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Face Recognition Combining Eigen Features with a Parzen Classifier 被引量:1
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作者 孙鑫 刘兵 刘本永 《Journal of Electronic Science and Technology of China》 2005年第1期18-21,共4页
A face recognition scheme is proposed, wherein a face image is preprocessed by pixel averaging and energy normalizing to reduce data dimension and brightness variation effect, followed by the Fourier transform to esti... A face recognition scheme is proposed, wherein a face image is preprocessed by pixel averaging and energy normalizing to reduce data dimension and brightness variation effect, followed by the Fourier transform to estimate the spectrum of the preprocessed image. The principal component analysis is conducted on the spectra of a face image to obtain eigen features. Combining eigen features with a Parzen classifier, experiments are taken on the ORL face database. 展开更多
关键词 face recognition Fourier transform principal component analysis Parzen classifier pixel averaging energy normalizing
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Passive multiple reverse time migration imaging based on wave decomposition and normalized imaging conditions 被引量:2
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作者 Cai Zhong-Zheng Han Li-Guo Xu Zhuo 《Applied Geophysics》 SCIE CSCD 2019年第3期338-348,396,共12页
With the development of seismic exploration,passive-source seismic data has attracted increasing attention.Ambient noise passive seismic sources exists widely in nature and industrial production.Passive seismic data i... With the development of seismic exploration,passive-source seismic data has attracted increasing attention.Ambient noise passive seismic sources exists widely in nature and industrial production.Passive seismic data is important in logging while drilling(LWD),large-scale structural exploration,etc.In this paper,we proposed a passive multiple reverse time migration imaging(PMRTMI)method based on wavefield decomposition and normalized imaging conditions method.This method differs from seismic interferometry in that it can use raw passive seismic data directly in RTM imaging without reconstruction of virtual active gather,and we use the wavefield decomposition method to eliminate the low frequency noise in RTM.Further,the energy normalized imaging condition is used in full wavefield decomposition,which can not only enhance the image quality of both edge and deep information but also overcome the wrong energy problem caused by uneven distribution of passive sources;furthermore,this method exhibits high efficiency.Finally,numerical examples with the Marmousi model show the effectiveness of the method. 展开更多
关键词 Passive source multiple imaging reverse time migration energy normalization wavefield decomposition
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A theoretical model of rigid projectile perforation of concrete slabs using the energy method 被引量:1
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作者 XU XiangZhao MA TianBao WANG ZhiHua 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2018年第5期699-710,共12页
Projectile perforation of concrete slabs will produce numerous concrete fragments on the rear face of the concrete slabs. These concrete fragments will cause serious secondary damage to the indoor personnel and equipm... Projectile perforation of concrete slabs will produce numerous concrete fragments on the rear face of the concrete slabs. These concrete fragments will cause serious secondary damage to the indoor personnel and equipment of protective structures.Accurately evaluating the damage area of concrete slabs is an important problem. Therefore, a theoretical model of a rigid projectile perforation of concrete slabs is constructed using the energy method in this paper. In this model, a new shear failure method is proposed to calculate the energy consumption of the shear formation by combining with the von-Mises failure criterion and failure strain. Based on the energy conservation and principle of minimum potential energy, explicit equations for the perforation performance are formulated. The theoretical predictions agree well with the experimental results. Furthermore,experiments on a high-speed projectile normal perforation of concrete are carried out to verify the accuracy of the corresponding theoretical prediction. 展开更多
关键词 concrete shear plugging normal perforation principle of minimum potential energy energy conservation
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Pores-Preserving Face Cleaning Based on Improved Empirical Mode Decomposition
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作者 刘艳丽 徐晓刚 +4 位作者 郭延文 王进 段鑫 陈曦 彭群生 《Journal of Computer Science & Technology》 SCIE EI CSCD 2009年第3期557-567,共11页
In this paper, we propose a novel method of cleaning up facial imperfections such as bumps and blemishes that may detract from a pleasing digital portrait. Contrasting with traditional methods which tend to blur facia... In this paper, we propose a novel method of cleaning up facial imperfections such as bumps and blemishes that may detract from a pleasing digital portrait. Contrasting with traditional methods which tend to blur facial details, our method fully retains fine scale skin textures (pores etc.) of the subject. Our key idea is to find a quantity, namely normalized local energy, to capture different characteristics of fine scale details and distractions, based on empirical mode decomposition, and then build a quantitative measurement of facial skin appearance which characterizes both imperfections and facial details in a unified framework. Finally, we use the quantitative measurement as a guide to enhance facial skin. We also introduce a few high-level, intuitive parameters for controlling the amount of enhancement. In addition, an adaptive local mean and neighborhood limited empirical mode decomposition algorithm is also developed to improve in two respects the performance of empirical mode decomposition. It can effectively avoid the gray spots effect commonly associated with traditional empirical mode decomposition when dealing with high-nonstationary images. 展开更多
关键词 image enhancement empirical mode decomposition normalized local energy
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ON THE NORMALIZED LAPLACIAN SPECTRUM OF A NEW JOIN OF TWO GRAPHS
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作者 Xianzhang Wu Lili Shen 《Annals of Applied Mathematics》 2018年第4期407-415,共9页
Given graphs Gand G, we define a graph operation on Gand G,namely the SSG-vertex join of Gand G, denoted by G★ G. Let S(G) be the subdivision graph of G. The SSG-vertex join G★Gis the graph obtained from S(G) and S(... Given graphs Gand G, we define a graph operation on Gand G,namely the SSG-vertex join of Gand G, denoted by G★ G. Let S(G) be the subdivision graph of G. The SSG-vertex join G★Gis the graph obtained from S(G) and S(G) by joining each vertex of Gwith each vertex of G. In this paper, when G(i = 1, 2) is a regular graph, we determine the normalized Laplacian spectrum of G★ G. As applications, we construct many pairs of normalized Laplacian cospectral graphs, the normalized Laplacian energy, and the degree Kirchhoff index of G★G. 展开更多
关键词 SPECTRUM SSG-vertex join normalized Laplacian cospectral graphs normalized Laplacian energy degree Kirchhoff index
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