各位数院老师和研究生同学：

研究生学术午餐会是在学院领导的大力支持下，由研究生会负责组织的系列学术交流活动。午餐会每次邀请一位同学作

为主讲人，面向全院各专业背景的研究生介绍自己科研方向的基本问题、概念和方法，并汇报近期的研究成果和进展，是研究生展示自我、促进交流的学术平台。

研究生会已经举办了三十七期活动，我们将于2019年3月15日周五举办第三十八期学术午餐会活动，欢迎感兴趣的老师和同学积极报名参加。

报告人简介：梁德才，北京大学数学科学学院2015级博士研究生，师从姚方教授，研究方向为时空统计、函数型数据。曾在2017-2018学年访问美国迈阿密大学Yongtao Guan教授。

Abstract: Severe air pollution affects billions of people around the world, particularly in developing

countries such as China. Effective emission control policies rely primarily on proper assessment of air

pollutants and accurate spatial clustering outcomes. Unfortunately, emission patterns are difficult to

observe as they are highly confounded by many meteorological and geographical factors. The standard

clustering techniques generally fail to exploit the spatiotemporal features of data. We propose a novel

approach for modeling and clustering daily PM2.5 concentrations all over China. Observed concentrations

from monitoring stations are modeled as spatially dependent functional data. We assume the latent

emission processes originate from a functional mixture model with each component as a spatiotemporal

process. Cluster memberships of stations follow a Markov random field model and geographical factors

are also considered. The superior performance of our approach compared to others is demonstrated using

extensive simulation studies. Our method is effective in dividing China and also the Beijing-Tianjin-Hebei

region into several regions based on PM2.5 concentrations, suggesting separate local emission control policies are needed.

报名方式：请有意参加的老师在 2019年3月14日（周四）中午12点前发送邮件至smsxueshu@126.com，我们将回

复邮件和您确认。邮件报名方式仅限于老师，有意参加的同学请点击链接 https://www.wjx.top/jq/35671009.aspx 报名，谢谢！