Results 41 to 50 of about 6,506,964 (218)

The quadrangle graph operator

open access: yesMathematics Open
The cycle graph of a graph G is the graph [Formula: see text] whose vertices are the induced cycles of G and where two vertices are adjacent if and only if they are distinct induced cycles that share a common edge.
Severino V. Gervacio, Yvette F. Lim
doaj   +1 more source

New graph classes characterized by weak vertex separators and two-pairs

open access: yesAKCE International Journal of Graphs and Combinatorics, 2017
A set of vertices whose deletion from a graph would increase the distance between two remaining vertices is called a weak vertex separator of the graph. Two vertices form a two-pair if all chordless paths between them have length .
Terry A. McKee
doaj   +1 more source

A Zero Knowledge Authentication Protocol Based on Novel Heuristic Algorithm of Dense Induced Subgraphs Isomorphism [PDF]

open access: yesEngineering and Technology Journal, 2015
Graphs provide an useful mathematical tool for modeling various real world phenomena. Dense graphs arise in many places of interest, for instance the internet and social networks to name just two. The density of a graph should be a real number reflecting
N. M. G. Al-Saidi   +2 more
doaj   +1 more source

Tractable but Hard to Approximate: The Bi‐Objective Minimum s$$ s $$‐t$$ t $$‐Cut Problem With Binary Capacities

open access: yesNetworks, EarlyView.
ABSTRACT The minimum s$$ s $$‐t$$ t $$‐cut problem is one of the most‐studied problems in discrete optimization and has a unique complexity status in multi‐objective optimization. Even though the single‐objective version of the problem can be solved in polynomial time, it has been shown in the seminal work of Papadimitriou and Yannakakis (2000) that ...
Jan Boeckmann   +4 more
wiley   +1 more source

Strong ƒ-Star Factors of Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2015
Let G be a graph and f : V (G) → {2, 3, . . .}. A spanning subgraph F is called strong f-star of G if each component of F is a star whose center x satisfies degF (x) ≤ ƒ(x) and F is an induced subgraph of G.
Yan Zheng
doaj   +1 more source

Influence of the Chemical Composition on the Perovskites Anharmonicity: Toward a Stable Inorganic Perovskite

open access: yesSolar RRL, EarlyView.
This study investigates the effect of the chemical composition on the properties of A(BB’)(XX’)3$_3$ inorganic halide perovskites with density functional theory. By correlating distortion amplitudes with both composition and the Goldschmidt tolerance factor, we propose a pragmatic approach to designing more stable and efficient perovskites, advancing ...
Antoine Gissler   +2 more
wiley   +1 more source

Quantifying functionally equivalent species and ecological network dissimilarity with optimal transport distances

open access: yesMethods in Ecology and Evolution, EarlyView.
Abstract Quantifying the structure and dynamics of species interactions in ecological communities is fundamental to studying ecology and evolution. While there are numerous approaches to analysing ecological networks, there is not yet an approach that can (1) quantify dissimilarity in the global structure of ecological networks that range from ...
Kai M. Hung   +4 more
wiley   +1 more source

Chromatic number and regular subgraphs

open access: yesBulletin of the London Mathematical Society, EarlyView.
Abstract In 1992, Erdős and Hajnal posed the following natural problem: Does there exist, for every r∈N$r\in \mathbb {N}$, an integer F(r)$F(r)$ such that every graph with chromatic number at least F(r)$F(r)$ contains r$r$ edge‐disjoint cycles on the same vertex set? We solve this problem in a strong form, by showing that there exist n$n$‐vertex graphs
Barnabás Janzer   +2 more
wiley   +1 more source

A new family of solutions for graph‐restricted cooperative games: rethinking the weight of intermediary power

open access: yesInternational Transactions in Operational Research, Volume 33, Issue 3, Page 1656-1677, May 2026.
Abstract In graph‐restricted cooperative games, a group of agents, represented by the nodes of a graph, work together to make a profit. However, two agents can cooperate within a coalition only if they are connected by the graph in the coalition. Several allocation rules have been proposed for these games, but there is something in common in all of ...
Antonio C. Alarcón   +2 more
wiley   +1 more source

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