结合方案的图表示

Graphic Expressions of Association Schemes

图论与结合方案有着某种共性。图论研究点与线之间的关系，结合方案则是处理之间的关系，将图论中的点看作处理，将线看作结合关系，则有些结合方案可以用图表示出来，该文对此作了些尝试，揭示了它们之间的关系。

The graph and assoiation scheme have some common properties. The graph deals with points and lines, and the association scheme deals with treatments. Same association schemes can be expressed by the graphs. This paper tries to demonstrate the relationship between them.