将压缩映射和同构映射引入核化图嵌入框架(kernel extension of graph embedding,简称KGE),从理论上证明了KGE框架内的各种核算法其实质是KPCA(kernel principal component analysis)+LGE(linear extension of graph embedding,简称LGE...将压缩映射和同构映射引入核化图嵌入框架(kernel extension of graph embedding,简称KGE),从理论上证明了KGE框架内的各种核算法其实质是KPCA(kernel principal component analysis)+LGE(linear extension of graph embedding,简称LGE)框架内的线性降维算法,并且基于所给出的理论框架提出了一种综合利用零空间和非零空间鉴别信息的组合方法.任何一种可以用核化图嵌入框架描述的核算法,都可以有相应的组合方法.在ORL,Yale,FERET和PIE人脸数据库上验证了所提出的理论和方法的有效性.展开更多
针对高维小样本数据在核化图嵌入过程中出现的复杂度问题,引入基于核化图嵌入(kernel extension of graph embedding)的快速求解模型,提出了一种新的KGE/CCA算法(KGE/CCA-S_t)。首先将样本数据投影到维数远低于原样本空间维数的总体散...针对高维小样本数据在核化图嵌入过程中出现的复杂度问题,引入基于核化图嵌入(kernel extension of graph embedding)的快速求解模型,提出了一种新的KGE/CCA算法(KGE/CCA-S_t)。首先将样本数据投影到维数远低于原样本空间维数的总体散度矩阵对应的秩空间,然后采用核典型相关分析进行特征提取,整个过程减少了核矩阵的计算量。在Yale人脸库和JAFFE人脸库上进行仿真实验,结果表明这种KGE/CCA算法的识别率明显优于KFD、KLPP和KNPE算法的识别率;和传统的KGE/CCA算法相比,在不影响识别率的情况下,KGE/CCA-S_t算法有效减少了计算时间。展开更多
Cryo-electron microscopy (cryo-EM) plays an important role in determining the structure of proteins, viruses, and even the whole cell. It can capture dynamic structural changes of large protein complexes, which other ...Cryo-electron microscopy (cryo-EM) plays an important role in determining the structure of proteins, viruses, and even the whole cell. It can capture dynamic structural changes of large protein complexes, which other methods such as X-ray crystallography and nuclear magnetic resonance analysis find difficult. The signal-to-noise ratio of cryo-EM images is low and the contrast is very weak, and therefore, the images are very noisy and require filtering. In this paper, a filtering method based on non-local means and Zernike moments is proposed. The method takes into account the rotational symmetry of some biological molecules to enhance the signal-to-noise ratio of cryo-EM images. The method may be useful in cryo-EM image processing such as the automatic selection of particles, orientation determination, and the building of initial models.展开更多
文摘将压缩映射和同构映射引入核化图嵌入框架(kernel extension of graph embedding,简称KGE),从理论上证明了KGE框架内的各种核算法其实质是KPCA(kernel principal component analysis)+LGE(linear extension of graph embedding,简称LGE)框架内的线性降维算法,并且基于所给出的理论框架提出了一种综合利用零空间和非零空间鉴别信息的组合方法.任何一种可以用核化图嵌入框架描述的核算法,都可以有相应的组合方法.在ORL,Yale,FERET和PIE人脸数据库上验证了所提出的理论和方法的有效性.
文摘针对高维小样本数据在核化图嵌入过程中出现的复杂度问题,引入基于核化图嵌入(kernel extension of graph embedding)的快速求解模型,提出了一种新的KGE/CCA算法(KGE/CCA-S_t)。首先将样本数据投影到维数远低于原样本空间维数的总体散度矩阵对应的秩空间,然后采用核典型相关分析进行特征提取,整个过程减少了核矩阵的计算量。在Yale人脸库和JAFFE人脸库上进行仿真实验,结果表明这种KGE/CCA算法的识别率明显优于KFD、KLPP和KNPE算法的识别率;和传统的KGE/CCA算法相比,在不影响识别率的情况下,KGE/CCA-S_t算法有效减少了计算时间。
基金supported by the National Basic Research Program of China (2010CB912400)
文摘Cryo-electron microscopy (cryo-EM) plays an important role in determining the structure of proteins, viruses, and even the whole cell. It can capture dynamic structural changes of large protein complexes, which other methods such as X-ray crystallography and nuclear magnetic resonance analysis find difficult. The signal-to-noise ratio of cryo-EM images is low and the contrast is very weak, and therefore, the images are very noisy and require filtering. In this paper, a filtering method based on non-local means and Zernike moments is proposed. The method takes into account the rotational symmetry of some biological molecules to enhance the signal-to-noise ratio of cryo-EM images. The method may be useful in cryo-EM image processing such as the automatic selection of particles, orientation determination, and the building of initial models.
