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Related papers: On the partial order competition dimensions of cho…

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Choi {\it et al.} [{J.~Choi, K.~S.~Kim, S.~-R.~Kim, J.~Y.~Lee, and Y.~Sano}: {On the competition graphs of $d$-partial orders}, \emph{Discrete Applied Mathematics} (2015), \texttt{http://dx.doi.org/10.1016/j.dam.2015.11.004}] introduced the…

Combinatorics · Mathematics 2016-01-11 Jihoon Choi , Suh-Ryung Kim , Jung Yeun Lee , Yoshio Sano

In this paper, we study the competition graphs of $d$-partial orders and obtain their characterization which extends results given by Cho and Kim \cite{chokim} in 2005. We also show that any graph can be made into the competition graph of a…

Combinatorics · Mathematics 2016-01-11 Jihoon Choi , Kyeong Seok Kim , Suh-Ryung Kim , Jung Yeun Lee , Yoshio Sano

In this paper, we study the competition graphs of $d$-partial orders and obtain their characterization which extends results given by Cho and Kim \cite{chokim} in 2005. We also show that any graph can be made into the competition graph of a…

Combinatorics · Mathematics 2016-01-11 Jihoon Choi , Kyeong Seok Kim , Suh-Ryung Kim , Jung Yeun Lee , Yoshio Sano

Since Cho and Kim (2005) showed that the competition graph of a doubly partial order is an interval graph, it has been actively studied whether or not the same phenomenon occurs for other variants of competition graph and interesting…

Combinatorics · Mathematics 2015-03-19 Suh-Ryung Kim , Jung Yeun Lee , Boram Park , Yoshio Sano

In this paper, we use the Erd\"{o}s-Szekeres lemma to show that there exists a graph with partial order competition dimension greater than five.

Combinatorics · Mathematics 2018-10-15 Jihoon Choi , Soogang Eoh , Suh-Ryung Kim

In prior work, Cho and Kim studied competition graphs arising from doubly partial orders. In this article, we consider a related problem where competition graphs are instead induced by permutations. We first show that this approach produces…

Combinatorics · Mathematics 2015-03-20 Brian Nakamura , Elizabeth Yang

The competition graph of a digraph D is a graph which has the same vertex set as D and has an edge between x and y if and only if there exists a vertex v in D such that (x,v) and (y,v) are arcs of D. For any graph G, G together with…

Combinatorics · Mathematics 2011-06-27 Boram Park , Yoshio Sano

We survey partial geometric designs and investigate their concurrences of points. The concurrence matrix of a design, which encodes the concurrences of pairs of points, can be used in the classification of designs in some extent. An…

Combinatorics · Mathematics 2022-01-04 Sung-Yell Song , Theodore Tranel

The competition graph of a doubly partial order is known to be an interval graph. The competition-common enemy graph of a doubly partial order is also known to be an interval graph unless it contains a cycle of length 4 as an induced…

Combinatorics · Mathematics 2010-06-01 Suh-Ryung Kim , Jung Yeun Lee , Boram Park , Won Jin Park , Yoshio Sano

The competition graph of a digraph D is a (simple undirected) graph which has the same vertex set as D and has an edge between x and y if and only if there exists a vertex v in D such that (x,v) and (y,v) are arcs of D. For any graph G, G…

Combinatorics · Mathematics 2011-11-14 Suh-Ryung Kim , Jung Yeun Lee , Boram Park , Yoshio Sano

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 orientable if there exists an $(i,j)$-step competitive orientation…

Combinatorics · Mathematics 2024-10-08 Myungho Choi , 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 orientation of $G$. The notion of competitive digraphs arose…

Combinatorics · Mathematics 2022-12-13 Myungho Choi , Minki Kwak , Suh-Ryung Kim

We study subclasses of grid intersection graphs from the perspective of order dimension. We show that partial orders of height two whose comparability graph is a grid intersection graph have order dimension at most four. Starting from this…

Combinatorics · Mathematics 2015-12-09 Steven Chaplick , Stefan Felsner , Udo Hoffmann , Veit Wiechert

This paper discusses the complete structure of the (bull, diamond)-free graphs. As an application of that, we give the characterization of the partitionable (bull, diamond)-free graphs. Moreover, we show that such a partition for a…

Combinatorics · Mathematics 2024-08-20 Suchismita Mishra

Chordal graphs are important in algorithmic graph theory. Chordal digraphs are a digraph analogue of chordal graphs and have been a subject of active studies recently. Unlike chordal graphs, chordal digraphs lack many structural properties…

Combinatorics · Mathematics 2022-11-29 Jing Huang , Ying Ying Ye

A graph is chordal if it does not contain an induced cycle of length greater than three. We determine the minimum size of a chordal graph with given order and minimum degree. In doing so, we have discovered interesting properties of chordal…

Combinatorics · Mathematics 2024-09-17 Xingzhi Zhan , Leilei Zhang

The competition graph of a directed acyclic graph D is the undirected graph on the same vertex set as D in which two distinct vertices are adjacent if they have a common out-neighbor in D. The competition number of an undirected graph G is…

Combinatorics · Mathematics 2013-10-24 Brendan D. McKay , Pascal Schweitzer , Patrick Schweitzer

We introduce a class of chordal graphs called ($d_1$,$d_2$,$\dots$,$d_q$)-trees. A graph belongs to this class if and only if its clique complex is sequentially Cohen-Macaulay, providing a complete classification of all sequentially…

Commutative Algebra · Mathematics 2025-10-14 Chwas Ahmed , Amir Mafi , Mohammed Rafiq Namiq

In this paper, we study $(1,2)$-step competition graphs of bipartite tournaments. A bipartite tournament means an orientation of a complete bipartite graph. We show that the $(1,2)$-step competition graph of a bipartite tournament has at…

Combinatorics · Mathematics 2016-11-11 Jihoon Choi , Soogang Eoh , Suh-Ryung Kim , So Jung Lee

We investigate new graph classes of bounded mim-width, strictly extending interval graphs and permutation graphs. The graphs $K_t \boxminus K_t$ and $K_t \boxminus S_t$ are graphs obtained from the disjoint union of two cliques of size $t$,…

Data Structures and Algorithms · Computer Science 2017-03-08 Dong Yeap Kang , O-joung Kwon , Torstein J. F. Strømme , Jan Arne Telle
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