全校师生：

我校定于2020年11月21日举办研究生灵犀学术殿堂——韩德仁教授报告会，现将有关事项通知如下：

1.报告会简介

报告人：韩德仁教授

时间：2020年11月21日（星期六）11:00

地点：友谊校区国际会议中心第一会议室

报告题目：Approximate first-order primal-dual algorithms for the saddle point problems

内容简介：Approximate first-order primal-dual algorithms for the saddle point problems}{We propose two approximate versions of the first-order primal-dual algorithm (PDA) for solving a class of convex-concave saddle point problems. The introduced approximate criteria are easy to implement in the sense that they only involve the subgradient of a certain function at the current iterate. The first approximate PDA solves both subproblems inexactly and adopts absolute error criteria, which are based on nonnegative summable sequences. The second approximate PDA, assuming that one of the PDA subproblems can be solved exactly, solves the other subproblem approximately and adopts a relative error criterion. The relative error criterion only involves a single parameter ranging in [0; 1), which makes the method more applicable. For both versions, we establish the global convergence and O(1=N) rate of convergence measured by the iteration complexity, where N counts the number of iteration. Under further assumptions that partial of the underlying functions and the whole underlying functions are strongly convex, we show the accelerated O(1=N 2) and linear rate of convergence, respectively, for the inexact PDA with absolute error criteria. We then prove that these inexact criteria can also be extended to solve a class of more general problems. Finally, we perform some numerical experiments on sparse recovery and image processing problems, and the results demonstrate the feasibility and superiority of the proposed methods.

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党委学生工作部

数学与统计学院

2020年11月19日

报告人简介

韩德仁教授，北京航空航天大学数学与系统科学学院院长，博士生导师，国家杰出青年基金获得者，入选江苏省333高层次人才培养工程、江苏省“青蓝工程”中青年学术带头人。2002年毕业于南京大学获计算数学博士学位。2002-2004年在新加坡国立大学从事博士后研究。2002-2017年任职于南京师范大学数学学院，2017年入职北京航空航天大学并担任数学与系统科学学院院长。曾获中国运筹学会青年运筹奖和江苏省科学技术二等奖；发表学术论文80余篇,其中SCI收录70余篇、运筹学国际顶尖杂志20余篇；担任中国运筹学会理事、数学规划分会常务理事,《计算数学》、《Journal of the Operations Research Society of China》编委。