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基张量和张量基的概念及其分析
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作者 王伯年 《上海理工大学学报》 CAS 北大核心 2001年第4期346-349,共4页
通常张量有整体表示式和分量(指标)表示式,但这二者尚不是全面而完整的. 因此,须将矢量中的基矢量和矢量基的概念推广到基张量和张量基. 为此,需以基矢量及张量外积为基础,导出基张量和张量基,任一张量可表达为诸基张量的线性和. 据此,... 通常张量有整体表示式和分量(指标)表示式,但这二者尚不是全面而完整的. 因此,须将矢量中的基矢量和矢量基的概念推广到基张量和张量基. 为此,需以基矢量及张量外积为基础,导出基张量和张量基,任一张量可表达为诸基张量的线性和. 据此,可以阐明并矢正是二矢量的外积,并建立了其与张量的对应关系. 这样的认识对于物理定律的张量方程及其应用有着重要的意义. 展开更多
关键词 张量 矢量 基张量 并矢 张量外积
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基于张量径向基核函数支持向量机的高光谱影像分类 被引量:21
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作者 李玉 宫学亮 赵泉华 《仪器仪表学报》 EI CAS CSCD 北大核心 2020年第12期253-262,共10页
针对如何利用高光谱影像的空间和光谱特征实现地物目标的精确分类,本文在径向基核函数(RBF)的基础上,提出一种基于张量径向基核函数(Tensor-RBF)和支持向量机(SVM)的高光谱影像分类算法。首先,用像素及其空间邻域像素的光谱向量组成的... 针对如何利用高光谱影像的空间和光谱特征实现地物目标的精确分类,本文在径向基核函数(RBF)的基础上,提出一种基于张量径向基核函数(Tensor-RBF)和支持向量机(SVM)的高光谱影像分类算法。首先,用像素及其空间邻域像素的光谱向量组成的三阶空-谱张量块表达该像素空-谱信息,并作为后续高光谱影像分类的基本处理单元;然后,定义作用在张量数据上的Tensor-RBF核函数;最后,设计基于Tensor-RBF核函数SVM的多分类器,实现结合空-谱信息的高光谱影像多类地物目标分类。为了验证提出算法的有效性,分别对3幅高光谱影像进行实验,将本文算法与3种对比算法的分类结果进行定性和定量对比分析。实验结果表明,本文算法对3幅高光谱影像的总体精度分别为93.10%、93.43%和86.38%,相对3种对比算法具有更高的总体精度。 展开更多
关键词 空-谱张量 张量径向核函数 支持向量机 高光谱影像分类
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Fingerprint singular points extraction based on orientation tensor field and Laurent series 被引量:3
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作者 刘琴 彭可 +4 位作者 刘巍 谢琴 李仲阳 兰浩 金耀 《Journal of Central South University》 SCIE EI CAS 2014年第5期1927-1934,共8页
Singular point(SP)extraction is a key component in automatic fingerprint identification system(AFIS).A new method was proposed for fingerprint singular points extraction,based on orientation tensor field and Laurent s... Singular point(SP)extraction is a key component in automatic fingerprint identification system(AFIS).A new method was proposed for fingerprint singular points extraction,based on orientation tensor field and Laurent series.First,fingerprint orientation flow field was obtained,using the gradient of fingerprint image.With these gradients,fingerprint orientation tensor field was calculated.Then,candidate SPs were detected by the cross-correlation energy in multi-scale Gaussian space.The energy was calculated between fingerprint orientation tensor field and Laurent polynomial model.As a global descriptor,the Laurent polynomial coefficients were allowed for rotational invariance.Furthermore,a support vector machine(SVM)classifier was trained to remove spurious SPs,using cross-correlation coefficient as a feature vector.Finally,experiments were performed on Singular Point Detection Competition 2010(SPD2010)database.Compared to the winner algorithm of SPD2010 which has best accuracy of 31.90%,the accuracy of proposed algorithm is 45.34%.The results show that the proposed method outperforms the state-of-the-art detection algorithms by large margin,and the detection is invariant to rotational transformations. 展开更多
关键词 fingerprint extraction singular point fingerprint orientation tensor field Laurent series rotational invariance supportvector machine (SVM)
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Constructions on Approximately Mutually Unbiased Bases by Galois Rings 被引量:3
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作者 LI Jin FENG Keqin 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第6期1440-1448,共9页
Several new series of approximately mutually unbiased bases are constructed by using Gauss sums and Jacobi sums over Galois rings GR(p2, r), and the tensor method.
关键词 MUB Galois rings Gauss sums Jacobi sums tensor method
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Fluctuation with dust of de Sitter ground state of scalar-tensor gravity 被引量:1
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作者 TANG YanKe ZHANG HongSheng +1 位作者 CHEN ChiYi LI XinZhou 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第3期411-417,共7页
An exact de Sitter solution of scalar-tensor gravity is found in our recent work, in which the non-minimal coupling scalar is rolling along a non-constant potential. Based on this solution, a dust-filled FRW universe ... An exact de Sitter solution of scalar-tensor gravity is found in our recent work, in which the non-minimal coupling scalar is rolling along a non-constant potential. Based on this solution, a dust-filled FRW universe is explored in frame of scalar-tensor gravity in this article. The effective dark energy induced by the sole non-minimal scalar can be quintessence-like, phantom-like, and more significantly, can cross the phantom divide. The rich and varied properties of scalar-tensor gravity even with only one scalar is shown. 展开更多
关键词 scalar tensor gravity de Sitter space dark energy phantom divide
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Prescribing Curvature Problems on the Bakry-Emery Ricci Tensor of a Compact Manifold with Boundary
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作者 Weimin SHENG Lixia YUAN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2014年第1期139-160,共22页
t The authors consider the problem of conformally deforming a metric such that the k-curvature defined by an elementary symmetric function of the eigenvalues of the Bakry-Emery Ricci tensor on a compact manifold with ... t The authors consider the problem of conformally deforming a metric such that the k-curvature defined by an elementary symmetric function of the eigenvalues of the Bakry-Emery Ricci tensor on a compact manifold with boundary to a prescribed function. A consequence of our main result is that there exists a complete metric such that the Monge-Amp^re type equation with respect to its Bakry-Emery Ricci tensor is solvable, provided that the initial Bakry-Emery Ricci tensor belongs to a negative convex cone. 展开更多
关键词 k-Curvature Bakry-Emery Ricci tensor Complete metric Dirichletproblem
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