Statistical physics of the collective behaviour of organisms  Page description

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Details of project

  
Identifier
49674
Type K
Principal investigator Vicsek, Tamás
Title in Hungarian Élőlények kollektív viselkedésének statisztikus fizikája
Title in English Statistical physics of the collective behaviour of organisms
Panel Physics 1
Department or equivalent Department of Biological Physics (Eötvös Loránd University)
Participants Derényi, Imre
Farkas, Illés
Palla, Gergely
Starting date 2005-01-01
Closing date 2009-06-30
Funding (in million HUF) 16.340
FTE (full time equivalent) 7.30
state closed project





 

Final report

  
Results in Hungarian
Experiments: We have carried out quantitative experiments on the collective motion of cells as a function of their density. A sharp transition could be observed from the random motility in sparse cultures to the flocking of dense islands of cells. Using ultra light GPS devices developed by us, we have determined the existing hierarchical relations within a flock of 10 homing pigeons. Modelling: From the simulations of our new model of flocking we concluded that the information exchange between particles was maximal at the critical point, in which the interplay of such factors as the level of noise, the tendency to follow the direction and the acceleration of others results in large fluctuations. Analysis: We have proposed a novel link-density based approach to finding overlapping communities in large networks. The algorithm used for the implementation of this technique is very efficient for most real networks, and provides full statistics quickly. Correspondingly, we have developed a by now popular, user-friendly, freely downloadable software for finding overlapping communities. Extending our method to the time-dependent regime, we found that large groups in evolving networks persist for longer if they are capable of dynamically altering their membership, thus, an ability to change the group composition results in better adaptability. We also showed that knowledge of the time commitment of members to a given community can be used for estimating the community’s lifetime.
Results in English
Experiments: We have carried out quantitative experiments on the collective motion of cells as a function of their density. A sharp transition could be observed from the random motility in sparse cultures to the flocking of dense islands of cells. Using ultra light GPS devices developed by us, we have determined the existing hierarchical relations within a flock of 10 homing pigeons. Modelling: From the simulations of our new model of flocking we concluded that the information exchange between particles was maximal at the critical point, in which the interplay of such factors as the level of noise, the tendency to follow the direction and the acceleration of others results in large fluctuations. Analysis: We have proposed a novel link-density based approach to finding overlapping communities in large networks. The algorithm used for the implementation of this technique is very efficient for most real networks, and provides full statistics quickly. Correspondingly, we have developed a by now popular, user-friendly, freely downloadable software for finding overlapping communities. Extending our method to the time-dependent regime, we found that large groups in evolving networks persist for longer if they are capable of dynamically altering their membership, thus, an ability to change the group composition results in better adaptability. We also showed that knowledge of the time commitment of members to a given community can be used for estimating the community’s lifetime.
Full text https://www.otka-palyazat.hu/download.php?type=zarobeszamolo&projektid=49674
Decision
Yes





 

List of publications

  
G. Palla, I. Derényi, I. Farkas, and T. Vicsek.: Uncovering the overlapping community structure of complex networks in nature and society, Nature 435, 814, 2005
G. Palla, I. Derényi and T. Vicsek.: Clique Percolation in Random Networks, Phys Rev. Lett 94, 160202, 2005
I. Farkas and T. Vicsek: Patterns in the Collective Behaviour of Humans, Modelling Cooperative Behaviour in the Social Sciences , Eds. P. L. Garrido, J. Marro and M. A. Munoz (AIP Conference Proceedings, New York, 2005) 1-16, 2005
T. Vicsek.: Complexity in the Collective Behaviour of Humans, Complexity, Metastability and Nonextensivity , Eds. C. Beck, G. Benedek, A. Rapisarda and C Tsallis (World Scientific, New Jersey, Singapore, 2005)p. 287-301, 2005
B. Adamcsek, G Palla, I. J. Farkas, I Derenyi and T Vicsek: CFinder: locating cliques and overlapping modules in biological networks, IOINFORMATICS, 22 (2006) 1021-1023, 2006
P. Pollner, G. Palla and T. Vicsek: Preferential attachment of communities: the same principle, but a higher level, Europhys. Lett 73 (3), (2006) 478-484, 2006
I. Farkas, and T. Vicsek: Initiating a Mexican wave: An instantaneous collective decision with both short- and long-range interactions,, Physica A, 369 (2006) 830-840, 2006
Farkas I J, Wu C, Chennubhotla C, Bahar I, Oltvai Z N.: Topological basis of signal integration in the transcriptional-regulatory network of the yeast, Saccharomyces cerevisiae., BMC Bioinformatics 7, 478 (2006), 2006
Farkas I J, Beg Q K, and Oltvai Z N: Exploring transcriptional regulatory networks in the worm (Preview article), Cell 125, 1032-1034 (2006), 2006
M. Nagy, I. Daruka and T. Vicsek,: New aspects of the continuous phase transition in the scalar noise model (SNM) of collective motion, Physica A 373, (2007) 445-454, 2007
T. Vicsek: Phase transitions and overlapping modules in complex networks, Physica A 378 (2007) 20-32 DOI: 10.1016/j.physa.2006.11.075, 2007
G. Palla, A-L. Barabasi and T. Vicsek:: Quantifying social group evolution, Nature , 446 (2007) 664-667, 2007
G. Palla, I. J Farkas, P. Pollner, I. Derényi and T. Vicsek: Directed network modules,, New J. Phys. 9 (2007) 186 doi:10.1088/1367-2630/9/6/186, 2007
I. Farkas, D. Ábel, G. Palla and T. Vicsek: Weighted network modules, New J. Phys. 9 (2007) 180 doi:10.1088/1367-2630/9/6/180, 2007
G. Palla, I. Derenyi and T. Vicsek T: The critical point of k-clique percolation in the Erdos-Renyi graph, J. Stat. Phys. 128 (1-2)(2007) 219-227, 2007
G. Palla, A-L. Barabasi and T. Vicsek:: Community dynamics in social networks,, Fluct. Noise Lett. 7 (2007) L273 - L287, 2007
Zs. Ákos, M. Nagy, and T. Vicsek: Comparing bird and human soaring strategies, Proc. Nat. Acad. Sci. USA., 105, No. 11 (2008) 4139-4143, 2008
B. Gönci, M. Nagy and T. Vicsek: Phase transition in the scalar noise model of collective motion in three dimensions,, European Physical Journal, 157 (2008) 53, 2008
P. Pollner, G. Palla, D. Ábel, A. Vicsek, I. J. Farkas, I. Derényi and T. Vicsek: Centrality properties of directed module members in social networks, Physica A 387 (2008) 4959–4966, 2008
G. Palla, I. Farkas, P. Pollner, I. Derényi,and T. Vicsek: Fundamental statistical features and self-similar properties of tagged networks,, New J. Phys. 10 (2008) 123026, 2008
P. Szabó, M. Nagy and T. Vicsek: Transitions in a self-propelled-particles model with coupling of accelerations., Phys. Review. E 79 (2009) 021908., 2008



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