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基于双注意力机制和改进L1-norm相似度的红外与可见光图像融合算法
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作者 喻康 孔祥婷 《湖北大学学报(自然科学版)》 2025年第6期822-832,共11页
针对红外与可见光图像融合方法容易造成图像特征提取不充分和易丢失中间层信息的问题,提出一种基于双注意力机制和改进L1-norm相似度的红外与可见光图像融合算法。该算法首先在编码器中引入Bottleneck残差网络,以减少模型的参数量,从而... 针对红外与可见光图像融合方法容易造成图像特征提取不充分和易丢失中间层信息的问题,提出一种基于双注意力机制和改进L1-norm相似度的红外与可见光图像融合算法。该算法首先在编码器中引入Bottleneck残差网络,以减少模型的参数量,从而高效提取出红外图像和可见光图像的深度特征图。其次,为了有效融合红外与可见光的图像特征,提出联合通道和空间的双注意力机制来提升网络捕捉重要特征信息的能力。接着,在L1-norm相似度融合策略中加入梯度提取算子对获得的深度特征图进行处理,得到对应的梯度图,并将初始融合图和对应的梯度图使用Max策略进行融合,以减少融合图像中目标信息的丢失。最后,将损失函数设置为梯度损失、像素损失和结构相似性损失的线性组合,以约束解码器重构融合图像。实验结果表明:与主流的融合算法(如DenseFuse、FusionGAN、PIAFusion、PMGI、RFN-Nest、U2Fusion等)相比,本算法在主观感受上融合效果更清晰;进一步采用标准差(SD)、互信息(MI)、视觉信息保真度(VIF)、质量指标(Qabf)、信息熵(EN)和空间频率(SF)等6个定量指标进行评估,与主流融合算法相比,前4个指标性能提升显著,较次优值分别提高了6.34%、30.48%、14.25%、4.91%,后2个指标性能接近最优的主流融合算法,融合速度约是U2Fusion的6倍。 展开更多
关键词 图像融合 红外与可见光图像 双注意力机制 L1-norm相似度 梯度转移
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Composition Analysis and Identification of Ancient Glass Products Based on L1 Regularization Logistic Regression
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作者 Yuqiao Zhou Xinyang Xu Wenjing Ma 《Applied Mathematics》 2024年第1期51-64,共14页
In view of the composition analysis and identification of ancient glass products, L1 regularization, K-Means cluster analysis, elbow rule and other methods were comprehensively used to build logical regression, cluste... In view of the composition analysis and identification of ancient glass products, L1 regularization, K-Means cluster analysis, elbow rule and other methods were comprehensively used to build logical regression, cluster analysis, hyper-parameter test and other models, and SPSS, Python and other tools were used to obtain the classification rules of glass products under different fluxes, sub classification under different chemical compositions, hyper-parameter K value test and rationality analysis. Research can provide theoretical support for the protection and restoration of ancient glass relics. 展开更多
关键词 Glass Composition L1 regularization Logistic Regression Model K-Means Clustering Analysis Elbow Rule Parameter Verification
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Freezing imaginarity of quantum states based onℓ_(1)-norm
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作者 Shuo Han Bingke Zheng Zhihua Guo 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期166-175,共10页
We discuss freezing of quantum imaginarity based onℓ_(1)-norm.Several properties about a quantity of imaginarity based onℓ_(1)-norm are revealed.For a qubit(2-dimensional)system,we characterize the structure of real q... We discuss freezing of quantum imaginarity based onℓ_(1)-norm.Several properties about a quantity of imaginarity based onℓ_(1)-norm are revealed.For a qubit(2-dimensional)system,we characterize the structure of real quantum operations that allow for freezing the quantity of imaginarity of any state.Furthermore,we characterize the structure of local real operations which can freeze the quantity of imaginarity of a class of N-qubit quantum states. 展开更多
关键词 imaginarity freezing ℓ_(1)-norm real operation
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APPROXIMATION ANALYSES FOR FUZZY VALUED FUNCTIONS IN L_1(μ)-NORM BY REGULAR FUZZY NEURAL NETWORKS 被引量:4
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作者 Liu Puyin (Dept. of System Eng. and Math., National Univ. of Defence Tech., Changsha 410073) 《Journal of Electronics(China)》 2000年第2期132-138,共7页
By defining fuzzy valued simple functions and giving L1(μ) approximations of fuzzy valued integrably bounded functions by such simple functions, the paper analyses by L1(μ)-norm the approximation capability of four-... By defining fuzzy valued simple functions and giving L1(μ) approximations of fuzzy valued integrably bounded functions by such simple functions, the paper analyses by L1(μ)-norm the approximation capability of four-layer feedforward regular fuzzy neural networks to the fuzzy valued integrably bounded function F : Rn → FcO(R). That is, if the transfer functionσ: R→R is non-polynomial and integrable function on each finite interval, F may be innorm approximated by fuzzy valued functions defined as to anydegree of accuracy. Finally some real examples demonstrate the conclusions. 展开更多
关键词 FUZZY VALUED simple function regular FUZZY neural network L1(μ) APPROXIMATION Universal approximator
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DOA estimation of high-dimensional signals based on Krylov subspace and weighted l_(1)-norm
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作者 YANG Zeqi LIU Yiheng +4 位作者 ZHANG Hua MA Shuai CHANG Kai LIU Ning LYU Xiaode 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期532-540,F0002,共10页
With the extensive application of large-scale array antennas,the increasing number of array elements leads to the increasing dimension of received signals,making it difficult to meet the real-time requirement of direc... With the extensive application of large-scale array antennas,the increasing number of array elements leads to the increasing dimension of received signals,making it difficult to meet the real-time requirement of direction of arrival(DOA)estimation due to the computational complexity of algorithms.Traditional subspace algorithms require estimation of the covariance matrix,which has high computational complexity and is prone to producing spurious peaks.In order to reduce the computational complexity of DOA estimation algorithms and improve their estimation accuracy under large array elements,this paper proposes a DOA estimation method based on Krylov subspace and weighted l_(1)-norm.The method uses the multistage Wiener filter(MSWF)iteration to solve the basis of the Krylov subspace as an estimate of the signal subspace,further uses the measurement matrix to reduce the dimensionality of the signal subspace observation,constructs a weighted matrix,and combines the sparse reconstruction to establish a convex optimization function based on the residual sum of squares and weighted l_(1)-norm to solve the target DOA.Simulation results show that the proposed method has high resolution under large array conditions,effectively suppresses spurious peaks,reduces computational complexity,and has good robustness for low signal to noise ratio(SNR)environment. 展开更多
关键词 direction of arrival(DOA) compressed sensing(CS) Krylov subspace l_(1)-norm dimensionality reduction
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Bayesian Regularization Neural Networks for Prediction of Austenite Formation Temperatures(A_(c1) and A_(c3)) 被引量:1
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作者 Masoud RAKHSHKHORSHID Sayyed-Amin TEIMOURI SENDESI 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2014年第2期246-251,共6页
A neural network with a feed forward topology and Bayesian regularization training algorithm is used to predict the austenite formation temperatures (At1 and A13) by considering the percentage of alloying elements i... A neural network with a feed forward topology and Bayesian regularization training algorithm is used to predict the austenite formation temperatures (At1 and A13) by considering the percentage of alloying elements in chemical composition of steel. The data base used here involves a large variety of different steel types such as struc- tural steels, stainless steels, rail steels, spring steels, high temperature creep resisting steels and tool steels. Scatter diagrams and mean relative error (MRE) statistical criteria are used to compare the performance of developed neural network with the results of Andrew% empirical equations and a feed forward neural network with "gradient descent with momentum" training algorithm. The results showed that Bayesian regularization neural network has the best performance. Also, due to the satisfactory results of the developed neural network, it was used to investigate the effect of the chemical composition on Ac1 and At3 temperatures. Results are in accordance with materials science theories. 展开更多
关键词 Bayesian regularization neural network STEEL chemical composition Ac1 Ae3
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Source reconstruction for bioluminescence tomography via L_(1/2)regularization 被引量:1
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作者 Jingjing Yu Qiyue Li Haiyu Wang 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2018年第2期8-16,共9页
Bioluminescence tomography(BLT)is an important noninvasive optical molecular imaging modality in preclinical research.To improve the image quality,reconstruction algorithms have to deal with the inherent ill-posedness... Bioluminescence tomography(BLT)is an important noninvasive optical molecular imaging modality in preclinical research.To improve the image quality,reconstruction algorithms have to deal with the inherent ill-posedness of BLT inverse problem.The sparse characteristic of bioluminescent sources in spatial distribution has been widely explored in BLT and many L1-regularized methods have been investigated due to the sparsity-inducing properties of L1 norm.In this paper,we present a reconstruction method based on L_(1/2) regularization to enhance sparsity of BLT solution and solve the nonconvex L_(1/2) norm problem by converting it to a series of weighted L1 homotopy minimization problems with iteratively updated weights.To assess the performance of the proposed reconstruction algorithm,simulations on a heterogeneous mouse model are designed to compare it with three representative sparse reconstruction algorithms,including the weighted interior-point,L1 homotopy,and the Stagewise Orthogonal Matching Pursuit algorithm.Simulation results show that the proposed method yield stable reconstruction results under different noise levels.Quantitative comparison results demonstrate that the proposed algorithm outperforms the competitor algorithms in location accuracy,multiple-source resolving and image quality. 展开更多
关键词 Bioluminescence tomography L_(1/2)regularization inverse problem reconstruction algorithm
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Wavelet-based L_(1/2) regularization for CS-TomoSAR imaging of forested area 被引量:1
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作者 BI Hui CHENG Yuan +1 位作者 ZHU Daiyin HONG Wen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第6期1160-1166,共7页
Tomographic synthetic aperture radar(TomoSAR)imaging exploits the antenna array measurements taken at different elevation aperture to recover the reflectivity function along the elevation direction.In these years,for ... Tomographic synthetic aperture radar(TomoSAR)imaging exploits the antenna array measurements taken at different elevation aperture to recover the reflectivity function along the elevation direction.In these years,for the sparse elevation distribution,compressive sensing(CS)is a developed favorable technique for the high-resolution elevation reconstruction in TomoSAR by solving an L_(1) regularization problem.However,because the elevation distribution in the forested area is nonsparse,if we want to use CS in the recovery,some basis,such as wavelet,should be exploited in the sparse L_(1/2) representation of the elevation reflectivity function.This paper presents a novel wavelet-based L_(2) regularization CS-TomoSAR imaging method of the forested area.In the proposed method,we first construct a wavelet basis,which can sparsely represent the elevation reflectivity function of the forested area,and then reconstruct the elevation distribution by using the L_(1/2) regularization technique.Compared to the wavelet-based L_(1) regularization TomoSAR imaging,the proposed method can improve the elevation recovered quality efficiently. 展开更多
关键词 tomographic synthetic aperture radar(TomoSAR) compressive sensing(CS) L_(1/2)regularization wavelet basis
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Solutions to SU(n+1)Toda systems with cone singularities via toric curves on compact Riemann surfaces
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作者 Jingyu Mu Yiqian Shi and Bin Xu 《中国科学技术大学学报》 北大核心 2025年第5期2-13,1,I0001,共14页
On a compact Riemann surface with finite punctures P_(1),…P_(k),we define toric curves as multivalued,totallyunramified holomorphic maps to P^(n)with monodromy in a maximal torus of PSU(n+1).Toric solutions to SU(n+1... On a compact Riemann surface with finite punctures P_(1),…P_(k),we define toric curves as multivalued,totallyunramified holomorphic maps to P^(n)with monodromy in a maximal torus of PSU(n+1).Toric solutions to SU(n+1)Todasystems on X\{P_(1);…;P_(k)}are recognized by the associated toric curves in.We introduce character n-ensembles as-tuples of meromorphic one-forms with simple poles and purely imaginary periods,generating toric curves on minus finitelymany points.On X,we establish a correspondence between character-ensembles and toric solutions to the SU(n+1)system with finitely many cone singularities.Our approach not only broadens seminal solutions with two conesingularities on the Riemann sphere,as classified by Jost-Wang(Int.Math.Res.Not.,2002,(6):277-290)andLin-Wei-Ye(Invent.Math.,2012,190(1):169-207),but also advances beyond the limits of Lin-Yang-Zhong’s existencetheorems(J.Differential Geom.,2020,114(2):337-391)by introducing a new solution class. 展开更多
关键词 SU(n+1)Toda system regular singularity unitary curve toric solution character ensemble
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L1/2 Regularization Based on Bayesian Empirical Likelihood
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作者 Yuan Wang Wanzhou Ye 《Advances in Pure Mathematics》 2022年第5期392-404,共13页
Bayesian empirical likelihood is a semiparametric method that combines parametric priors and nonparametric likelihoods, that is, replacing the parametric likelihood function in Bayes theorem with a nonparametric empir... Bayesian empirical likelihood is a semiparametric method that combines parametric priors and nonparametric likelihoods, that is, replacing the parametric likelihood function in Bayes theorem with a nonparametric empirical likelihood function, which can be used without assuming the distribution of the data. It can effectively avoid the problems caused by the wrong setting of the model. In the variable selection based on Bayesian empirical likelihood, the penalty term is introduced into the model in the form of parameter prior. In this paper, we propose a novel variable selection method, L<sub>1/2</sub> regularization based on Bayesian empirical likelihood. The L<sub>1/2</sub> penalty is introduced into the model through a scale mixture of uniform representation of generalized Gaussian prior, and the posterior distribution is then sampled using MCMC method. Simulations demonstrate that the proposed method can have better predictive ability when the error violates the zero-mean normality assumption of the standard parameter model, and can perform variable selection. 展开更多
关键词 Bayesian Empirical Likelihood Generalized Gaussian Prior L1/2 regularization MCMC Method
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Design of Polynomial Fuzzy Neural Network Classifiers Based on Density Fuzzy C-Means and L2-Norm Regularization
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作者 Shaocong Xue Wei Huang +1 位作者 Chuanyin Yang Jinsong Wang 《国际计算机前沿大会会议论文集》 2019年第1期594-596,共3页
In this paper, polynomial fuzzy neural network classifiers (PFNNCs) is proposed by means of density fuzzy c-means and L2-norm regularization. The overall design of PFNNCs was realized by means of fuzzy rules that come... In this paper, polynomial fuzzy neural network classifiers (PFNNCs) is proposed by means of density fuzzy c-means and L2-norm regularization. The overall design of PFNNCs was realized by means of fuzzy rules that come in form of three parts, namely premise part, consequence part and aggregation part. The premise part was developed by density fuzzy c-means that helps determine the apex parameters of membership functions, while the consequence part was realized by means of two types of polynomials including linear and quadratic. L2-norm regularization that can alleviate the overfitting problem was exploited to estimate the parameters of polynomials, which constructed the aggregation part. Experimental results of several data sets demonstrate that the proposed classifiers show higher classification accuracy in comparison with some other classifiers reported in the literature. 展开更多
关键词 POLYNOMIAL FUZZY neural network CLASSIFIERS Density FUZZY clustering L2-norm regularization FUZZY rules
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基于截断总体最小二乘法与L_(1)正则化的结构损伤识别
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作者 骆紫薇 蔡楚欣 +1 位作者 赖小李 刘焕林 《振动与冲击》 北大核心 2025年第15期217-223,共7页
模态参数因其易于获取且对结构损伤敏感等特点常被用于结构损伤识别。基于模态参数和有限元模型的损伤识别方法能有效定位和量化结构损伤,但在测量噪声和模型误差等因素的共同影响下,识别结果可能与实际情况存在较大偏差,难以准确评估... 模态参数因其易于获取且对结构损伤敏感等特点常被用于结构损伤识别。基于模态参数和有限元模型的损伤识别方法能有效定位和量化结构损伤,但在测量噪声和模型误差等因素的共同影响下,识别结果可能与实际情况存在较大偏差,难以准确评估结构的安全状态。针对此问题,基于截断总体最小二乘法与L_(1)正则化技术,提出了一种新的结构损伤识别方法。该方法首先分析了既有灵敏度方程中误差的来源;然后,通过截断总体最小二乘法构造了损伤折减系数改变量与模态参数改变量之间新的近似关系式;最后,结合结构损伤的稀疏性,引入L_(1)正则化对问题进行约束,以改善问题的不适定性并提高识别精度。数值仿真和试验结果表明,所提方法能有效地识别结构的多种损伤工况,且误判较少,具有较高的识别精度和较强的鲁棒性。 展开更多
关键词 结构损伤识别 一阶灵敏度分析 L_(1)正则化 截断总体最小二乘法
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Estimating primaries by sparse inversion of the 3D Curvelet transform and the L1-norm constraint 被引量:7
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作者 冯飞 王德利 +1 位作者 朱恒 程浩 《Applied Geophysics》 SCIE CSCD 2013年第2期201-209,237,共10页
In this paper, we built upon the estimating primaries by sparse inversion (EPSI) method. We use the 3D curvelet transform and modify the EPSI method to the sparse inversion of the biconvex optimization and Ll-norm r... In this paper, we built upon the estimating primaries by sparse inversion (EPSI) method. We use the 3D curvelet transform and modify the EPSI method to the sparse inversion of the biconvex optimization and Ll-norm regularization, and use alternating optimization to directly estimate the primary reflection coefficients and source wavelet. The 3D curvelet transform is used as a sparseness constraint when inverting the primary reflection coefficients, which results in avoiding the prediction subtraction process in the surface-related multiples elimination (SRME) method. The proposed method not only reduces the damage to the effective waves but also improves the elimination of multiples. It is also a wave equation- based method for elimination of surface multiple reflections, which effectively removes surface multiples under complex submarine conditions. 展开更多
关键词 Sparse inversion primary reflection coefficients 3D Curvelet transformation L1regularization convex optimization
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1-Norm/2-Norm约束及小波多尺度2D体波走时成像 被引量:1
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作者 高级 方洪健 《物探化探计算技术》 CAS CSCD 2016年第6期765-772,共8页
在对浅地表复杂地下介质层析成像时,由于观测系统局限性及方法本身对特定岩石地球物理属性的不敏感性等因素,造成地球物理反演存在多解性。在地震走时成像中,地震射线数量在低速区域分布较少形成阴影区,造成其对低速区域成像分辨率较低... 在对浅地表复杂地下介质层析成像时,由于观测系统局限性及方法本身对特定岩石地球物理属性的不敏感性等因素,造成地球物理反演存在多解性。在地震走时成像中,地震射线数量在低速区域分布较少形成阴影区,造成其对低速区域成像分辨率较低。同时因为观测数据包含干扰信息以及不同反演方法的局限性等因素造成反演结果包含次生假异常。这里主要研究了空间域的L1-norm、L2-norm约束反演及小波域小波系数稀疏约束反演,对比不同反演方式及约束条件对地质模型的分辨能力。通过测试孤立异常模型、层状地层模型、倾斜地层模型,得出三种不同反演方式分别具有对不同特定模型的分辨特性。在实际资料成像中,可以通过使用多种反演方式,对比反演结果合理性以期达到更准确的地质构造解释。 展开更多
关键词 体波走时 层析成像 1-norm 2-norm 小波多尺度
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Bernoulli-based random undersampling schemes for 2D seismic data regularization 被引量:4
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作者 蔡瑞 赵群 +3 位作者 佘德平 杨丽 曹辉 杨勤勇 《Applied Geophysics》 SCIE CSCD 2014年第3期321-330,351,352,共12页
Seismic data regularization is an important preprocessing step in seismic signal processing. Traditional seismic acquisition methods follow the Shannon–Nyquist sampling theorem, whereas compressive sensing(CS) prov... Seismic data regularization is an important preprocessing step in seismic signal processing. Traditional seismic acquisition methods follow the Shannon–Nyquist sampling theorem, whereas compressive sensing(CS) provides a fundamentally new paradigm to overcome limitations in data acquisition. Besides the sparse representation of seismic signal in some transform domain and the 1-norm reconstruction algorithm, the seismic data regularization quality of CS-based techniques strongly depends on random undersampling schemes. For 2D seismic data, discrete uniform-based methods have been investigated, where some seismic traces are randomly sampled with an equal probability. However, in theory and practice, some seismic traces with different probability are required to be sampled for satisfying the assumptions in CS. Therefore, designing new undersampling schemes is imperative. We propose a Bernoulli-based random undersampling scheme and its jittered version to determine the regular traces that are randomly sampled with different probability, while both schemes comply with the Bernoulli process distribution. We performed experiments using the Fourier and curvelet transforms and the spectral projected gradient reconstruction algorithm for 1-norm(SPGL1), and ten different random seeds. According to the signal-to-noise ratio(SNR) between the original and reconstructed seismic data, the detailed experimental results from 2D numerical and physical simulation data show that the proposed novel schemes perform overall better than the discrete uniform schemes. 展开更多
关键词 Seismic data regularization compressive sensing Bernoulli distribution sparse transform UNDERSAMPLING 1-norm reconstruction algorithm.
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Adaptive multiple subtraction using a constrained L1-norm method with lateral continuity 被引量:10
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作者 Pang Tinghua Lu Wenkai Ma Yongjun 《Applied Geophysics》 SCIE CSCD 2009年第3期241-247,299,300,共9页
The Lt-norm method is one of the widely used matching filters for adaptive multiple subtraction. When the primaries and multiples are mixed together, the L1-norm method might damage the primaries, leading to poor late... The Lt-norm method is one of the widely used matching filters for adaptive multiple subtraction. When the primaries and multiples are mixed together, the L1-norm method might damage the primaries, leading to poor lateral continuity. In this paper, we propose a constrained L1-norm method for adaptive multiple subtraction by introducing the lateral continuity constraint for the estimated primaries. We measure the lateral continuity using prediction-error filters (PEF). We illustrate our method with the synthetic Pluto dataset. The results show that the constrained L1-norm method can simultaneously attenuate the multiples and preserve the primaries. 展开更多
关键词 Multiple attenuation adaptive multiple subtraction L1-norm lateral continuity
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A NEURAL-BASED NONLINEAR L_1-NORM OPTIMIZATION ALGORITHM FOR DIAGNOSIS OF NETWORKS* 被引量:8
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作者 He Yigang (Department of Electrical Engineering, Hunan University, Changsha 410082)Luo Xianjue Qiu Guanyuan(School of Electrical Engineering, Xi’an Jiaotong University, Xi’an 710049) 《Journal of Electronics(China)》 1998年第4期365-371,共7页
Based on exact penalty function, a new neural network for solving the L1-norm optimization problem is proposed. In comparison with Kennedy and Chua’s network(1988), it has better properties.Based on Bandler’s fault ... Based on exact penalty function, a new neural network for solving the L1-norm optimization problem is proposed. In comparison with Kennedy and Chua’s network(1988), it has better properties.Based on Bandler’s fault location method(1982), a new nonlinearly constrained L1-norm problem is developed. It can be solved with less computing time through only one optimization processing. The proposed neural network can be used to solve the analog diagnosis L1 problem. The validity of the proposed neural networks and the fault location L1 method are illustrated by extensive computer simulations. 展开更多
关键词 FAULT DIAGNOSIS L1-norm NEURAL OPTIMIZATION
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‘渝城1号’核桃矿质元素周年吸收规律研究
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作者 魏立本 黄小辉 +4 位作者 王玉书 唐佳佳 杨华均 冯大兰 邹孝文 《西南大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第4期55-62,共8页
以‘渝城1号’核桃为研究对象,通过测定不同生育期的主要器官样品的生物量和N,P,K,Ca,Mg质量分数,总结分析核桃对5种矿质元素的吸收规律.结果表明:①开花坐果以后,核桃干物质快速增加,增加的干物质主要累积在果实、根和茎中,并在果实膨... 以‘渝城1号’核桃为研究对象,通过测定不同生育期的主要器官样品的生物量和N,P,K,Ca,Mg质量分数,总结分析核桃对5种矿质元素的吸收规律.结果表明:①开花坐果以后,核桃干物质快速增加,增加的干物质主要累积在果实、根和茎中,并在果实膨大期后,果实中的干物质累积量显著高于其他器官;②从各器官矿质元素质量分数上看,茎、营养枝和果枝中的N,P,K质量分数在展叶抽梢期最高,茎和营养枝中的Ca质量分数在果实膨大期最高,营养枝和果枝中Mg质量分数在落叶期最高.③从各器官矿质元素的累积量看,开花坐果前,N,P,K在根部的累积量最高.开花坐果后,果实中N,P,K的累积量逐渐升高.整个生育期,Ca在根部中的累积量最高,而Mg在果实膨大期前以根部累积量最高,之后在果实中的累积量最高;④5个矿质元素中,核桃对N,K,Ca吸收量大于P和Mg,其中核桃对N,P吸收量最大的时间在开花坐果期,对K和Mg吸收量最大的时间在坐果初期,对Ca吸收量最大的时间在果实膨大期.因此,开花坐果期到果实膨大期是核桃施肥的关键时期,在该时期应及时补充相应的矿质元素,以实现核桃的科学高效施肥. 展开更多
关键词 ‘渝城1号’核桃 矿质元素 吸收规律
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基于L_(1/2)正则化的抛物线Radon变换多次波压制方法
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作者 吴秋莹 胡斌 +1 位作者 刘财 高锐 《吉林大学学报(地球科学版)》 CAS CSCD 北大核心 2024年第1期323-336,共14页
在地震数据处理中,多次波的存在会对地震数据成像和地震资料解释带来影响,如何有效地压制多次波干扰是地震勘探中的重要问题。抛物线Radon变换因其高效的特点被广泛应用于多次波压制中,但在野外地震数据采集时,炮检距的有限性会导致变... 在地震数据处理中,多次波的存在会对地震数据成像和地震资料解释带来影响,如何有效地压制多次波干扰是地震勘探中的重要问题。抛物线Radon变换因其高效的特点被广泛应用于多次波压制中,但在野外地震数据采集时,炮检距的有限性会导致变换域中的能量扩散,产生假象,使多次波压制达不到理想的效果。针对此问题,提出一种基于L_(1/2)正则化的稀疏反演高分辨抛物线Radon变换,并应用广义迭代收缩算法(generalized iterated shrinkage algorithm,GISA)进行求解。研究结果表明,L_(1/2)正则化有很强的稀疏约束能力,能提高解的稀疏度,改进信噪分离的效果。与最小二乘反演和基于L_(1)正则化的稀疏反演相比,基于L_(1/2)正则化的稀疏反演高分辨抛物线Radon变换能更有效地压制多次波,并确保了重构数据与原始数据的一致性。 展开更多
关键词 多次波压制 高分辨率抛物线Radon变换 L_(1/2)正则化
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An l^(1) Regularized Method for Numerical Differentiation Using Empirical Eigenfunctions
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作者 Junbin LI Renhong WANG Min XU 《Journal of Mathematical Research with Applications》 CSCD 2017年第4期496-504,共9页
We propose an ?~1 regularized method for numerical differentiation using empirical eigenfunctions. Compared with traditional methods for numerical differentiation, the output of our method can be considered directly ... We propose an ?~1 regularized method for numerical differentiation using empirical eigenfunctions. Compared with traditional methods for numerical differentiation, the output of our method can be considered directly as the derivative of the underlying function. Moreover,our method could produce sparse representations with respect to empirical eigenfunctions.Numerical results show that our method is quite effective. 展开更多
关键词 numerical differentiation empirical eigenfunctions ?~1 regularization mercer kernel
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