“…The revolution took place in 2010 after the close collaboration between academic and industrial research groups, including the University of Toronto, Microsoft, and IBM [1,4,5]. This research found that very significant performance improvements can be accomplished with the NN-based hybrid approach, with a few novel techniques and design choices: (1) extending NNs to DNNs, i.e., involving a large number of hidden layers (usually 4 to 8); (2) employing appropriate initialization methods, e.g., pre-training with restricted Boltzmann machines (RBMs); and (3) using fine-grained NN targets, e.g., context-dependent states.…”