RMS Pooling
Root-of-Mean-Squared Pooling
**RMS Pooling** is a pooling operation that calculates the square mean root for patches of a feature map, and uses it to create a downsampled (pooled) feature map.  It is usually used after a convolutional layer.

$$ z_{j} = \sqrt{\frac{1}{M}\sum^{M}_{i=1}u{ij}^{2}} $$