Myungho Choi

activity

20192026

most citedOn

(1, 2)

-step competition graphs of multipartite tournaments II

1 citations · 2 across the 12 of their papers we have counts for

collaborators

13 papers

math.CO2026

Det-extremal cubic graphs and the total domatic number

Myungho Choi, Hyemin Kwon, Boram Park

A graph $G$ is det-extremal if $∣ det A ∣ = per A$ for its adjacency matrix $A$ . Det-extremal cubic bipartite graphs arise in the study of Pólya's permane…

math.CO2026

$2$ -limited broadcast domination in cubic graphs

Myungho Choi, Boram Park

For a graph $G$ , a function $f : V (G) \to {0, 1, 2}$ is called a $2$ -limited dominating broadcast on $G$ if for every vertex $u$ , there exists a vertex $v$ such that $f (v) > 0$ and the…

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

Competition-common enemy graphs of degree-bounded digraphs

Myungho Choi, Hojin Chu, Suh-Ryung Kim

The competition-common enemy graph (CCE graph) of a digraph $D$ is the graph with the vertex set $V (D)$ and an edge $uv$ if and only if $u$ and $v$ have a common predator and a com…

math.CO2024

Digraphs in which every $t$ vertices have exactly $λ$ common out-neighbors

Myungho Choi, Hojin Chu, Suh-Ryung Kim

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

math.CO2024

On $(1, 2)$ -step competition graphs of multipartite tournaments

Myungho Choi, Suh-Ryung Kim

A multipartite tournament is an orientation of a complete $k$ -partite graph for some positive integer $k \geq 3$ . We say that a multipartite tournament $D$ is tight if every partite…

math.CO2024★ 1 cited

On $(1, 2)$ -step competition graphs of multipartite tournaments II

Myungho Choi, Suh-Ryung Kim

A multipartite tournament is an orientation of a complete $k$ -partite graph for some positive integer $k \geq 3$ . We say that a multipartite tournament $D$ is tight if every partite…

math.CO2023

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.CO2022

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…

math.CO2020

The triangle-free graphs which are competition graphs of multipartite tournaments

Myungho Choi, Minki Kwak, Suh-Ryung Kim

In this paper, we discover all the triangle-free graphs that are competition graphs of multipartite tournaments.

math.CO2020

Digraphs whose m-step competition graphs are trees

Myungho Choi, Suh-Ryung Kim

In this paper, we completely characterize the digraphs of order $n$ whose $m$ -step competition graphs are star graphs for positive integers $2 \leq m < n$ . This result in matrix ver…

math.CO2020★ 1 cited

Competitively orientable complete multipartite graphs

Myungho Choi, Minki Kwak, Suh-Ryung Kim

We say that a digraph $D$ is competitive if any pair of vertices has a common out-neighbor in $D$ and that a graph $G$ is competitively orientable if there exists a competitive ori…

math.CO2019

The niche graphs of multipartite tournaments

Soogang Eoh, Myungho Choi, Suh-Ryung Kim

The niche graph of a digraph $D$ has $V (D)$ as the vertex set and an edge $uv$ if and only if $(u, w) \in A (D)$ and $(v, w) \in A (D)$ , or $(w, u) \in A (D)$ and $(w, v) \in A (D)$ for so…

Det-extremal cubic graphs and the total domatic number

2-limited broadcast domination in cubic graphs

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

Competition-common enemy graphs of degree-bounded digraphs

Digraphs in which every t vertices have exactly λ common out-neighbors

On (1,2)-step competition graphs of multipartite tournaments

On (1,2)-step competition graphs of multipartite tournaments II

A digraph version of the Friendship Theorem

Extensions of results on phylogeny graphs of degree bounded digraphs

The triangle-free graphs which are competition graphs of multipartite tournaments

Digraphs whose m-step competition graphs are trees

Competitively orientable complete multipartite graphs

The niche graphs of multipartite tournaments

$2$ -limited broadcast domination in cubic graphs

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

Digraphs in which every $t$ vertices have exactly $λ$ common out-neighbors

On $(1, 2)$ -step competition graphs of multipartite tournaments

On $(1, 2)$ -step competition graphs of multipartite tournaments II