This paper discusses the 3x+1 problem,gives an estimate of the range of the questionable num-bers which make this conjecture untenable,derives a recurrence relation,and simplifies the 3x+1 operation by the ternary number system.
本文对使叙拉古猜想不成立的可疑数范围，给出了较［１］更精确的结论，还导出一个递推关系，并用三进数制简化了叙拉古运算。
First the system model of multiple access communications was founded,then ternary complementary set and its recursive construction method were analyzed,and then the performance evaluation structure of multiple access communications based the ternary complementary sets by use of the Rake receiver was put forward.
针对DS-UWB在室内高速短距离通信上的诸多优势,文章介绍了基于采用一组正交脉冲UWB信号的三进制互补集。