title: The concept of straight through estimator (STE)
body: <p>I have seen straight through estimator (STE) in many Neural Network related papers e.g. <a href="http://arxiv.org/pdf/1308.3432v1.pdf" rel="noreferrer">this</a> and <a href="https://arxiv.org/pdf/1606.06160.pdf" rel="noreferrer">this</a>. But I cannot understand the concept.  I wonder if anyone could explain STE or refer me to a simple resource? </p>