ELiSH

The Exponential Linear Squashing Activation Function, or ELiSH, is an activation function used for neural networks. It shares common properties with Swish, being made up of an ELU and a Sigmoid:

$f\left(x\right) = \frac{x}{1+e^{-x}} \text{ if } x \geq 0$ $f\left(x\right) = \frac{e^{x} - 1}{1+e^{-x}} \text{ if } x < 0$

The Sigmoid part of ELiSH improves information flow, while the linear parts solve issues of vanishing gradients.