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Fully-dynamic Approximation of Betweenness Centrality [article]

Elisabetta Bergamini, Henning Meyerhenke
2015 arXiv   pre-print
Using approximation, our algorithms are the first to make in-memory computation of betweenness in fully-dynamic networks with millions of edges feasible.  ...  Betweenness is a well-known centrality measure that ranks the nodes of a network according to their participation in shortest paths.  ...  We thank Moritz von Looz for providing the synthetic dynamic networks and the numerous contributors to the NetworKit project.  ... 
arXiv:1504.07091v2 fatcat:zhe7ockhavbn7kywum725wzf2y

Fully-Dynamic Approximation of Betweenness Centrality [chapter]

Elisabetta Bergamini, Henning Meyerhenke
2015 Lecture Notes in Computer Science  
Using approximation, our algorithms are the first to make in-memory computation of betweenness in fully-dynamic networks with millions of edges feasible.  ...  Betweenness is a well-known centrality measure that ranks the nodes of a network according to their participation in shortest paths.  ...  We thank Moritz von Looz for providing the synthetic dynamic networks and the numerous contributors to the NetworKit project.  ... 
doi:10.1007/978-3-662-48350-3_14 fatcat:e332kxucpfefrg6jk3vsad7o6y

Binary dynamics on star networks under external perturbations

Carolina A. Moreira, David M. Schneider, Marcus A. M. de Aguiar
2015 Physical Review E  
We obtain approximate analytical solutions that hold near the transition and that clarify the role of the central node in the process.  ...  We study a binary dynamical process that is a representation of the voter model with opinion makers.  ...  with respect to the fully connected dynamics.  ... 
doi:10.1103/physreve.92.042812 pmid:26565294 fatcat:y27dnhmiwbcflnhptkrezok4tm

Recent Advances in Fully Dynamic Graph Algorithms [article]

Kathrin Hanauer, Monika Henzinger, Christian Schulz
2021 arXiv   pre-print
In recent years, significant advances have been made in the design and analysis of fully dynamic algorithms.  ...  Here, we present a quick reference guide to recent engineering and theory results in the area of fully dynamic graph algorithms.  ...  For some classical dynamic algorithms, experimental studies have been performed, such as for fully dynamic graph clustering [80] and fully dynamic approximation of betweenness centrality [35] .  ... 
arXiv:2102.11169v5 fatcat:tcs3lkgcg5f7jax672adyzrstm

Converting a real quantum spin bath to an effective classical noise acting on a central spin

Wayne M. Witzel, Kevin Young, Sankar Das Sarma
2014 Physical Review B  
We present a cluster expansion method for approximating quantum spin-bath dynamics in terms of a classical Gaussian stochastic process.  ...  We study several instances of the central spin decoherence problem in which the central spin and randomly-located bath spins are alike and dipolarly coupled.  ...  A semiclassical stochastic noise model should well approximate the dynamics of a fully quantum model if two conditions are met: (i) the bath dynamics are independent of the central spin state, i.e. back  ... 
doi:10.1103/physrevb.90.115431 fatcat:epdmizg4yzftbeapro6icgb6ey

Approximating Betweenness Centrality in Fully Dynamic Networks

Elisabetta Bergamini, Henning Meyerhenke
2016 Internet Mathematics  
In this article, we propose the first betweenness centrality approximation algorithms with a provable guarantee on the maximum approximation error for dynamic networks.  ...  Using approximation, our algorithms are the first to make in-memory computation of betweenness in dynamic networks with millions of edges feasible.  ...  We also thank Matteo Riondato for his constructive comments on earlier versions of the material presented in this article.  ... 
doi:10.1080/15427951.2016.1177802 fatcat:gr6zvp4bkbd25jbl2spg4tyzaq

Heuristic Algorithm for Approximation Betweenness Centrality Using Graph Coarsening

Mikhail Chernoskutov, Yves Ineichen, Costas Bekas
2015 Procedia Computer Science  
Here we focus on approximating the computation of betweenness centrality for dynamically changing graphs.  ...  Our approach demonstrates more than 60% speedup compared to the exact recalculation of the betweenness centrality for dynamically changing graphs.  ...  We implemented a prototype of our approach to approximating betweenness centrality (for dynamic graphs) with NetworkX citenetwork in Python.  ... 
doi:10.1016/j.procs.2015.11.011 fatcat:mwhtka25fbfjpj2nkhgtjneqxq

Page 765 of Astronomy and Astrophysics Vol. 312, Issue 3 [page]

1996 Astronomy and Astrophysics  
The existence of this central dynamical decoupling is made easier by the presence of the x4 orbits.  ...  The lifetime of the counter-rotating nested bar phase is about | Gyr, i.e. approximately between t= 1500 and t=2500.  ... 

Centrality Measures: A Tool to Identify Key Actors in Social Networks [article]

Rishi Ranjan Singh
2020 arXiv   pre-print
In this chapter, we summarize some of the centrality measures that are extensively applied for mining social network data. We also discuss various directions of research related to these measures.  ...  Experts from several disciplines have been widely using centrality measures for analyzing large as well as complex networks.  ...  Pontecorvi and Ramachandran [138] gave a fully dynamic algorithm for updating APASPs and extended the algorithm to develop a fully dynamic approach to update betweenness scores [140, 139] .  ... 
arXiv:2011.01627v1 fatcat:hsocyivf5jgstkled67osd6w6q

Generalized mean field approximation for parallel dynamics of the Ising model

Hamed Mahmoudi, David Saad
2014 Journal of Statistical Mechanics: Theory and Experiment  
The dynamics of non-equilibrium Ising model with parallel updates is investigated using a generalized mean field approximation that incorporates multiple two-site correlations at any two time steps, which  ...  The method is also employed to obtain parameter values for the kinetic inverse Ising modeling problem, where couplings and local fields values of a fully connected spin system are inferred from data.  ...  A central macroscopic quantity in studying the dynamics of spin glasses is the spin correlation function that describes the correlation between microscopic states at two time steps.  ... 
doi:10.1088/1742-5468/2014/07/p07001 fatcat:7m3ztygdv5czjgmjbn42tin36a

A dynamically optimized finite difference scheme for Large-Eddy Simulation

D. Fauconnier, C. De Langhe, E. Dick
2010 Journal of Computational and Applied Mathematics  
The scheme is optimized dynamically through the real-time adaption of a dynamic coefficient according to the spectral content of the flow, such that the global dispersion error is minimal.  ...  In the case of DNS-resolution, the dynamic scheme reduces to the standard Taylor-based finite difference scheme with formal asymptotic order of accuracy.  ...  Acknowledgment The first author's research was funded by a Ph.D. grant of the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen).  ... 
doi:10.1016/j.cam.2009.08.066 fatcat:2jaj3wigivfqnfhpqmu2l54aua

Revisiting time discretisation of spiking network models

Bruno Cessac, Thierry Viéville
2007 BMC Neuroscience  
The effects of the discretisation approximation have been analytically and experimentally analyzed, in detail.  ...  dynamics [1] and a discrete time neural network model with spiking neurons Open Access Poster presentation (page number not for citation purposes) Publish with Bio Med Central and every  ... 
doi:10.1186/1471-2202-8-s2-p76 fatcat:djo26wh7anh2hf3vnx57x33dyi

Inferring effective dynamics in large-scale networks of cortical neurons

Netta Haroush, Shimon Marom, Paolo Giudice, Maurizio Mattia
2013 BMC Neuroscience  
Nevertheless, spontaneously PBs, those that occur without exogenous stimulations, show a variability which is not fully captured by the identified two dimensional dynamics.  ...  Inferred fatigue dynamics largely correlates both with failure rate in evoking PBs and with response delay between stimulation times and PB onsets.  ...  © 2013 Haroush et al; licensee BioMed Central Ltd.  ... 
doi:10.1186/1471-2202-14-s1-p266 pmcid:PMC3704394 fatcat:3utqgrg33rgu3e6isjdsamsmiy

A numerical procedure for minimizing the maximum cost [chapter]

Silvia Marco, Roberto L. V. González
1996 System Modelling and Optimization  
We give an optimal estimate for the error between the approximated solution and the optimal cost of the original problem.  ...  We present an approximation method which employs both discretization on time and on spatial variables. In this way, we obtain a computational implementable fully discrete problem.  ...  Central result: Rate of convergence The central result of convergence is given by the following theorem which establishes an estimate of the difference between the optimal cost and the fully discrete solution  ... 
doi:10.1007/978-0-387-34897-1_33 fatcat:n7nma2dwz5e3pnkl25fulqf224

Exact dynamics in the inhomogeneous central-spin model

Michael Bortz, Joachim Stolze
2007 Physical Review B  
We study the dynamics of a single spin-1/2 coupled to a bath of spins-1/2 by inhomogeneous Heisenberg couplings including a central magnetic field.  ...  This central-spin model describes decoherence in quantum bit systems. An exact formula for the dynamics of the central spin is presented, based on the Bethe ansatz.  ...  CONCLUSION AND OUTLOOK The approximate analytical and exact numerical evaluations of the general formula for the time evolution of the central spin polarization S z 0 for an initially fully polarized spin  ... 
doi:10.1103/physrevb.76.014304 fatcat:eg3rb2wvffg4xlrjt3pyeovkme
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