论文标题
使用贝叶斯进化算法优化的时间效率
Time Efficiency in Optimization with a Bayesian-Evolutionary Algorithm
论文作者
论文摘要
并非所有生成测试搜索算法都是相等的。贝叶斯优化(BO)投入了大量计算时间来生成候选解决方案,该解决方案可以在所有以前的数据中最好地平衡预测值和不确定性,随着进行的评估数量的增长,越来越多的时间会增加。另一方面,进化算法(EA)依赖于通常不取决于所有先前数据并且可以在恒定时间内完成的搜索启发式方法。 BO和EA社区通常都会评估其性能,这是评估次数的函数。但是,一旦我们开始比较这些类别算法的效率,这是不公平的,因为生成候选解决方案的间接时间大不相同。我们建议衡量生成测试搜索算法的效率作为所花费的计算时间的目标值的预期增益。我们观察到,在进行许多函数评估后,要使用的算法的偏好可能会改变。因此,我们提出了一种新的算法,即贝叶斯优化和一种进化算法的组合,简称为BE,从BO开始,然后将知识转移到EA,然后运行EA。我们将BEA与BO和EA进行比较。结果表明,BEA在时间效率方面都胜过BO和EA,并最终导致许多本地Optima在众所周知的基准目标函数上表现更好。此外,我们在机器人学习问题的九个测试案例上测试了三种算法,在这里,我们再次发现BEA胜过其他算法。
Not all generate-and-test search algorithms are created equal. Bayesian Optimization (BO) invests a lot of computation time to generate the candidate solution that best balances the predicted value and the uncertainty given all previous data, taking increasingly more time as the number of evaluations performed grows. Evolutionary Algorithms (EA) on the other hand rely on search heuristics that typically do not depend on all previous data and can be done in constant time. Both the BO and EA community typically assess their performance as a function of the number of evaluations. However, this is unfair once we start to compare the efficiency of these classes of algorithms, as the overhead times to generate candidate solutions are significantly different. We suggest to measure the efficiency of generate-and-test search algorithms as the expected gain in the objective value per unit of computation time spent. We observe that the preference of an algorithm to be used can change after a number of function evaluations. We therefore propose a new algorithm, a combination of Bayesian optimization and an Evolutionary Algorithm, BEA for short, that starts with BO, then transfers knowledge to an EA, and subsequently runs the EA. We compare the BEA with BO and the EA. The results show that BEA outperforms both BO and the EA in terms of time efficiency, and ultimately leads to better performance on well-known benchmark objective functions with many local optima. Moreover, we test the three algorithms on nine test cases of robot learning problems and here again we find that BEA outperforms the other algorithms.