Professor and Chair of Statistics

Ph.D. in Statistics, University of North Carolina at Chapel Hill, 1985

Website

Research Interests

• Applied and computational statistics
• Biostatistics
• Semiparametric statistical methods
• Multivariate data analysis
• Ordinal and censored data

Honors and Appointments

• Fellow, Institute of Mathematical Statistics (1998)
• Fellow, American Statistical Association (2000)
• Associate Editor, J. Amer. Statistical Society (1996-1999)
• Associate Editor, Biometrics (2000-2006)
• Director, Illinois Statistics Office (1995-2000)
• Chair, Department of Statistics (2000-)

Selected Publications

• Yang Y, Simpson DG. (2012). Conditional decomposition diagnostics for regression analysis of zero-inflated and left-censored data. Statistical Methods in Medical Research, Vol.21, p.379-392.
• Smith BW, Simpson DG, Sarwate S, Miller RJ, Blue JP, Haak A, O'Brien WD, Erdman JW (2012). Contrast ultrasound imaging of the aorta alters vascular morphology and circulating von Willebrand Factor in hypercholesterolemic rabbits. Journal of Ultrasound in Medicine, 31, 711-720.
• Wirtzfeld LA, Ghoshal G, Hafez ZT, Nam K, Labyed Y, Anderson JJ, Herd M-T, Haak A, He Z, Miller RJ, Sarwate S, Simpson DG, Zagzebski JA, Bigelow TA, Oelze ML, Hall TJ, O'Brien WD. (2010). Cross-imaging platform comparison of ultrasonic backscatter coefficient measurements of live rat tumors. Journal of Ultrasound in Medicine, Vol. 29, pp. 1117-1123.
• Yang Y, Simpson DG (2010). Unified computational methods for regression analysis of zero-inflated and bound-inflated data. Computational Statistics and Data Analysis, Vol. 54, pp.1525-1534.
• Xie M, Simpson DG, Carroll RJ (2008). Semiparametric analysis of heterogeneous data using varying-scale generalized linear models. Journal of the American Statistical Association, Vol. 103, pp.650-660.