For the sentence-level Transformer, in order to make the positional encoding insensitive to the lengths of the phraselevel fragment, we set: Multi-head Attention: We modify the selfattention mechanism in the encoders and decoders by setting a different receptive field for each granularity, as illustrated in Figure 2.
the m-encoder and m-decoder are composed of multiple independent encoders and decoders, with each corresponding to a specific level of granularity.