I have extensive interests and expertise in Statistics and Mathematics. My main research area is simultaneous inference for high-dimensional dependent data and for high-dimensional discrete data. I have also worked on mathematical problems on Ito diffusion processes, time series models, probability, and complex analysis.

**Please click on research document for some details (less than given in the preprints but more than given
by the abstracts) on some projects listed below.**

**Estimating the proportion of true null hypotheses or false null hypotheses****Under strong covariance dependence**Xiongzhi Chen and R.W. Doerge (2014):

*A consistent estimator of the proportion of nonzero Normal means under certain strong covariance dependence.*Preprint.

**Under independence**Xiongzhi Chen and John D. Storey (2014):

*Estimating the proportion of true null hypotheses via goodness of fit.*Mansucript.

**False discoverate rate (FDR) procedures****Under independence but mainly for discrete and heterogeneous null distributions**Xiongzhi Chen and R.W. Doerge (2015):

*A weighted FDR procedure under discrete and heterogeneous null distributions.*Preprint; R package ‘‘fdrDiscreteNull’’ on CRAN.Xiongzhi Chen and R.W. Doerge (2014):

*Generalized estimators for multiple testing: proportion of true nulls and false discovery rate.*Preprint; R package ‘‘fdrDiscreteNull’’ on CRAN.

**Under independence but for continuous and homogeneous null distributions**Xiongzhi Chen, David G. Robinson and John D. Storey (2014):

*Functional false discovery rate with application to genomics.*Manuscript.

**Simultaneous estimation and inference****Without a linear trend but under exogeneity**Xiongzhi Chen and John D. Storey (2014):

*Consistent estimation of low-dimensional latent structure in high-dimensional data.*Preprint.

**With a linear trend but under exogeneity**John D. Storey, Keyur H. Desai and Xiongzhi Chen (2013):

*Empirical Bayes inference of dependent high-dimensional data.*Manuscript.Xiongzhi Chen and John D. Storey (2014):

*Nonparametric empirical Bayes estimation of the surrogate variable analysis model.*Manuscript.

**With a linear trend but under endogeneity**Xiongzhi Chen, Wei Hao and John D. Storey:

*Regression herding.*In preparation.

**Multiple testing from the perspective of stochastic processes**

**Theory on one-parameter natural exponential families (NEFs)**Xiongzhi Chen (2016):

*Resolution of a conjecture on variance functions for one-parameter natural exponential family.***Statistics and Probability Letters**.Xiongzhi Chen (2015):

*Reduction functions for the variance function of one-parameter natural exponential family.*Preprint.

**Time series models**Xiongzhi Chen (2015): Explicit solutions to a vector time series model and its induced model for business cycles. Preprint.

**Diffusion processes: modelling and estimation****Geometric probability**Xiongzhi Chen (2015+):

*On Samuel Karlin's problem of geometric probability and a variant.*In prepartion.

**Neural networks**Xiongzhi Chen and Changlin Cai (2006):

*A new architecture for multilayer perceptrons as function approximators.*Natural Science Edition, Journal of Sichuan University, Vol. 2.Changlin Cai, Zhongzhi Shi, Xiongzhi Chen (2006):

*The Fisher information matrix on neural manifolds of multilayer perceptrons.*Natural Science Edition, Journal of Sichuan University, Accepted. pdf.