***** To join INSNA, visit http://www.insna.org *****
Nice seeing so many of you at the Beijing Sunbelt
Barry Wellman
A vision is just a vision if it's only in your head
Step by step, link by link, putting it together
Streisand/Sondheim
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NetLab Network FRSC INSNA Founder
http://www.chass.utoronto.ca/~wellman twitter: @barrywellman
NETWORKED: The New Social Operating System Lee Rainie & Barry Wellman
http://amzn.to/zXZg39
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Date: Mon, 12 Jun 2017 11:04:06 +0000
From: "[utf-8] Complexity Digest" <[log in to unmask]>
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To: "[utf-8] Barry" <[log in to unmask]>
Subject: [utf-8] Latest Complexity Digest Posts
Learn about the latest and greatest related to complex systems research. More at http://unam.us4.list-manage1.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=a3a651bfa5&e=55e25a0e3e
A Theory of Reality as More Than the Sum of Its Parts
http://unam.us4.list-manage.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=501dd355dd&e=55e25a0e3e
New math shows how, contrary to conventional scientific wisdom, conscious beings and other macroscopic entities might have greater influence over the future than does the sum of their microscopic components.
Source: www.quantamagazine.org (http://unam.us4.list-manage.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=25bb96a014&e=55e25a0e3e)
A generalized model of social and biological contagion
We present a model of contagion that unifies and generalizes existing models of the spread of social influences and micro-organismal infections. Our model incorporates individual memory of exposure to a contagious entity (e.g., a rumor or disease), variable magnitudes of exposure (dose sizes), and heterogeneity in the susceptibility of individuals. Through analysis and simulation, we examine in detail the case where individuals may recover from an infection and then immediately become susceptible again (analogous to the so-called SIS model). We identify three basic classes of contagion models which we call \textit{epidemic threshold}, \textit{vanishing critical mass}, and \textit{critical mass} classes, where each class of models corresponds to different strategies for prevention or facilitation. We find that the conditions for a particular contagion model to belong to one of the these three classes depend only on memory length and the probabilities of being infected by one
and two exposures respectively. These parameters are in principle measurable for real contagious influences or entities, thus yielding empirical implications for our model. We also study the case where individuals attain permanent immunity once recovered, finding that epidemics inevitably die out but may be surprisingly persistent when individuals possess memory.
A generalized model of social and biological contagion
Peter Sheridan Dodds, Duncan J. Watts
Source: arxiv.org (http://unam.us4.list-manage.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=d4ea8ef4a2&e=55e25a0e3e)
The Self-Organization of Dragon Kings
Surprisingly common outliers of a distribution tail, known as Dragon Kings, are seen in many complex systems. It has been argued that the general conditions for Dragon Kings in self-organized systems are high system coupling and low heterogeneity. In this Letter, we introduce a novel mechanism of Dragon Kings by discussing two closely-related stylized models of cascading failures. Although the first variant (based on simple contagion spreading and inoculation) exhibits well-studied self-organized criticality, the second one (based on both simple and complex contagion spreading) creates self-organized Dragon Kings in the failure size distribution. Next, we begin to understand the mechanistic origin of these Dragon Kings by mapping the probability of an initial cascade to a generalized birthday problem, which helps demonstrate that the Dragon King cascade is due to initial failures whose size exceeds a threshold that is infinitesimal compared to the size of the network. We use
this finding to predict the onset of Dragon Kings with high accuracy using only logistic regression. Finally, we devise a simple control strategy that can decrease the frequency of Dragon Kings by orders of magnitude. We conclude with remarks on the applicability of both models to natural and engineered systems.
The Self-Organization of Dragon Kings
Yuansheng Lin, Keith Burghardt, Martin Rohden, Pierre-André Noël, Raissa M. D'Souza
Source: arxiv.org (http://unam.us4.list-manage.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=d14222b2f5&e=55e25a0e3e)
Multiplex model of mental lexicon reveals explosive learning in humans
Similarities among words affect language acquisition and processing in a multi-relational way barely accounted for in the literature. We propose a multiplex network representation of word similarities in a mental lexicon as a natural framework for investigating large-scale cognitive patterns. Our model accounts for semantic, taxonomic, and phonological interactions and identifies a cluster of words of higher frequency, easier to identify, memorise and learn and with more meanings than expected at random. This cluster emerges around age 7 yr through an explosive transition not reproduced by null models. We relate this phenomenon to polysemy, i.e. redundancy in word meanings. We show that the word cluster acts as a core for the lexicon, increasing both its navigability and robustness to degradation in cognitive impairments. Our findings provide quantitative confirmation of existing psycholinguistic conjectures about core structure in the mental lexicon and the importance of
integrating multi-relational word-word interactions in suitable frameworks.
Multiplex model of mental lexicon reveals explosive learning in humans
Massimo Stella, Nicole M. Beckage, Markus Brede, Manlio De Domenico
Source: arxiv.org (http://unam.us4.list-manage1.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=ab173b61fd&e=55e25a0e3e)
Complexity research in Nature Communications
This web collection showcases the potential of interdisciplinary complexity research by bringing together a selection of recent Nature Communications articles investigating complex systems. Complexity research aims to characterize and understand the behaviour and nature of systems made up of many interacting elements. Such efforts often require interdisciplinary collaboration and expertise from diverse schools of thought. Nature Communications publishes papers across a broad range of topics that span the physical and life sciences, making the journal an ideal home for interdisciplinary studies.
Source: www.nature.com (http://unam.us4.list-manage.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=f694a2a5cf&e=55e25a0e3e)
Complexity Science Hub Vienna Workshop Series: Reinventing Society in the Digital Age
http://unam.us4.list-manage2.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=bc8d3d7785&e=55e25a0e3e
Source: www.youtube.com (http://unam.us4.list-manage.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=dc4a82ee4a&e=55e25a0e3e)
Collective navigation of complex networks: Participatory greedy routing
http://unam.us4.list-manage1.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=51378627c3&e=55e25a0e3e
Many networks are used to transfer information or goods, in other words, they are navigated. The larger the network, the more difficult it is to navigate efficiently. Indeed, information routing in the Internet faces serious scalability problems due to its rapid growth, recently accelerated by the rise of the Internet of Things. Large networks like the Internet can be navigated efficiently if nodes, or agents, actively forward information based on hidden maps underlying these systems. However, in reality most agents will deny to forward messages, which has a cost, and navigation is impossible. Can we design appropriate incentives that lead to participation and global navigability? Here, we present an evolutionary game where agents share the value generated by successful delivery of information or goods. We show that global navigability can emerge, but its complete breakdown is possible as well. Furthermore, we show that the system tends to self-organize into local clusters of
agents who participate in the navigation. This organizational principle can be exploited to favor the emergence of global navigability in the system.
Collective navigation of complex networks: Participatory greedy routing
Kaj-Kolja Kleineberg & Dirk Helbing
Scientific Reports 7, Article number: 2897 (2017)
doi:10.1038/s41598-017-02910-x
Source: www.nature.com (http://unam.us4.list-manage.com/track/click?u=0eb0ac9b4e8565f2967a8304b&id=82da6d7b39&e=55e25a0e3e)
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