arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1310.7697math.NAcs.NA
收藏

基于比较的自适应随机搜索的线性收敛性:通过马尔可夫链的稳定性

Linear Convergence of Comparison-based Step-size Adaptive Randomized Search via Stability of Markov Chains

Inria, LRI, Bât 660, University Paris Sud(法国国家信息与自动化研究所,研究与教学实验室,660号楼,巴黎南大学)

Anne Auger, Nikolaus Hansen

AI总结:

本文研究了基于比较的自适应随机搜索算法在缩放不变目标函数上的线性收敛性,通过马尔可夫链的稳定性分析,推导了全局线性收敛的充分条件。

摘要:

本文考虑了用于解决数值优化问题的基于比较的自适应随机算法。我们考虑了一种特定子类的算法,称为基于比较的自适应步长随机搜索(CB-SARS),其中在给定迭代中的状态变量是一个搜索空间的向量和一个正参数,即步长,通常控制底层搜索分布的整体标准差。我们研究了CB-SARS在缩放不变目标函数上的线性收敛性。缩放不变函数在点被相同正参数缩放时保持点的顺序。此类函数包括由严格递增函数组成的范数以及许多非准凸和非连续函数。在缩放不变函数上,我们证明了存在一个均匀的马尔可夫链,这是CB-SARS的自然不变性性质(本质上是缩放不变性和对目标函数严格递增变换的不变性)的结果。我们进一步推导了CB-SARS全局线性收敛的充分条件,用不同马尔可夫链的稳定性条件(不可约性、正性、Harris复发、几何平稳性)来表达,并因此定义了一种证明CB-SARS算法在缩放不变函数上全局线性收敛的一般方法。作为副产品,我们提供了基于比较的自适应随机算法与马尔可夫链蒙特卡罗算法之间的联系。

英文摘要:

In this paper, we consider comparison-based adaptive stochastic algorithms for solving numerical optimisation problems. We consider a specific subclass of algorithms that we call comparison-based step-size adaptive randomized search (CB-SARS), where the state variables at a given iteration are a vector of the search space and a positive parameter, the step-size, typically controlling the overall standard deviation of the underlying search distribution.We investigate the linear convergence of CB-SARS on\emph{scaling-invariant} objective functions. Scaling-invariantfunctions preserve the ordering of points with respect to their functionvalue when the points are scaled with the same positive parameter (thescaling is done w.r.t. a fixed reference point). This class offunctions includes norms composed with strictly increasing functions aswell as many non quasi-convex and non-continuousfunctions. On scaling-invariant functions, we show the existence of ahomogeneous Markov chain, as a consequence of natural invarianceproperties of CB-SARS (essentially scale-invariance and invariance tostrictly increasing transformation of the objective function). We thenderive sufficient conditions for \emph{global linear convergence} ofCB-SARS, expressed in terms of different stability conditions of thenormalised homogeneous Markov chain (irreducibility, positivity, Harrisrecurrence, geometric ergodicity) and thus define a general methodologyfor proving global linear convergence of CB-SARS algorithms onscaling-invariant functions. As a by-product we provide aconnexion between comparison-based adaptive stochasticalgorithms and Markov chain Monte Carlo algorithms.

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。

↑