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Technology

Learning Rate Schedules and Warmup

A learning rate schedule changes the value of η over the course of training instead of keeping it fixed. It starts with a warmup that raises η from near zero, holds a peak and then lowers it with step, exponential or cosine decay so the network converges faster and with far less oscillation.

Technology

AdaGrad and RMSProp: Adaptive Learning Rates

AdaGrad and RMSProp are optimisers that give every weight its own learning rate. AdaGrad accumulates the square of all past gradients and divides the step by its root, which slowly fades it out. RMSProp fixes this with a moving average that forgets the past using a decay factor of about 0.9.