Ecological Neural Architecture Search
Benjamin David Winter, William J. Teahan
TL;DR
ENAS tackles the NAS hyperparameter tuning problem by evolving evolutionary parameters alongside architecture traits, encoding four ecological genes into each candidate's genome. It dynamically adjusts population size, mutation rate, cloning rate, and max generations based on fitness, enabling self-regulation and reducing wasted compute. Across four binary classification datasets, ENAS achieves higher average fitness across all datasets and higher maximum fitness in 3 of 4 datasets, with a time reduction of $18.3\%$ and dataset-specific architectural preferences emerging. The approach promises automated hyperparameter control and efficiency gains, with potential extensions to more complex architectures and multi-objective optimization.
Abstract
When employing an evolutionary algorithm to optimize a neural networks architecture, developers face the added challenge of tuning the evolutionary algorithm's own hyperparameters - population size, mutation rate, cloning rate, and number of generations. This paper introduces Neuvo Ecological Neural Architecture Search (ENAS), a novel method that incorporates these evolutionary parameters directly into the candidate solutions' phenotypes, allowing them to evolve dynamically alongside architecture specifications. Experimental results across four binary classification datasets demonstrate that ENAS not only eliminates manual tuning of evolutionary parameters but also outperforms competitor NAS methodologies in convergence speed (reducing computational time by 18.3%) and accuracy (improving classification performance in 3 out of 4 datasets). By enabling "greedy individuals" to optimize resource allocation based on fitness, ENAS provides an efficient, self-regulating approach to neural architecture search.
