?츮 ?????? 1980?? ????????? ?????? ??u??? ???? ????? ???? ??????, ?????o? ??????? ?¸? ??????? ??? 537?????? ???λ??? ??? ???? ????? ???? ?? ???? ???????δ? 597?????? ??????? ?? ??? ???? ???? ????????? ?????? ??????, ?????? ????? ????꿡?? ????? ?????? ???? ?뵿o?? ???λ꿡?? ??????? ????? ?????? ???????? ????o?? ???????? ???? ??????.
????? ?????? ???????濡 ?????? ??? ???? ???????? ??? ???濡 ????? ??缺?????? ?????? ?? ??????, ?????? ??????????κ??? ?????? ????? ???????? ??? ?????? ????? ?u????? ??????κ??? ?????? ????? ???????? ??´????? ????? ?u????? ??????κ??? ?????? ????? ?????? ??? ???? ?????? ??????.
1?? ????????? 53.8%?? ?????? ?????? ??????, ????? ???????? ??? ???? ??????. ????? 1?? ??? ???????? 1.488mm(??? 5??)???, ????? ????? 13.3??? ?α? ?????? ? ????? ?????? ??? ??????, ??? ????? ??? ?????? ª??? ?????? 4?????? ????? ????????.