grpvar 기간 그룹 콘발 조건
1 log_uranium_ppm 0 0.667653 0.465584
2 log_uranium_ppm 1 0.697805 0.123133
log_uranium_ppm 2 -0.010856 0.847489
4 log_uranium_ppm -0.068872 0.422883
5 log_uranium_ppm 4 0.036075 0.825677