2015年最新的深度学习综述文献，对目前深度学习的发展和主要问题进行了深入全面的分析，对初涉深度学习和从事相关研究的同学有较大帮助。-2015 new depth study literature review, the main problem of the current development and depth of learning in-depth and comprehensive analysis of the depth of learning and new entrants