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De-Noising Brain MRI Images by Mixing Concatenation and Residual Learning(MCR)
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作者 Kazim Ali Adnan N.Qureshi +3 位作者 Muhammad Shahid Bhatti Abid Sohail Muhammad Hijji Atif Saeed 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期1167-1186,共20页
Brain magnetic resonance images(MRI)are used to diagnose the different diseases of the brain,such as swelling and tumor detection.The quality of the brain MR images is degraded by different noises,usually salt&pep... Brain magnetic resonance images(MRI)are used to diagnose the different diseases of the brain,such as swelling and tumor detection.The quality of the brain MR images is degraded by different noises,usually salt&pepper and Gaussian noises,which are added to the MR images during the acquisition process.In the presence of these noises,medical experts are facing problems in diagnosing diseases from noisy brain MR images.Therefore,we have proposed a de-noising method by mixing concatenation,and residual deep learning techniques called the MCR de-noising method.Our proposed MCR method is to eliminate salt&pepper and gaussian noises as much as possible from the brain MRI images.The MCR method has been trained and tested on the noise quantity levels 2%to 20%for both salt&pepper and gaussian noise.The experiments have been done on publically available brain MRI image datasets,which can easily be accessible in the experiments and result section.The Structure Similarity Index Measure(SSIM)and Peak Signal-to-Noise Ratio(PSNR)calculate the similarity score between the denoised images by the proposed MCR method and the original clean images.Also,the Mean Squared Error(MSE)measures the error or difference between generated denoised and the original images.The proposed MCR denoising method has a 0.9763 SSIM score,84.3182 PSNR,and 0.0004 MSE for salt&pepper noise;similarly,0.7402 SSIM score,72.7601 PSNR,and 0.0041 MSE for Gaussian noise at the highest level of 20%noise.In the end,we have compared the MCR method with the state-of-the-art de-noising filters such as median and wiener de-noising filters. 展开更多
关键词 MR brain images median filter wiener filter concatenation learning residual learning MCR de-noising method
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New immune regulators of sciatic nerve regeneration?Lessons from the neighborhood
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作者 AndréL.Bombeiro Rodrigo G.Q.Fernandes Julie C.Ribot 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第4期705-706,共2页
For decades,the immune system has been associated with host protection against infectious pathogens or tumors,while also contributing to autoimmunity.Notwithstanding,this paradigm is now changing,with recent studies h... For decades,the immune system has been associated with host protection against infectious pathogens or tumors,while also contributing to autoimmunity.Notwithstanding,this paradigm is now changing,with recent studies highlighting novel roles for immune mediators in the maintenance of steady-state tissue homeostasis.In this perspective,we review some of the latest findings featuring immune modulators of the nervous system pathophysiology,with a special focus on interleukin(IL)-17. 展开更多
关键词 HOMEOSTASIS neighborhood finding
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Which Neighborhoods Have Easier Access to Online Home Delivery Services?A Spatiotemporal Accessibility Analysis in Nanjing,China
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作者 KONG Yu ZHEN Feng +1 位作者 ZHANG Shanqi SHEN Lizhen 《Chinese Geographical Science》 SCIE CSCD 2024年第4期722-738,共17页
The rise in online home delivery services(OHDS)has had a significant impact on how urban services are supplied and used in recent years.Studies on the spatial accessibility of OHDS are emerging,but few is known about ... The rise in online home delivery services(OHDS)has had a significant impact on how urban services are supplied and used in recent years.Studies on the spatial accessibility of OHDS are emerging,but few is known about the temporal dimension of OHDS accessibility as well as the geographic and socioeconomic differences in the spatiotemporal accessibility of OHDS.This study measures the spatiotemporal accessibility of four types of OHDS,namely leisure,fresh and convenient,medical,and catering services.The geographic and socioeconomic disparities in the spatiotemporal accessibility of these four types of OHDS are then identified using spatial statistical methods and the Kruskal-Wallis test(K-W test).The case study in Nanjing,China,suggests that:1)spatiotemporal accessibility better reflects the temporal variation of OHDS accessibility and avoids overestimation of OHDS accessibility when only considering its spatial dimension.2)The spatiotemporal accessibility of OHDS varies geographically and socioeconomically.Neighborhoods located in the main city or neighborhoods with higher housing prices,higher population density,and higher point of interest(POI)mix have better OHDS spatiotemporal accessibility.Our study contributes to the understanding of OHDS accessibility from a spatiotemporal perspective,and the empirical insights can assist policymakers in creating intervention plans that take into account variations in OHDS spatiotemporal accessibility. 展开更多
关键词 online home delivery services(OHDS) spatiotemporal accessibility neighborhoods accessibility differences Nanjing City China
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New Developments in the Security Situation in China’s Neighborhood and the Building of a Community with a Shared Future for Neighbors
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作者 Zhou Fangyin 《Contemporary World》 2024年第2期8-12,共5页
The world is undergoing a new round of turbulence and changes,with severe conflicts in multiple regions.This has far-reaching implications for the evolution of the international situation.In this context,China’s neig... The world is undergoing a new round of turbulence and changes,with severe conflicts in multiple regions.This has far-reaching implications for the evolution of the international situation.In this context,China’s neighboring regions have been impacted in many ways,and the security situation in the neighborhood is undergoing complex changes.This inevitably affects the building of a community with a shared future in the region. 展开更多
关键词 neighborhood neighborhood SECURITY
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Relations with Neighboring Countries, Neighboring Region and China’s Neighborhood Environment
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作者 Zhang Yunling 《Contemporary World》 2024年第2期2-7,共6页
The Chinese government released the Outlook on China’s Foreign Policy on Its Neighborhood In the New Era in October 2023,which explicitly stated that“the neighborhood is where China survives and thrives and the foun... The Chinese government released the Outlook on China’s Foreign Policy on Its Neighborhood In the New Era in October 2023,which explicitly stated that“the neighborhood is where China survives and thrives and the foundation of its development and prosperity”.Such a high positioning of the neighborhood indicates that China attaches great importance to its neighborhood and is resolutely determined to deal well with it.The neighborhood relationship features a dual structure:one is the state-to-state relations,meaning the bilateral relations between China and its neighboring countries;the other is regional relations,meaning relationship between China and its neighboring countries as a coexisting region,which collectively make up the overall neighborhood environment.Fostering a sound neighborhood environment is imperative to China’s security and development. 展开更多
关键词 neighborhood neighborhood COLLECTIVE
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GNN Representation Learning and Multi-Objective Variable Neighborhood Search Algorithm for Wind Farm Layout Optimization
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作者 Yingchao Li JianbinWang HaibinWang 《Energy Engineering》 EI 2024年第4期1049-1065,共17页
With the increasing demand for electrical services,wind farm layout optimization has been one of the biggest challenges that we have to deal with.Despite the promising performance of the heuristic algorithm on the rou... With the increasing demand for electrical services,wind farm layout optimization has been one of the biggest challenges that we have to deal with.Despite the promising performance of the heuristic algorithm on the route network design problem,the expressive capability and search performance of the algorithm on multi-objective problems remain unexplored.In this paper,the wind farm layout optimization problem is defined.Then,a multi-objective algorithm based on Graph Neural Network(GNN)and Variable Neighborhood Search(VNS)algorithm is proposed.GNN provides the basis representations for the following search algorithm so that the expressiveness and search accuracy of the algorithm can be improved.The multi-objective VNS algorithm is put forward by combining it with the multi-objective optimization algorithm to solve the problem with multiple objectives.The proposed algorithm is applied to the 18-node simulation example to evaluate the feasibility and practicality of the developed optimization strategy.The experiment on the simulation example shows that the proposed algorithm yields a reduction of 6.1% in Point of Common Coupling(PCC)over the current state-of-the-art algorithm,which means that the proposed algorithm designs a layout that improves the quality of the power supply by 6.1%at the same cost.The ablation experiments show that the proposed algorithm improves the power quality by more than 8.6% and 7.8% compared to both the original VNS algorithm and the multi-objective VNS algorithm. 展开更多
关键词 GNN representation learning variable neighborhood search multi-objective optimization wind farm layout point of common coupling
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Multi-Granularity Neighborhood Fuzzy Rough Set Model on Two Universes
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作者 Ju Wang Xinghu Ai Li Fu 《Journal of Intelligent Learning Systems and Applications》 2024年第2期91-106,共16页
The two universes multi-granularity fuzzy rough set model is an effective tool for handling uncertainty problems between two domains with the help of binary fuzzy relations. This article applies the idea of neighborho... The two universes multi-granularity fuzzy rough set model is an effective tool for handling uncertainty problems between two domains with the help of binary fuzzy relations. This article applies the idea of neighborhood rough sets to two universes multi-granularity fuzzy rough sets, and discusses the two-universes multi-granularity neighborhood fuzzy rough set model. Firstly, the upper and lower approximation operators are defined in the two universes multi-granularity neighborhood fuzzy rough set model. Secondly, the properties of the upper and lower approximation operators are discussed. Finally, the properties of the two universes multi-granularity neighborhood fuzzy rough set model are verified through case studies. 展开更多
关键词 Fuzzy Set Two Universes Multi-Granularity Rough Set Multi-Granularity neighborhood Fuzzy Rough Set
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My Neighborhood
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作者 郭闯闯 张超(指导) 《中学生英语》 2024年第2期7-7,共1页
I live in Haihe Neighborhood.It'sa beautifu1l community with 30 tall buildings.I have some neighbors.They are kind and friendly.On the one hand,they are always ready to help others.For example,they help others by ... I live in Haihe Neighborhood.It'sa beautifu1l community with 30 tall buildings.I have some neighbors.They are kind and friendly.On the one hand,they are always ready to help others.For example,they help others by taking care of their pets and offering umbrellas on rainy days.On the other hand. 展开更多
关键词 offering neighborhood ALWAYS
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Research on the Index System of Old Neighborhood Renovation Based on Green Building Evaluation Standard
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作者 Yufei Que 《Journal of Architectural Research and Development》 2024年第3期140-146,共7页
With the advancement of the transformation,the contradiction between the residents’demand for a better living environment and the convenience of living in the settlements comes to the fore.Effective identification,or... With the advancement of the transformation,the contradiction between the residents’demand for a better living environment and the convenience of living in the settlements comes to the fore.Effective identification,organic integration,timely adoption,and correct decision-making for the transformation of old neighborhoods are pressing issues in the transformation of old neighborhoods.Therefore,this paper takes the green building evaluation standards of various countries as the research basis and support for the construction of the transformation strategy of old neighborhoods.Through the collection and comparative analysis of the indicators of green building evaluation standards,the index system of transformation is formed,and it also provides a certain foundation for the subsequent related research. 展开更多
关键词 Old neighborhoods Green building evaluation standards RENOVATION CRITERIA
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Attribute Reduction of Neighborhood Rough Set Based on Discernment
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作者 Biqing Wang 《Journal of Electronic Research and Application》 2024年第1期80-85,共6页
For neighborhood rough set attribute reduction algorithms based on dependency degree,a neighborhood computation method incorporating attribute weight values and a neighborhood rough set attribute reduction algorithm u... For neighborhood rough set attribute reduction algorithms based on dependency degree,a neighborhood computation method incorporating attribute weight values and a neighborhood rough set attribute reduction algorithm using discernment as the heuristic information was proposed.The reduction algorithm comprehensively considers the dependency degree and neighborhood granulation degree of attributes,allowing for a more accurate measurement of the importance degrees of attributes.Example analyses and experimental results demonstrate the feasibility and effectiveness of the algorithm. 展开更多
关键词 neighborhood rough set Attribute reduction DISCERNMENT ALGORITHM
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Living in a Condominium Regime:Neighborhood Conflicts in Low-Income Housing,Tijuana,Baja California-A Secondary Publication
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作者 M.Zárate López A.Almejo Ornelas M.Sahagún Valenzuela 《Journal of World Architecture》 2024年第2期96-107,共12页
This paper analyzes neighborhood conflicts arising from the condominium property regime,under which social housing promoted by Mexican government institutions and private developers is acquired.This regime has facilit... This paper analyzes neighborhood conflicts arising from the condominium property regime,under which social housing promoted by Mexican government institutions and private developers is acquired.This regime has facilitated access to housing for the salaried population,but it is far from contributing to the attainment of the right to housing.The research takes as case studies housing complexes located in the city of Tijuana,Baja California,Mexico.The analysis included a mixed methodology.Firstly,similar case studies were analyzed;secondly,a review of the Condominium Property Regime Law was carried out in order to understand its implications.In view of the pandemic situation,a virtual survey was applied to the inhabitants of these areas,as well as interviews with presidents of neighborhood committees of these complexes.From the above,it was found that this form of ownership generates conflicts,reflected in the dissatisfaction of the inhabitants with their housing,disagreements and controversies in their organization and coexistence.The inhabitants have to collectively solve the problems they face,related to the maintenance and use of common areas,insecurity,and cleanliness,among others.In addition,there is a lack of support from local authorities.With this,it is concluded that although the inhabitants have a space that solves their housing problem,it does not manage to be a space that adequately guarantees their right to housing. 展开更多
关键词 neighborhood conflicts Right to housing Condominium property Social interest Affordable housing
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Applications of Wavelet Analysis in Differential Propagation Phase Shift Data De-noising 被引量:18
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作者 HU Zhiqun LIU Liping 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2014年第4期825-835,共11页
Using numerical simulation data of the forward differential propagation shift (ΦDP) of polarimetric radar,the principle and performing steps of noise reduction by wavelet analysis are introduced in detail.Profiting... Using numerical simulation data of the forward differential propagation shift (ΦDP) of polarimetric radar,the principle and performing steps of noise reduction by wavelet analysis are introduced in detail.Profiting from the multiscale analysis,various types of noises can be identified according to their characteristics in different scales,and suppressed in different resolutions by a penalty threshold strategy through which a fixed threshold value is applied,a default threshold strategy through which the threshold value is determined by the noise intensity,or a ΦDP penalty threshold strategy through which a special value is designed for ΦDP de-noising.Then,a hard-or soft-threshold function,depending on the de-noising purpose,is selected to reconstruct the signal.Combining the three noise suppression strategies and the two signal reconstruction functions,and without loss of generality,two schemes are presented to verify the de-noising effect by dbN wavelets:(1) the penalty threshold strategy with the soft threshold function scheme (PSS); (2) the ΦDP penalty threshold strategy with the soft threshold function scheme (PPSS).Furthermore,the wavelet de-noising is compared with the mean,median,Kalman,and finite impulse response (FIR) methods with simulation data and two actual cases.The results suggest that both of the two schemes perform well,especially when ΦDP data are simultaneously polluted by various scales and types of noises.A slight difference is that the PSS method can retain more detail,and the PPSS can smooth the signal more successfully. 展开更多
关键词 polarimetric radar wavelet analysis differential propagation phase shift de-noising
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Research on fiber optic gyro signal de-noising based on wavelet packet soft-threshold 被引量:7
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作者 Qian Huaming & Ma Jichen Coll.of Automation,Harbin Engineering Univ.,Harbin 150001,P.R.China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第3期607-612,共6页
Gyro's drift is not only the main drift error which influences gyro's precision but also the primary factor that affects gyro's reliability. Reducing zero drift and random drift is a key problem to the output of a ... Gyro's drift is not only the main drift error which influences gyro's precision but also the primary factor that affects gyro's reliability. Reducing zero drift and random drift is a key problem to the output of a gyro signal. A three-layer de-nosing threshold algorithm is proposed based on the wavelet decomposition to dispose the signal which is collected from a running fiber optic gyro (FOG). The coefficients are obtained from the three-layer wavelet packet decomposition. By setting the high frequency part which is greater than wavelet packet threshold as zero, then reconstructing the nodes which have been filtered out noise and interruption, the soft threshold function is constructed by the coefficients of the third nodes. Compared wavelet packet de-noise with forced de-noising method, the proposed method is more effective. Simulation results show that the random drift compensation is enhanced by 13.1%, and reduces zero drift by 0.052 6°/h. 展开更多
关键词 wavelet transform DRIFT fiber optic gyro soft-threshold signal de-noising
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Geotechnical engineering blasting:a new modal aliasing cancellation methodology of vibration signal de-noising 被引量:4
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作者 Yi Wenhua Yan Lei +3 位作者 Wang Zhenhuan Yang Jianhua Tao Tiejun Liu Liansheng 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2022年第2期313-323,共11页
In the present study of peak particle velocity(PPV)and frequency,an improved algorithm(principal empirical mode decomposition,PEMD)based on principal component analysis(PCA)and empirical mode decomposition(EMD)is prop... In the present study of peak particle velocity(PPV)and frequency,an improved algorithm(principal empirical mode decomposition,PEMD)based on principal component analysis(PCA)and empirical mode decomposition(EMD)is proposed,with the goal of addressing poor filtering de-noising effects caused by the occurrences of modal aliasing phenomena in EMD blasting vibration signal decomposition processes.Test results showed that frequency of intrinsic mode function(IMF)components decomposed by PEMD gradually decreases and that the main frequency is unique,which eliminates the phenomenon of modal aliasing.In the simulation experiment,the signal-to-noise(SNR)and root mean square errors(RMSE)ratio of the signal de-noised by PEMD are the largest when compared to EMD and ensemble empirical mode decomposition(EEMD).The main frequency of the de-noising signal through PEMD is 75 Hz,which is closest to the frequency of the noiseless simulation signal.In geotechnical engineering blasting experiments,compared to EMD and EEMD,the signal de-noised by PEMD has the lowest level of distortion,and the frequency band is distributed in a range of 0-64 Hz,which is closest to the frequency band of the blasting vibration signal.In addition,the proportion of noise energy was the lowest,at 1.8%. 展开更多
关键词 blasting vibration frequency empirical mode decomposition modal aliasing de-noising
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Moving horizon based wavelet de-noising method of dual-observed geomagnetic signal for nonlinear high spin projectile roll positioning 被引量:3
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作者 Ting-ting Yin Fang-xiu Jia Xiao-ming Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第2期417-424,共8页
Phase-frequency characte ristics of approximate sinusoidal geomagnetic signals can be used fo r projectile roll positioning and other high-precision trajectory correction applications.The sinusoidal geomagnetic signal... Phase-frequency characte ristics of approximate sinusoidal geomagnetic signals can be used fo r projectile roll positioning and other high-precision trajectory correction applications.The sinusoidal geomagnetic signal deforms in the exposed and magnetically contaminated environment.In order to preciously recognize the roll information and effectively separate the noise component from the original geomagnetic sequence,based on the error source analysis,we propose a moving horizon based wavelet de-noising method for the dual-observed geomagnetic signal filtering where the captured rough roll frequency value provides reasonable wavelet decomposition and reconstruction level selection basis for sampled sequence;a moving horizon window guarantees real-time performance and non-cumulative calculation amount.The complete geomagnetic data in full ballistic range and three intercepted paragraphs are used for performance assessment.The positioning performance of the moving horizon wavelet de-noising method is compared with the band-pass filter.The results show that both noise reduction techniques improve the positioning accuracy while the wavelet de-noising method is always better than the band-pass filter.These results suggest that the proposed moving horizon based wavelet de-noising method of the dual-observed geomagnetic signal is more applicable for various launch conditions with better positioning performance. 展开更多
关键词 High-spin PROJECTILE ROLL POSITIONING Dual-observed GEOMAGNETIC signal WAVELET de-noising Discrete WAVELET transform
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Fault Diagnosis of Motor in Frequency Domain Signal by Stacked De-noising Auto-encoder 被引量:4
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作者 Xiaoping Zhao Jiaxin Wu +2 位作者 Yonghong Zhang Yunqing Shi Lihua Wang 《Computers, Materials & Continua》 SCIE EI 2018年第11期223-242,共20页
With the rapid development of mechanical equipment,mechanical health monitoring field has entered the era of big data.Deep learning has made a great achievement in the processing of large data of image and speech due ... With the rapid development of mechanical equipment,mechanical health monitoring field has entered the era of big data.Deep learning has made a great achievement in the processing of large data of image and speech due to the powerful modeling capabilities,this also brings influence to the mechanical fault diagnosis field.Therefore,according to the characteristics of motor vibration signals(nonstationary and difficult to deal with)and mechanical‘big data’,combined with deep learning,a motor fault diagnosis method based on stacked de-noising auto-encoder is proposed.The frequency domain signals obtained by the Fourier transform are used as input to the network.This method can extract features adaptively and unsupervised,and get rid of the dependence of traditional machine learning methods on human extraction features.A supervised fine tuning of the model is then carried out by backpropagation.The Asynchronous motor in Drivetrain Dynamics Simulator system was taken as the research object,the effectiveness of the proposed method was verified by a large number of data,and research on visualization of network output,the results shown that the SDAE method is more efficient and more intelligent. 展开更多
关键词 Big data deep learning stacked de-noising auto-encoder fourier transform
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Technology of signal de-noising and singularity elimination based on wavelet transform 被引量:1
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作者 赵国建 韩宝玲 +1 位作者 罗庆生 王鑫 《Journal of Beijing Institute of Technology》 EI CAS 2011年第4期509-513,共5页
Based on wavelet transform theory,a method for signal de-noising and singularity detection and elimination is proposed,which can reduce the noises and express local singularity.Each singularity can also be detected an... Based on wavelet transform theory,a method for signal de-noising and singularity detection and elimination is proposed,which can reduce the noises and express local singularity.Each singularity can also be detected and located through the local modulus maxima of wavelet transform.Simulation experiments are conducted with MATLAB software.The experimental results demonstrate that the method proposed in this paper is effective and feasible. 展开更多
关键词 industrial palletizing robot photoelectric sensor wavelet transform wavelet de-noising SINGULARITY
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SAR image de-noising via grouping-based PCA and guided filter 被引量:3
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作者 FANG Jing HU Shaohai MA Xiaole 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第1期81-91,共11页
A novel synthetic aperture radar(SAR)image de-noising method based on the local pixel grouping(LPG)principal component analysis(PCA)and guided filter is proposed.This method contains two steps.In the first step,we pro... A novel synthetic aperture radar(SAR)image de-noising method based on the local pixel grouping(LPG)principal component analysis(PCA)and guided filter is proposed.This method contains two steps.In the first step,we process the noisy image by coarse filters,which can suppress the speckle effectively.The original SAR image is transformed into the additive noise model by logarithmic transform with deviation correction.Then,we use the pixel and its nearest neighbors as a vector to select training samples from the local window by LPG based on the block similar matching.The LPG method ensures that only the similar sample patches are used in the local statistical calculation of PCA transform estimation,so that the local features of the image can be well preserved after coefficients shrinkage in the PCA domain.In the second step,we do the guided filtering which can effectively eliminate small artifacts left over from the coarse filtering.Experimental results of simulated and real SAR images show that the proposed method outstrips the state-of-the-art image de-noising methods in the peak signalto-noise ratio(PSNR),the structural similarity(SSIM)index and the equivalent number of looks(ENLs),and is of perceived image quality. 展开更多
关键词 synthetic aperture radar(SAR)image de-noising local pixel grouping(LPG) principal component analysis(PCA) guided filter
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Partial Discharge Source Classification and De-Noising in Rotating Machines Using Discrete Wavelet Transform and Directional Coupling Capacitor 被引量:1
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作者 Mohammad Amin Kashiha Diman Zad Tootaghaj Dolat Jamshidi 《Journal of Electromagnetic Analysis and Applications》 2009年第2期92-96,共5页
This paper introduces a new method to separate PD1 from other disturbing signals present on the high voltage genera-tors and motors. The method is based on combination of a pattern classifier, the Discrete Wavelet Tra... This paper introduces a new method to separate PD1 from other disturbing signals present on the high voltage genera-tors and motors. The method is based on combination of a pattern classifier, the Discrete Wavelet Transform (DWT), to de-noise PD and Time-Of-Arrival method to separate PD sources. Furthermore, it will be shown that it can recognize PD sources including rotating machine’s internal and external discharge pulses (e.g. on the bus bar). 展开更多
关键词 Partial DISCHARGE Discrete WAVELET Transform TIME-OF-ARRIVAL ROTATING Machines de-noising Coupling CAPACITOR
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Application of S-transform threshold filtering in Anhui experiment airgun sounding data de-noising 被引量:1
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作者 Chenglong Zheng Xiaofeng Tian +2 位作者 Zhuoxin Yang Shuaijun Wang Zhenyu Fan 《Geodesy and Geodynamics》 2018年第4期320-327,共8页
As a relatively new method of processing non-stationary signal with high time-frequency resolution, S transform can be used to analyze the time-frequency characteristics of seismic signals. It has the following charac... As a relatively new method of processing non-stationary signal with high time-frequency resolution, S transform can be used to analyze the time-frequency characteristics of seismic signals. It has the following characteristics: its time-frequency resolution corresponding to the signal frequency, reversible inverse transform, basic wavelet that does not have to meet the permit conditions. We combined the threshold method, proposed the S-transform threshold filtering on the basis of S transform timefrequency filtering, and processed airgun seismic records from temporary stations in "Yangtze Program"(the Anhui experiment). Compared with the results of the bandpass filtering, the S transform threshold filtering can improve the signal to noise ratio(SNR) of seismic waves and provide effective help for first arrival pickup and accurate travel time. The first arrival wave seismic phase can be traced farther continuously, and the Pm seismic phase in the subsequent zone is also highlighted. 展开更多
关键词 S transform Time-frequency filtering Airgun data Threshold filtering de-noising
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