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共轭梯度法中预条件子的优化
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作者 郭存柱 《应用数学进展》 2017年第4期651-658,共8页
为了降低方程组求解中共轭梯度法系数矩阵的条件数,提高收敛速度,常用预处理方法将原方程进行等价转化,同时预条件子既要接近原系数矩阵,又要容易求其逆矩阵。本文从寻求对角预条件子出发,用矩阵的特征值分解方法解出了预处理后系数矩... 为了降低方程组求解中共轭梯度法系数矩阵的条件数,提高收敛速度,常用预处理方法将原方程进行等价转化,同时预条件子既要接近原系数矩阵,又要容易求其逆矩阵。本文从寻求对角预条件子出发,用矩阵的特征值分解方法解出了预处理后系数矩阵特征值矩阵的显式表达,得到对角预条件子矩阵的最优选择,并予以证明。给出了三个p-范数预条件子,将之与常用的预条件子进行对比,实例检验表明三个p-范数预条件子的作用更优越,且使算法收敛更快。 展开更多
关键词 条件 条件 特征值分解 p-范数条件
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学习理论中的MLP方法 被引量:1
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作者 任静静 徐艳艳 陈广贵 《四川师范大学学报(自然科学版)》 CAS CSCD 北大核心 2013年第2期247-251,共5页
移动最小二乘(MLS)法是数据插值、数值分析和统计等学科领域的一种逼近方法.H.Y.Wang,D.H.Xiang,D.X.Zhou(J Approx Theory,2010,162:599-614.)用MLS方法研究了L2框架下学习理论中的回归问题,从而得到了样本误差、逼近误差的更优结果.... 移动最小二乘(MLS)法是数据插值、数值分析和统计等学科领域的一种逼近方法.H.Y.Wang,D.H.Xiang,D.X.Zhou(J Approx Theory,2010,162:599-614.)用MLS方法研究了L2框架下学习理论中的回归问题,从而得到了样本误差、逼近误差的更优结果.但是很多函数类在L2框架下很难研究,于是本文用移动最小p乘(MLP)法将L2框架下学习理论中回归问题的一些理论推广到Lp(1≤p≤∞)框架下,从而为研究Lp框架下学习算法的泛化性能提供了理论基础. 展开更多
关键词 学习理论 Lp框架 p-样本误差 范数条件 条件
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Inner Product and Norm
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作者 赵舜仁 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第3期39-43,共5页
In this paper,we give some new equivalent forms of the norm in inner produt space.
关键词 normed linear space immerproduct space NOR
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Some Equivalent Conditions for the Differentiability of Continuous Gauge Functions on Banach Space
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作者 南朝勋 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第4期84-88,共5页
In this paper,some equivalent conditions for differentiability of condtinuous gauge function are given.
关键词 gauge function SUBGRADIENT Gauteaux differentiability Frechet differentiability
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Nonconforming Finite Element Method for Gradient flow Equations in Robin Conditions
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作者 Changhui Yao Shaorong Li 《Journal of Mathematics and System Science》 2014年第5期315-326,共12页
In this paper, Crouzeix-Raveart type nonconforming rectangular element is applied to the Mumford-Shah functional for image segmentation subjected to Robin boundary conditions. Meanwhile, by using the special orthogona... In this paper, Crouzeix-Raveart type nonconforming rectangular element is applied to the Mumford-Shah functional for image segmentation subjected to Robin boundary conditions. Meanwhile, by using the special orthogonality of this element's basic functions, the convergence analysis for L2-norm and broken H1-norm with semi-implicit scheme is presented. And the error order is improved to the optimal, too. 展开更多
关键词 Image segmentation nonconforming finite element Robbin boundary conditions error estimate.
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Hardy-type inequalities on strong and weak Orlicz-Lorentz spaces 被引量:3
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作者 LI HongLiang 《Science China Mathematics》 SCIE 2012年第12期2493-2505,共13页
In the present paper, the characterization of strong-type modular inequality ∫ 0 ∞φ(Sf (t))w(t)dt≤∫0∞ φ(Cf (t))w(t)dt, f↓ is given, where φ∈Δ' and S is a Hardy operator. Furthermore, the equivalent con... In the present paper, the characterization of strong-type modular inequality ∫ 0 ∞φ(Sf (t))w(t)dt≤∫0∞ φ(Cf (t))w(t)dt, f↓ is given, where φ∈Δ' and S is a Hardy operator. Furthermore, the equivalent conditions of modular inequalities and norm inequalities related to weak Orlicz-Lorentz spaces are researched. We also explore the conditions for Orlicz-Lorentz spaces and weak Orlicz-Lorentz spaces to be normable. Finally, the weak boundedness of certain Hardy-type operators on Orlicz-Lorentz spaces is studied. 展开更多
关键词 Orlicz-Lorentz spaces weak Orlicz-Lorentz spaces Hardy operator modular inequalities norminequalities
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Operator Equations and Duality Mappings in Sobolev Spaces with Variable Exponents
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作者 Philippe G.CIARLET George DINCA Pavel MATEI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2013年第5期639-666,共28页
After studying in a previous work the smoothness of the space where dr- measF0 〉 O, with p(.) E C(~) and p(x) 〉 1 for all x E , the authors study in this paper the strict and uniform convexity as well as some ... After studying in a previous work the smoothness of the space where dr- measF0 〉 O, with p(.) E C(~) and p(x) 〉 1 for all x E , the authors study in this paper the strict and uniform convexity as well as some special properties of duality mappings defined on the same space. The results obtained in this direction are used for proving existence results for operator equations having the form Ju = Niu, where J is a duality mapping on Uro corresponding to the gauge function ~, and Nf is the Nemytskij operator generated by a Caratheodory function f satisfying an appropriate growth condition ensuring that Nf may be viewed as acting from Ur0 into its dual. 展开更多
关键词 Monotone operators SMOOTHNESS Strict convexity Uniform convexity Duality mappings Sobolev spaces with a variable exponent Nemytskijoperators
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NEW WAVELET BASES FOR NON-HOMOGENEOUS SYMBOLIC SPACE OpS1,1^m AND RELATED KERNEL-DISTRIBUTION SPACES 被引量:1
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作者 YANG QIXIANGDepartment of Mathematics, Wuhan University, Wuhan 430072, China. 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2002年第4期551-562,共12页
This paper constructs several classes of new wavelet bases, which are unconditional bases for related operator spaces. Using these bases, the author analyzes non-homogeneous symbolic space OpSm1,1 and two related kern... This paper constructs several classes of new wavelet bases, which are unconditional bases for related operator spaces. Using these bases, the author analyzes non-homogeneous symbolic space OpSm1,1 and two related kernel-distribution spaces, and characterizes them in two wavelet coefficients spaces. Besides, some properties for singular integral operators are studied. 展开更多
关键词 Wavelet bases Symbolic spaces Kernel-distribution spaces
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Globally generated vector bundles on a smooth quadric surface
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作者 BALLICO Edoardo HUH Sukmoon MALASPINA Francesco 《Science China Mathematics》 SCIE CSCD 2015年第3期633-652,共20页
We give the classification of globally generated vector bundles of rank 2 on a smooth quadric surface with c1(2,2)in terms of the indices of the bundles,and extend the result to arbitrary higher rank case.We also inve... We give the classification of globally generated vector bundles of rank 2 on a smooth quadric surface with c1(2,2)in terms of the indices of the bundles,and extend the result to arbitrary higher rank case.We also investigate their indecomposability and give the sufficient and necessary condition on numeric data of vector bundles for indecomposability. 展开更多
关键词 higher rank vector bundles globally generated smooth quadric surface
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