▁Short ▁P aper ▁Pro ceed ings ▁of ▁ 3 rd ▁World ▁Congress ▁of ▁Struct ural ▁and ▁Mult id is cipl inary ▁Opt im ization , ▁Vol . ▁ 1 , ▁pp 2 6 3 – 2 6 5 , ▁Buff alo , ▁NY . ▁ ▁B . ▁M ob ash er , ▁S - Y . Ch en , ▁C . ▁Young ▁and ▁S . ▁D . ▁Raj an , ▁Oct . ▁ 1 9 9 8 , ▁" A ▁Cost ▁Based ▁Appro ach ▁To ▁Design ▁Of ▁Res ident ial ▁Ste el ▁Ro of ▁Systems ", ▁ 1 4 th ▁International ▁Special ty ▁Conference , ▁Rec ent ▁Research ▁and ▁Develop ments ▁in ▁Cold - Form ed ▁Ste el ▁Design ▁and ▁Const ruction , ▁University ▁of ▁Missouri - R ol la , ▁Ed ited ▁By ▁Wei - W en ▁Yu ▁and ▁R . ▁La B ou be , ▁pp 6 1 3 – 6 2 5 . ▁ ▁S - Y . ▁Chen ▁and ▁S . D . ▁Raj an , ▁ 1 9 9 8 , ▁" Im pro ving ▁the ▁E ffic iency ▁of ▁Gen etic ▁Alg orithms ▁for ▁Frame ▁Design s ", ▁Engineering ▁Opt im ization , ▁Vol . ▁ 3 0 , ▁pp 2 8 1 – 3 0 7 . ▁ ▁S - Y . ▁Chen , ▁December ▁ 1 9 9 7 , ▁" Using ▁Gen etic ▁Alg orithms ▁for ▁the ▁Opt imal ▁Design ▁of ▁Struct ural ▁System ", Dis sert ation ▁for ▁Doctor ▁of ▁Philosoph y ,