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arXiv 2306.02001math.OC
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一种全局收敛的凸差分算法框架及其在对数行列式优化问题中的应用

A globally convergent difference-of-convex algorithmic framework and application to log-determinant optimization problems

Chaorui Yao, Xin Jiang

AI总结:

针对凸差分算法(DCA)理论与框架不足,本文提出扩展Polyak–Łojasiewicz条件下的线性全局收敛理论,并构建高效DCProx邻近计算框架,成功应用于网络信息论中的对数行列式优化问题。

摘要:

凸差分算法(DCA)是一种概念上简单的方法,用于最小化表示为两个凸函数之差的(可能为)非凸函数。在每次迭代中,DCA构造目标函数的全局过估计子,并求解由此产生的凸子问题。尽管其概念简单,但DCA的理论理解和算法框架仍需进一步研究。本文在扩展的Polyak–Łojasiewicz条件下,建立了DCA以线性速率全局收敛的结论。所提出的条件适用于一类具有有界、闭且凸约束集的DC规划,而现有分析无法涵盖此类问题中DCA的全局收敛性。此外,本文提出了DCProx计算框架,其中DCA子问题通过带Bregman距离的原始–对偶邻近算法求解。通过适当选择Bregman距离,DCProx具有简单的更新规则,且每次迭代的计算成本较低。作为应用,DCA被用于网络信息论中的若干基本问题,目前尚无数值方法能够计算这些问题的全局最优解。对于这些问题,本文分析证明了DCA的全局收敛性;更重要的是,DCProx能够高效求解DCA子问题。数值实验验证了DCProx的效率。

英文摘要:

The difference-of-convex algorithm (DCA) is a conceptually simple method for the minimization of (possibly) nonconvex functions that are expressed as the difference of two convex functions. At each iteration, DCA constructs a global overestimator of the objective and solves the resulting convex subproblem. Despite its conceptual simplicity, the theoretical understanding and algorithmic framework of DCA needs further investigation. In this paper, global convergence of DCA at a linear rate is established under an extended Polyak--Łojasiewicz condition. The proposed condition holds for a class of DC programs with a bounded, closed, and convex constraint set, for which global convergence of DCA cannot be covered by existing analyses. Moreover, the DCProx computational framework is proposed, in which the DCA subproblems are solved by a primal--dual proximal algorithm with Bregman distances. With a suitable choice of Bregman distances, DCProx has simple update rules with cheap per-iteration complexity. As an application, DCA is applied to several fundamental problems in network information theory, for which no existing numerical methods are able to compute the global optimum. For these problems, our analysis proves the global convergence of DCA, and more importantly, DCProx solves the DCA subproblems efficiently. Numerical experiments are conducted to verify the efficiency of DCProx.

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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