Results 31 to 40 of about 467,517 (284)

The Q-index and Connectivity of Graphs

Journal of the Operations Research Society of China, 2022
A connected graph $G$ is said to be $k$-connected if it has more than $k$ vertices and remains connected whenever fewer than $k$ vertices are deleted. In this paper, for a connected graph $G$ with sufficiently large order, we present a tight sufficient condition for $G$ with fixed minimum degree to be $k$-connected based on the $Q$-index.
Peng-Li Zhang, Li-Hua Feng, Wei-Jun Liu, Xiao-Dong Zhang   +3 more
openaire   +2 more sources

About the Randić Connectivity, Modify Randić Connectivity and Sum-connectivity Indices of Titania Nanotubes TiO2(m,n)

Acta Chimica Slovenica, 2017
The Randić Connectivity Index R(G) is one of the oldest connectivity index, introduced by Randić in 1975. Another connectivity indices is the Sum-Connectivity Index X(G) introduced in 2008 by Zhou and Trinajstić.
Wei Gao, Mohammad Reza Farahani, Muhammad Imran   +2 more
doaj   +1 more source

Spatio-Temporal Variation of Hydrological Connectivity and Natural–Human Coupling Driving Forces Analysis in the Beijing-Tianjin-Hebei Region

Land
Hydrological connectivity is crucial for maintaining the stability and function of regional ecology and is a fundamental link to solving regional water and ecological environmental problems.
Wenxuan Wang, Meirong Tian, Haijun Zhang, Kun Liu   +3 more
doaj   +1 more source

Minimum Variable Connectivity Index of Trees of a Fixed Order

Discrete Dynamics in Nature and Society, 2020
The connectivity index, introduced by the chemist Milan Randić in 1975, is one of the topological indices with many applications. In the first quarter of 1990s, Randić proposed the variable connectivity index by extending the definition of the ...
Shamaila Yousaf, Akhlaq Ahmad Bhatti, Akbar Ali   +2 more
doaj   +1 more source

Closed Formulas for Some New Degree Based Topological Descriptors Using M-polynomial and Boron Triangular Nanotube

Frontiers in Chemistry, 2021
In this article, we provide new formulas to compute the reduced reciprocal randić index, Arithmetic geometric1 index, SK index, SK1 index, SK2 index, edge version of the first zagreb index, sum connectivity index, general sum connectivity index, and the ...
Dong Yun Shin, Sabir Hussain, Farkhanda Afzal, Choonkil Park, Deeba Afzal, Mohammad R. Farahani   +5 more
doaj   +1 more source

On a lower bound for the eccentric connectivity index of graphs

, 2018
The eccentric connectivity index of a graph $G$, denoted by $\xi^{c}(G)$, defined as $\xi^{c}(G)$ = $\sum_{v \in V(G)}\epsilon(v) \cdot d(v)$, where $\epsilon(v)$ and $d(v)$ denotes the eccentricity and degree of a vertex $v$ in a graph $G$, respectively.
Bantva, Devsi
core   +1 more source

Ranking Territorial Units Using Entropy-Based Pedodiversity

Spanish Journal of Soil Science
The pedodiversity concept integrates diversity indices and GIS techniques to assess the spatial heterogeneity of soils. This study proposes using pedodiversity indices for Romania’s geographic regions and relief units to evaluate their connectivity ...
Cristian Vasilică Secu, Radu Gabriel Pîrnău   +1 more
doaj   +1 more source

Critical comments on EEG sensor space dynamical connectivity analysis

, 2016
Many different analysis techniques have been developed and applied to EEG recordings that allow one to investigate how different brain areas interact. One particular class of methods, based on the linear parametric representation of multiple interacting ...
Faes, Luca, Karahan, Esin, Marinazzo, Daniele, Songsiri, Jitkomut, Sosa, Pedro Antonio Valdes, van de Steen, Frederik   +5 more
core   +1 more source

Evidence for Solar Tether-cutting Magnetic Reconnection from Coronal Field Extrapolations [PDF]

, 2013
Magnetic reconnection is one of the primary mechanisms for triggering solar eruptive events, but direct observation of its rapid process has been of challenge. In this Letter we present, using a nonlinear force-free field (NLFFF) extrapolation technique,
Deng, Na, Lee, Jeongwoo, Liu, Chang, Moore, Ronald L., Wang, Haimin, Wiegelmann, Thomas   +5 more
core   +1 more source

Connecting Microstructures for Multiscale Topology Optimization With Connectivity Index Constraints [PDF]

Journal of Mechanical Design, 2018
Abstract With the rapid developments of advanced manufacturing and its ability to manufacture microscale features, architected materials are receiving ever increasing attention in many physics fields. Such a design problem can be treated in topology optimization as architected material with repeated unit cells using the homogenization ...
Du, Zongliang, Zhou, Xiao-Yi, Picelli, Renato, Kim, Hyunsun Alicia   +3 more
openaire   +3 more sources