* Accepted as a conference paper in ICASSP 2019. But this copy is an
extended version of the submitted manuscript. With more theoretical analysis
and human evaluation Access Paper or Ask Questions
* In The 27th ACM International Conference on Information and Knowledge
Management (CIKM 18), October 22-26, 2018, Torino, Italy. ACM, New York, NY,
USA, 9 pages Access Paper or Ask Questions