As illustrated in Figure 2, given a sentence A = {w 1 , w 2 , .., w n } written by a user in Tree Hole, where n is the length of a sentence, the aim of suicidal expression classification is to classify whether this sentence contains expression about suicidal ideation or not.
we feed the word embeddings X into the LSTM as following: (1) where h t−1 , h t represent the hidden states at time t − 1 and t, H a = {h 1 , h 2 , ..., h n } ∈ R n×de is sentence representation of A, [k 1 , k 2 ] stand for the possibility of whether the sentence contains expression about suicidal ideation or not.