报告题目∶Some Convex Hull Presentations and Applications

报告人：夏勇 博士
        北京航空航天大学 数学与应用数学系

报告时间∶2月26日(星期二)下午∶15:30-16:30

报告地点∶蓝白楼311, 中国科学院数学与系统科学研究院

报告摘要：In this talk, we first present a nice mathematical description of
the convex hull of
{Y=XBX^T: X^TX=XX^T=I_n } for given symmetric real matrix B. Then the
convex hull of the general set
{Y=XBX^T: X^TX=I_k} (k<=n) is obtained, which extends the convex hull
presentation of the set of projection
matrices of rank k. We use the convex hull presentation to solve a
kind of quadratic programmings arised from
quadratic assignment problems and multidimensional total least squares
problems. As a result, the well-known result
on the sum of the largest k eigenvalues of a symmetric matrix is extended.