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Does ReLU avoid vanishing gradient?
ReLU has gradient 1 when input > 0, and zero otherwise. Thus, multiplying a bunch of ReLU derivatives together in the backprop equations has the nice property of being either 1 or 0. There is no “vanishing” or “diminishing” of the gradient.
Which activation function is used to avoid the vanishing gradient?
ReLU
Other activation functions Rectifiers such as ReLU suffer less from the vanishing gradient problem, because they only saturate in one direction.
How does ReLu solve vanishing gradient problem?
This involves first calculating the prediction error made by the model and using the error to estimate a gradient used to update each weight in the network so that less error is made next time. This error gradient is propagated backward through the network from the output layer to the input layer.
Why is the vanishing gradient problem solved using ReLU activation function?
The ReLU activation solves the problem of vanishing gradient that is due to sigmoid-like non-linearities (the gradient vanishes because of the flat regions of the sigmoid). The other kind of “vanishing” gradient seems to be related to the depth of the network ( e.g. see this for example).
Which is the best description of the vanishing gradient problem?
It describes the situation where a deep multilayer feed-forward network or a recurrent neural network is unable to propagate useful gradient information from the output end of the model back to the layers near the input end of the model.
What is the problem with vanishing gradients in FFN?
This is referred to as the “ exploding gradient ” problem. The term vanishing gradient refers to the fact that in a feedforward network (FFN) the backpropagated error signal typically decreases (or increases) exponentially as a function of the distance from the final layer.
Vanishing gradients is a particular problem with recurrent neural networks as the update of the network involves unrolling the network for each input time step, in effect creating a very deep network that requires weight updates. A modest recurrent neural network may have 200-to-400 input time steps, resulting conceptually in a very deep network.