419 – Contributed Oral Poster Presentations: Section on Physical and Engineering Sciences
Asymptotically Efficient Estimation of a Bivariate Gaussian-Weibull Distribution and an Introduction to the Associated Pseudo-Truncated Weibull
James Evans
USDA Forest Products Laboratory
Cherilyn Hatfield
USDA Forest Products Laboratory
David Kretschmann
USDA Forest Products Laboratory
Steve Verrill
USDA Forest Products Laboratory
Motivated by wood product reliability issues, we define a bivariate Gaussian-Weibull, obtain asymptotically efficient estimates of its parameters, establish their asymptotic normality, discuss simulations that investigated the small sample properties of these estimators, and describe a web-based program that fits the distribution and obtains both asymptotic and simulation-based confidence bounds on its parameters. We also introduce the related pseudo-truncated Weibull distribution. This distribution arises when wood stiffness and wood strength have a bivariate Gaussian-Weibull distribution, and (as in "machine stress rating") wood is binned based on its stiffness.
