二次输入 meaning in English

secondary input
secondaryinput

If capp and cam system want to use of these information about a part in cad , they have to transfer these information to proper style , and then they can recognize and use them . these years , there are many researches about how to make full use of the information in cad system and how to describe a part in other systems . during these researches , many methods about part information description have been developed , such as gt code method , language description method , knowledge description method , feature description method , and so on
多年来，为了使capp 、 cam等后续系统能够有效地利用cad系统中相关的零件信息，亦即对零件信息进行合理的描述，人们进行了大量的研究，提出了分类编码法、语言描述法、知识表示描述法、基于形状特征或表面元素的描述法等各种方法对零件信息进行描述，但是，这些方法都需要人来对零件图纸进行识别和分析，即需要人工来对已设计好的零件图进行二次输入，由于输入过程繁琐、费时、易出错，因此这些信息描述方法无法满足信息集成的要求，也不能适应集成环境下capp系统的需要。