Authors:

(1) Liang Wang, Microsoft Corporation, and Correspondence to ([email protected]);

(2) Nan Yang, Microsoft Corporation, and correspondence to ([email protected]);

(3) Xiaolong Huang, Microsoft Corporation;

(4) Linjun Yang, Microsoft Corporation;

(5) Rangan Majumder, Microsoft Corporation;

(6) Furu Wei, Microsoft Corporation and Correspondence to ([email protected]).