Suh-Ryung Kim

collaborators

5 papers

math.CO2025

Digraphs in which every $t$ vertices have exactly $I^»$ common out-neighbors

Myungho Choi, Hojin Chu, Suh-Ryung Kim

We say that a digraph is a $(t, I^»)$ -liking digraph if every $t$ vertices have exactly $I^»$ common out-neighbors. In 1975, PlesnÃk [Graphs with a homogeneity, 1975. {\it Glasnik Ma…

math.CO2025

Competition graphs of degree bounded digraphs

Hojin Chu, Suh-Ryung Kim

If each vertex of an acyclic digraph has indegree at most $i$ and outdegree at most $j$ , then it is called an $(i, j)$ digraph, which was introduced by Hefner~{\it et al.}~(1991). W…

math.CO2025

A digraph version of the Friendship Theorem

Myungho Choi, Hojin Chu, Suh-Ryung Kim

The Friendship Theorem states that if in a party any pair of persons has precisely one common friend, then there is always a person who is everybody's friend and the theorem has be…

math.CO2024

Multipartite tournaments in which any two vertices have an $(i, j)$ -step common out-neighbor

Myungho Choi, Suh-Ryung Kim

We say that a digraph $D$ is $(i, j)$ -step competitive if any two vertices have an $(i, j)$ -step common out-neighbor in $D$ and that a graph $G$ is $(i, j)$ -step competitively orienta…

math.CO2024

Extensions of results on phylogeny graphs of degree bounded digraphs

Myungho Choi, Suh-Ryung Kim

An acyclic digraph in which every vertex has indegree at most $i$ and outdegree at most $j$ is called an $(i, j)$ digraph for some positive integers $i$ and $j$ . The phylogeny graph…

Digraphs in which every t vertices have exactly I^» common out-neighbors

Competition graphs of degree bounded digraphs

A digraph version of the Friendship Theorem

Multipartite tournaments in which any two vertices have an (i,j)-step common out-neighbor

Extensions of results on phylogeny graphs of degree bounded digraphs

Digraphs in which every $t$ vertices have exactly $I^»$ common out-neighbors

Multipartite tournaments in which any two vertices have an $(i, j)$ -step common out-neighbor