Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America. xing@ams.sunysb.edu|Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America. xing@ams.sunysb.edu|Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America. xing@ams.sunysb.edu|Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America. xing@ams.sunysb.edu