Results 61 to 70 of about 4,390 (196)

A Conversation With David Bellhouse

International Statistical Review, EarlyView.
Summary David Richard Bellhouse was born in Winnipeg, Manitoba, on 19 July 1948. He studied actuarial mathematics and statistics at the University of Manitoba (BA, 1970; MA, 1972) and completed his PhD at the University of Waterloo, Ontario, in 1975. After being an Assistant Professor for 1 year at his alma mater, he joined the University of Western ...
Christian Genest
wiley   +1 more source

The bounds of the energy and Laplacian energy of chain graphs

AIMS Mathematics, 2021
Let $G$ be a simple connected graph of order $n$ with $m$ edges. The energy $\varepsilon(G)$ of $G$ is the sum of the absolute values of all eigenvalues of the adjacency matrix $A$.
Yinzhen Mei, Chengxiao Guo, Mengtian Liu
doaj   +1 more source

On bicyclic graphs with maximal energy

Linear Algebra and its Applications, 2007
The energy of a graph is the sum the absolute values of its eigenvalues. The main result of the article is the construction of the graph with maximal energy in the set of bicyclic graphs. This result gives a partial solution to Gutman's conjecture for molecular graphs with maximal energy.
Li, Xueliang, Zhang, Jianbin
openaire   +2 more sources

A matheuristic for the traveling salesman problem with positional consistency constraints

International Transactions in Operational Research, EarlyView.
Abstract We propose a matheuristic for the traveling salesman problem with positional consistency constraints, where we seek to generate a set of routes with minimum total cost, in which the nodes visited in more than one route (consistent nodes) must occupy the same relative position in all routes.
Luís Gouveia, Ana Paias, Mafalda Ponte
wiley   +1 more source

Extremal Bicyclic Graphs with Respect to Permanental Sums and Hosoya Indices

Axioms
Graph polynomials is one of the important research directions in mathematical chemistry. The coefficients of some graph polynomials, such as matching polynomial and permanental polynomial, are related to structural properties of graphs.
Tingzeng Wu, Yinggang Bai, Shoujun Xu
doaj   +1 more source

The extremal problems on the inertia of weighted bicyclic graphs [PDF]

, 2013
Let $G_w$ be a weighted graph. The number of the positive, negative and zero eigenvalues in the spectrum of $G_w$ are called positive inertia index, negative inertia index and nullity of $G_w$, and denoted by $i_{+}(G_w)$, $i_{-}(G_w)$, $i_{0}(G_w ...
Deng, Shibing, Li, Shuchao, Song, Feifei
core  

On Sum--Connectivity Index of Bicyclic Graphs

, 2009
We determine the minimum sum--connectivity index of bicyclic graphs with $n$ vertices and matching number $m$, where $2\le m\le \lfloor\frac{n}{2}\rfloor$, the minimum and the second minimum, as well as the maximum and the second maximum sum--connectivity indices of bicyclic graphs with $n\ge 5$ vertices. The extremal graphs are characterized.
Du, Zhibin, Zhou, Bo
openaire   +3 more sources

Heterogeneity of iridoid biosynthesis in catmints: Molecular background in a phylogenetic context

Journal of Integrative Plant Biology, EarlyView.
Evolutionary gains and losses of key biosynthetic genes likely resulting from multiple independent evolutionary events explain why certain Nepeta (catnip) species produce both the active, cat‐attracting nepetalactones and sugar‐bound iridoids, while others make only the sugar‐bound forms, and some have lost iridoid production entirely.
Tijana Banjanac, Milica Milutinović, Dragana Matekalo, Neda Popović, Luka Petrović, Uroš Gašić, Marijana Skorić, Branislav Šiler, Tamara Lukić, Ana Stupar, Slavica Dmitrović, Jasmina Nestorović Živković, Biljana Filipović, Jelena Božunović, Miloš Todorović, Danijela Mišić   +15 more
wiley   +1 more source

Graphs with 3-rainbow index $n-1$ and $n-2$ [PDF]

, 2013
Let $G$ be a nontrivial connected graph with an edge-coloring $c:E(G)\rightarrow \{1,2,\ldots,q\},$ $q\in \mathbb{N}$, 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.
Li, Xueliang, Yang, Kang, Zhao, Yan
core  

The inertia of unicyclic graphs and bicyclic graphs

Discussiones Mathematicae - General Algebra and Applications, 2013
Let G be a graph with n vertices and (G) be the matching number of G. The inertia of a graph G, In(G) = (n+;n ;n0) is an integer triple specifying the numbers of positive, negative and zero eigenvalues of the adjacency matrix A(G), respectively. Let (G) = n0 denote the nullity of G (the multiplicity of the eigenvalue zero of G).
openaire   +1 more source