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Ensemble Transform Sensitivity Method for Adaptive Observations 被引量:2
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作者 Yu ZHANG Yuanfu XIE +2 位作者 Hongli WANG Dehui CHEN Zoltan TOTH 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第1期10-20,共11页
The Ensemble Transform(ET) method has been shown to be useful in providing guidance for adaptive observation deployment.It predicts forecast error variance reduction for each possible deployment using its correspond... The Ensemble Transform(ET) method has been shown to be useful in providing guidance for adaptive observation deployment.It predicts forecast error variance reduction for each possible deployment using its corresponding transformation matrix in an ensemble subspace.In this paper,a new ET-based sensitivity(ETS) method,which calculates the gradient of forecast error variance reduction in terms of analysis error variance reduction,is proposed to specify regions for possible adaptive observations.ETS is a first order approximation of the ET;it requires just one calculation of a transformation matrix,increasing computational efficiency(60%-80%reduction in computational cost).An explicit mathematical formulation of the ETS gradient is derived and described.Both the ET and ETS methods are applied to the Hurricane Irene(2011) case and a heavy rainfall case for comparison.The numerical results imply that the sensitive areas estimated by the ETS and ET are similar.However,ETS is much more efficient,particularly when the resolution is higher and the number of ensemble members is larger. 展开更多
关键词 adaptive observation high impact weather ensemble transform
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A NEW ADAPTIVE FILTERING SCHEME BASED ON WAVELET TRANSFORM
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作者 Wang Yongde He Peiyu Wang Chunxia(Dept. of Radio Electronics, Sichuan University, Chengdu 610064) 《Journal of Electronics(China)》 1999年第3期257-262,共6页
Based on the scale function representation for a function in L2(R), a new wavelet transform based adaptive system identification scheme is proposed. It can reduce the amount of computation by exploiting the decimation... Based on the scale function representation for a function in L2(R), a new wavelet transform based adaptive system identification scheme is proposed. It can reduce the amount of computation by exploiting the decimation properties and keep the advantage of quasi-orthogonal transform of the discrete wavelet, transform (DWT). The issue has been supported by computer simulations. 展开更多
关键词 IIR SP NLMS A NEW adaptive FILTERING SCHEME BASED ON WAVELET transform DWT IEEE
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FM interference suppression for PRC-CW radar based on adaptive STFT and time-varying filtering 被引量:9
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作者 Zhao Zhao Xiangquan Shi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第2期219-223,共5页
The influence of frequency modulation (FM) interfer- ence on correlation detection performance of the pseudo random code continuous wave (PRC-CW) radar is analyzed. It is found that the correlation output deterior... The influence of frequency modulation (FM) interfer- ence on correlation detection performance of the pseudo random code continuous wave (PRC-CW) radar is analyzed. It is found that the correlation output deteriorates greatly when the FM inter- ference power exceeds the anti-jamming limit of the radar. Accord- ing to the fact that the PRC-CW radar echo is a wideband pseudo random signal occupying the whole TF plane, while the FM in- terference only concentrates in a small portion, a new method is proposed based on adaptive short-time Fourier transform (STFT) and time-varying filtering for FM interference suppression. This method filters the received signal by using a binary mask to excise only the portion of the TF plane corrupted by the interference. Two types of interference, linear FM (LFM) and sinusoidal FM (SFM), under different signal-to-jamming ratio (S JR) are studied. It is shown that the proposed method can effectively suppress the FM interference and improve the performance of target detection. 展开更多
关键词 interference suppression frequency modulation in- terference adaptive short-time Fourier transform (STFT) time- varying filtering pseudo random code continuous wave (PRC-CW) radar.
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Adaptive Fourier Decomposition Based Time-Frequency Analysis 被引量:3
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作者 Li-Ming Zhang 《Journal of Electronic Science and Technology》 2014年第2期201-205,共5页
The attempt to represent a signal simultaneously in time and frequency domains is full of challenges. The recently proposed adaptive Fourier decomposition (AFD) offers a practical approach to solve this problem. Thi... The attempt to represent a signal simultaneously in time and frequency domains is full of challenges. The recently proposed adaptive Fourier decomposition (AFD) offers a practical approach to solve this problem. This paper presents the principles of the AFD based time-frequency analysis in three aspects: instantaneous frequency analysis, frequency spectrum analysis, and the spectrogram analysis. An experiment is conducted and compared with the Fourier transform in convergence rate and short-time Fourier transform in time-frequency distribution. The proposed approach performs better than both the Fourier transform and short-time Fourier transform. 展开更多
关键词 adaptive Fourier decomposition Fourier transform instantaneous frequency time frequency analysis
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一种新的多尺度非线性阈值斑点噪声抑制方法 被引量:25
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作者 郝晓辉 高上凯 高小榕 《信号处理》 CSCD 1999年第1期76-81,共6页
本文针对影响医学超声图象质量的斑点噪声问题,提出了一种基于自适应前处理的多尺度非线性阈值斑点噪声抑制方法。方法的特点是有机地将自适应加权中值滤波和小波分析多尺度非线性阈值两种方法结合在一起.对离体器官超声图象处理的结... 本文针对影响医学超声图象质量的斑点噪声问题,提出了一种基于自适应前处理的多尺度非线性阈值斑点噪声抑制方法。方法的特点是有机地将自适应加权中值滤波和小波分析多尺度非线性阈值两种方法结合在一起.对离体器官超声图象处理的结果表明,这一新方法在有效去除斑点噪声的同时,很好地保留了图象细节。 展开更多
关键词 斑点噪声 小波变换 非线性阈值 噪声抑制
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The Translation of Neologisms From the Perspective of Eco-Translatology
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作者 ZHU Yu 《Sino-US English Teaching》 2022年第2期65-73,共9页
Based on relevant theories of eco-translatology,this paper analyzes the translation of neologisms in the English book,The Money Is Coming from the perspective of adaptive transformation from three basic dimensions-the... Based on relevant theories of eco-translatology,this paper analyzes the translation of neologisms in the English book,The Money Is Coming from the perspective of adaptive transformation from three basic dimensions-the linguistic,cultural,and communicative dimensions. 展开更多
关键词 the translation of neologisms ECO-TRANSLATOLOGY adaptive transformation from three dimensions translation strategy
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Multi-Label Chinese Comments Categorization: Comparison of Multi-Label Learning Algorithms 被引量:4
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作者 Jiahui He Chaozhi Wang +2 位作者 Hongyu Wu Leiming Yan Christian Lu 《Journal of New Media》 2019年第2期51-61,共11页
Multi-label text categorization refers to the problem of categorizing text througha multi-label learning algorithm. Text classification for Asian languages such as Chinese isdifferent from work for other languages suc... Multi-label text categorization refers to the problem of categorizing text througha multi-label learning algorithm. Text classification for Asian languages such as Chinese isdifferent from work for other languages such as English which use spaces to separate words.Before classifying text, it is necessary to perform a word segmentation operation to converta continuous language into a list of separate words and then convert it into a vector of acertain dimension. Generally, multi-label learning algorithms can be divided into twocategories, problem transformation methods and adapted algorithms. This work will usecustomer's comments about some hotels as a training data set, which contains labels for allaspects of the hotel evaluation, aiming to analyze and compare the performance of variousmulti-label learning algorithms on Chinese text classification. The experiment involves threebasic methods of problem transformation methods: Support Vector Machine, Random Forest,k-Nearest-Neighbor;and one adapted algorithm of Convolutional Neural Network. Theexperimental results show that the Support Vector Machine has better performance. 展开更多
关键词 Multi-label classification Chinese text classification problem transformation adapted algorithms
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IMPROVED METHOD FOR HILBERT INSTANTANEOUS FREQUENCY ESTIMATION 被引量:3
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作者 BO Lin LIU Xiaofeng QIN Shuren 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第6期94-98,共5页
In the mechanical fault detection and diagnosis field, it is more and more important to analyze the instantaneous frequency (IF) character of complex vibration signal. The improved IF estimation method is put forwar... In the mechanical fault detection and diagnosis field, it is more and more important to analyze the instantaneous frequency (IF) character of complex vibration signal. The improved IF estimation method is put forward aiming at the shortage of traditional Hilbert transform. It is based on Hilbert transform in wavelet domain. With the help of relationship between the real part and the imaginary part obtained from the complex coefficient of continuous wavelet transform or the analyti- cal signal reconstructed in wavelet packet decomposition, the instantaneous phase function of the subcomponent is extracted. In order to improve the precise of IF estimated out, some means such as Linear regression, adaptive filtering, resampling are applied into the instantaneous phase obtained, then, the central differencing operator is used to get desired IF. Simulation results with synthetic and gearbox fault signals are included to illustrate the proposed method. 展开更多
关键词 Instantaneous frequency Hilbert transform Wavelet transform Linear regression adaptive filtering Resampling
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Adaptive self-assembly and induced-fit transformations of anion-binding metal-organic macrocyclic receptors
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《Science Foundation in China》 CAS 2017年第3期34-34,共1页
Subject Code:B01With the financial support from the National Natural Science Foundation of China,the research group led by Prof.Sun Qingfu(孙庆福)from the Fujian Institute of Research on the Structure of Matter,Chines... Subject Code:B01With the financial support from the National Natural Science Foundation of China,the research group led by Prof.Sun Qingfu(孙庆福)from the Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences has recently reported a dynamic anion-adaptive self-assembly system 展开更多
关键词 adaptive self-assembly and induced-fit transformations of anion-binding metal-organic macrocyclic receptors
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AN IMPROVED ALGORITHM OF GMM VOICE CONVERSION SYSTEM BASED ON CHANGING THE TIME-SCALE
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作者 Zhou Ying Zhang Linghua 《Journal of Electronics(China)》 2011年第4期518-523,共6页
This paper improves and presents an advanced method of the voice conversion system based on Gaussian Mixture Models(GMM) models by changing the time-scale of speech.The Speech Transformation and Representation using A... This paper improves and presents an advanced method of the voice conversion system based on Gaussian Mixture Models(GMM) models by changing the time-scale of speech.The Speech Transformation and Representation using Adaptive Interpolation of weiGHTed spectrum(STRAIGHT) model is adopted to extract the spectrum features,and the GMM models are trained to generate the conversion function.The spectrum features of a source speech will be converted by the conversion function.The time-scale of speech is changed by extracting the converted features and adding to the spectrum.The conversion voice was evaluated by subjective and objective measurements.The results confirm that the transformed speech not only approximates the characteristics of the target speaker,but also more natural and more intelligible. 展开更多
关键词 Gaussian Mixture Models(GMM) Speech transformation and Representation using adaptive Interpolation of weiGHTed spectrum(STRAIGHT) TIME-SCALE Voice conversion
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The Performance Comparisons between the Unconstrained and Constrained Equalization Algorithms 被引量:2
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作者 HE Zhong-qiu,LI Dao-ben(School of Information Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, P. R. China) 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2003年第4期50-58,共9页
This paper proposes two unconstrained algorithms, the Steepest Decent (SD)algorithm and the Conjugate Gradient (CG) algorithm, based on a superexcellent cost function. At thesame time, two constrained algorithms which... This paper proposes two unconstrained algorithms, the Steepest Decent (SD)algorithm and the Conjugate Gradient (CG) algorithm, based on a superexcellent cost function. At thesame time, two constrained algorithms which include the Constrained Steepest Decent (CSD) algorithmand the Constrained Conjugate Gradient algorithm (CCG) are deduced subject to a new constraincondition. They are both implemented in unitary transform domain. The computational complexities ofthe constrained algorithms are compared to those of the unconstrained algorithms. Resultingsimulations show their performance comparisons. 展开更多
关键词 transform domain adaptive equalization constrained equalization algorithm
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An approach for parameter estimation of combined CPPM and LFM radar signal 被引量:3
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作者 Zhang Wei Xiong Ying +2 位作者 Wang Pei Wang Jun Tang Bin 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第4期986-992,共7页
In this paper, the problem of parameter estimation of the combined radar signal adopting chaotic pulse position modulation (CPPM) and linear frequency modulation (LFM), which can be widely used in electronic count... In this paper, the problem of parameter estimation of the combined radar signal adopting chaotic pulse position modulation (CPPM) and linear frequency modulation (LFM), which can be widely used in electronic countermeasures, is addressed. An approach is proposed to estimate the initial frequency and chirp rate of the combined signal by exploiting the second-order cyclostationarity of the intra-pulse signal. In addition, under the condition of the equal pulse width, the pulse repetition interval (PRI) of the combined signal is predicted using the low-order Volterra adaptive filter. Simulations demonstrate that the proposed cyclic autocorrelation Hough transform (CHT) algorithm is theoretically tolerant to additive white Gaussian noise. When the value of signal noise to ratio (SNR) is less than 4 dB, it can still estimate the intra-pulse parameters well. When SNR = 3 dB, a good prediction of the PRI sequence can be achieved by the Volterra adaptive filter algorithm, even only 100 training samples. 展开更多
关键词 Chaotic pulse position modulation Combined radar signal Cyclic autocorrelation Electronic countermeasures Hough transform Linear frequency modulation Volterra adaptive filter
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