back shift meaning in English

第二班
二次变换
非出煤班

Employing idef to establish framework , dynamitic and functional models , the system also designs a non - back shifting search arithmetic for double - scanning buffer zone and a double - track structure for searching process . according to the characteristics of e - mail control and electronic documentary mining technology , bayes classifiers are made to strengthen the electronic control system in which electronic documentary mining technology is used ; and moreover the double systematic structure of c / s & b / s is constructor with the presence of some function relationships in mining process as well as systematic mining and program handling
系统采用i _ 2def方法建立了结构模型、动态模型和功能模型；设计了双扫描缓冲区的无回溯搜索算法及搜索过程的双栈结构；根据电子邮件监控系统和电子文档挖掘技术的特征，设计了bayes分类器并使用了增强型方法，提出了一种运用电子文档挖掘技术的电子邮件监控系统；构建了c / s和b / s双重体系结构；并给出了挖掘过程的部分函数调用关系及系统挖掘的处理过程、部分处理程序。