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arXiv 1602.05149stat.MLmath.OC
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昂贵函数的并行贝叶斯全局优化

Parallel Bayesian Global Optimization of Expensive Functions

Jialei Wang, Scott C. Clark, Eric Liu, Peter I. Frazier

摘要:

我们考虑了无导数代价函数的并行全局优化,并提出了一种基于随机逼近的有效方法,用于实现Ginsbourger等人(2007)提出的概念性贝叶斯优化算法。该算法的核心是最大化称为“多点预期改善”或q-EI的信息标准。为了实现这一点,我们使用无穷小扰动分析(IPA),构建一个随机梯度估计,并证明该估计是无偏的。我们还表明,使用构造的梯度估计的随机梯度上升算法收敛到一个平稳点的q-EI表面,因此,作为梯度上升算法的多个开始的数量和每个开始的步骤的数量变大,一步贝叶斯最优点集被恢复。我们在数值实验中表明,我们的方法最大化的q-EI是更快的方法,基于封闭形式的评价,使用高维集成,考虑许多并行功能的评价时,速度相当,当考虑很少。我们还表明,由此产生的一步贝叶斯优化算法并行全局优化发现高质量的解决方案,比启发式的基础上,大约最大化的q-EI的评价更少。该算法的高质量开源实现可在开源的MySQL优化引擎(MoE)中获得。

英文摘要:

We consider parallel global optimization of derivative-free expensive-to-evaluate functions, and propose an efficient method based on stochastic approximation for implementing a conceptual Bayesian optimization algorithm proposed by Ginsbourger et al. (2007). At the heart of this algorithm is maximizing the information criterion called the "multi-points expected improvement'', or the q-EI. To accomplish this, we use infinitessimal perturbation analysis (IPA) to construct a stochastic gradient estimator and show that this estimator is unbiased. We also show that the stochastic gradient ascent algorithm using the constructed gradient estimator converges to a stationary point of the q-EI surface, and therefore, as the number of multiple starts of the gradient ascent algorithm and the number of steps for each start grow large, the one-step Bayes optimal set of points is recovered. We show in numerical experiments that our method for maximizing the q-EI is faster than methods based on closed-form evaluation using high-dimensional integration, when considering many parallel function evaluations, and is comparable in speed when considering few. We also show that the resulting one-step Bayes optimal algorithm for parallel global optimization finds high-quality solutions with fewer evaluations than a heuristic based on approximately maximizing the q-EI. A high-quality open source implementation of this algorithm is available in the open source Metrics Optimization Engine (MOE).

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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