Improving exploration strategies in large dimensions and rate of convergence of global random search algorithms

Abstract

We consider global optimization problems, where the feasible region $\X$ is a compact subset of $\mathbb{R}^d$ with $d \geq 10$. For these problems, we demonstrate the following. First: the actual convergence of global random search algorithms is much slower than that given by the classical estimates, based on the asymptotic properties of random points. Second: the usually recommended space exploration schemes are inefficient in the non-asymptotic regime. Specifically, (a) uniform sampling on entire~$\X$ is much less efficient than uniform sampling on a suitable subset of $\X$, and (b) the effect of replacement of random points by low-discrepancy sequences is negligible.