Results 11 to 20 of about 333,465 (75)

Characterizations of probe interval graphs [PDF]

arXiv, 2008
In this paper we obtain several characterizations of the adjacency matrix of a probe interval graph. In course of this study we describe an easy method of obtaining interval representation of an interval bipartite graph from its adjacency matrix. Finally, we note that if we add a loop at every probe vertex of a probe interval graph, then the Ferrers ...
arxiv  

A Characterization of Mixed Unit Interval Graphs [PDF]

arXiv, 2013
We give a complete characterization of mixed unit interval graphs, the intersection graphs of closed, open, and half-open unit intervals of the real line. This is a proper superclass of the well known unit interval graphs. Our result solves a problem posed by Dourado, Le, Protti, Rautenbach and Szwarcfiter (Mixed unit interval graphs, Discrete Math ...
arxiv  

Antipodal Interval-Valued Fuzzy Graphs [PDF]

International Journal of Applications of Fuzzy Sets and Artificial Intelligence (ISSN 2241-1240), Vol. 3 ( 2013), 107-130, 2014
Concepts of graph theory have applications in many areas of computer science including data mining, image segmentation, clustering, image capturing, networks, etc . An interval-valued fuzzy set is a generalization of the notion of a fuzzy set. Interval-valued fuzzy models give more precision, flexibility and compatibility to the system as compared to ...
arxiv  

Forecasting Bitcoin Price Using Interval Graph and ANN Model: A Novel Approach. [PDF]

SN Comput Sci, 2022
Murugesan R, Shanmugaraja V, Vadivel A.
europepmc   +1 more source

Interval Graphs with Containment Restrictions [PDF]

Proceedings of the Thirty-Ninth Southeastern International Conference on Combinatorics, Graph Theory and Computing. Congr. Numer. 191 (2008), 117-128, 2011
An interval graph is proper iff it has a representation in which no interval contains another. Fred Roberts characterized the proper interval graphs as those containing no induced star $K_{1,3}$. Proskurowski and Telle have studied $q$-proper graphs, which are interval graphs having a representation in which no interval is properly contained in more ...
arxiv  

On the Classes of Interval Graphs of Limited Nesting and Count of Lengths [PDF]

arXiv, 2015
In 1969, Roberts introduced proper and unit interval graphs and proved that these classes are equal. Natural generalizations of unit interval graphs called $k$-length interval graphs were considered in which the number of different lengths of intervals is limited by $k$.
arxiv  

Simultaneous Interval Graphs [PDF]

arXiv, 2010
In a recent paper, we introduced the simultaneous representation problem (defined for any graph class C) and studied the problem for chordal, comparability and permutation graphs. For interval graphs, the problem is defined as follows. Two interval graphs G_1 and G_2, sharing some vertices I (and the corresponding induced edges), are said to be ...
arxiv  

The Maximum Clique Problem in Multiple Interval Graphs [PDF]

arXiv, 2011
Multiple interval graphs are variants of interval graphs where instead of a single interval, each vertex is assigned a set of intervals on the real line. We study the complexity of the MAXIMUM CLIQUE problem in several classes of multiple interval graphs.
arxiv  

Irregular Interval Valued Fuzzy Graphs [PDF]

Annals of Pure and Applied Mathematics, 3(1) (2013) 56-66, 2014
In this paper, we define irregular interval-valued fuzzy graphs and their various classifications. Size of regular interval-valued fuzzy graphs is derived. The relation between highly and neighbourly irregular interval-valued fuzzy graphs are established. Some basic theorems related to the stated graphs have also been presented.
arxiv  

Coloring problem of signed interval graphs [PDF]

arXiv, 2016
The chromatic number of signed graphs is defined recently. The coloring and clique problem of interval graphs has been studied and polynomial time algorithms are established. Here we consider these problems for signed interval graphs and prove that the coloring problem of signed interval graphs is NP-complete whereas their ordinary clique problem is in
arxiv