Janmark, Meyer, and Wong showed that continuous-time quantum walk search on known families of strongly regular graphs（SRGs） with parameters（N, k, λ, μ） achieves full quantum speedup. The problem is reconsidered ...Janmark, Meyer, and Wong showed that continuous-time quantum walk search on known families of strongly regular graphs（SRGs） with parameters（N, k, λ, μ） achieves full quantum speedup. The problem is reconsidered in terms of scattering quantum walk, a type of discrete-time quantum walks. Here, the search space is confined to a low-dimensional subspace corresponding to the collapsed graph of SRGs. To quantify the algorithm＇s performance, we leverage the fundamental pairing theorem, a general theory developed by Cottrell for quantum search of structural anomalies in star graphs.The search algorithm on the SRGs with k scales as N satisfies the theorem, and results can be immediately obtained, while search on the SRGs with k scales as√N does not satisfy the theorem, and matrix perturbation theory is used to provide an analysis. Both these cases can be solved in O（√N） time steps with a success probability close to 1. The analytical conclusions are verified by simulation results on two SRGs. These examples show that the formalism on star graphs can be applied more generally.展开更多
A novel inverse scattering method to reconstruct the permittivity profile of one-dimensional multi-layered media is proposed in this paper.Based on the equivalent network ofthe medium,a concept of time domain signal f...A novel inverse scattering method to reconstruct the permittivity profile of one-dimensional multi-layered media is proposed in this paper.Based on the equivalent network ofthe medium,a concept of time domain signal flow graph and its basic principles are introduced,from which the reflection coefficient of the medium in time domain can be shown to be a series ofDirac δ-functions(pulse responses).In terms of the pulse responses,we will reconstruct both thepermittivity and the thickness of each layer will accurately be reconstructed.Numerical examplesverify the applicability of this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
基金supported by the National Natural Science Foundation of China(Grant Nos.61502101 and 61170321)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20140651)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20110092110024)
文摘Janmark, Meyer, and Wong showed that continuous-time quantum walk search on known families of strongly regular graphs（SRGs） with parameters（N, k, λ, μ） achieves full quantum speedup. The problem is reconsidered in terms of scattering quantum walk, a type of discrete-time quantum walks. Here, the search space is confined to a low-dimensional subspace corresponding to the collapsed graph of SRGs. To quantify the algorithm＇s performance, we leverage the fundamental pairing theorem, a general theory developed by Cottrell for quantum search of structural anomalies in star graphs.The search algorithm on the SRGs with k scales as N satisfies the theorem, and results can be immediately obtained, while search on the SRGs with k scales as√N does not satisfy the theorem, and matrix perturbation theory is used to provide an analysis. Both these cases can be solved in O（√N） time steps with a success probability close to 1. The analytical conclusions are verified by simulation results on two SRGs. These examples show that the formalism on star graphs can be applied more generally.
文摘A novel inverse scattering method to reconstruct the permittivity profile of one-dimensional multi-layered media is proposed in this paper.Based on the equivalent network ofthe medium,a concept of time domain signal flow graph and its basic principles are introduced,from which the reflection coefficient of the medium in time domain can be shown to be a series ofDirac δ-functions(pulse responses).In terms of the pulse responses,we will reconstruct both thepermittivity and the thickness of each layer will accurately be reconstructed.Numerical examplesverify the applicability of this
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。
