Statistics Seminar (2019-11)

Topic: Feedback limitations in nonlinear discrete-time control

Speaker: Chanying Li, the Key Laboratory of Systems and Control, CAS

Time: Thursday, May 23, 14:00-15:00

Place: Room 217, Guanghua Building 2

Abstract:

An interesting phenomenon occurs when one attempts to control systems with output nonlinearity growing faster than linearity, where similarities between the continuous- and discrete-time cases of adaptive control no longer exist. It is generally known that a large class of continuous-time nonlinear parametric systems, regardless of how fast the growth rate is, can be globally stabilized by the nonlinear damping or back-stepping approach in adaptive control. However, fundamental difficulties arise for the discrete-time case. These difficulties are caused by the inherent limitations of the feedback principle in dealing with uncertainties, which means that systems with uncertainties beyond the feedback capability cannot be stabilized by any discrete-time feedback control law. This talk is aimed at the identification and control of discrete-time nonlinear parametric systems and trying to give an appropriate characterization of feedback limitations.

Introduction:

Chanying Li received the B.S. degree in Mathematics from Sichuan University in 2002, and the M.S. and Ph.D. degrees in control theory from Academy of Mathematics and Systems Science, Chinese Academy of Sciences, in 2005 and 2008, respectively. She was a Postdoctoral Fellow at the Wayne State University from 2008 to 2009, and the University of Hong Kong from 2009 to 2011. She joined the Institute of Systems Science at Chinese Academy of Sciences in 2011, and is currently a professor at the Key Laboratory of Systems and Control, Chinese Academy of Sciences. Her current research interests include the maximum capability of feedback, adaptive nonlinear control, system identification and stochastic control systems.

Topic:One-Child Policy, Marriage Distortion and Welfare Loss

Speaker:Yi Zhou, Peking University

Time:Thursday, May 23, 15:00-16:00

Place:Room 217, Guanghua Building 2

Abstract:

This paper studies the marriage distortion and associated welfare loss caused by the One-Child Policy (OCP) in China. Using the variation in the ethnicity-specific assigned birth quotas and different fertility penalties across provinces over time, we first show that the OCP induced a significantly higher unmarried rate and more interethnic marriages. Using the sufficient statistics approach, we derive a formula for the social welfare loss caused by the OCP-induced lower fertility and marriage distortion that depends only on the estimated reduced-form elasticities. Our estimates imply that the welfare losses caused by lowered fertility and by marriage distortion are 2.6 and 1.1 percent of annual household income, respectively.

Introduction:

Yi Zhou is an assistant professor in Center for Social Research at Peking University. He holds a PhD in Demography from University of California at Berkeley, a MA in Economics and a BA in Accounting from Peking University. His research interests include economic demography, organizational demography and population aging. His research has appeared in journals such as Population and Development Review, Social Science & Medicine, Auditing: A Journal of Practice & Theory and Chinese Sociological Review. He received 18th National An-Zijie International Trade Outstanding Research Award in 2014.

Your participation is warmly welcomed!