期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
一种改进和提取Zernike特征矩的方法
1
作者 陈玲 李熙莹 罗玲 《计算机工程与应用》 CSCD 2012年第20期182-186,共5页
数字图像的离散性使Zernike矩的计算存在误差,降低了特征描述能力。采用一种方圆转换方法将矩形图像转化为抽象的圆形图像,计算转化后图像Zernike矩,改进Zernike矩的计算方法,从而减少计算误差,提高计算速率,提高Zernike矩的特征描述能... 数字图像的离散性使Zernike矩的计算存在误差,降低了特征描述能力。采用一种方圆转换方法将矩形图像转化为抽象的圆形图像,计算转化后图像Zernike矩,改进Zernike矩的计算方法,从而减少计算误差,提高计算速率,提高Zernike矩的特征描述能力。同时根据统计理论,提出一种规范的特征提取方法。经车牌字符识别实验验证,改进方法能够很好地提取图像特征,用于模式识别。 展开更多
关键词 ZERNIKE矩 方圆变换 特征选择
下载PDF
Breather Lattice Solutions to Negative mKdV Equation
2
作者 ZHAO Xia FU Zun-Tao +1 位作者 MAO Jiang-Yu LIU Shi-Kuo 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第7期23-29,共7页
In this paper,dependent and independent variable transformations are introduced to solve the negativemKdV equation systematically by using the knowledge of elliptic equation and Jacobian elliptic functions.It is shown... In this paper,dependent and independent variable transformations are introduced to solve the negativemKdV equation systematically by using the knowledge of elliptic equation and Jacobian elliptic functions.It is shownthat different kinds of solutions can be obtained to the negative mKdV equation,including breather lattice solution andperiodic wave solution. 展开更多
关键词 Jacobian elliptic function the negative mKdV equation periodic wave solution breather lattice solution
下载PDF
Hardy spaces H_L^p(R^n) associated with operators satisfying k-Davies-Gaffney estimates 被引量:13
3
作者 CAO Jun YANGDaChun 《Science China Mathematics》 SCIE 2012年第7期1403-1440,共38页
Let L be a one-to-one operator of type w having a bounded H∞ functional calculus and satisfying the k-Davies-Gaffney estimates with k C N. In this paper, the authors introduce the Hardy space HPL(Rn) with p ∈(0, ... Let L be a one-to-one operator of type w having a bounded H∞ functional calculus and satisfying the k-Davies-Gaffney estimates with k C N. In this paper, the authors introduce the Hardy space HPL(Rn) with p ∈(0, 1] associated with L in terms of square functions defined via {e-t2kL}t〉O and establish their molecular and generalized square function characterizations. Typical examples of such operators include the 2k-order divergence form homogeneous elliptic operator L1 with complex bounded measurable coefficients and the 2k-order Schr6dinger type operator L2 := (-△)k + Vk, where A is the Laplacian and 0≤V C Llkoc(Rn). Moreover, as an application, for i E {1, 2}, the authors prove that the associated Riesz transform Vk(Li-1/2) p n HP(Rn) for @ (n/(n + k), 1] and establish the Riesz transform characterizations is bounded from HLI(IR ) to p of HPL1(]Rn) for p C (rn/(n + kr), 1] if {e-tL1 }t〉o satisfies the Lr - L2 k-off-diagonal estimates with r C (1, 2]. These results when k := I and L := L1 are known. 展开更多
关键词 Hardy space Hardy-Sobolev space k-Davies-Gaffney estimate Schr6dinger type operator higherorder elliptic operator SEMIGROUP square function higher order IZiesz transform molecule
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部