Distribution of extinction sizes constructed from original fossil records exhibits not a single, but a double power-law, with tail exponents being roughly the same in different scales, i.e., for species, families and orders. Moreover, time correlations of extinction sizes decrease with a...

Recent results [Sznajd-Weron and P ̧ekalski, Physica A 259 (1998) 457] have shown that the competition of two forces – gene flow and natural selection (GFS) – is responsible for three basic types of population structures. Using Monte Carlo simulations a critical value above which there is...

A simple Ising spin model which can describe the mechanism of advertising in a duopoly market is proposed. In contrast to other agent-based models, the influence does not flow inward from the surrounding neighbors to the center site, but spreads outward from the center to the neighbors. The...

A simple Ising spin model which can describe the mechanism of advertising in a duopoly market is proposed. In contrast to other agent-based models, the influence does not flow inward from the surrounding neighbors to the center site, but spreads outward from the center to the neighbors. The...