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arXiv 2402.13641cs.LG
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FlexHB:一种更高效且更灵活的超参数优化框架

FlexHB: a More Efficient and Flexible Framework for Hyperparameter Optimization

Tencent(腾讯);Tsinghua University(清华大学)

Yang Zhang, Haiyang Wu, Yuekui Yang

AI总结:

本文提出FlexHB框架,通过细粒度保真度方法和自适应SH括号分配提升多保真度贝叶斯优化的效率与灵活性,在HPO任务上相比MFES-HB和BOHB分别实现最高6.9倍和11.1倍加速。

摘要:

给定一个超参数优化(HPO)问题,如何设计一种算法来高效地找到最优配置?贝叶斯优化(BO)和多保真度BO方法利用代理模型基于历史评估来采样配置。近期研究通过将BO与HyperBand(HB)相结合获得了更好的性能,HB通过早停机制加速评估。然而,这些方法忽视了在默认HyperBand之上采用合适评估方案的优势,并且BO的能力仍然受到有偏评估结果的制约。在本文中,我们提出了FlexHB,这是一种将多保真度BO推向极限的新方法,同时重新设计了一个结合逐次减半(SH)的早停框架。对FlexHB的全面研究表明:(1)我们的细粒度保真度方法显著提高了搜索最优配置的效率;(2)我们的FlexBand框架(SH括号的自适应分配,以及当前和过去SH过程中配置的全局排序)赋予算法更大的灵活性并改善了任意时间性能。我们的方法在各种HPO任务上实现了卓越的效率并优于其他方法。实验结果表明,FlexHB相较于最先进的MFES-HB和BOHB分别可实现高达6.9倍和11.1倍的加速。

英文摘要:

Given a Hyperparameter Optimization(HPO) problem, how to design an algorithm to find optimal configurations efficiently? Bayesian Optimization(BO) and the multi-fidelity BO methods employ surrogate models to sample configurations based on history evaluations. More recent studies obtain better performance by integrating BO with HyperBand(HB), which accelerates evaluation by early stopping mechanism. However, these methods ignore the advantage of a suitable evaluation scheme over the default HyperBand, and the capability of BO is still constrained by skewed evaluation results. In this paper, we propose FlexHB, a new method pushing multi-fidelity BO to the limit as well as re-designing a framework for early stopping with Successive Halving(SH). Comprehensive study on FlexHB shows that (1) our fine-grained fidelity method considerably enhances the efficiency of searching optimal configurations, (2) our FlexBand framework (self-adaptive allocation of SH brackets, and global ranking of configurations in both current and past SH procedures) grants the algorithm with more flexibility and improves the anytime performance. Our method achieves superior efficiency and outperforms other methods on various HPO tasks. Empirical results demonstrate that FlexHB can achieve up to 6.9X and 11.1X speedups over the state-of-the-art MFES-HB and BOHB respectively.

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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