Issue 44

N.M. Khansari et alii, Frattura ed Integrità Strutturale, 44 (2018) 106-122; DOI: 10.3221/IGF-ESIS.44.09 122 N OMENCLATURE b Unbiased estimator b of the coefficient vector β X n k  Model matrix F Quadratic polynomial function Y 1 n  Vector of the observations C jj Element of number j of variance covariance matrix β Unknown coefficients R 2 Adjusted coefficient of multiple determinations β 1 k  Vector of the regression coefficients x i Independent Variables ε 1 n  vector of random errors y Estimated Response σ Error of Y