alternation

名词 alternation:

1. being regularly exchangeable
2. successive change from one thing or state to another and back again

1. The process of recording everything pertinent to a machine run, including identification of the machine run, recording the alternation switch settings, identification of input and output tapes, copy of manual key-ins, identification of all stops, and a record of the action taken on all stops.
   有关计算机运行的全部事项记录的过程，包括计算机运行的标识、记录转换开关的置位、输入输出带的标识、人工键入信息的拷贝、所有停止的标识以及所有为停机所采取的动作记录。
2. The rapid alternation of two tones either a whole or a half tone apart.
   颤音两个相距一个音或半个音的音的迅速交替