Auto-encoder -Pre-training DNN Greedy Layer-wise Pre-training again output 10 500 1000 784 合 Wr 1000 1000 合 1w1 Input 784 Input 784Auto-encoder – Pre-training DNN • Greedy Layer-wise Pre-training again Target 784 1000 1000 10 Input output Input 784 1000 784 W1 𝑥 𝑥 ො 500 W1 ’