Issue 44

N.M. Khansari et alii, Frattura ed Integrità Strutturale, 44 (2018) 106-122; DOI: 10.3221/IGF-ESIS.44.09

N OMENCLATURE

n k  Model matrix

X Y

b F

Unbiased estimator b of the coefficient vector β

1 n  Vector of the observations

Quadratic polynomial function

Element of number j of variance covariance matrix Adjusted coefficient of multiple determinations

β β

Unknown coefficients

C jj R 2

1 k  Vector of the regression coefficients

1 n  vector of random errors

x i

Independent Variables Estimated Response

ε

σ

Error of Y

y

122