scholarly journals A process of rumour scotching on finite populations

2015 ◽  
Vol 2 (9) ◽  
pp. 150240 ◽  
Author(s):  
Guilherme Ferraz de Arruda ◽  
Elcio Lebensztayn ◽  
Francisco A. Rodrigues ◽  
Pablo Martín Rodríguez

Rumour spreading is a ubiquitous phenomenon in social and technological networks. Traditional models consider that the rumour is propagated by pairwise interactions between spreaders and ignorants. Only spreaders are active and may become stiflers after contacting spreaders or stiflers. Here we propose a competition-like model in which spreaders try to transmit an information, while stiflers are also active and try to scotch it. We study the influence of transmission/scotching rates and initial conditions on the qualitative behaviour of the process. An analytical treatment based on the theory of convergence of density-dependent Markov chains is developed to analyse how the final proportion of ignorants behaves asymptotically in a finite homogeneously mixing population. We perform Monte Carlo simulations in random graphs and scale-free networks and verify that the results obtained for homogeneously mixing populations can be approximated for random graphs, but are not suitable for scale-free networks. Furthermore, regarding the process on a heterogeneous mixing population, we obtain a set of differential equations that describes the time evolution of the probability that an individual is in each state. Our model can also be applied for studying systems in which informed agents try to stop the rumour propagation, or for describing related susceptible–infected–recovered systems. In addition, our results can be considered to develop optimal information dissemination strategies and approaches to control rumour propagation.

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Nicole Balashov ◽  
Reuven Cohen ◽  
Avieli Haber ◽  
Michael Krivelevich ◽  
Simi Haber

Abstract We consider optimal attacks or immunization schemes on different models of random graphs. We derive bounds for the minimum number of nodes needed to be removed from a network such that all remaining components are fragments of negligible size.We obtain bounds for different regimes of random regular graphs, Erdős-Rényi random graphs, and scale free networks, some of which are tight. We show that the performance of attacks by degree is bounded away from optimality.Finally we present a polynomial time attack algorithm and prove its optimal performance in certain cases.


2014 ◽  
Vol 15 (3) ◽  
pp. 211-221 ◽  
Author(s):  
Li Wang ◽  
Chao Lei ◽  
Yingcheng Xu ◽  
Yuexiang Yang ◽  
Siqing Shan ◽  
...  

2015 ◽  
Vol 26 (06) ◽  
pp. 1550070
Author(s):  
João P. da Cruz ◽  
Nuno A. M. Araújo ◽  
Frank Raischel ◽  
Pedro G. Lind

We describe an ensemble of growing scale-free networks in an equilibrium framework, providing insight into why the exponent of empirical scale-free networks in nature is typically robust. In an analogy to thermostatistics, to describe the canonical and microcanonical ensembles, we introduce a functional, whose maximum corresponds to a scale-free configuration. We then identify the equivalents to energy, Zeroth-law, entropy and heat capacity for scale-free networks. Discussing the merging of scale-free networks, we also establish an exact relation to predict their final "equilibrium" degree exponent. All analytic results are complemented with Monte Carlo simulations. Our approach illustrates the possibility to apply the tools of equilibrium statistical physics to study the properties of growing networks, and it also supports the recent arguments on the complementarity between equilibrium and nonequilibrium systems.


2007 ◽  
Vol 22 (3) ◽  
pp. 27-41
Author(s):  
Alexandre Steyer ◽  
Renaud Garcia-Bardidia ◽  
Pascale Quester

This research examines the process by which information diffuses within newsgroups on the Internet. Our results empirically demonstrate that these newsgroups are scale-free networks where the potential for information dissemination is important, albeit somewhat unpredictable. This leads us to reconsider the econometric foundations of forecasting methods typically used by marketers.


2008 ◽  
Vol 18 (07) ◽  
pp. 2123-2131
Author(s):  
R. DORAT ◽  
J. P. DELAHAYE

In this paper, we propose a new very simple mechanism supporting the emergence of cooperation in a population of memoryless agents playing a prisoner's dilemma game. Each agent belongs to a community and interacts with the agents of its community and with the agents belonging to linked communities. A simple rule governs the dynamics of the system: a community grows (resp. decreases) if the average score of its members is superior (resp. inferior) to the average score calculated for the entire population. Starting from a random initialization, the system can evolve towards a majority of cooperators, towards the elimination of cooperators, or towards a situation with periodic evolutions of the populations of cooperators and defectors. The initial presence of clusters of C-strategies accounts for the convergence towards cooperative final states. We consider various topologies: Erdös and Rényi random graphs, square lattices and scale-free graphs. Clusters are not as likely to appear in all these topologies, so that there are significant differences between the average frequencies of cooperators associated with each topology. We show that random graphs favor cooperation whereas scale-free graphs tend to inhibit it. The relation between periodic evolutions and topological features is less clear. Nonetheless, we also state the importance of specific C-clusters for the survival of C-strategies in periodic oscillations. A major lesson of this paper is that the evolution of cooperation is very sensitive to initial conditions in models with global variables.


2006 ◽  
Vol 74 (4) ◽  
Author(s):  
Paulo R. A. Campos ◽  
Jaime Combadão ◽  
Francisco Dionisio ◽  
Isabel Gordo

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