Introduction and general discussion

• Nuno Castro (LIP, DF/ECUM)
• Guilherme Milhano (LIP)

Room: Zoom video-conference only Please bring up any relevant points you might have

Journal Club: tuning of hyperparameters in neural networks

• Giles Strong (LIP)

Room: Zoom video-conference only discussion of https://arxiv.org/abs/1803.09820 A disciplined approach to neural network hyper-parameters: Part 1 -- learning rate, batch size, momentum, and weight decay by Leslie N. Smith Abstract: Although deep learning has produced dazzling successes for applications of image, speech, and video processing in the past few years, most trainings are with suboptimal hyper-parameters, requiring unnecessarily long training times. Setting the hyper-parameters remains a black art that requires years of experience to acquire. This report proposes several efficient ways to set the hyper-parameters that significantly reduce training time and improves performance. Specifically, this report shows how to examine the training validation/test loss function for subtle clues of underfitting and overfitting and suggests guidelines for moving toward the optimal balance point. Then it discusses how to increase/decrease the learning rate/momentum to speed up training. Our experiments show that it is crucial to balance every manner of regularization for each dataset and architecture. Weight decay is used as a sample regularizer to show how its optimal value is tightly coupled with the learning rates and momentums. Files to help replicate the results reported here are available.