To validate the contribution of each component, we exclude one of key components from our model as follows: (i) -NoDilated with conventional convolutions instead, (ii) -NoMulti with no multi-level memory (iii) -NoNGTU with existing gated linear units (Gehring et al., 2017).
-NoDilated quantifies the improvement by the dilated convolution, -NoMulti assesses the effect of multi-level memory, and -NoNGTU validates the normalized gated tanh unit.