Jari Saramaki

Dynamics of latent voters (2008)

Lambiotte, Renaud, Saramaki, Jari, Blondel, Vincent D.

We study the effect of latency on binary-choice opinion formation models. Latency is introduced into the models as an additional dynamic rule: after a voter changes its opinion, it enters a waiting...

Maximal spanning trees, asset graphs and random matrix denoising in the analysis of dynamics of financial networks (2008)

Heimo, Tapio, Kaski, Kimmo, Saramaki, Jari

We study the time dependence of maximal spanning trees and asset graphs based on correlation matrices of stock returns. In these networks the nodes represent companies and links are related to the...

A sequential algorithm for fast clique percolation (2008)

Kumpula, Jussi M., Kivela, Mikko, Kaski, Kimmo, Saramaki, Jari

In complex network research clique percolation, introduced by Palla et al., is a deterministic community detection method, which allows for overlapping communities and is purely based on local...

Detecting modules in dense weighted networks with the Potts method (2008)

Heimo, Tapio, Kumpula, Jussi, Kaski, Kimmo, Saramaki, Jari

We address the problem of multiresolution module detection in dense weighted networks, where the modular structure is encoded in the weights rather than topology. We discuss a weighted version of the...

Spectral methods and cluster structure in correlation-based networks (2007)

Heimo, Tapio, Tibely, Gergely, Saramaki, Jari, Kaski, Kimmo, Kertesz, Janos

We investigate how in complex systems the eigenpairs of the matrices derived from the correlations of multichannel observations reflect the cluster structure of the underlying networks. For this we...

Spectral and network methods in the analysis of correlation matrices of stock returns (2007)

Heimo, Tapio, Saramaki, Jari, Onnela, Jukka-Pekka, Kaski, Kimmo

Correlation matrices inferred from stock return time series contain information on the behaviour of the market, especially on clusters of highly correlating stocks. Here we study a subset of New York...

Analysis of a large-scale weighted network of one-to-one human communication (2007)

Onnela, Jukka-Pekka, Saramaki, Jari, Hyvonen, Jorkki, Szabo, Gabor, De Menezes, M. Argollo, Kaski, Kimmo, ...

We construct a connected network of 3.9 million nodes from mobile phone call records, which can be regarded as a proxy for the underlying human communication network at the societal level. We assign...

Emergence of self-sustained patterns in small-world excitable media (2007)

Sinha, Sitabhra, Saramaki, Jari, Kaski, Kimmo

Motivated by recent observations that long-range connections (LRC) play a role in various brain phenomena, we have observed two distinct dynamical transitions in the activity of excitable media where...

Limited resolution in complex network community detection with Potts model approach (2006)

Kumpula, Jussi M., Saramaki, Jari, Kaski, Kimmo, Kertesz, Janos

According to Fortunato and Barthelemy, modularity-based community detection algorithms have a resolution threshold such that small communities in a large network are invisible. Here we generalize...

Spatial snowdrift game with myopic agents (2004)

Sysi-Aho, Marko, Saramaki, Jari, Kertesz, Janos, Kaski, Kimmo

We have studied a spatially extended snowdrift game, in which the players are located on the sites of two-dimensional square lattices and repeatedly have to choose one of the two strategies, either...

Scale-Free Networks Generated By Random Walkers (2004)

Saramaki, Jari, Kaski, Kimmo

We present a simple mechanism for generating undirected scale-free networks using random walkers, where the network growth is determined by choosing parent vertices by sequential random walks. We...

Invisible Hand Effect in an Evolutionary Minority Game Model (2004)

Sysi-Aho, Marko, Saramaki, Jari, Kaski, Kimmo

In this paper we study the properties of a Minority Game with evolution realized by using genetic crossover to modify fixed-length decision-making strategies of agents. Although the agents in this...