I conducted the following research with co-researchers:
Three problems focused on the characterization of digraphs under common neighbor conditions;
One problem from each of Combinatorial matrix Theory, Discrete Algorithms, and Extremal graph theory,
One problem related to graph planarity;
Two problem related to a competition graph and its variants.
Submitted Papers & Preprints
On 2-connected graphs avoiding cycles of length 0 modulo 4
(with Boram Park, Homoon Ryu), arxiv:2507.12798
Linear-Time Computation of the Frobenius Normal Form for Symmetric Toeplitz Matrices via Graph-Theoretic Decomposition
(with Homoon Ryu), arxiv:2505.20811
Competition-common enemy graphs of degree-bounded digraphs
(with Myungho Choi, Suh-Ryung Kim), arxiv:2405.13363
Digraphs in which every t vertices share exactly λ out-neighbors and exactly λ in-neighbors
(with Suh-Ryung Kim), arxiv:2405.13293
Planarity of generalized ladder graphs
(with Suh-Ryung Kim, Homoon Ryu), arxiv:2208.13637
Accepted & Published Papers
Digraphs in which every t vertices have exactly λ common out-neighbors (with Myungho Choi, Suh-Ryung Kim),
Discrete Mathematics, 348(10):114580 (2025), arxiv
Structural properties of symmetric Toeplitz and Hankel matrices (with Homoon Ryu),
Linear Algebra and its Applications, 708:204-216 (2025), arxiv
A digraph version of the Friendship Theorem (with Myungho Choi, Suh-Ryung Kim),
Discrete Mathematics, 348(1):114238 (2025), arxiv
Competition graphs of degree bounded digraphs (with Suh-Ryung Kim),
Discrete Applied Mathematics, 343:106-114 (2024), arxiv
For this research, I received a grant (with the same title) from Basic Science Research Program, National Research Foundation of Korea (KRW 20,000,000).
List of co-authors (# papers with me)
Myungho Choi (3), Suh-Ryung Kim (6), Boram Park (1), Homoon Ryu (4)
