were reviewed,and data saturation was reached.Results:The results of the concept analysis of transformative learning within the context of nursing education identified three categories,namely,1)Antecedents as cognitive and affective perspective,democratic education principles and inspiration;2)Process through three phases,namely i)awareness through self-reflection,ii)the meaningful interactive,integrative and democratic construction process,and iii)metacognitive reasoning abilities;and 3)Outcomes.A theoretical definition of transformative learning was formulated.Theoretical validity was ensured.Conclusion:The results of the concept analysis of transformative learning were used to describe a model to facilitate transformative learning within the context of nursing education. 展开更多
关键词 CONCEPT analysis NURSING EDUCATION transformative LEARNING
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Imaging Analysis by Means of Fractional Fourier Transform 被引量:2
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作者 CHENJian-nong TAORong-jia 《Journal of Shanghai University(English Edition)》 CAS 2001年第4期292-294,共3页
Starting from the diffraction imaging process,we have discussed the relationship between optical imaging system and fractional Fourier transform, and proposed a specific system which can form an inverse amplified imag... Starting from the diffraction imaging process,we have discussed the relationship between optical imaging system and fractional Fourier transform, and proposed a specific system which can form an inverse amplified image of input function. 展开更多
关键词 imaging analysis fractional Fourier transform
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Analysis of Thermal Behavior of High Frequency Transformers Using Finite Element Method 被引量:2
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作者 Hossein Babaie Hassan Feshki Farahani 《Journal of Electromagnetic Analysis and Applications》 2010年第11期627-632,共6页
High frequency transformer is used in many applications among the Switch Mode Power Supply (SMPS), high voltage pulse power and etc can be mentioned. Regarding that the core of these transformers is often the ferrite ... High frequency transformer is used in many applications among the Switch Mode Power Supply (SMPS), high voltage pulse power and etc can be mentioned. Regarding that the core of these transformers is often the ferrite core;their functions partly depend on this core characteristic. One of the characteristics of the ferrite core is thermal behavior that should be paid attention to because it affects the transformer function and causes heat generation. In this paper, a typical high frequency transformer with ferrite core is designed and simulated in ANSYS software. Temperature rise due to winding current (Joule-heat) is considered as heat generation source for thermal behavior analysis of the transformer. In this simulation, the temperature rise and heat distribution are studied and the effects of parameters such as flux density, winding loss value, using a fan to cool the winding and core and thermal conductivity are investigated. 展开更多
关键词 High Frequency transformERS Thermal Behavior FERRITE Core and FINITE ELEMENT analysis
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Detection of Mechanical Deformation in Old Aged Power Transformer Using Cross Correlation Co-Efficient Analysis Method 被引量:2
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作者 Asif Islam Shahidul Islam Khan Aminul Hoque 《Energy and Power Engineering》 2011年第4期585-591,共7页
Detection of minor faults in power transformer active part is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. Sweep Frequency Response Analysis (SFRA) is an... Detection of minor faults in power transformer active part is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. Sweep Frequency Response Analysis (SFRA) is an effective low-voltage, off-line diagnostic tool used for finding out any possible winding displacement or mechanical deterioration inside the Transformer, due to large electromechanical forces occurring from the fault currents or due to Transformer transportation and relocation. In this method, the frequency response of a transformer is taken both at manufacturing industry and concern site. Then both the response is compared to predict the fault taken place in active part. But in old aged transformers, the primary reference response is unavailable. So Cross Correlation Co-Efficient (CCF) measurement technique can be a vital process for fault detection in these transformers. In this paper, theoretical background of SFRA technique has been elaborated and through several case studies, the effectiveness of CCF parameter for fault detection has been represented. 展开更多
关键词 Core Damage RADIAL DEFORMATION AXIAL DEFORMATION SWEEP Frequency Response analysis Cross Correlation Co-efficient Power transformer
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A Discrete State Event Driven Simulation based Losses Analysis for Multi-terminal Megawatt Power Electronic Transformer 被引量:9
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作者 Jialin Zheng Zhengming Zhao +3 位作者 Bochen Shi Zhujun Yu Jiahe Ju Zhiqiang Fan 《CES Transactions on Electrical Machines and Systems》 CSCD 2020年第4期275-284,共10页
At present,power electronic transformers(PETs)have been widely used in power systems.With the increase of PET capacity to the megawatt level.the problem of increased losses need to be taken seriously.As an important i... At present,power electronic transformers(PETs)have been widely used in power systems.With the increase of PET capacity to the megawatt level.the problem of increased losses need to be taken seriously.As an important indicator of power electronic device designing,losses have always been the focus of attention.At present,the losses are generally measured through experiments,but it takes a lot of time and is difficult to quantitatively analyze the internal distribution of PET losses.To solve the above problems,this article first qualitatively analyzes the losses of power electronic devices and proposes a loss calculation method based on pure simulation.This method uses the Discrete State Event Driven(DSED)modeling method to solve the problem of slow simulation speed of large-capacity power electronic devices and uses a loss calculation method that considers the operating conditions of the device to improve the calculation accuracy.For the PET prototype in this article,a losses model of the PET is established.The comparison of experimental and simulation results verifies the feasibility of the losses model.Then the losses composition of PET was analyzed to provide reference opinions for actual operation.It can help pre-analyze the losses distribution of PET,thereby providing a potential method for improving system efficiency. 展开更多
关键词 Power electronic transformer(PET) losses analysis efficiency losses branch model discrete-state event-driven
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Transformer’s Condition Assessment Method Based on Combination of Cloud Matter Element and Principal Component Analysis 被引量:1
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作者 Qianli Hong Jiantao Zhang +4 位作者 Qing Xie Shaodong Liang Yuqin Xu Si Li Weitao Hu 《Energy and Power Engineering》 2017年第4期659-666,共8页
With the development of power grid, as one of the key equipment, the transformer’s condition assessment method has always receive attention from experts, scholars concern more and more about the method’s practicalit... With the development of power grid, as one of the key equipment, the transformer’s condition assessment method has always receive attention from experts, scholars concern more and more about the method’s practicality and reliability. In the traditional condition assessment method, due to the characteristics of the transformer’s complex structure, the assessment system is not comprehensive enough, or the assessment system is too complex, the indexes are not easy to quantify, such problems are emerging. The traditional method is complex and the degree of quantification is not enough. Therefore it is necessary to propose a condition assessment method that is easy to carry out the condition assessment work and does not affect the assessment results. In this paper, we propose a method to assess the state of the transformer’s complex structure. First, we establish a comprehensive assessment system, then apply the method of principal component analysis to optimize the index system, and then use the theory of cloud-matter-element. Finally the reliability and rationality of the method are verified by an example. 展开更多
关键词 transformer Assessment Method PRINCIPLE COMPONENT analysis CLOUD Model
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Developing strategy for rural transformation to alleviate poverty in Pakistan:Stylized facts from panel analysis 被引量:1
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作者 ABEDULLAH Shujaat FAROOQ Farah NAZ 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第12期3610-3623,共14页
Sustainable income growth and poverty reduction remain critical challenges at the forefront of research in Pakistan,particularly in rural areas.To overcome these challenges,the role of rural transformation(RT)has emer... Sustainable income growth and poverty reduction remain critical challenges at the forefront of research in Pakistan,particularly in rural areas.To overcome these challenges,the role of rural transformation(RT)has emerged and gained importance in recent years.The present study is based on district-level data and covers the period from 1981 to 2019.The study attempts to quantify the role of rural transformation in boosting rural per capita income and alleviating rural poverty in the country.The study also aims to explore the impact of stages of rural transformation on rural per capita income and rural poverty alleviation.The empirical findings reveal that rural transformation(RT_(1)and RT_(2))is essential in enhancing rural per capita income and alleviating rural poverty.The role of the share of high-value crops(RT_(1))is more pronounced than the share of non-farm employment(RT_(2))in boosting rural per capita income and poverty alleviation.The trend of larger contribution of RT_(1)to enhance rural per capita income also continued at 2nd stage of rural transformation.In the case of poverty reduction,at 3rd stage of rural transformation,the role of RT_(2)is dominant.Our results indicate that districts at higher stages of rural transformation(both RT_(1)and RT_(2))tend to correlate positively with increased rural per capita income and reduced poverty rates,suggesting that progress in rural transformation is associated with improved economic conditions.However,it is important to note that this correlation does not necessarily imply a direct causal relationship between rural transformation and these economic outcomes;other factors may have influenced this relationship.In addition,the welfare impacts are more noticeable among the districts where a simultaneous shift from grain crops to cash crops and from farm employment to non-farm employment is observed.The study provides baseline information to learn experiences from fast-growing districts and to replicate the strategies in other districts,which boosts the RT process that may increase rural per capita income and enhance poverty reduction efforts. 展开更多
关键词 rural transformation rural income rural poverty AGRICULTURE panel analysis
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