分层有向图 meaning in Chinese

hierarchical directed graph

The establishment of layered orientation graph model and its expressing method were studied in this paper and application verification was made by taking certain typed airplane wing box as an example
研究了分层有向图模型的建立和表示方法，并以某型机翼翼盒为实例予以应用验证。
Aiming at this kind of problem a method utilizing the division of assembly unit was put forward to carrying out division of layers ; the layered orientation graph model of the information of assembling positioning relationship was expressed in every layer by the use of embedded orientation graph
针对这种问题，提出利用装配单元划分的方法进行分层；在每层中，用嵌套式的有向图表示装配定位关系信息的分层有向图模型。