Update tutorials for pytorch 0.4.0

Author: yunjey

tutorials/03-advanced/image_captioning/README.md

@@ -7,7 +7,7 @@ The goal of image captioning is to convert a given input image into a natural la
 For the encoder part, the pretrained CNN extracts the feature vector from a given input image. The feature vector is linearly transformed to have the same dimension as the input dimension of the LSTM network. For the decoder part, source and target texts are predefined. For example, if the image description is **"Giraffes standing next to each other"**, the source sequence is a list containing **['\<start\>', 'Giraffes', 'standing', 'next', 'to', 'each', 'other']** and the target sequence is a list containing **['Giraffes', 'standing', 'next', 'to', 'each', 'other', '\<end\>']**. Using these source and target sequences and the feature vector, the LSTM decoder is trained as a language model conditioned on the feature vector.
 
 #### Test phase
-In the test phase, the encoder part is almost same as the training phase. The only difference is that batchnorm layer uses moving average and variance instead of mini-batch statistics. This can be easily implemented using [encoder.eval()](https://github.com/yunjey/pytorch-tutorial/blob/master/tutorials/03-advanced/image_captioning/sample.py#L43). For the decoder part, there is a significant difference between the training phase and the test phase. In the test phase, the LSTM decoder can't see the image description. To deal with this problem, the LSTM decoder feeds back the previosly generated word to the next input. This can be implemented using a [for-loop](https://github.com/yunjey/pytorch-tutorial/blob/master/tutorials/03-advanced/image_captioning/model.py#L48).
+In the test phase, the encoder part is almost same as the training phase. The only difference is that batchnorm layer uses moving average and variance instead of mini-batch statistics. This can be easily implemented using [encoder.eval()](https://github.com/yunjey/pytorch-tutorial/blob/master/tutorials/03-advanced/image_captioning/sample.py#L37). For the decoder part, there is a significant difference between the training phase and the test phase. In the test phase, the LSTM decoder can't see the image description. To deal with this problem, the LSTM decoder feeds back the previosly generated word to the next input. This can be implemented using a [for-loop](https://github.com/yunjey/pytorch-tutorial/blob/master/tutorials/03-advanced/image_captioning/model.py#L48).