title: Is there any difference between TrainingHelper and GreedyEmbeddingHelper in Tensorflow r.1.1(predict result different)?
body: <p>I'm a beginner in tensorflow.
  I want to study tensorflow by using <a href="https://github.com/j-min/tf_tutorial_plus/blob/master/RNN_seq2seq/contrib_seq2seq/04_AttentionWrapper.ipynb" rel="nofollow noreferrer">this tutorial</a>.</p>
  
  <p>After reading this tutorial, I want to run this code by using my data(Korea title for tokenizing)
  In training model(use <code>TrainingHelper</code>), the prediction results seems to be OK.
  But In inference model(use <code>GreedyEmbeddingHelper</code>), the prediction results are really bad(even though using train data). It looks like first epoch's training model prediction.
  Is there any difference <code>TrainingHelper</code> and <code>GreedyEmbeddingHelper</code>?</p>
  
  <p>I think the difference between tutorial and my code is just hyper-parameter.</p>