humans

We (together with Kimmo Kaski, Aalto University) are organizing the ECCS'11 Satellite conference “Complex Dynamics of Human Interactions” to be held at Vienna, September 14th. You can find more info at http://www.complexdynamics.org “It’s not enough to have a map of the structure. It is crucial to understand the dynamics of a process”, L. Barábasi Scope The nature of human interaction has undergone a substantial change in the past years and the change does not seem to be over. ...

Each day trillions of emails, phone calls, comments on blogs, twitter messages, exchanges in online social networks, etc. are done. Not only the number of communications has increased, but also each of these transactions leaves a digital trace that can be recorded to reconstruct our high-frequency human activity. It is not only the amount and variety of data that is recorded what is important. Also its high-frequency character and its comprehensive nature have allowed researchers, companies and agencies to investigate individual and group dynamics at an unprecedented level of detail and applied them to client modeling, organizational analysis or epidemic spreading [1]. ...

We have just published an experimental/theoretical work on the speed of information diffusion in social networks in Physical Review Letters. Specifically we have studied the impact of the heterogeneity of human activity in propagation of emails, rumors, hoaxes, etc. Tracking email marketing campaigns, executed by IBM Corporation in 11 European countries, we were able to compare their viral propagation with our theory (see below the campaigns details). The results are very simple. ...

Authors: J. L. Iribarren and E. Moro Journal: Physical Review Letters 103, 038702 (2009) LINK arXiv Abstract: We study the impact of human activity patterns on information diffusion. To this end we ran a viral email experiment involving 31183 individuals in which we were able to track a specific piece of information through the social network. We found that, contrary to traditional models, information travels at an unexpectedly slow pace. By using a branching model which accurately describes the experiment, we show that the large heterogeneity found in the response time is responsible for the slow dynamics of information at the collective level. ...

When tea is poured in a cup of hot water, we observe a phenomenon called diffusion: in the end particles of tea spread evenly throughout the mass of water and we enjoy our cup of tea. Diffusion occurs as a result of the second law of thermodynamics (increase of entropy) and can be modeled quantitatively using the diffusion equation (or heat equation). This is a funny equation, since it establishes that the velocity of spreading is infinite while the mean root square fluctuations of the position of the particles grows in time as ...