Question 2
How does unsupervised layerwise pretraining help in alleviating the vanishing gradient problem?
It allows the network to learn a better representation of the data in each layer, which leads to better- initialized weights for subsequent supervised training.
It adds skip connections to the network, which are then removed before the supervised training.
It replaces the sigmoid functions with ReLU functions during the pretraining phase.
It regularizes the network’s weights, making them smaller and less likely to cause the gradients to explode.