Xiongtao Dai - Colloquium Speaker

Assistant Professor, Department of Statistics, Iowa State University
Thursday, September 23, 2021 - 3:15pm
Colloquium Title: 
Nonparametric Estimation of Repeated Densities with Heterogeneous Sample Sizes


Functional data analysis concerns a sample of random functions, such as a collection of body growth trajectories. Dimension reduction tools, such as functional principal component analysis, are available to reduce and represent the infinite-dimensional functions. In this work, we are interested in estimating densities as functions, where each density comes from a subpopulation. For example, in the context of epidemiology, the age distributions of patients with different diseases are of central interest, where the disease defines a subpopulation. A key challenge comes from the highly variable sample sizes for different conditions, making the estimation of age profiles difficult for rare conditions. We propose a fully data-driven approach to estimate the densities without the need of specifying the parametric form of the density families. The idea is to map the density functions to a Hilbert space and then apply functional data analytic methods so as to derive low-dimensional approximates. I will show that the proposed methods yield interpretable results and are efficient for modeling electronic medical records and extreme rainfall.

[Joint work with Jiaming Qiu and Zhengyuan Zhu]


Topic: Colloquia: Department of Statistics and Actuarial Science, The University of Iowa

Time: September 23, 2021 03:15 PM Central Time (US and Canada)

Join Zoom Meeting


Meeting ID: 989 2869 3758

One tap mobile

+13126266799,,98928693758# US (Chicago)

+16468769923,,98928693758# US (New York)

Dial by your location

        +1 312 626 6799 US (Chicago)

        +1 646 876 9923 US (New York)

        +1 301 715 8592 US (Washington DC)

        +1 346 248 7799 US (Houston)

        +1 669 900 6833 US (San Jose)

        +1 253 215 8782 US (Tacoma)

Meeting ID: 989 2869 3758

Find your local number: https://uiowa.zoom.us/u/adodl1V2PF

Join by SIP


Join by H.323 (US West) (US East) (India Mumbai) (India Hyderabad) (Amsterdam Netherlands) (Germany) (Australia Sydney) (Australia Melbourne) (Brazil) (Canada Toronto) (Canada Vancouver) (Japan Tokyo) (Japan Osaka)

Meeting ID: 989 2869 3758