2 citations · 9 across the 21 of their papers we have counts for
21 papers
Diagonals in Riordan matrices and applications
Gi-Sang Cheon, Ana Luzón, Manuel A. Morón +1
We introduce a method for describing Riordan matrices via recurrence relations along their diagonals. This provides a new structural description that complements the classical row-…
A matrix approach to the structure, enumeration, and applications of partially ordered sets
Gi-Sang Cheon, Hong Joon Choi, Gukwon Kwon +2
We present a matrix-theoretic approach for studying and enumerating finite posets through their incidence representations, referred to as poset matrices. Naturally labelled posets…
Generating naturally labeled posets through matrix extensions, order ideals and automorphism groups
Gi-Sang Cheon, Samuele Giraudo, Gukwon Kwon +1
We propose a matrix approach for generating naturally labeled posets by representing each poset on the set as a Boolean poset matrix . This algebraic representation en…
Matrix periods and competition periods of Boolean Toeplitz matrices II
Gi-Sang Cheon, Bumtle Kang, Suh-Ryung Kim +1
This paper is a follow-up to the paper [Matrix periods and competition periods of Boolean Toeplitz matrices, {\it Linear Algebra Appl.} 672:228--250, (2023)]. Given subsets and…
Operad Structure of Poset Matrices
Arnauld Mesinga Mwafise, Gi-Sang Cheon, Hong Joon Choi +1
This paper examines operad structures derived from poset matrices by formulating a set of new construction rules for poset matrices. In this direction, eleven different partial com…
On naturally labelled posets and permutations avoiding 12-34
David Bevan, Gi-Sang Cheon, Sergey Kitaev
A partial order on is naturally labelled (NL) if implies . We establish a bijection between {3, 2+2}-free NL posets and 12-34-avoiding permutations, d…
Row graphs of Toeplitz matrices
Gi-Sang Cheon, Bumtle Kang, Suh-Ryung Kim +1
In this paper, we study row graphs of Toeplitz matrices. The notion of row graphs was introduced by Greenberg et al. in 1984 and is closely related to the notion of competition gra…
On the zeros of certain Sheffer sequences and their cognate sequences
Gi-Sang Cheon, Tamás Forgács, Khang Tran
Given a Sheffer sequence of polynomials, we introduce the notion of an associated sequence called the cognate sequence. We study the relationship between the zeros of this pair of…
Matrix periods and competition periods of Boolean Toeplitz matrices
Gi-Sang Cheon, Bumtle Kang, Suh-Ryung Kim +1
In this paper, we study the matrix period and the competition period of Toeplitz matrices over a binary Boolean ring . Given subsets and of $\{1,\ldot…
The zero locus and some combinatorial properties of certain exponential Sheffer sequences
Gi-Sang Cheon, Tamás Forgács, Arnauld Mesinga Mwafise +1
We present combinatorial and analytical results concerning a Sheffer sequence with an exponential generating function of the form , where $α, β, c \in…
On Toeplitz graphs being line graphs
Gi-Sang Cheon, Bumtle Kang, Suh-Ryung Kim +2
A Toeplitz graph is a simple graph with the vertex set such that two vertices and are adjacent if and only if fo…
Structural properties of Toeplitz graphs
Seyed Ahmad Mojallal, Ji-Hwan Jung, Gi-Sang Cheon +2
In this paper, we study structural properties of Toeplitz graphs. We characterize -free Toeplitz graphs for an integer and give equivalent conditions for a Toeplitz…
Decompositions and eigenvectors of Riordan matrices
Gi-Sang Cheon, Marshall M. Cohen, Nikolaos Pantelidis
Riordan matrices are infinite lower triangular matrices determined by a pair of formal power series over the real or complex field. These matrices have been mainly studied as combi…
On combinatorial properties and the zero distribution of certain Sheffer sequences
Gi-Sang Cheon, Tamás Forgács, Hana Kim +1
We present combinatorial and analytical results concerning a Sheffer sequence with a generating function of the form , where is a quadratic polynomi…
Algebraic and topological properties of Riordan groups over finite fields
Gi-Sang Cheon, Nhan-Phu Chung, Minh-Nhat Phung
In this paper, we investigate algebraic and topological properties of the Riordan groups over finite fields. These groups provide a new class of topologically finitely generated pr…
Counting independent sets in Riordan graphs
Gi-Sang Cheon, Ji-Hwan Jung, Bumtle Kang +4
The notion of a Riordan graph was introduced recently, and it is a far-reaching generalization of the well-known Pascal graphs and Toeplitz graphs. However, apart from a certain su…
Word-representability of Toeplitz graphs
Gi-Sang Cheon, Jinha Kim, Minki Kim +1
Distinct letters and alternate in a word if after deleting in all letters but the copies of and we either obtain a word of the form (of even or…
On k-11-representable graphs
Gi-Sang Cheon, Jinha Kim, Minki Kim +2
Distinct letters and alternate in a word if after deleting in all letters but the copies of and we either obtain a word of the form (of even or…
Riordan graphs II: Spectral properties
Gi-Sang Cheon, Ji-Hwan Jung, Sergey Kitaev +1
The authors of this paper have used the theory of Riordan matrices to introduce the notion of a Riordan graph in \cite{CJKM}. Riordan graphs are proved to have a number of interest…
Riordan graphs I: Structural properties
Gi-Sang Cheon, Ji-Hwan Jung, Sergey Kitaev +1
In this paper, we use the theory of Riordan matrices to introduce the notion of a Riordan graph. The Riordan graphs are a far-reaching generalization of the well known and well stu…
Mutation effects in ordered trees
Gi-Sang Cheon, Hana Kim, Louis W. Shapiro
A mutation will affect an individual and some or all of its descendants. In this paper, we investigate ordered trees with a distinguished vertex called the mutator. We describe var…