中文摘要：

基于存取结构与连通超图之间的关系，给出了顶点数为9，秩为3，超边数为4和5的一共226种不同构的连通超图存取结构，进而估算了它们的最优信息率。本文首先证明了具有4条超边的一类超星可以用理想的秘密共享方案来实现，并证明了满足一定条件的顶点数为n（5≤n≤11），超边数为5且秩为3的连通超图其最优信息率的下界为2/3。运用超图的相关理论对其中的16种超图存取结构最优信息率的精确值进行了计算，对余下的210种超图存取结构进行了分类，并估算了这些超图存取结构最优信息率的界。

英文摘要：

Based on the relationship between access structures and connected hypergraph,226 connected hypergraph ac-cess structures with 9 vertices,3 ranks and 4 or 5 hyperedges were given.These structures are not mutually isomor-phism,and their optimal information rates were estimated.First,it was proved that there exists ideal secret sharing scheme for a kind of hyperstar with 4 hyperedges and shown that the lower bounds of the optimal information rates of the connected hypergraph with n（5≤n≤1 1 ）vertices and 3 ranks are 2/3 .Then using the theory of hypergraphs,the exact values for the optimal information rate of 16 access structures were computed.Final,the remaining 210 access structures were classified,and the bounds of the optimal information rates of these access structures were estimated.