Created by: L-lei

场景文字识别attention_model存在收敛问题，这个模型文档上说在1.5上面存在，实则在1.5，1.4，1.6的版本上都存在收敛问题。在aistudio平台上面1.4版本日志，1.5和1.6是开始训练就有。 Time: 1572957349.9853573; Iter[16000]; Avg loss: 0.217; Avg seq err: 0.016 kpis train_cost 0.216565 kpis train_acc 0.984461

Time: 1572957645.2934074; Iter[16000]; Test seq error: 0.0085.

kpis test_acc 0.991500

Time: 1572958057.7032695; Iter[17000]; Avg loss: 0.202; Avg seq err: 0.014 kpis train_cost 0.202122 kpis train_acc 0.985672

Time: 1572958362.20513; Iter[17000]; Test seq error: 0.0081.

kpis test_acc 0.991900

Time: 1572958767.431849; Iter[18000]; Avg loss: nan; Avg seq err: 0.771 kpis train_cost nan kpis train_acc 0.228555

Time: 1572959085.0010662; Iter[18000]; Test seq error: 1.0.

kpis test_acc 0.000000

Time: 1572959485.3717132; Iter[19000]; Avg loss: nan; Avg seq err: 1.000 kpis train_cost nan kpis train_acc 0.000000`