共查询到20条相似文献,搜索用时 15 毫秒
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《Quaestiones Mathematicae》2013,36(4):443-452
Abstract The proximal limit spaces are introduced which fill the gap arising from the existence of proximity spaces, uniform spaces, and uniform limit spaces. It is shown that the proximal limit spaces can be considered as a bireflective subcategory of the topological category of uniform limit spaces. A limit space is induced by a proximal limit space if and only if it is a S1-limit space. 相似文献
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在大数据时代,随着数据采集手段的不断提升,大规模复合凸优化问题大量的出现在包括统计数据分析,机器与统计学习以及信号与图像处理等应用中.本文针对大规模复合凸优化问题介绍了一类快速邻近点算法.在易计算的近似准则和较弱的平稳性条件下,本文给出了该算法的全局收敛与局部渐近超线性收敛结果.同时,我们设计了基于对偶原理的半光滑牛顿法来高效稳定求解邻近点算法所涉及的重要子问题.最后,本文还讨论了如何通过深入挖掘并利用复合凸优化问题中由非光滑正则函数所诱导的非光滑二阶信息来极大减少半光滑牛顿算法中求解牛顿线性系统所需的工作量,从而进一步加速邻近点算法. 相似文献
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《Numerical Functional Analysis & Optimization》2013,34(7-8):1013-1035
We present a unified framework for the design and convergence analysis of a class of algorithms based on approximate solution of proximal point subproblems. Our development further enhances the constructive approximation approach of the recently proposed hybrid projection–proximal and extragradient–proximal methods. Specifically, we introduce an even more flexible error tolerance criterion, as well as provide a unified view of these two algorithms. Our general method possesses global convergence and local (super)linear rate of convergence under standard assumptions, while using a constructive approximation criterion suitable for a number of specific implementations. For example, we show that close to a regular solution of a monotone system of semismooth equations, two Newton iterations are sufficient to solve the proximal subproblem within the required error tolerance. Such systems of equations arise naturally when reformulating the nonlinear complementarity problem. 相似文献
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本文研究球面上的$\ell_1$正则优化问题,其目标函数由一般光滑函数项和非光滑$\ell_1$正则项构成,且假设光滑函数的随机梯度可由随机一阶oracle估计.这类优化问题被广泛应用在机器学习,图像、信号处理和统计等领域.根据流形临近梯度法和随机梯度估计技术,提出一种球面随机临近梯度算法.基于非光滑函数的全局隐函数定理,分析了子问题解关于参数的Lipschtiz连续性,进而证明了算法的全局收敛性.在基于随机数据集和实际数据集的球面$\ell_1$正则二次规划问题、有限和SPCA问题和球面$\ell_1$正则逻辑回归问题上数值实验结果显示所提出的算法与流形临近梯度法、黎曼随机临近梯度法相比CPU时间上具有一定的优越性. 相似文献
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本文对DC函数(即两凸函数之差)的最小化问题提出了一个非精确邻近点算法,并证明此算法的下降性和全局收敛性. 相似文献
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关于单调变分不等式的不精确邻近点算法的收敛性分析 总被引:7,自引:0,他引:7
王治华 《高等学校计算数学学报》2003,25(4):336-343
We consider a proximal point algorithm(PPA) for solving monotone variational inequalities. PPA generates a sequence by solving a sequence of strongly monotone subproblems .However,solving the subproblems is either expensive or impossible. Some inexact proximal point algorithms(IPPA) have been developed in many literatures. In this paper, we present a criterion for approximately solving subproblems. It only needs one simple additional work on the basis of original algorithm, and the convergence criterion becomes milder. We show that this method converges globally under new criterion provided that the solution set of the problem is nonempty. 相似文献
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广义非线性变分包含的带误差的近似点算法 总被引:2,自引:0,他引:2
引入和研究了一类新的广义非线性变分包含.在Hilbert空间中利用与极大η-单调映象相联系的预解算子的性质,对新的广义非线性变分包含建立了一个新的寻求近似解的带误差的近似点算法,并证明了求近似解序列强收敛于精确解.其所得结果是近期相关结果的改进和推广. 相似文献
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In this paper we prove the convergence of the approximate proximal method for DC functions proposed by Sun et al [6]. Our analysis also permits to treat the exact method. We then propose an interesting result in the case where the second component of the DC function is differentiable and provide some computational experiences which proved the efficiency of our method. 相似文献
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本文提出了一种求解低秩张量填充问题的加速随机临近梯度算法.张量填充模型可以松弛为平均组合形式的无约束优化问题,在迭代过程中,随机选取该组合中的某一函数进行变量更新,有效减少了张量展开、矩阵折叠及奇异值分解带来的较大的计算花费.本文证明了算法的收敛率为$O (1/k^{2})$.最后,随机生成的和真实的张量填充实验结果表明新算法在CPU时间上优于现有的三种算法. 相似文献
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§1 Introduction and preliminariesA set T Rn×Rnis called a monotone operator on Rn,if T has the property(x,y) ,(x′,y′)∈T 〈x -x′,y -y′〉≥0 ,where〈·,·〉denotes the inner product on Rn.T is maximal if(considered as a graph) itis not strictly contained in any other monotone operator on Rn.It is well known that thetheory of maximal monotone operators plays an important role in the study of convexprogramming and variational inequalities since itcan provide a powerful general framework… 相似文献
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《Quaestiones Mathematicae》2013,36(4):707-714
Abstract We show that a strengthened form of a property of Roth-berger implies that a certain polarized partition relation holds for the ω-covers of a space and that this partition relation implies a strengthened form of a property of Menger. 相似文献
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本文考虑具有不等式约束条件不可微优化问题,假定目标函数和约束函数既是Lipschitz的也是拟可微的.证明了该问题拟微分形式下的FritzJohn点必是Clarke广义梯度形式下的FritzJohn点.另外,还给出了拟微分和Clarke广义梯度之间的关系. 相似文献
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幂格的同态与同余关系 总被引:1,自引:1,他引:0
本文在文[1]已引入幂格同态概念的基础上,进一步引入幂格同余关系的概念,并得到它们的一些相关性质.以及幂格同态与幂格同余关系的对应关系. 相似文献
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本文利用奇异摄动的内、外解匹配方法,分析了各向异性时在相态场模型的边界层上表面张菌、法向速度、平均曲率和各向异性函数的影响,得到了各向异性时的Gibbs-Thompson关系,以及边界层所满足的方程。 相似文献
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本文通过提出软代数中心核概念,讨论了软代数中理想与同余关系的联系,证明了软代数的每个中理想,都存在相应的同余关系,使其中心核恰为该中理想;每个中理想都是某个满同态的中心核;并通过中心核,构造出了相应的最小与最大同余关系. 相似文献