Characterizing Convolutional Neural Network Early Learning and Accelerating Non-Adaptive, First-Order Methods with Localized Lagrangian Restricted Memory Level Bundling
[Technical Report, Doctoral Thesis]
AIR FORCE INSTITUTE OF TECHNOLOGY WRIGHT-PATTERSON AFB OH
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This dissertation studies the underlying optimization problem encountered during the early-learning stages of convolutional neural networks and introduces a training algorithm competitive with existing state-of-the-art methods. A Design of Experiments method is introduced to systematically measure empirical second-order Lipschitz upper bound and region size estimates for local regions of convolutional neural network loss surfaces experienced during the early-learning stages. This method demonstrates that architecture choices can significantly impact the local loss surfaces traversed during training. A Design of Experiments method is used to study the effects convolutional neural network architecture hyper parameters have on different optimization routines abilities to effectively train and find solutions that generalize well during early learning, demonstrating a relationship between routine selection and network architecture. A method to accelerate the early learning of non-adaptive, first-order optimization routines is developed. The method decomposes the neural network training problem into a series of unconstrained optimization problems within localized trailing Euclidean trust regions and allows non-adaptive methods to exhibit training results which are competitive with adaptive methods.
- Computer Systems