welding               package:statmod               R Documentation

_D_a_t_a: _T_e_n_s_i_l_e _S_t_r_e_n_g_t_h _o_f _W_e_l_d_s

_D_e_s_c_r_i_p_t_i_o_n:

     This is a highly fractionated two-level factorial design employed
     as a screening design in an off-line welding experiment performed
     by the National Railway Corporation of Japan. There were 16 runs
     and 9 experimental factors. The response variable is the observed
     tensile strength of the weld, one of several quality
     characteristics measured. All other variables are at plus and
     minus levels.

_U_s_a_g_e:

     data(welding)

_F_o_r_m_a_t:

     A data frame containing the following variables. All the
     explanatory variables are numeric with two levels, '-1' and '1'.

         *Variable*  *Description*
         Rods        Kind of welding rods
         Drying      Period of drying
         Material    Welded material
         Thickness   Thickness
         Angle       Angle
         Opening     Opening
         Current     Current
         Method      Welding method
         Preheating  Preheating
         Strength    Tensile strength of the weld in kg/mm. The response variable.

_S_o_u_r_c_e:

     <URL: http://www.statsci.org/data/general/welding.html>

_R_e_f_e_r_e_n_c_e_s:

     Smyth, G. K., Huele, F., and Verbyla, A. P. (2001). Exact and
     approximate REML for heteroscedastic regression. _Statistical
     Modelling_ *1*, 161-175.

     Smyth, G. K. (2002). An efficient algorithm for REML in
     heteroscedastic regression. _Journal of Computational and
     Graphical Statistics_ *11*, 1-12.

