Results 31 to 40 of about 39,392 (275)
Extremal graphs of multiplicative sum Zagreb index [PDF]
Notes on Number Theory and Discrete MathematicsThe multiplicative sum Zagreb index, regarded as the multiplicative version of the first Zagreb index, is defined as the product of the degree sum over all pairs of adjacent vertices.
Chunlei Xu +3 more
doaj +1 more source
An advance in infinite graph models for the analysis of transportation networks
International Journal of Applied Mathematics and Computer Science, 2016 This paper extends to infinite graphs the most general extremal issues, which are problems of determining the maximum number of edges of a graph not containing a given subgraph.
Cera Martín, Fedriani Eugenio M.
doaj +1 more source
The Connectivity and the Harary Index of a Graph [PDF]
, 2012 The Harary index of a graph is defined as the sum of reciprocals of distances between all pairs of vertices of the graph. In this paper we provide an upper bound of the Harary index in terms of the vertex or edge connectivity of a graph.
Das +17 more
core +1 more source
Ars Mathematica Contemporanea, 2012 A graph G is singular if the zero-one adjacency matrix has the eigenvalue zero. The multiplicity of the eigenvalue zero is called the nullity of G . For two vertices y and z of G , we call ( G , y , z ) a device with respect to y and z .
Irene Sciriha +4 more
openaire +2 more sources
Tur\'an Graphs, Stability Number, and Fibonacci Index
, 2008 The Fibonacci index of a graph is the number of its stable sets. This parameter is widely studied and has applications in chemical graph theory. In this paper, we establish tight upper bounds for the Fibonacci index in terms of the stability number and ...
A. Knopfmacher +20 more
core +1 more source
Maximal tree and unicylic graph for Euler Sombor index with given diameter
AKCE International Journal of Graphs and CombinatoricsThe study of topological descriptors is essential for understanding the underlying structures of graphs and networks. Numerous numerical descriptors associated with graphs have been used to analyze their overall structure.
Zahid Raza +3 more
doaj +1 more source
P_{m}-saturated graphs with minimum size [PDF]
Opuscula Mathematica, 2004 By \(P_m\) we denote a path of order \(m\). A graph \(G\) is said to be \(P_m\)-saturated if \(G\) has no subgraph isomorphic to \(P_m\) and adding any new edge to \(G\) creates a \(P_m\) in \(G\). In 1986 L. Kászonyi and Zs.
Aneta Dudek, A. Paweł Wojda
doaj
Maximum Reciprocal Degree Resistance Distance Index of Unicyclic Graphs
Discrete Dynamics in Nature and Society, 2020 The reciprocal degree resistance distance index of a connected graph G is defined as RDRG=∑u,v⊆VGdGu+dGv/rGu,v, where rGu,v is the resistance distance between vertices u and v in G. Let Un denote the set of unicyclic graphs with n vertices.
Gai-Xiang Cai, Xing-Xing Li, Gui-Dong Yu
doaj +1 more source
Graph Embedded Extreme Learning Machine [PDF]
IEEE Transactions on Cybernetics, 2016 In this paper, we propose a novel extension of the extreme learning machine (ELM) algorithm for single-hidden layer feedforward neural network training that is able to incorporate subspace learning (SL) criteria on the optimization process followed for the calculation of the network's output weights. The proposed graph embedded ELM (GEELM) algorithm is
Pitas, Ioannis +2 more
openaire +4 more sources
Zeroth-order general Randić index of cactus graphs
AKCE International Journal of Graphs and Combinatorics, 2019 A connected graph G is said to be cactus if no two cycles of G have any common edge. The present note is devoted to developing some extremal results for the zeroth-order general Randić index of cactus graphs and finding some sharp bounds on this index ...
Hassan Ahmed +2 more
doaj +2 more sources