arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1907.13402math.OC
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交替投影法的变分方法

A variational approach to the alternating projections method

Carlo A. De Bernardi, Enrico Miglierina

摘要:

2-集凸可行性问题的目的是在Hilbert空间$X$中的两个闭凸集$A$和$B$的非空交集中寻找一个点。交替投影法是求解问题的最简单的迭代过程,它可以追溯到冯·诺依曼。在本文中,我们研究了这种方法的一些稳定性性质在以下意义下:我们考虑两个序列的集合,每一个都收敛,关于Attouch-Wets变分收敛,分别为$A$和$B$。给定一个起始点$a_0$,我们考虑通过在“扰动”集上投影而获得的点序列,即,由$b_n=P_{B_n}(a_{n-1})$和$a_n=P_{A_n}(b_n)$给出的序列$\{a_n\}$和$\{b_n\}$。在适当的几何和拓扑假设的极限集的交集,我们确保序列$\{a_n\}$和$\{b_n\}$收敛于规范的$A$和$B$相交的一点。特别是,我们认为当交叉$A\cap B$减少到一个单例,当内部的$A \cap B$是非空的。最后,我们考虑的情况下,极限集$A$和$B$是子空间。

英文摘要:

The 2-sets convex feasibility problem aims at finding a point in the nonempty intersection of two closed convex sets $A$ and $B$ in a Hilbert space $X$. The method of alternating projections is the simplest iterative procedure for finding a solution and it goes back to von Neumann. In the present paper, we study some stability properties for this method in the following sense: we consider two sequences of sets, each of them converging, with respect to the Attouch-Wets variational convergence, respectively, to $A$ and $B$. Given a starting point $a_0$, we consider the sequences of points obtained by projecting on the "perturbed" sets, i.e., the sequences $\{a_n\}$ and $\{b_n\}$ given by $b_n=P_{B_n}(a_{n-1})$ and $a_n=P_{A_n}(b_n)$. Under appropriate geometrical and topological assumptions on the intersection of the limit sets, we ensure that the sequences $\{a_n\}$ and $\{b_n\}$ converge in norm to a point in the intersection of $A$ and $B$. In particular, we consider both when the intersection $A\cap B$ reduces to a singleton and when the interior of $A \cap B$ is nonempty. Finally we consider the case in which the limit sets $A$ and $B$ are subspaces.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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