# Steve P. Verrill

Mathematical Statistician

One Gifford Pinchot Drive

Madison

Wisconsin

United States

53726-2398

Phone: 608-231-9375

Contact Steve P. Verrill

## Research Interests

- X-ray determination of microfibril angle
- Predictor-sort sampling
- Coefficient of variation estimation and testing
- Modeling air-drying of logs
- Repetitive member reliability calculations

## Featured Publications & Products

- Verrill, Steve P.; Kretschmann, David E.; Herian, Victoria L.; Wiemann, Michael; Alden, Harry A. 2010. Concerns about a variance approach to the X-ray diffractometric estimation of microfibril angle in wood.
- Verrill, Steve V.; Johnson, Richard A.; Evans, James W. 2009. Statistical framework for comparing lumber sorting procedures.
- Verrill, Steve; Kretschmann, David E. 2009. Material variability and repetitive member factors for the allowable properties of engineered wood products.
- Wang, Xiping; Bergman, Richard, PhD.; Simpson, William T.; Verrill, Steve; Mace, Terry. 2009. Heat-treatment options and heating times for ash firewood.
- Forkman, Johannes; Verrill, Steve P. 2008. The distribution of McKay's approximation for the coefficient of variation.

## Publications

- Owens, Frank C.; Verrill, Steve P.; Shmulsky, Rubin ; Ross, Robert J. 2020. Distributions of MOE and MOR in eight mill-run lumber populations (four mills at two times).
- Verrill, Steve P.; Owens, Frank C.; Arvanitis, Matthew A.; Kretschmann, David E.; Shmulsky, Rubin ; Ross, Robert J.; Lebow, Patricia . 2020. Estimated probability of breakage of lumber of a fixed grade can vary greatly from mill to mill and time to time.
- Owens, Frank ; Verrill, Steve ; Shmulsky, Rubin ; Ross, Robert J. 2019. Distributions of modulus of elasticity and modulus of rupture in four mill run lumber populations.
- Verrill, Steve P.; Kretschmann, David E. 2019. Simulations of nonparametric analyses of predictor sort (matched specimens) data.
- Verrill, Steve P.; Owens, Frank C.; Kretschmann, David E.; Shmulsky, Rubin ; Brown, Linda S. 2019. Visual and MSR grades of lumber are not 2-parameter Weibulls and why this may matter.
- Verrill, Steve P.; Owens, Frank C.; Kretschmann, David E.; Shmulsky, Rubin ; Brown, Linda S. 2019. Visual and MSR grades of lumber are not two-parameter Weibulls and why it matters (with a discussion of censored data fitting).
- Verrill, Steve P.; Owens, Frank C.; Kretschmann, David E.; Shmulsky, Rubin . 2018. A fit of a mixture of bivariate normals to lumber stiffness strength data.
- Owens, Frank C.; Verrill, Steve P.; Shmulsky, Rubin ; Kretschmann, David E. 2018. Distributions of MOE and MOR in a full lumber population.
- Agarwal, Umesh P.; Ralph, Sally A.; Baez, Carlos; Reiner, Richard S.; Verrill, Steve P. 2017. Effect of sample moisture content on XRD-estimated cellulose crystallinity index and crystallite size.
- Verrill, Steve; Kretschmann, David E. 2017. Reminder about potentially serious problems with a type of blocked ANOVA analysis.
- Verrill, Steve; Kretschmann, David E.; Evans, James W. 2017. Simulations of solid lumber strength property monitoring tests.
- Verrill, Steve P.; Owens, Frank C.; Kretschmann, David E.; Shmulsky, Rubin. 2017. Statistical models for the distribution of modulus of elasticity and modulus of rupture in lumber with implications for reliability calculations.
- Verrill, Steve P.; Kretschmann, David E.; Evans, James W. 2016. Maximum likelihood estimation of the parameters of a bivariate Gaussian-Weibull distribution from machine stress-rated data.
- Wang, Xiping; Ross, Robert J.; Verrill, Steve; Lowell, Eini; Barbour, Jamie. 2015. Acoustic Evaluation of Thinning and Biosolid Fertilization Effects on Wood Quality of a Douglas-fir stand.
- Verrill, Steve P.; Evans, James W.; Kretschmann, David E.; Hatfield, Cherilyn A. 2015. Asymptotically Efficient Estimation of a Bivariate Gaussian-Weibull Distribution and an Introduction to the Associated Pseudo-truncated Weibull.
- Verrill, Steve P.; Evans, James W.; Kretschmann, David E.; Hatfield, Cherilyn A. 2014. Reliability Implications in Wood Systems of a Bivariate Gaussian-Weibull Distribution and the Associated Univariate Pseudo-truncated Weibull.
- Wang, Xiping; Verrill, Steve; Lowell, Eini; Ross, Robert J.; Herian, Vicki L. 2013. Acoustic sorting models for improved log segregation.
- Verrill, Steve P; Evans, James W.; Kretschmann, David E.; Hatfield, Cherilyn A. 2013. An Evaluation of a Proposed Revision of the ASTM D 1990 Grouping Procedure.
- Carll, Charles; Boardman, Charles R.; Verrill, Steve P. 2013. Durability of Hardboard Lap Siding.
- Wang, Q.Q.; Zhu, J.Y.; Reiner, R.S.; Verrill, S.P.; Baxa, U.; McNeil, S.E. 2012. Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CNC.
- Verrill, Steve P.; Evans, James W.; Kretschmann, David E.; Hatfield, Cherilyn A. 2012. Small Sample Properties of Asymptotically Efficient Estimators of the Parameters of a Bivariate Gaussian Weibull Distribution.
- Verrill, S.; Kretschmann, D. 2012. Sources of Confusion in the Determination of ASTM Repetitive Member Factors for the Allowable Properties of Wood Products.
- Verrill, Steve P.; Kretschmann, David E.; Herian, Victoria L.; Wiemann, Michael C.; Alden, Harry A. 2011. Concerns about a variance approach to X-ray diffractometric estimation of microfibril angle in wood.
- Zhu, J.Y.; Verrill, Steve P.; Liu, Hao; Herian, Victoria L.; Pan, Xuejun; Rockwood, Donald L. 2011. On polydispersity of plant biomass recalcitrance and its effects on pretreatment optimization for sugar production.
- Verrill, Steve; Kretschmann, David. 2010. Repetitive member factors for the allowable properties of wood products.
- Verrill, Steve; Kretschmann, David. 2008. Material variability and repetitive member allowable property adjustments in forest products engineering.
- Verrill, Steve; Johnson, Richard A. 2007. Confidence bounds and hypothesis tests for normal distribution coefficients of variation.
- Verrill, Steve P.; Johnson, Richard A. 2007. Confidence bounds and hypothesis tests for normal distribution coefficients of variation.
- Verrill, Steve. 2007. Rate of convergence of k-step Newton estimators to efficient likelihood estimators.
- Verrill, Steve P.; Kretschmann, David E.; Herian, Victoria L. 2006. JMFA2 a graphically interactive Java program that fits microfibril angle X-ray diffraction data.
- Verrill, Steve; Durst, Mark. 2005. The decline and fall of Type II error rates.
- Verrill, Steve P.; Herian, Victoria L.; Spelter, Henry N. 2004. Estimating the board foot to cubic foot ratio.
- Verrill, Steve. 2003. Confidence bounds for normal and lognormal distribution coefficients of variation.
- Simpson, William T.; Wang, Xiping; Verrill, Steve. 2003. Heat sterilization time of ponderosa pine and Douglas-fir boards and square timbers.
- Verrill, Steve; Herian, Victoria L.; Green, David W. 2002. Predictor sort sampling and one-sided confidence bounds on quantiles.
- Liu, Jen Y.; Simpson, William T.; Verrill, Steve P. 2001. An inverse moisture diffusion algorithm for the determination of diffusion coefficient.
- Verrill, Steve. 2001. Rolling your own : linear model hypothesis testing and power calculations via the singular value decomposition.
- Liu, Jen Y.; Simpson, William T.; Verrill, Steve P. 2000. An inverse moisture diffusion algorithm for the determination of diffusion coefficient.

## Research Highlights

Highlight | Title | Year |

FPL-2013-144 | Traditional Grading System Updated for Structural Lumber The Forest Products Laboratory has traditionally provided unbiased information on the properties, characteristics, design, and use of structural ... | 2013 |

*Last updated on :*10/26/2020