Table 5.

Comparison of training time between CLSTM (contextual long short-term memory networks [LSTMs] with conditional random fields [CRF])and comparative methods for the NCBI, GM, and CDR corpora

Training time (Hours)		NCBI	GM	CDR
BiLSTM		4.08	10.77	4.39
BiLSTM-CRF		4.70	12.56	5.23
GRAM-CNN		11.27	34.08	12.64
BERT		1.01	10.04	3.72
CLSTM	word level	5.54	14.57	5.98
	character level	4.84	13.30	5.64
	word+char levels	5.84	14.73	5.91
	Average	5.41	14.20	5.84