LISTSERV mailing list manager LISTSERV 16.0

Help for SOCNET Archives


SOCNET Archives

SOCNET Archives


SOCNET@LISTS.UFL.EDU


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

SOCNET Home

SOCNET Home

SOCNET  August 2014

SOCNET August 2014

Subject:

[comdig] Latest Complexity Digest Posts (fwd)

From:

Barry Wellman <[log in to unmask]>

Reply-To:

Barry Wellman <[log in to unmask]>

Date:

Tue, 5 Aug 2014 18:34:35 -0400

Content-Type:

MULTIPART/MIXED

Parts/Attachments:

Parts/Attachments

TEXT/PLAIN (168 lines)

*****  To join INSNA, visit http://www.insna.org  *****


selected

   Barry Wellman
  _______________________________________________________________________
   FRSC		              NetLab Network              INSNA Founder
                      Faculty of Information (iSchool)
   University of Toronto                          Toronto Canada M5S 3G6
   http://www.chass.utoronto.ca/~wellman          twitter: @barrywellman
   NETWORKED:The New Social Operating System. Lee Rainie & Barry Wellman
   MIT Press            http://amzn.to/zXZg39      Print $15  Kindle $9
                  Old/NewCyberTimes http://bit.ly/c8N9V8
   ________________________________________________________________________


---------- Forwarded message ----------
Date: Tue, 5 Aug 2014 16:45:19 -0500
From: Complexity Digest Administration <[log in to unmask]>
To: [log in to unmask]
Subject: [comdig] Latest Complexity Digest Posts

Learn about the latest and greatest related to complex systems research. More at http://comdig.unam.mx



A network framework of cultural history

    The emergent processes driving cultural history are a product of complex interactions among large numbers of individuals, determined by difficult-to-quantify historical conditions. To characterize these processes, we have reconstructed aggregate intellectual mobility over two millennia through the birth and death locations of more than 150,000 notable individuals. The tools of network and complexity theory were then used to identify characteristic statistical patterns and determine the cultural and historical relevance of deviations. The resulting network of locations provides a macroscopic perspective of cultural history, which helps us to retrace cultural narratives of Europe and North America using large-scale visualization and quantitative dynamical tools and to derive historical trends of cultural centers beyond the scope of specific events or narrow time intervals.

A network framework of cultural historyMaximilian Schich (http://www.sciencemag.org/search?author1=Maximilian+Schich&sortspec=date&submit=Submit) , Chaoming Song (http://www.sciencemag.org/search?author1=Chaoming+Song&sortspec=date&submit=Submit) ,  Yong-Yeol Ahn (http://www.sciencemag.org/search?author1=Yong-Yeol+Ahn&sortspec=date&submit=Submit) ,  Alexander Mirsky (http://www.sciencemag.org/search?author1=Alexander+Mirsky&sortspec=date&submit=Submit) , Mauro Martino (http://www.sciencemag.org/search?author1=Mauro+Martino&sortspec=date&submit=Submit) , Albert-László Barabási (http://www.sciencemag.org/search?author1=Albert-L%C3%A1szl%C3%B3+Barab%C3%A1si&sortspec=date&submit=Submit) , Dirk Helbing (http://www.sciencemag.org/search?author1=Dirk+Helbing&sortspec=date&submit=Submit)

Science 1 August 2014:
Vol. 345 no. 6196 pp. 558-562
http://dx.doi.org/10.1126/science.1240064

See it on Scoop.it (http://www.scoop.it/t/papers/p/4025585457/2014/08/04/a-network-framework-of-cultural-history) , via Papers (http://www.scoop.it/t/papers)



On the structural stability of mutualistic systems

    Structural stability has played a major role in several fields such as evolutionary developmental biology, in which it has brought the view that some morphological structures are more common than others because they are compatible with a wider range of developmental conditions. In community ecology, structural stability is the sort of framework needed to study the consequences of global environmental change˙˙by definition, large and directional˙˙on species coexistence. Structural stability will serve to assess both the range of variability a given community can withstand and why some community patterns are more widespread than others.

On the structural stability of mutualistic systems
Rudolf P. Rohr, Serguei Saavedra, Jordi Bascompte

Science 25 July 2014:
Vol. 345 no. 6195
http://dx.doi.org/10.1126/science.1253497

See it on Scoop.it (http://www.scoop.it/t/papers/p/4025405087/2014/08/03/on-the-structural-stability-of-mutualistic-systems) , via Papers (http://www.scoop.it/t/papers)



Stigmergy as a Universal Coordination Mechanism: components, varieties and applications

    The concept of stigmergy has been used to analyze self-organizing activities in an ever-widening range of domains, from social insects via robotics and social media to human society. Yet, it is still poorly understood, and as such its full power remains underappreciated. The present paper clarifies the issue by defining stigmergy as a mechanism of indirect coordination in which the trace left by an action in a medium stimulates a subsequent action. It then analyses the fundamental components of the definition: action, agent, medium, trace and coordination. Stigmergy enables complex, coordinated activity without any need for planning, control, communication, simultaneous presence, or even mutual awareness. This makes the concept applicable to a very broad variety of cases, from chemical reactions to individual cognition and Internet-supported collaboration in Wikipedia.  The paper classifies different varieties of stigmergy according to general aspects (number of agents,
scope, persistence, sematectonic vs. marker-based, and quantitative vs. qualitative), while emphasizing the fundamental continuity between these cases. This continuity can be understood from a non-linear, self-organizing dynamic that lets more complex forms of coordination evolve out of simpler ones. The paper concludes with two specifically human applications in cognition and cooperation, suggesting that without stigmergy these phenomena may never have evolved.

Heylighen, F. (2015). Stigmergy as a Universal Coordination Mechanism: components, varieties and applications. To appear in T. Lewis & L. Marsh (Eds.), Human Stigmergy: Theoretical Developments and New Applications, Studies in Applied Philosophy, Epistemology and Rational Ethics. Springer.
http://pespmc1.vub.ac.be/papers/stigmergy-varieties.pdf

See it on Scoop.it (http://www.scoop.it/t/papers/p/4025399758/2014/08/02/stigmergy-as-a-universal-coordination-mechanism-components-varieties-and-applications) , via Papers (http://www.scoop.it/t/papers)



From Dyson to Hopfield: Processing on hierarchical networks

    We consider statistical-mechanical models for spin systems built on hierarchical structures, which provide a simple example of non-mean-field framework. We show that the coupling decay with spin distance can give rise to peculiar features and phase diagrams much richer that their mean-field counterpart. In particular, we consider the Dyson model, mimicking ferromagnetism in lattices, and we prove the existence of a number of meta-stabilities, beyond the ordered state, which get stable in the thermodynamic limit. Such a feature is retained when the hierarchical structure is coupled with the Hebb rule for learning, hence mimicking the modular architecture of neurons, and gives rise to an associative network able to perform both as a serial processor as well as a parallel processor, depending crucially on the external stimuli and on the rate of interaction decay with distance; however, those emergent multitasking features reduce the network capacity with respect to the
mean-field counterpart. The analysis is accomplished through statistical mechanics, graph theory, signal-to-noise technique and numerical simulations in full consistency. Our results shed light on the biological complexity shown by real networks, and suggest future directions for understanding more realistic models.

From Dyson to Hopfield: Processing on hierarchical networks
Elena Agliari, Adriano Barra, Andrea Galluzzi, Francesco Guerra, Daniele Tantari, Flavia Tavani

http://arxiv.org/abs/1407.5019

See it on Scoop.it (http://www.scoop.it/t/papers/p/4025403072/2014/07/31/from-dyson-to-hopfield-processing-on-hierarchical-networks) , via Papers (http://www.scoop.it/t/papers)



Self-organization on social media: endo-exo bursts and baseline fluctuations

    A salient dynamic property of social media is bursting behavior. In this paper, we study bursting behavior in terms of the temporal relation between a preceding baseline fluctuation and the successive burst response using a frequency time series of 3,000 keywords on Twitter. We found that there is a fluctuation threshold up to which the burst size increases as the fluctuation increases and that above the threshold, there appears a variety of burst sizes. We call this threshold the critical threshold. Investigating this threshold in relation to endogenous bursts and exogenous bursts based on peak ratio and burst size reveals that the bursts below this threshold are endogenously caused and above this threshold, exogenous bursts emerge. Analysis of the 3,000 keywords shows that all the nouns have both endogenous and exogenous origins of bursts and that each keyword has a critical threshold in the baseline fluctuation value to distinguish between the two. Having a threshold for
an input value for activating the system implies that Twitter is an excitable medium. These findings are useful for characterizing how excitable a keyword is on Twitter and could be used, for example, to predict the response to particular information on social media.

Self-organization on social media: endo-exo bursts and baseline fluctuations

Mizuki Oka, Yasuhiro Hashimoto, Takashi Ikegami
http://arxiv.org/abs/1407.6447

See it on Scoop.it (http://www.scoop.it/t/papers/p/4025402494/2014/07/30/self-organization-on-social-media-endo-exo-bursts-and-baseline-fluctuations) , via Papers (http://www.scoop.it/t/papers)



Null Models for Community Detection in Spatially-Embedded, Temporal Networks

    In the study of networks, it is often insightful to use algorithms to determine mesoscale features such as "community structure", in which densely connected sets of nodes constitute "communities" that have sparse connections to other communities. The most popular way of detecting communities algorithmically is to optimize the quality function known as modularity. When optimizing modularity, one compares the actual connections in a (static or time-dependent) network to the connections obtained from a random-graph ensemble that acts as a null model. The communities are then the sets of nodes that are connected to each other densely relative to what is expected from the null model. Clearly, the process of community detection depends fundamentally on the choice of null model, so it is important to develop and analyze novel null models that take into account appropriate features of the system under study. In this paper, we investigate the effects of using null models that take
incorporate spatial information, and we propose a novel null model based on the radiation model of population spread. We also develop novel synthetic spatial benchmark networks in which the connections between entities are based on distance or flux between nodes, and we compare the performance of both static and time-dependent radiation null models to the standard ("Newman-Girvan") null model for modularity optimization and a recently-proposed gravity null model. In our comparisons, we use both the above synthetic benchmarks and time-dependent correlation networks that we construct using countrywide dengue fever incidence data for Peru. We also evaluate a recently-proposed correlation null model, which was developed specifically for correlation networks that are constructed from time series, on the epidemic-correlation data.

Null Models for Community Detection in Spatially-Embedded, Temporal Networks
Marta Sarzynska, Elizabeth A. Leicht, Gerardo Chowell, Mason A. Porter

http://arxiv.org/abs/1407.6297

See it on Scoop.it (http://www.scoop.it/t/papers/p/4025403092/2014/07/29/null-models-for-community-detection-in-spatially-embedded-temporal-networks) , via Papers (http://www.scoop.it/t/papers)



Short-range interaction vs long-range correlation in bird flocks

    We use the maximum entropy method to study how the strength of effective alignment between birds depends on distance. We find in all analyzed flocks that the interaction decays exponentially. Such short-range form is noteworthy, considering that the velocity correlation that is input of the calculation is long-ranged. We use our method to study the directional anisotropy in the alignment interaction and find that the interaction strength along the direction of motion is weaker than in the transverse direction, which may account for the anisotropic spatial distribution of birds observed in natural flocks.

Short-range interaction vs long-range correlation in bird flocks
Andrea Cavagna, Lorenzo Del Castello, Supravat Dey, Irene Giardina, Stefania Melillo, Leonardo Parisi, Massimiliano Viale

http://arxiv.org/abs/1407.6887

See it on Scoop.it (http://www.scoop.it/t/papers/p/4025403085/2014/07/29/short-range-interaction-vs-long-range-correlation-in-bird-flocks) , via Papers (http://www.scoop.it/t/papers)



Introduction to Hypernetworks

    A new module on the Étoile Platform, by Jeffrey Johnson


Based on the course presented at the 4th Ph.D. summer School - conference on ˙˙Mathematical Modeling of Complex Systems˙˙, Cultural Foundation ˙˙Kritiki Estia˙˙, 14 ˙˙ 25 July, 2014, Athens.

The modern world is complex beyond human understanding and control. The science of complex systems aims to find new ways of thinking about the many interconnected networks of interaction that defy traditional approaches. Thus far, research into networks has largely been restricted to pairwise relationships represented by links between two nodes.

This course marks a major extension of networks to multidimensional hypernetworks for modeling multi-element relationships, such as companies making up the stock market, the neighborhoods forming a city, people making up committees, divisions making up companies, computers making up the internet, men and machines making up armies, or robots working as teams. This course makes an important contribution to the science of complex systems by: (i) extending network theory to include dynamic relationships between many elements; (ii) providing a mathematical theory able to integrate multilevel dynamics in a coherent way; (iii) providing a new methodological approach to analyze complex systems; and (iv) illustrating the theory with practical examples in the design, management and control of complex systems taken from many areas of application.

See it on Scoop.it (http://www.scoop.it/t/cxannouncements/p/4025399562/2014/07/28/introduction-to-hypernetworks) , via CxAnnouncements (http://www.scoop.it/t/cxannouncements)


See it on Scoop.it (http://www.scoop.it/t/cxbooks/p/4025103623/2014/07/28/a-systems-theoretic-approach-to-systems-and-synthetic-biology-i-models-and-system-characterizations-edited-by-vishwesh-kulkarni-et-al) , via CxBooks (http://www.scoop.it/t/cxbooks)



Interview: Prof  Geoffrey West on complexity science

    CLC interviewed Prof. Geoffrey West, Distinguished Professor and Past President of Sante Fe Institute, at the World Cities Summit 2014 on the study of cities in relation to complexity science....

See it on Scoop.it (http://www.scoop.it/t/talks/p/4025380795/2014/07/28/interview-prof-geoffrey-west-on-complexity-science) , via Talks (http://www.scoop.it/t/talks)



==============================================
Sponsored by the Complex Systems Society.
Founding Editor: Gottfried Mayer.
Editor-in-Chief: Carlos Gershenson.

To manage subscriptions, please go to http://comdig.unam.mx/subscriptions.php

You can contribute to Complexity Digest selecting one of our topics (http://www.scoop.it/u/complexity-digest ) and using the "Suggest" button.
==============================================
==============================================


_____________________________________________________________________
SOCNET is a service of INSNA, the professional association for social
network researchers (http://www.insna.org). To unsubscribe, send
an email message to [log in to unmask] containing the line
UNSUBSCRIBE SOCNET in the body of the message.

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

April 2021
March 2021
February 2021
January 2021
December 2020
November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008, Week 62
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003
December 2002
November 2002
October 2002
September 2002
August 2002
July 2002
June 2002
May 2002
April 2002
March 2002
February 2002
January 2002
December 2001
November 2001
October 2001
September 2001
August 2001
July 2001
June 2001
May 2001

ATOM RSS1 RSS2



LISTS.UFL.EDU

CataList Email List Search Powered by the LISTSERV Email List Manager