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An Orthogonal Wavelet Transform Fractionally Spaced Blind Equalization Algorithm Based on the Optimization of Genetic Algorithm
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作者 廖娟 郭业才 季童莹 《Defence Technology(防务技术)》 SCIE EI CAS 2011年第2期65-71,共7页
An orthogonal wavelet transform fractionally spaced blind equalization algorithm based on the optimization of genetic algorithm(WTFSE-GA) is proposed in viewof the lowconvergence rate,large steady-state mean square er... An orthogonal wavelet transform fractionally spaced blind equalization algorithm based on the optimization of genetic algorithm(WTFSE-GA) is proposed in viewof the lowconvergence rate,large steady-state mean square error and local convergence of traditional constant modulus blind equalization algorithm(CMA).The proposed algorithm can reduce the signal autocorrelation through the orthogonal wavelet transform of input signal of fractionally spaced blind equalizer,and decrease the possibility of CMA local convergence by using the global random search characteristics of genetic algorithm to optimize the equalizer weight vector.The proposed algorithm has the faster convergence rate and smaller mean square error compared with FSE and WT-FSE.The efficiency of the proposed algorithm is proved by computer simulation of underwater acoustic channels. 展开更多
关键词 information processing technique genetic algorithm orthogonal wavelet transform fractionally spaced equalizer blind equalization underwater acoustic channel
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A Two-dimensional Genetic Algorithm Based on the Eno-Haar Wavelet Transform
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作者 宋锦萍 赵晨萍 李登峰 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第3期377-383,共7页
A two-dimensional genetic algorithm of wavelet coefficient is presented by using the ENO wavelet transform and the decomposed characterization of the two-dimensional Haar wavelet. And simulated by the ENO interpolatio... A two-dimensional genetic algorithm of wavelet coefficient is presented by using the ENO wavelet transform and the decomposed characterization of the two-dimensional Haar wavelet. And simulated by the ENO interpolation the article shows the affectivity and the superiority of this algorithm. 展开更多
关键词 wavelet transform ENO-Haar wavelet transform two-dimensional genetic algorithm
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Audio Watermarking Using Wavelet Transform and Genetic Algorithm for Realizing High Tolerance to MP3 Compression
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作者 Shinichi Murata Yasunari Yoshitomi Hiroaki Ishii 《Journal of Information Security》 2011年第3期99-112,共14页
Recently, several digital watermarking techniques have been proposed for hiding data in the frequency domain of audio signals to protect the copyrights. However, little attention has been given to the optimal position... Recently, several digital watermarking techniques have been proposed for hiding data in the frequency domain of audio signals to protect the copyrights. However, little attention has been given to the optimal position in the frequency domain for embedding watermarks. In general, there is a tradeoff between the quality of the watermarked audio and the tolerance of watermarks to signal processing methods, such as compression. In the present study, a watermarking method developed for a visual image by using a wavelet transform was applied to an audio clip. We also improved the performance of both the quality of the watermarked audio and the extraction of watermarks after compression by the MP3 technique. To accomplish this, we created a multipurpose optimization problem for deciding the positions of watermarks in the frequency domain and obtaining a near-optimum solution. The near-optimum solution is obtained by using a genetic algorithm. The experimental results show that the proposed method generates watermarked audios of good quality and high tolerance to MP3 compression. In addition, the security was improved by using the characteristic secret key to embed and extract the watermark information. 展开更多
关键词 AUDIO WATERMARKING genetic algorithm Optimization WAVELET transforms SECRET Key
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A New Image Watermarking Scheme Using Genetic Algorithm and Residual Numbers with Discrete Wavelet Transform
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作者 Peter Awonnatemi Agbedemnab Mohammed Akolgo Moses Apambila Agebure 《Journal of Information Security》 2023年第4期422-436,共15页
Transmission of data over the internet has become a critical issue as a result of the advancement in technology, since it is possible for pirates to steal the intellectual property of content owners. This paper presen... Transmission of data over the internet has become a critical issue as a result of the advancement in technology, since it is possible for pirates to steal the intellectual property of content owners. This paper presents a new digital watermarking scheme that combines some operators of the Genetic Algorithm (GA) and the Residue Number (RN) System (RNS) to perform encryption on an image, which is embedded into a cover image for the purposes of watermarking. Thus, an image watermarking scheme uses an encrypted image. The secret image is embedded in decomposed frames of the cover image achieved by applying a three-level Discrete Wavelet Transform (DWT). This is to ensure that the secret information is not exposed even when there is a successful attack on the cover information. Content creators can prove ownership of the multimedia content by unveiling the secret information in a court of law. The proposed scheme was tested with sample data using MATLAB2022 and the results of the simulation show a great deal of imperceptibility and robustness as compared to similar existing schemes. 展开更多
关键词 Discrete Wavelet transform (DWT) Digital Watermarking Encryption genetic algorithm (GA) Residue Number System (RNS) GARN
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Adaptive template filter method for image processing based on immune genetic algorithm 被引量:1
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作者 谭冠政 吴建华 +1 位作者 范必双 江斌 《Journal of Central South University》 SCIE EI CAS 2010年第5期1028-1035,共8页
To preserve the original signal as much as possible and filter random noises as many as possible in image processing,a threshold optimization-based adaptive template filtering algorithm was proposed.Unlike conventiona... To preserve the original signal as much as possible and filter random noises as many as possible in image processing,a threshold optimization-based adaptive template filtering algorithm was proposed.Unlike conventional filters whose template shapes and coefficients were fixed,multi-templates were defined and the right template for each pixel could be matched adaptively based on local image characteristics in the proposed method.The superiority of this method was verified by former results concerning the matching experiment of actual image with the comparison of conventional filtering methods.The adaptive search ability of immune genetic algorithm with the elitist selection and elitist crossover(IGAE) was used to optimize threshold t of the transformation function,and then combined with wavelet transformation to estimate noise variance.Multi-experiments were performed to test the validity of IGAE.The results show that the filtered result of t obtained by IGAE is superior to that of t obtained by other methods,IGAE has a faster convergence speed and a higher computational efficiency compared with the canonical genetic algorithm with the elitism and the immune algorithm with the information entropy and elitism by multi-experiments. 展开更多
关键词 image characteristic template match adaptive template filter wavelet transform elitist selection elitist crossover immune genetic algorithm
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The Role of High Precision Arithmetic in Calculating Numerical Laplace and Inverse Laplace Transforms
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作者 Zinovi Krougly Matt Davison Sid Aiyar 《Applied Mathematics》 2017年第4期562-589,共28页
In order to find stable, accurate, and computationally efficient methods for performing the inverse Laplace transform, a new double transformation approach is proposed. To validate and improve the inversion solution o... In order to find stable, accurate, and computationally efficient methods for performing the inverse Laplace transform, a new double transformation approach is proposed. To validate and improve the inversion solution obtained using the Gaver-Stehfest algorithm, direct Laplace transforms are taken of the numerically inverted transforms to compare with the original function. The numerical direct Laplace transform is implemented with a composite Simpson’s rule. Challenging numerical examples involving periodic and oscillatory functions, are investigated. The numerical examples illustrate the computational accuracy and efficiency of the direct Laplace transform and its inverse due to increasing the precision level and the number of terms included in the expansion. It is found that the number of expansion terms and the precision level selected must be in a harmonious balance in order for correct and stable results to be obtained. 展开更多
关键词 NUMERICAL laplace transform NUMERICAL laplace transform Inversion Composite Simpson’s RULE Gaver-Stehfest algorithm High Precision Computation
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New Optimal DWT Domain Image Watermarking Technique via Genetic Algorithm
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作者 钟宁 匡镜明 何遵文 《Journal of Beijing Institute of Technology》 EI CAS 2007年第4期465-470,共6页
A novel optimal image watermarking scheme is proposed in which the genetic algorithm (GA) is employed to obtain the improvement of algorithm performance. Arnold transform is utilized to obtain the scrambled watermark,... A novel optimal image watermarking scheme is proposed in which the genetic algorithm (GA) is employed to obtain the improvement of algorithm performance. Arnold transform is utilized to obtain the scrambled watermark, and then the embedding and extraction of watermark are implemented in digital wavelet transform (DWT) domain. During the watermarking process, GA is employed to search optimal parameters of embedding strength and times of Arnold transform to gain the optimization of watermarking performance. Simulation results show that the proposed method can improve the quality of watermarked image and give almost the same robustness of the watermark. 展开更多
关键词 image watermarking genetic algorithm (GA) digital wavelet transform (DWT)
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Method and application of wavelet shrinkage denoising based on genetic algorithm
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作者 马启明 王宣银 杜拴平 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第3期361-367,共7页
Genetic algorithm (GA) based on wavelet transform threshold shrinkage (WTS) and translation-invariant threshold shrinkage (TIS) is introduced into the method of noise reduction, where parameters used in WTS and TIS, s... Genetic algorithm (GA) based on wavelet transform threshold shrinkage (WTS) and translation-invariant threshold shrinkage (TIS) is introduced into the method of noise reduction, where parameters used in WTS and TIS, such as wavelet function, decomposition levels, hard or soft threshold and threshold can be selected automatically. This paper ends by comparing two noise reduction methods on the basis of their denoising performances, computation time, etc. The effectiveness of these methods in-troduced in this paper is validated by the results of analysis of the simulated and real signals. 展开更多
关键词 Wavelet transform Translation-invariant wavelet transform genetic algorithm (GA) Correlation function
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A Novel Approach for Iris Recognition System Using Genetic Algorithm
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作者 Jayesh Mohanrao Sarwade Sandip Bankar +4 位作者 Surekha Janrao Kishor Sakure Rohini Patil Shudhodhan Bokefode Nilesh Kulal 《Journal of Artificial Intelligence and Technology》 2024年第1期9-17,共9页
In a brand new era,with chaotic scenario that exists within the world,people are undermined with diverse psychological assaults.There have been numerous sensible approaches on the way to understand and lessen those at... In a brand new era,with chaotic scenario that exists within the world,people are undermined with diverse psychological assaults.There have been numerous sensible approaches on the way to understand and lessen those attacks.Bioscrypt developments have verified to be one of the beneficial approaches for intercepting these troubles.Identifying recognition through human iris organ is said as one of the well-known biometric strategies because of its reliability and higher accurate return in comparison to different developments.Reviewing beyond literatures,terrible imaging condition,low flexibility of version,and small length iris image dataset are the constraints desiring solutions.Among these kinds of developments,the iris popularity structures are suitable gear for the human identification.Iris popularity has been an energetic studies location for the duration of previous couple of decades,due to its extensive packages in the areas,from airports to native land protection border protection.In the past,various functions and methods for iris recognition have been presented.Despite of the very fact that there are many approaches published in this field,there are still liberal amount of problems in this methodology like tedious and computational intricacy.We suggest an all-encompassing deep learning architecture for iris recognition supported by a genetic algorithm and a wavelet transformation,which may jointly learn the feature representation and perform recognition to realize high efficiency.With just a few training photos from each class,we train our model on a well-known iris recognition dataset and demonstrate improvements over prior methods.We think that this architecture can be frequently employed for various biometric recognition jobs,assisting in the development of a more scalable and precise system.The exploratory aftereffects of the proposed technique uncover that the strategy is effective inside the iris acknowledgment. 展开更多
关键词 BIOMETRICS genetics algorithm(GA) iris recognition machine learning wavelet transformation
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逆Laplace变换新算法及其在时间域电磁响应计算中的应用 被引量:1
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作者 王萌 罗维斌 《地球物理学进展》 CSCD 北大核心 2018年第2期740-747,共8页
时间域电磁响应的正演计算多是由频率域响应经逆Laplace变换而得到.逆Laplace变换的计算精度和效率是时间域电磁响应计算中方法选择的重要指标.论文分析了几种逆Laplace变换的算法机制,并优选出Talbot算法计算了水平电偶源层状模型的时... 时间域电磁响应的正演计算多是由频率域响应经逆Laplace变换而得到.逆Laplace变换的计算精度和效率是时间域电磁响应计算中方法选择的重要指标.论文分析了几种逆Laplace变换的算法机制,并优选出Talbot算法计算了水平电偶源层状模型的时间域电磁响应.逆Laplace变换常用的算法有折线法、数字滤波算法和Gaver-Stehfest算法(简称G-S算法).折线法需要精细地确定分割步长以提高精度,数字滤波算法系数很多,适应频率范围受计算问题所限,而G-S算法受计算机字长和问题对象的影响大.本文在64位计算平台中计算比较了G-S算法、Euler算法和Talbot算法的节点数对于精度的影响,发现Talbot算法受节点数影响小,计算精度高,适应频率范围宽.最后利用21点Talbot算法计算了水平电偶源轴向偶极装置均匀大地模型径向电场的阶跃响应和冲激响应,计算精度及响应时间范围均优于G-S算法.计算了水平电偶源赤道偶极装置均匀大地模型垂直磁场的阶跃响应和冲激响应,冲激响应峰值时刻对于电阻率的变化响应灵敏,与轴向偶极径向电场响应能力相当,但垂直磁场随收发距增大,衰减较快.根据层状模型阶跃响应晚期渐近值计算的视电阻率,水平电偶源轴向偶极径向电场有能力发现大埋深高阻或低阻薄层,收发距应大于中间目标层埋深的5~6倍方可完整探测,类似的,采用水平电偶源赤道偶极装置测量垂直磁场也能达到与之相当的探测能力.计算结果证实了21点Talbot算法适应不同地电模型、不同观测方式的时间域电磁响应计算. 展开更多
关键词 时间域电磁响应 频率域电磁响应 laplace变换 G-S算法 Talbot算法
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A Numerical Algorithm for Arbitrary Real-Order Hankel Transform
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作者 YANG Yonglin LI Xing +1 位作者 DING Shenghu WANG Wenshuai 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2022年第1期26-34,共9页
The Hankel transform is widely used to solve various engineering and physics problems,such as the representation of electromagnetic field components in the medium,the representation of dynamic stress intensity factors... The Hankel transform is widely used to solve various engineering and physics problems,such as the representation of electromagnetic field components in the medium,the representation of dynamic stress intensity factors,vibration of axisymmetric infinite membrane and displacement intensity factors which all involve this type of integration.However,traditional numerical integration algorithms cannot be used due to the high oscillation characteristics of the Bessel function,so it is particularly important to propose a high precision and efficient numerical algorithm for calculating the integral of high oscillation.In this paper,the improved Gaver-Stehfest(G-S)inverse Laplace transform method for arbitrary real-order Bessel function integration is presented by using the asymptotic characteristics of the Bessel function and the accumulation of integration,and the optimized G-S coefficients are given.The effectiveness of the algorithm is verified by numerical examples.Compared with the linear transformation accelerated convergence algorithm,it shows that the G-S inverse Laplace transform method is suitable for arbitrary real order Hankel transform,and the time consumption is relatively stable and short,which provides a reliable calculation method for the study of electromagnetic mechanics,wave propagation,and fracture dynamics. 展开更多
关键词 Hankel transform large argument approximate expression of the Bessel function linear transformation accelerated convergence algorithm(LTACA) G-S inverse laplace transform method(G-SILTM)
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A Robust Image Watermarking Based on DWT and RDWT Combined with Mobius Transformations
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作者 Atheer Alrammahi Hedieh Sajedi 《Computers, Materials & Continua》 2025年第7期887-918,共32页
Ensuring digital media security through robust image watermarking is essential to prevent unauthorized distribution,tampering,and copyright infringement.This study introduces a novel hybrid watermarking framework that... Ensuring digital media security through robust image watermarking is essential to prevent unauthorized distribution,tampering,and copyright infringement.This study introduces a novel hybrid watermarking framework that integrates Discrete Wavelet Transform(DWT),Redundant Discrete Wavelet Transform(RDWT),and Möbius Transformations(MT),with optimization of transformation parameters achieved via a Genetic Algorithm(GA).By combining frequency and spatial domain techniques,the proposed method significantly enhances both the imper-ceptibility and robustness of watermark embedding.The approach leverages DWT and RDWT for multi-resolution decomposition,enabling watermark insertion in frequency subbands that balance visibility and resistance to attacks.RDWT,in particular,offers shift-invariance,which improves performance under geometric transformations.Möbius transformations are employed for spatial manipulation,providing conformal mapping and spatial dispersion that fortify watermark resilience against rotation,scaling,and translation.The GA dynamically optimizes the Möbius parameters,selecting configurations that maximize robustness metrics such as Peak Signal-to-Noise Ratio(PSNR),Structural Similarity Index Measure(SSIM),Bit Error Rate(BER),and Normalized Cross-Correlation(NCC).Extensive experiments conducted on medical and standard benchmark images demonstrate the efficacy of the proposed RDWT-MT scheme.Results show that PSNR exceeds 68 dB,SSIM approaches 1.0,and BER remains at 0.0000,indicating excellent imperceptibility and perfect watermark recovery.Moreover,the method exhibits exceptional resilience to a wide range of image processing attacks,including Gaussian noise,JPEG compression,histogram equalization,and cropping,achieving NCC values close to or equal to 1.0.Comparative evaluations with state-of-the-art watermarking techniques highlight the superiority of the proposed method in terms of robustness,fidelity,and computational efficiency.The hybrid framework ensures secure,adaptive watermark embedding,making it highly suitable for applications in digital rights management,content authentication,and medical image protection.The integration of spatial and frequency domain features with evolutionary optimization presents a promising direction for future watermarking technologies. 展开更多
关键词 Digital watermarking Möbius transforms discrete wavelet transform redundant discrete wavelet transform genetic algorithm ROBUSTNESS geometric attacks
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Improved Multi-Fusion Black-Winged Kite Algorithm for Optimizing Stochastic Configuration Networks for Lithium Battery Remaining Life Prediction
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作者 Yuheng Yin Lin Wang 《Energy Engineering》 2025年第7期2845-2864,共20页
The accurate estimation of lithium battery state of health(SOH)plays an important role in the health management of battery systems.In order to improve the prediction accuracy of SOH,this paper proposes a stochastic co... The accurate estimation of lithium battery state of health(SOH)plays an important role in the health management of battery systems.In order to improve the prediction accuracy of SOH,this paper proposes a stochastic configuration network based on a multi-converged black-winged kite search algorithm,called SBKA-CLSCN.Firstly,the indirect health index(HI)of the battery is extracted by combining it with Person correlation coefficients in the battery charging and discharging cycle point data.Secondly,to address the problem that the black-winged kite optimization algorithm(BKA)falls into the local optimum problem and improve the convergence speed,the Sine chaotic black-winged kite search algorithm(SBKA)is designed,which mainly utilizes the Sine mapping and the golden-sine strategy to enhance the algorithm’s global optimality search ability;secondly,the Cauchy distribution and Laplace regularization techniques are used in the SCN model,which is referred to as CLSCN,thereby improving the model’s overall search capability and generalization ability.Finally,the performance of SBKA and SBKA-CLSCN is evaluated using eight benchmark functions and the CALCE battery dataset,respectively,and compared in comparison with the Long Short-Term Memory(LSTM)model and the Gated Recurrent Unit(GRU)model,and the experimental results demonstrate the feasibility and effectiveness of the SBKA-CLSCN algorithm. 展开更多
关键词 Random configuration networks black-winged kite algorithm sine chaotic mapping laplace transform
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TCN-Transformer模型在鄂尔多斯盆地长8储层孔隙度预测精准评价
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作者 刘心如 曾滨鑫 刘卫东 《河北地质大学学报》 2025年第5期48-56,共9页
孔隙度是储层评价的重要参数。然而传统方法主要依赖物理实验测定、测井解释经验公式受限于非线性地质建模能力,导致预测精度有限。为提高储层参数预测精度,论文建立了一种基于时间卷积网络(TCN)与Transformer融合的储层参数预测模型,... 孔隙度是储层评价的重要参数。然而传统方法主要依赖物理实验测定、测井解释经验公式受限于非线性地质建模能力,导致预测精度有限。为提高储层参数预测精度,论文建立了一种基于时间卷积网络(TCN)与Transformer融合的储层参数预测模型,基于皮尔逊相关系数优选测井数据作为模型输入,同时采用遗传算法对模型进行超参数寻优,将该方法应用于鄂尔多斯盆地西南部长8油层组,并对比其与单一Transformer、CNN及TCN模型的预测效果。实验结果表明:相较于其他3种模型,TCN-Transformer模型的平均绝对误差(MAE)以及均方根误差(RMSE)更低,拟合优度(R^(2))更接近于1,表明其有更高的预测精度。此外,TCN-Transformer模型在未经训练和调参的独立测试集上的预测误差最低,展现出较强的泛化能力。该方法为孔隙度预测提供了高精度工具,对储层评价与开发方案有实际应用价值。 展开更多
关键词 孔隙度预测 深度学习 TCN-transformer模型 测井数据 遗传算法
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PARAMETERS OPTIMIZATION OF CONTINUOUS WAVELET TRANSFORM AND ITS APPLICATION IN ACOUSTIC EMISSION SIGNAL ANALYSIS OF ROLLING BEARING 被引量:8
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作者 ZHANG Xinming HE Yongyong HAO Rujiang CHU Fulei 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第2期104-108,共5页
Morlet wavelet is suitable to extract the impulse components of mechanical fault signals. And thus its continuous wavelet transform (CWT) has been successfully used in the field of fault diagnosis. The principle of ... Morlet wavelet is suitable to extract the impulse components of mechanical fault signals. And thus its continuous wavelet transform (CWT) has been successfully used in the field of fault diagnosis. The principle of scale selection in CWT is discussed. Based on genetic algorithm, an optimization strategy for the waveform parameters of the mother wavelet is proposed with wavelet entropy as the optimization target. Based on the optimized waveform parameters, the wavelet scalogram is used to analyze the simulated acoustic emission (AE) signal and real AE signal of rolling bearing. The results indicate that the proposed method is useful and efficient to improve the quality of CWT. 展开更多
关键词 Rolling bearing Fault diagnosis Acoustic emission (AE) Continuous wavelet transform (CWT) genetic algorithm
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ALGORITHM FOR THE DETECTION AND PARAMETER ESTIMATION OF MULTICOMPONENT LFM SIGNALS 被引量:7
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作者 YuanWeiming WangMin WuShunjun 《Journal of Electronics(China)》 2005年第2期185-189,共5页
A novel algorithm based on Radon-Ambiguity Transform (RAT) and Adaptive Signal Decomposition (ASD) is presented for the detection and parameter estimation of multicompo-nent Linear Frequency Modulated (LFM) signals. T... A novel algorithm based on Radon-Ambiguity Transform (RAT) and Adaptive Signal Decomposition (ASD) is presented for the detection and parameter estimation of multicompo-nent Linear Frequency Modulated (LFM) signals. The key problem lies in the chirplet estimation. Genetic algorithm is employed to search for the optimization parameter of chirplet. High estimation accuracy can be obtained even at low Signal-to-Noisc Ratio(SNR). Finally simulation results are provided to demonstrate the performance of the proposed algorithm. 展开更多
关键词 Multicomponent Linear Frequency Modulated(LFM) signals Parameter estimation Radon-Ambiguity transform (RAT) Adaptive Signal Decomposition (ASD) genetic algorithm
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Optimum Design of Structures for Earthquake Induced Loading by Genetic Algorithm Using Wavelet Transform 被引量:1
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作者 Ali Heidari 《Advances in Applied Mathematics and Mechanics》 SCIE 2010年第1期107-117,共11页
Optimum design of structures is achieved by genetic algorithm.The evolutionary algorithm is employed to design structures.The method improves the computing efficiency of the large-scale optimization problems and enhan... Optimum design of structures is achieved by genetic algorithm.The evolutionary algorithm is employed to design structures.The method improves the computing efficiency of the large-scale optimization problems and enhances the global convergence of the design process.The loads are considered as earthquake loads.A time history analysis is carried out for the dynamic analysis.To decrease the computational work,a wavelet transform is used by which the number of points in the earthquake record is reduced.A reverse wavelet transform is also employed to reconstruct the functions under consideration in the time domain.A number of space structures are designed for minimum weight and the results are compared with exact dynamic analysis. 展开更多
关键词 genetic algorithm discrete wavelet transform reverse wavelet transform dynamic analysis
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Adjustment of Model Parameters to Estimate Distribution Transformers Remaining Lifespan 被引量:1
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作者 Victor A. Jimenez Adrian Will +1 位作者 Jorge Gotay Sebastián Rodríguez 《Smart Grid and Renewable Energy》 2018年第9期151-170,共20页
Currently, the electrical system in Argentina is working at its maximum capacity, decreasing the margin between the installed power and demanded consumption, and drastically reducing the service life of transformer su... Currently, the electrical system in Argentina is working at its maximum capacity, decreasing the margin between the installed power and demanded consumption, and drastically reducing the service life of transformer substations due to overload (since the margin for summer peaks is small). The advent of the Smart Grids allows electricity distribution companies to apply data analysis techniques to manage resources more efficiently at different levels (avoiding damages, better contingency management, maintenance planning, etc.). The Smart Grids in Argentina progresses slowly due to the high costs involved. In this context, the estimation of the lifespan reduction of distribution transformers is a key tool to efficiently manage human and material resources, maximizing the lifetime of this equipment. Despite the current state of the smart grids, the electricity distribution companies can implement it using the available data. Thermal models provide guidelines for lifespan estimation, but the adjustment to particular conditions, brands, or material quality is done by adjusting parameters. In this work we propose a method to adjust the parameters of a thermal model using Genetic Algorithms, comparing the estimation values of top-oil temperature with measurements from 315 kVA distribution transformers, located in the province of Tucumán, Argentina. The results show that, despite limited data availability, the adjusted model is suitable to implement a transformer monitoring system. 展开更多
关键词 Distribution transformER Thermal Model transformER LIFESPAN Parameters Adjustment genetic algorithms
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Developing an Evolutionary Algorithm to Search for an Optimal Multi-Mother Wavelet Packets Combination
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作者 Ohad Bar Siman Tov J. David Schaffer Kenneth J. McLeod 《Journal of Biomedical Science and Engineering》 2015年第7期458-470,共13页
The wavelet transform is a popular analysis tool for non-stationary data, but in many cases, the choice of the mother wavelet and basis set remains uncertain, particularly when dealing with physiological data. Further... The wavelet transform is a popular analysis tool for non-stationary data, but in many cases, the choice of the mother wavelet and basis set remains uncertain, particularly when dealing with physiological data. Furthermore, the possibility exists for combining information from numerous mother wavelets so as to exploit different features from the data. However, the combinatorics become daunting given the large number of basis sets that can be utilized. Recent work in evolutionary computation has produced a subset selection genetic algorithm specifically aimed at the discovery of small, high-performance, subsets from among a large pool of candidates. Our aim was to apply this algorithm to the task of locating subsets of packets from multiple mother wavelet decompositions to estimate cardiac output from chest wall motions while avoiding the computational cost of full signal reconstruction. We present experiments which show how a continuous assessment metric can be extracted from the wavelets coefficients, but the dual-objective nature of the algorithm (high accuracy with small feature sets) imposes a need to restrict the sensitivity of the continuous accuracy metric in order to achieve the small subset size desired. A possibly subtle tradeoff seems to be needed to meet the dual objectives. 展开更多
关键词 WAVELET transform Data Mining genetic algorithm
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Study on Power Transformers Fault Diagnosis Based on Wavelet Neural Network and D-S Evidence Theory
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作者 LIANG Liu-ming CHEN Wei-gen +2 位作者 YUE Yan-feng WEI Chao YANG Jian-feng 《高电压技术》 EI CAS CSCD 北大核心 2008年第12期2694-2700,共7页
>Transformer faults are quite complicated phenomena and can occur due to a variety of reasons.There have been several methods for transformer fault synthetic diagnosis,but each of them has its own limitations in re... >Transformer faults are quite complicated phenomena and can occur due to a variety of reasons.There have been several methods for transformer fault synthetic diagnosis,but each of them has its own limitations in real fault diagnosis applications.In order to overcome those shortcomings in the existing methods,a new transformer fault diagnosis method based on a wavelet neural network optimized by adaptive genetic algorithm(AGA)and an improved D-S evidence theory fusion technique is proposed in this paper.The proposed method combines the oil chromatogram data and the off-line electrical test data of transformers to carry out fault diagnosis.Based on the fusion mechanism of D-S evidence theory,the comprehensive reliability of evidence is constructed by considering the evidence importance,the outputs of the neural network and the expert experience.The new method increases the objectivity of the basic probability assignment(BPA)and reduces the basic probability assigned for uncertain and unimportant information.The case study results of using the proposed method show that it has a good performance of fault diagnosis for transformers. 展开更多
关键词 小波神经网络 D-S证据理论 电力变压器 故障诊断 适应基因算法
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