1 research outputs found
Genetic-algorithm-optimized neural networks for gravitational wave classification
Gravitational-wave detection strategies are based on a signal analysis
technique known as matched filtering. Despite the success of matched filtering,
due to its computational cost, there has been recent interest in developing
deep convolutional neural networks (CNNs) for signal detection. Designing these
networks remains a challenge as most procedures adopt a trial and error
strategy to set the hyperparameter values. We propose a new method for
hyperparameter optimization based on genetic algorithms (GAs). We compare six
different GA variants and explore different choices for the GA-optimized
fitness score. We show that the GA can discover high-quality architectures when
the initial hyperparameter seed values are far from a good solution as well as
refining already good networks. For example, when starting from the
architecture proposed by George and Huerta, the network optimized over the
20-dimensional hyperparameter space has 78% fewer trainable parameters while
obtaining an 11% increase in accuracy for our test problem. Using genetic
algorithm optimization to refine an existing network should be especially
useful if the problem context (e.g. statistical properties of the noise, signal
model, etc) changes and one needs to rebuild a network. In all of our
experiments, we find the GA discovers significantly less complicated networks
as compared to the seed network, suggesting it can be used to prune wasteful
network structures. While we have restricted our attention to CNN classifiers,
our GA hyperparameter optimization strategy can be applied within other machine
learning settings.Comment: 25 pages, 8 figures, and 2 tables; Version 2 includes an expanded
discussion of our hyperparameter optimization mode