Steiner Minimal Trees on Sets of Four Points.
Straight-line drawings of binary trees with linear area and arbitrary aspect ratio.
Strong Equality Between the Roman Domination and Independent Roman Domination Numbers in Trees
A Roman dominating function (RDF) on a graph G = (V,E) is a function f : V −→ {0, 1, 2} satisfying the condition that every vertex u for which f(u) = 0 is adjacent to at least one vertex v for which f(v) = 2. The weight of an RDF is the value f(V (G)) = P u2V (G) f(u). An RDF f in a graph G is independent if no two vertices assigned positive values are adjacent. The Roman domination number R(G) (respectively, the independent Roman domination number iR(G)) is the minimum weight of an RDF (respectively,...
Structure of cubic mapping graphs for the ring of Gaussian integers modulo
Let be the ring of Gaussian integers modulo . We construct for a cubic mapping graph whose vertex set is all the elements of and for which there is a directed edge from to if . This article investigates in detail the structure of . We give suffcient and necessary conditions for the existence of cycles with length . The number of -cycles in is obtained and we also examine when a vertex lies on a -cycle of , where is induced by all the units of while is induced by all the...
Structures ofW(2.2) Lie conformal algebra
The purpose of this paper is to study W(2, 2) Lie conformal algebra, which has a free ℂ[∂]-basis L, M such that [...] [LλL]=(∂+2λ)L,[LλM]=(∂+2λ)M,[MλM]=0 . In this paper, we study conformal derivations, central extensions and conformal modules for this Lie conformal algebra. Also, we compute the cohomology of this Lie conformal algebra with coefficients in its modules. In particular, we determine its cohomology with trivial coefficients both for the basic and reduced complexes.
Subarborians
Subtree Matching by Pushdown Automata
Superization and -specialization in combinatorial Hopf algebras.
Sur la réunion des arbres maximaux d'un graphe totalement préordonné. Note auto-critique
Un algorithme pour la recherche de la réunion des arbres maximaux (RAM) d'un graphe préordonné était proposé dans un article précédent (Math. Inf. Sci. hum. n°114, 1991, 35-40). Cet algorithme, qui était incorrect, est complété, justifié et illustré par un exemple dans cette note.
Sur la topologie d'un arbre phylogénétique : aspects théoriques, algorithmes et applications à l'analyse de données textuelles
Sur le nombre de registres nécessaires à l'évaluation d'une expression arithmétique
Sur les arbres logiques de M. Krasner
Sur les valeurs propres de la transformation de Coxeter.
Sur quelques aspects combinatoires du calcul des probabilités
Survey of certain valuations of graphs
The study of valuations of graphs is a relatively young part of graph theory. In this article we survey what is known about certain graph valuations, that is, labeling methods: antimagic labelings, edge-magic total labelings and vertex-magic total labelings.
Teorie grafů, 1736–1963 [Book]
The 3-path-step operator on trees and unicyclic graphs
E. Prisner in his book Graph Dynamics defines the -path-step operator on the class of finite graphs. The -path-step operator (for a positive integer ) is the operator which to every finite graph assigns the graph which has the same vertex set as and in which two vertices are adjacent if and only if there exists a path of length in connecting them. In the paper the trees and the unicyclic graphs fixed in the operator are studied.
The 3-Rainbow Index of a Graph
Let G be a nontrivial connected graph with an edge-coloring c : E(G) → {1, 2, . . . , q}, q ∈ ℕ, where adjacent edges may be colored the same. A tree T in G is a rainbow tree if no two edges of T receive the same color. For a vertex subset S ⊆ V (G), a tree that connects S in G is called an S-tree. The minimum number of colors that are needed in an edge-coloring of G such that there is a rainbow S-tree for each k-subset S of V (G) is called the k-rainbow index of G, denoted by rxk(G). In this paper,...
The Abel-type polynomial identities.
The block connectivity of random trees.