报告题目：Dimensionality determination: a thresholding double ridge ratio approach

时间：2016年9月21（星期三）14：30-15：30

地点：学院南路校区，主教103

报告人：朱力行教授，香港浸会大学

摘要：

Analysis of networks and in particular discovering communities within networks has been a focus of recent work in several fields, with applications ranging from citation and friendship networks to food webs and gene regulatory networks. Most of the existing community detection methods focus on partitioning the network into cohesive communities, with the expectation of many links between the members of the same community and few links between different communities. However, many real-world networks contain, in addition to communities, a number of sparsely connected nodes that are best classified as "background". To address this problem, we propose a new criterion for community extraction, which aims to separate tightly linked communities from a sparsely connected background, extracting one community at a time. The new criterion is shown to perform well in simulation studies and on several real networks. We also establish asymptotic consistency of the proposed method under the block model assumption. This is joint work with Yunpeng Zhao and Elizaveta Levina.

报告人简介：

朱力行，1990年在中国科学院获得理学博士，1993年在中国科学院应用数学所评为研究员、博士导师。1998年去香港大学统计与精算系工作，2005年到香港浸会大学数学系工作，现在是统计学讲座教授。曾经担任两届系主任。1998年获得德国洪堡研究奖，是自然科学，工程，医学，经济和管理 领域 中，大陆，香港，台湾，澳门第一位获 奖者，此后的11位获奖者有5位中科院院士，4位台湾中研院院士。迄今为止，还是亚洲统计学界唯一获奖 者。国际华人统计学界第一位获奖者。2003年和2007年 分别当选为 美国数理统计研究院会士,和美国统计协会会士。2013年获得中国国家自然科学奖二等奖（独立获奖人）。1997年获得杰出青年基金 资助，1999年入选中科院百人计划。国 家人事部九五--九六“百千万人才工程”入选者。