The traditional text classifications are mostly based on the vectorial space, and the structure of classification is flat structure.
传统的文本分类大多基于向量空间，分类体系为甲面体系，忽视了类别间的层次关系。
2
In order to calculate the equivalent step index of the periodic structure of the cladding holey optical fiber, all-vectorial fundamental space filling mode approach was utilized.