论文标题

通过热启动政策在数值黑框优化算法之间切换

Switching between Numerical Black-box Optimization Algorithms with Warm-starting Policies

论文作者

Schröder, Dominik, Vermetten, Diederick, Wang, Hao, Doerr, Carola, Bäck, Thomas

论文摘要

当通过黑框方法解决优化问题时,算法在优化过程中收集了有关问题实例的宝贵信息。此信息用于调整对新解决方案候选者采样的分布。实际上,进化计算的关键目标是确定收集和利用实例知识的最有效方法。但是,虽然大量工作致力于调整即时黑盒优化算法的超参数或交换其某些模块化组件,但我们几乎不知道如何有效地在不同的黑色盒子优化算法之间切换。 在这项工作中,我们基于对Vermetten等人的最新研究。 [GECCO 2020],他提出了一种数据驱动的方法,以研究数值黑盒优化的算法对之间有希望的开关。我们使用五种算法的投资组合复制了他们的方法,并研究在执行最有前途的开关时是否实现了预测的性能提高。我们的结果表明,通过两种算法之间的单个切换,我们在120个考虑的问题实例中,在48个算法的五种算法中,我们比最佳的静态选择优于最佳静态选择,这24个BBOB在五个不同的维度中函数。我们还表明,对于在BFG和CMA-E之间进行切换,对参数的适当温暖启动对于实现高性能增长至关重要。最后,通过敏感性分析,我们发现每次运行的实际性能增长在很大程度上受开关点的影响,在某些情况下,开关点产生的最佳实际性能与从理论增益计算出的开关不同。

When solving optimization problems with black-box approaches, the algorithms gather valuable information about the problem instance during the optimization process. This information is used to adjust the distributions from which new solution candidates are sampled. In fact, a key objective in evolutionary computation is to identify the most effective ways to collect and exploit instance knowledge. However, while considerable work is devoted to adjusting hyper-parameters of black-box optimization algorithms on the fly or exchanging some of its modular components, we barely know how to effectively switch between different black-box optimization algorithms. In this work, we build on the recent study of Vermetten et al. [GECCO 2020], who presented a data-driven approach to investigate promising switches between pairs of algorithms for numerical black-box optimization. We replicate their approach with a portfolio of five algorithms and investigate whether the predicted performance gains are realized when executing the most promising switches. Our results suggest that with a single switch between two algorithms, we outperform the best static choice among the five algorithms on 48 out of the 120 considered problem instances, the 24 BBOB functions in five different dimensions. We also show that for switching between BFGS and CMA-ES, a proper warm-starting of the parameters is crucial to realize high-performance gains. Lastly, with a sensitivity analysis, we find the actual performance gain per run is largely affected by the switching point, and in some cases, the switching point yielding the best actual performance differs from the one computed from the theoretical gain.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源