OPINION DYNAMICS IN POPULATIONS WITH IMPLICIT COMMUNITY STRUCTURE

2009 ◽  
Vol 20 (12) ◽  
pp. 2013-2026 ◽  
Author(s):  
XIAMENG SI ◽  
YUN LIU ◽  
ZHENJIANG ZHANG
Keyword(s):  
Community Structure ◽  
Opinion Dynamics ◽  
Initial Distribution ◽  
Contact Network ◽  
Space And Time ◽  
Opinion Evolution ◽  
Majority Model

Web encounter facilitate contacts between people from different communities outside space and time. Implicit Community Structure is exhibited because of highly connected links within community and sparse encounters between communities. Considering the imperceptible influence of encounter on opinions, Sznajd updating rules are used to mimic people's behaviors after encountering a stranger in another community. We introduce a model for opinion evolution, in which the interconnectivity between different communities is represented as encounter frequency, and leadership is introduced to control the strength of community's opinion guide. In this scenario, the effects of Implicit Community Structure of contact network on opinion evolution, for asymmetric and random initial distribution but with heterogeneous opinion guide, are investigated respectively. It is shown that large encounter frequency favors consensus of the whole populations and successful opinion spreading, which is qualitatively agree with the results observed in Majority model defined on substrates with predefined community structure.

COMPARING EFFECTS OF CLUSTER-COUPLED PATTERNS ON OPINION DYNAMICS

2012 ◽  
Vol 23 (07) ◽  
pp. 1250050 ◽  
Author(s):  
YUN LIU ◽  
XIA-MENG SI ◽  
YAN-CHAO ZHANG
Keyword(s):  
Community Structure ◽  
Social Cohesion ◽  
Small World ◽  
Opinion Dynamics ◽  
Scale Free ◽  
Update Rules ◽  
Opinion Evolution ◽  
Multiple Cluster ◽  
Better Than ◽  
Continuous Opinions

Community structure is another important feature besides small-world and scale-free property of complex networks. Communities can be coupled through specific fixed links between nodes, or occasional encounter behavior. We introduce a model for opinion evolution with multiple cluster-coupled patterns, in which the interconnectivity denotes the coupled degree of communities by fixed links, and encounter frequency controls the coupled degree of communities by encounter behaviors. Considering the complicated cognitive system of people, the CODA (continuous opinions and discrete actions) update rules are used to mimic how people update their decisions after interacting with someone. It is shown that, large interconnectivity and encounter frequency both can promote consensus, reduce competition between communities and propagate some opinion successfully across the whole population. Encounter frequency is better than interconnectivity at facilitating the consensus of decisions. When the degree of social cohesion is same, small interconnectivity has better effects on lessening the competence between communities than small encounter frequency does, while large encounter frequency can make the greater degree of agreement across the whole populations than large interconnectivity can.

scholarly journals Paths to Polarization: How Extreme Views, Miscommunication, and Random Chance Drive Opinion Dynamics

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Matthew A. Turner ◽  
Paul E. Smaldino
Keyword(s):  
Opinion Dynamics ◽  
Initial Distribution ◽  
Polarization Measurement ◽  
Cultural Complexity ◽  
Stochastic Variation ◽  
Social Phenomena ◽  
Agent Based ◽  
The Social ◽  
Apparent Reduction ◽  
Path Dependent

Understanding the social conditions that tend to increase or decrease polarization is important for many reasons. We study a network-structured agent-based model of opinion dynamics, extending a model previously introduced by Flache and Macy (2011), who found that polarization appeared to increase with the introduction of long-range ties but decrease with the number of salient opinions, which they called the population’s “cultural complexity.” We find the following. First, polarization is strongly path dependent and sensitive to stochastic variation. Second, polarization depends strongly on the initial distribution of opinions in the population. In the absence of extremists, polarization may be mitigated. Third, noisy communication can drive a population toward more extreme opinions and even cause acute polarization. Finally, the apparent reduction in polarization under increased “cultural complexity” arises via a particular property of the polarization measurement, under which a population containing a wider diversity of extreme views is deemed less polarized. This work has implications for understanding the population dynamics of beliefs, opinions, and polarization as well as broader implications for the analysis of agent-based models of social phenomena.

scholarly journals Host community structure and the maintenance of pathogen diversity

2007 ◽  
Vol 274 (1619) ◽  
pp. 1715-1721 ◽  
Author(s):  
Caroline Buckee ◽  
Leon Danon ◽  
Sunetra Gupta
Keyword(s):  
Community Structure ◽  
Spatial Differentiation ◽  
Host Community ◽  
Contact Network ◽  
Strong Mixing ◽  
Metapopulation Model ◽  
Pathogen Population ◽  
Antigenic Diversity ◽  
Pathogen Diversity ◽  
Pathogen Populations

Community structure has been widely identified as a feature of many real-world networks. It has been shown that the antigenic diversity of a pathogen population can be significantly affected by the contact network of its hosts; however, the effects of community structure have not yet been explored. Here, we examine the congruence between patterns of antigenic diversity in pathogen populations in neighbouring communities, using both a deterministic metapopulation model and individual-based formulations. We show that the spatial differentiation of the pathogen population can only be maintained at levels of coupling far lower than that necessary for the host populations to remain distinct. Therefore, identifiable community structure in host networks may not reflect differentiation of the processes occurring upon them and, conversely, a lack of genetic differentiation between pathogens from different host communities may not reflect strong mixing between them.

scholarly journals Influential Node Control Strategy for Opinion Evolution on Social Networks

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Cheng Ju ◽  
Jinde Cao ◽  
Weiqi Zhang ◽  
Mengxin Ji
Keyword(s):  
Social Networks ◽  
Control Strategy ◽  
Small World ◽  
Opinion Dynamics ◽  
Node Degree ◽  
New Model ◽  
New Strategy ◽  
Influential Nodes ◽  
Basic Features ◽  
Opinion Evolution

We study opinion dynamics in social networks and present a new strategy to control the invasive opinion. A developed continuous-opinion evolution model is proposed to describe the mechanism of making decision in closed community. Two basic strategies of evolution are determined, and some basic features of our new model are analyzed. We study the different invasive strategies. It is shown via using Monte Carlo simulations that our new model shows different invulnerability with traditional model. Node degree and cohesion in invasive small-world community plays less significant role when the evolution of opinion is continuous rather than dichotomous. Using simulation, we find one kind of Influential Nodes that can affect the outcome dramatically, while these Influential Nodes are sensitive to their node degree and the evolution weight. Thus, we develop invasive control strategy based on these features.

scholarly journals Disentangling metacommunity processes using multiple metrics in space and time

2020 ◽  
Author(s):  
Laura Melissa Guzman ◽  
Patrick L. Thompson ◽  
Duarte S Viana ◽  
Bram Vanschoenwinkel ◽  
Zsófia Horváth ◽  
...  
Keyword(s):  
Community Structure ◽  
Community Dynamics ◽  
Variation Partitioning ◽  
Species Abundance ◽  
Emergent Properties ◽  
Sampling Effort ◽  
Summary Statistics ◽  
Space And Time ◽  
Metacommunity Dynamics ◽  
Analytical Approaches

AbstractMetacommunity ecology has focused on using observational and analytical approaches to disentangle the role of critical assembly processes, such as dispersal limitation and environmental filtering. Many methods have been proposed for this purpose, most notably multivariate analyses of species abundance and its association with variation in spatial and environmental conditions. These approaches tend to focus on few emergent properties of metacommunities and have largely ignored temporal community dynamics. By doing so, these are limited in their ability to differentiate metacommunity dynamics. Here, we develop a Virtual ecologist’ approach to evaluate critical metacommunity assembly processes based on a number of summary statistics of community structure across space and time. Specifically, we first simulate metacommunities emphasizing three main processes that underlie metacommunity dynamics (density-independent responses to abiotic conditions, density-dependent biotic interactions, and dispersal). We then calculate a number of commonly used summary statistics of community structure in space and time, and use random forests to evaluate their utility for understanding the strength of these three processes. We found that: (i) time series are necessary to disentangle metacommunity processes, (ii) each of the three studied processes is distinguished with different descriptors, (iii) each summary statistic is differently sensitive to temporal and spatial sampling effort. Some of the most useful statistics include the coefficient of variation of abundances through time and metrics that incorporate variation in the relative abundances (evenness) of species. Surprisingly, we found that when we only used a single snapshot of community variation in space, the most commonly used approaches based on variation partitioning were largely uninformative regarding assembly processes, particularly, variation in dispersal. We conclude that a combination of methods and summary statistics will be necessary to understand the processes that underlie metacommunity assembly through space and time.

scholarly journals Spatial and Temporal Variation of Fish Assemblages in Seti Gandaki River, Tanahu, Nepal

2020 ◽  
Vol 10 (2) ◽  
pp. 93-104
Author(s):  
ARCHANA PRASAD ◽  
ANJANA SHRESTHA ◽  
JASH HANG LIMBU ◽  
DEEP SWAR
Keyword(s):  
Community Structure ◽  
Fish Community ◽  
Fish Assemblages ◽  
Mesh Size ◽  
Spatial And Temporal Variation ◽  
Total Hardness ◽  
Medium Size ◽  
Fish Community Structure ◽  
Space And Time ◽  
Significant Difference

The space and time variations of the fish community structure in hill streams of Nepal are poorly understood. This research aims at studying the space and time variation of fish community structure in the Seti Gandaki River, Tanahu, Nepal. The field survey was conducted from July 2017 to June 2018 and the fishes were sampled from six sites using a medium size cast net of mesh size ranging from 3 mm to 6 mm mesh size, 25-33 feet length and 3.5-5 feet width, with the help of local fisher man. A total of 1,440 individuals were caught representing 46 species belonging to three order, nine families and 23 genera. The analysis of similarity (ANOSIM) showed significant difference in space (R = 0.824, P = 0.001) but not in time (R = 0.135, P = 0.021). On the basis of similarity percentage (SIMPER) analysis, 85.43% similarity was found among the seasons and major contributing species were Barilius bendelisis (8.44%) followed by B. vagra (7.79%), Tor putitora (7.27%), Garra gotyla (7%), Acanthocobotis botia (6.7%), Neolissochilus hexagonolepis (6.64%), Barilius shacra (6%), B. barila (4.5%) and Opsarius barna (4.37%). On the other hand, 85.24% similarity was found among the sites and major contributing species were B. bendelisis (8.8%) followed by B. vagra (7.6%), G. gotyla (7.27%), T. putitora (7.17%), A. botia (6.97%), N. hexagonolepis (6.7%), B. shacra (6.34%), B. barila (4.7%) and O. barna (4.39%). Results from the Canonical Correspondence Analysis indicated that the environmental variables, such as pH, total hardness, alkalinity, dissolved oxygen and water temperature have shown to determine the fish community structure of Seti Gandaki River. Keywords: Fish diversity, freshwater, habitat, spatio-temporal, stream

scholarly journals The Impact of Community Structure on the Convergence Time of Opinion Dynamics

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
An Lu ◽  
Chunhua Sun ◽  
Yezheng Liu
Keyword(s):  
Community Structure ◽  
Social Network ◽  
Social Influence ◽  
Opinion Dynamics ◽  
Matrix Analysis ◽  
Convergence Time ◽  
Influence Matrix ◽  
The Social ◽  
The Impact ◽  
Second Largest Eigenvalue

We analyze the convergence time of opinion dynamics in a social network with community structure. Using matrix analysis, we prove that the convergence time is determined by the second largest eigenvalue modulus. This modulus is close to 1 if the social influence matrix is nearly uncoupled. Furthermore, we discuss and analyze the factors of community structure affecting the convergence time.

scholarly journals Submesoscale physicochemical dynamics directly shape bacterioplankton community structure in space and time

2021 ◽  
Author(s):  
Eduard Fadeev ◽  
Matthias Wietz ◽  
Wilken‐Jon von Appen ◽  
Morten H. Iversen ◽  
Eva‐Maria Nöthig ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterioplankton Community ◽  
Space And Time

scholarly journals Countering the potential re-emergence of a deadly infectious disease - information warfare, identifying strategic threats, launching countermeasures

2020 ◽  
Author(s):  
Rex N. Ali ◽  
Harvey Rubin ◽  
Saswati Sarkar
Keyword(s):  
Infectious Disease ◽  
Disease Outbreaks ◽  
Opinion Dynamics ◽  
Initial Distribution ◽  
Information Warfare ◽  
Mobility Patterns ◽  
Substantial Impact ◽  
Social Exchanges ◽  
Disease Information ◽  
Spatio Temporal

AbstractEradicated infectious diseases like smallpox can re-emerge through accident or designs of bioterrorists, and perpetrate heavy casualties. Currently, only a small percentage of the populace is vaccinated, and their protection is likely to have waned. Most therefore are susceptible today. And when the disease re-emerges the susceptible individuals may be manipulated by disinformation on Social Media to refuse vaccines. Thus, a combination of countermeasures consisting of antiviral drugs and vaccines and a range of policies for their application need to be investigated. Opinions as to receptivity of vaccines evolve with time through social exchanges over networks that overlap with but are not identical to the disease propagation networks. These couple the spread of the biological and information contagion and necessitate a joint investigation of the two. Towards these, we develop a computationally tractable metapopulation epidemiological model that captures the joint spatio-temporal evolution of smallpox and opinion dynamics. The computations based on the model show that opinion dynamics has a substantial impact on the fatality count. Towards understanding how perpetrators are likely to seed the infection we identify a) the initial distribution of infected individuals that maximize the overall fatality count regardless of mobility patterns, and b) which habitation structures are more vulnerable to outbreaks. We assess the relative efficacy of different countermeasures and conclude that a combination of vaccines and drugs minimizes the fatalities, and by itself, for smallpox, drugs reduce fatalities more than the vaccine. Accordingly, we assess the efficacies of three separate policies for administering the drugs and identify the best among them for various parameter combinations. When the availability of the drug is finite, we show that increase in its supply substantially reduces the overall fatality. Our findings lead to policy recommendations for public health and urban design authorities towards thwarting smallpox and other infectious disease outbreaks.

scholarly journals Fish community structure along altitudinal gradients with relation to environmental variables in Ratuwa River of Eastern, Nepal

Our Nature ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 70-81
Author(s):  
Dipak Rajbanshi ◽  
Jash Hang Limbu ◽  
Niraj Khadka ◽  
Prakash Kumar ◽  
Jeevan Kumar Gurung ◽  
...  
Keyword(s):  
Community Structure ◽  
Altitudinal Gradient ◽  
Fish Community ◽  
Fish Diversity ◽  
Fish Assemblage Structure ◽  
Fish Community Structure ◽  
Brachydanio Rerio ◽  
Altitudinal Gradients ◽  
Space And Time ◽  
Significant Difference

Studies on fish community structure along altitudinal gradients of rivers are lacking in Nepal. This study was carried out to gauge the fish diversity and composition along elevational gradient in Ratuwa River. The altitudinal gradient varies between 70 m to 1300 m. Fish samples were collected based on habitat representativeness from April (spring) 10-18, July (summer) 10-18, October (autumn) 10-18, 2020 and January (winter) 10-18, 2021. A total of 3447 specimens representing 4 orders, 14 families and 36 species were identified. Both fish diversity and abundance of studied ichthyofauna vary with altitudinal gradient. The present study affirmed that fish species of Opsarius bendelisis, Schistura multifasciatus, Garra annandalei, Brachydanio rerio, Aspidoparia morar, and Schistura scaturigina are the major contributory species (>1%) for both space and time spectrums. Fish community structure testing for both to space and time showed significant difference in spatial spectrum (R=0.72, P<0.01) but no significant difference in temporal variation (R=-0.034, P>0.05). The present results hinted that fish assemblage structure varied significantly from low to high elevations, altitude, water temperature, water velocity, dissolved oxygen and pH was found as major influential factors (P<0.05) for species distribution.

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