http://www.bibsonomy.org/burst/user/andreab/dynamicsBibSonomy BuRST Feed for /user/andreab/dynamics2008-07-21T00:40:28+02:00[0803.2189v1] Robust dynamic classes revealed by measuring the response function of a social systemhttp://www.bibsonomy.org/bibtex/2bb04260be64a4d856319719cb688f5dc/andreabandreab2008-04-08T23:41:07+02:00social dynamics video imported youtube fdt <span style="color:#555555;">R. <a href="http://www.bibsonomy.org/author/Crane">Crane</a> and D. <a href="http://www.bibsonomy.org/author/Sornette">Sornette</a> </span>(<em>2008</em>)Tue Apr 08 23:41:07 CEST 2008Robust dynamic classes revealed by measuring the response function of a social system2008social dynamics video imported youtube fdt We study the relaxation response of a social system after endogenous and exogenous bursts of activity using the time-series of daily views for nearly 5 million videos on YouTube. We find that most activity can be described accurately as a Poisson process. However, we also find hundreds of thousands of examples in which a burst of activity is followed by an ubiquitous power-law relaxation governing the timing of views. We find that these relaxation exponents cluster into three distinct classes, and allow for the classification of collective human dynamics. This is consistent with an epidemic model on a social network containing two ingredients: A power law distribution of waiting times between cause and action and an epidemic cascade of actions becoming the cause of future actions. This model is a conceptual extension of the fluctuation-dissipation theorem to social systems, and provides a unique framework for the investigation of timing in complex systems.http://www.bibsonomy.org/bibtex/2a5c498249b75bd8f8ba1ce70bb4c19af/andreabandreab2007-10-18T12:38:40+02:00africa dynamics topography plate geophysics <span style="color:#555555;">Carolina <a href="http://www.bibsonomy.org/author/Lithgow-Bertelloni">Lithgow-Bertelloni</a> and Paul <a href="http://www.bibsonomy.org/author/Silver">Silver</a> </span><em>Nature</em><em>Sep1998. </em><em>10.1038/26212 . </em>Thu Oct 18 12:38:40 CEST 2007NatureSep10.1038/26212269--272Dynamic topography, plate driving forces and the African superswell3951998africa dynamics topography plate geophysics 17[cond-mat/0603120] Beyond Boltzmann-Gibbs statistics: Maximum entropy hyperensembles out-of-equilibriumhttp://www.bibsonomy.org/bibtex/273a6a41abfbaa20b46110f9620991a41/andreabandreab2007-04-28T16:39:27+02:00imported dynamics non-equilibrium physics entropy <span style="color:#555555;">Gavin E. <a href="http://www.bibsonomy.org/author/Crooks">Crooks</a> </span>(<em>2006</em>)Sat Apr 28 16:39:27 CEST 2007Beyond Boltzmann-Gibbs statistics: Maximum entropy hyperensembles out-of-equilibrium2006imported dynamics non-equilibrium physics entropy http://www.bibsonomy.org/bibtex/2d3f0e67942afdcded3c689280a6cf27e/andreabandreab2007-04-12T18:06:40+02:00dynamics brownian physics nonequilibrium experiments entropy stochastic imported processes flictuations <span style="color:#555555;">D. <a href="http://www.bibsonomy.org/author/Andrieux">Andrieux</a> and P. <a href="http://www.bibsonomy.org/author/Gaspard">Gaspard</a> and S. <a href="http://www.bibsonomy.org/author/Ciliberto">Ciliberto</a> and N. <a href="http://www.bibsonomy.org/author/Garnier">Garnier</a> and S. <a href="http://www.bibsonomy.org/author/Joubaud">Joubaud</a> and A. <a href="http://www.bibsonomy.org/author/Petrosyan">Petrosyan</a> </span><em>Physical Review Letters</em><em>98(15):150601</em>(<em>2007</em>)Thu Apr 12 18:06:40 CEST 2007Physical Review Letters15150601Entropy Production and Time Asymmetry in Nonequilibrium Fluctuations982007dynamics brownian physics nonequilibrium experiments entropy stochastic imported processes flictuations The time-reversal symmetry of nonequilibrium fluctuations is experimentally investigated in two out- of-equilibrium systems: namely, a Brownian particle in a trap moving at constant speed and an electric circuit with an imposed mean current. The dynamical randomness of their nonequilibrium fluctuations is characterized in terms of the standard and time-reversed entropies per unit time of dynamical systems theory. We present experimental results showing that their difference equals the thermodynamic entropy production in units of Boltzmann’s constant. http://www.bibsonomy.org/bibtex/2ceb9c88723801129a13ff1f98fa463af/andreabandreab2007-04-11T19:19:12+02:00tagora cattuto 2006 yulesimon delicious semiotic del.icio.us collaborative tagging d4.1 yule semioticdynamic dynamics loreto folksonomy <span style="color:#555555;">Ciro <a href="http://www.bibsonomy.org/author/Cattuto">Cattuto</a> and Vittorio <a href="http://www.bibsonomy.org/author/Loreto">Loreto</a> and Luciano <a href="http://www.bibsonomy.org/author/Pietronero">Pietronero</a> </span><em>Proceedings of the National Academy of Sciences United States of America</em>(<em>2007</em>)Wed Apr 11 19:19:12 CEST 2007http://xxx.lanl.gov/abs/cs.CY/0605015Proceedings of the National Academy of Sciences United States of America1461Semiotic dynamics and collaborative tagging1042007tagora cattuto 2006 yulesimon delicious semiotic del.icio.us collaborative tagging d4.1 yule semioticdynamic dynamics loreto folksonomy Collaborative tagging has been quickly gaining ground because of its ability to recruit the activity of web users into effectively organizing and sharing vast amounts of information. Here we collect data from a popular system and investigate the statistical properties of tag co-occurrence. We introduce a stochastic model of user behavior embodying two main aspects of collaborative tagging: (i) a frequency-bias mechanism related to the idea that users are exposed to each other's tagging activity; (ii) a notion of memory - or aging of resources - in the form of a heavy-tailed access to the past state of the system. Remarkably, our simple modeling is able to account quantitatively for the observed experimental features, with a surprisingly high accuracy. This points in the direction of a universal behavior of users, who - despite the complexity of their own cognitive processes and the uncoordinated and selfish nature of their tagging activity - appear to follow simple activity patterns.tagging communities vocabulary evolutionhttp://www.bibsonomy.org/bibtex/2582641c05e7a0b9396945a951822c83f/andreabandreab2007-04-10T15:40:05+02:00d4.1 2006 tagging userbehavior dynamics banff tags imported <span style="color:#555555;">Shilad <a href="http://www.bibsonomy.org/author/Sen">Sen</a> and Shyong K. <a href="http://www.bibsonomy.org/author/Lam">Lam</a> and Al Mamunur <a href="http://www.bibsonomy.org/author/Rashid">Rashid</a> and Dan <a href="http://www.bibsonomy.org/author/Cosley">Cosley</a> and Dan <a href="http://www.bibsonomy.org/author/Frankowski">Frankowski</a> and Jeremy <a href="http://www.bibsonomy.org/author/Osterhouse">Osterhouse</a> and F. <a href="http://www.bibsonomy.org/author/Maxwell Harper">Maxwell Harper</a> and John <a href="http://www.bibsonomy.org/author/Riedl">Riedl</a> </span><em>CSCW '06: Proceedings of the 2006 20th anniversary conference on Computer supported cooperative work, </em><em>page181--190. </em><em>New York, NY, USA, </em><em>ACM Press, </em>(<em>2006</em>)Tue Apr 10 15:40:05 CEST 2007New York, NY, USACSCW '06: Proceedings of the 2006 20th anniversary conference on Computer supported cooperative work181--190tagging, communities, vocabulary, evolution2006d4.1 2006 tagging userbehavior dynamics banff tags imported A tagging community's vocabulary of tags forms the basis for social navigation and shared expression. We present a user-centric model of vocabulary evolution in tagging communities based on community in uence and personal tendency. We evaluate our model in an emergent tagging system by introducing tagging features into the MovieLens recommender system. We explore four tag selection algorithms for displaying tags applied by other community members. We analyze the algorithms ehttp://www.bibsonomy.org/bibtex/2bee150ec34ffb83d24fdd0c2fef544ac/andreabandreab2007-03-09T16:29:44+01:00dynamics cooling theory materials granular citingme correlations physics simulations molecular method kinetic <span style="color:#555555;">Syed Rashid <a href="http://www.bibsonomy.org/author/Ahmad">Ahmad</a> and Sanjay <a href="http://www.bibsonomy.org/author/Puri">Puri</a> </span><em>Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)</em><em>75(3):031302</em>(<em>2007</em>)Fri Mar 09 16:29:44 CET 2007Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)3031302Velocity distributions and aging in a cooling granular gas752007dynamics cooling theory materials granular citingme correlations physics simulations molecular method kinetic http://www.bibsonomy.org/bibtex/2780d463a467c2ac74b0ffb5e84db8aef/andreabandreab2006-11-22T15:35:34+01:00social wikipedia dynamics network d4.1 tagora phsyics <span style="color:#555555;">A. <a href="http://www.bibsonomy.org/author/Capocci">Capocci</a> and V. D. P. <a href="http://www.bibsonomy.org/author/Servedio">Servedio</a> and F. <a href="http://www.bibsonomy.org/author/Colaiori">Colaiori</a> and L. S. <a href="http://www.bibsonomy.org/author/Buriol">Buriol</a> and D. <a href="http://www.bibsonomy.org/author/Donato">Donato</a> and S. <a href="http://www.bibsonomy.org/author/Leonardi">Leonardi</a> and G. <a href="http://www.bibsonomy.org/author/Caldarelli">Caldarelli</a> </span><em>Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)</em><em>74(3):036116</em>(<em>2006</em>)Wed Nov 22 15:35:34 CET 2006Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)3036116Preferential attachment in the growth of social networks: The internet encyclopedia Wikipedia742006social wikipedia dynamics network d4.1 tagora phsyics http://www.bibsonomy.org/bibtex/29d5ca9e60e7510b7d124ee01b11f068c/andreabandreab2006-10-17T16:51:17+02:00myown spinglasses imported 1998 simulations sk aging dynamics <span style="color:#555555;">Andrea <a href="http://www.bibsonomy.org/author/Baldassarri">Baldassarri</a> </span><em>Phys. Rev. E</em><em>58(6):7047--7053</em><em>Dec1998. </em>Tue Oct 17 16:51:17 CEST 2006Phys. Rev. EDec67047--7053Numerical study of the out-of-equilibrium phase space of a mean-field spin glass model581998myown spinglasses imported 1998 simulations sk aging dynamics We present a numerical study of the nonequilibrium dynamics of the Sherrington-Kirkpatrick model. We analyze the behavior of the system for different system sizes N and time scales t, in order to identify the correct out-of-equilibrium regime. We find evidence of aging behavior in the dynamics of the system, compatible with a weak-ergodicity breaking scenario. In addition, we obtain a pictorial characterization of the out-of-equilibrium phase space that presents some analogies with the hierarchy of states found in equilibrium.