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Related papers: On some subclasses of circular-arc catch digraphs

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Threshold tolerance graphs and their complement graphs, known as co-TT graphs, were introduced by Monma, Reed, and Trotter[24]. Building on this, Hell et al.[19] introduced the concept of negative interval. Then they proceeded to define…

Discrete Mathematics · Computer Science 2024-11-15 Ashok Kumar Das , Indrajit Paul

In this article, we present two new characterizations of circular-arc bigraphs based on their vertex ordering. Also, we provide a characterization of circular-arc bigraphs in terms of forbidden patterns with respect to a particular ordering…

Combinatorics · Mathematics 2026-03-19 Indrajit Paul , Ashok Kumar Das

Proximity maps and regions are defined based on the relative allocation of points from two or more classes in an area of interest and are used to construct random graphs called proximity catch digraphs (PCDs) which have applications in…

Metric Geometry · Mathematics 2009-02-10 Elvan Ceyhan

For two or more classes of points in $\R^d$ with $d \ge 1$, the class cover catch digraphs (CCCDs) can be constructed using the relative positions of the points from one class with respect to the points from the other class. The CCCDs were…

Probability · Mathematics 2008-10-13 Elvan Ceyhan

Undirected co-graphs are those graphs which can be generated from the single vertex graph by disjoint union and join operations. Co-graphs are exactly the P_4-free graphs (where P_4 denotes the path on 4 vertices). Co-graphs itself and…

Discrete Mathematics · Computer Science 2020-10-23 Frank Gurski , Dominique Komander , Carolin Rehs

We introduce the notion of a graph derangement, which naturally interpolates between perfect matchings and Hamiltonian cycles. We give a necessary and sufficient condition for the existence of graph derangements on a locally finite graph.…

Combinatorics · Mathematics 2013-07-04 Pete L. Clark

Circular-arc graphs are graphs that can be represented as intersection graphs of subpaths of a cycle. Interval graphs are graphs that can be represented as intersection graphs of subpaths of a path. Since cycles are locally paths, every…

Combinatorics · Mathematics 2025-12-23 Tara Abrishami , Sandra Albrechtsen , Nathan Bowler , Paul Knappe , Jana Katharina Nickel

The notion of p-competition graphs of digraphs was introduced by S-R. Kim, T. A. McKee, F. R. McMorris, and F. S. Roberts [p-competition graphs, Linear Algebra Appl., 217 (1995) 167--178] as a generalization of the competition graphs of…

Combinatorics · Mathematics 2010-06-01 Suh-Ryung Kim , Boram Park , Yoshio Sano

Intersection graphs of geometric objects have been extensively studied, both due to their interesting structure and their numerous applications; prominent examples include interval graphs and permutation graphs. In this paper we study a…

Data Structures and Algorithms · Computer Science 2014-01-29 George B. Mertzios

The min-rank of a digraph was shown by Bar-Yossef et al. (2006) to represent the length of an optimal scalar linear solution of the corresponding instance of the Index Coding with Side Information (ICSI) problem. In this work, the graphs…

Information Theory · Computer Science 2013-03-19 Son Hoang Dau , Vitaly Skachek , Yeow Meng Chee

We study the family of \emph{derangement action digraphs}, which are a subfamily of the group action graphs introduced in [Fred Annexstein, Marc Baumslag, and Arnold L. Rosenberg, Group action graphs and parallel architectures, \emph{SIAM…

Combinatorics · Mathematics 2018-04-05 Moharram N. Iradmusa , Cheryl E. Praeger

In this paper, we first give a new result characterizing the strongly connected digraphs with a diameter equal to that of their line digraphs. Then, we introduce the concepts of the inner diameter and inner radius of a digraph and study…

Combinatorics · Mathematics 2024-09-05 N. H. Bong , C. Dalfó , M. A. Fiol , D. Závacká

An interval $k$-graph is the intersection graph of a family $\mathcal{I}$ of intervals of the real line partitioned into at most $k$ classes with vertices adjacent if and only if their corresponding intervals intersect and belong to…

Combinatorics · Mathematics 2016-03-01 David E. Brown , Breeann M. Flesch , Larry J. Langley

Max-point-tolerance graphs (MPTG) was introduced by Catanzaro et al. in 2017 as a generalization of interval graphs. This graph class has many practical applications in study of human genome as well as in signal processing for networks. The…

Combinatorics · Mathematics 2020-05-07 Sanchita Paul

We consider the following fundamental realization problem of directed graphs. Given a sequence $S:={a_1 \choose b_1},\dots,{a_n \choose b_n}$ with $a_i,b_i\in \mathbb{Z}_0^+.$ Does there exist a digraph (no loops and no parallel arcs are…

Combinatorics · Mathematics 2018-08-24 Annabell Berger

A Stick graph G=(A\cup B, E) is the intersection graph of a set A of horizontal segments and a set B of vertical segments in the plane, whose left and respectively bottom endpoints lie on the same ground line with slope -1. These endpoints…

Discrete Mathematics · Computer Science 2021-06-24 Irena Rusu

We use a geometric digraph family called class cover catch digraphs (CCCDs) to tackle the class imbalance problem in statistical classification. CCCDs provide graph theoretic solutions to the class cover problem and have been employed in…

Machine Learning · Statistics 2019-04-10 Artür Manukyan , Elvan Ceyhan

An intersection digraph is a digraph where every vertex $v$ is represented by an ordered pair $(S_v, T_v)$ of sets such that there is an edge from $v$ to $w$ if and only if $S_v$ and $T_w$ intersect. An intersection digraph is reflexive if…

Combinatorics · Mathematics 2021-05-05 Lars Jaffke , O-joung Kwon , Jan Arne Telle

We present a dynamic algorithm for the recognition of proper circular-arc (PCA) graphs, that supports the insertion and removal of vertices (together with its incident edges). The main feature of the algorithm is that it outputs a minimally…

Data Structures and Algorithms · Computer Science 2015-09-22 Francisco J. Soulignac

Shift graphs, introduced by Erd\H{o}s and Hajnal in 1964, form one of the simplest known non-recursive constructions of triangle-free graphs with arbitrarily large chromatic number. In this note, we identify a suprising property: for each…

Combinatorics · Mathematics 2026-01-26 Tomáš Kaiser , Matěj Stehlík , Riste Škrekovski