DISSCUSSION ON “CALCULATION OF REFERENCED STRENGTH BY JOINT PROBABILITY DENSITY FUNCTION OF NON-NORMAL RANDOM VARIABLES”

(Noboru NAKAMURA, Kazumi HORIE and Yasuo IIJIMA, J. Struct. Constr. Eng., AIJ, No. 615, 169-172, May, 2007)

Abstract

The derivation of the joint probability density function of non-normal random variables in the above paper is discussed as follows:
1) The relationship between the non-normal random variable and the standard normal random variable is generally nonlinear and Eq. (2) in the paper is generally incorrect.
2) The correlation coefficient between the standard normal random variables transformed from the non-normal random variables is generally different from that between the non-normal random variables.
3) The joint probability density function of non-normal random variables derived in the paper is generally incorrect.