6 papers
Penna bit-string model with constant population
S. Moss de Oliveira, P. M. C de Oliveira, J. S. Sa Martins
We removed from the Penna model for biological ageing any random killing Verhulst factor. Deaths are due only to genetic diseases and the population size is fixed, instead of fluct…
Corrections to Finite Size Scaling in Percolation
P. M. C. de Oliveira, R. A. Nobrega, D. Stauffer
A 1/L-expansion for percolation problems is proposed, where L is the lattice finite length. The square lattice with 27 different sizes L = 18, 22 ... 1594 is considered. Certain sp…
Simulation consensus model of never changed opinions in Sznajd consensus model using multi-spin coding
Dietrich Stauffer, Paulo Murilo C. de Oliveira
The density of never changed opinions during the Sznajd consensus-finding process decays with time t as 1/t^{theta}. We find theta ~= 3/8 for a chain, compatible with the exact Isi…
Dynamic Drop Models
P. M. C. de Oliveira, T. J. P. Penna, A. R. Lima +3
We follow the dynamic evolution of a cluster of Ising spins pointing up surrounded by other spins pointing down, on a lattice. The cluster represents a liquid drop. Under a microsc…
Computer Simulations for Biological Ageing and Sexual Reproduction
D. Stauffer, P. M. C. de Oliveira, S. Moss de Oliveira +2
The sexual version of the Penna model of biological ageing, simulated since 1996, is compared here with alternative forms of reproduction as well as with models not involving agein…
A comparison between broad histogram and multicanonical methods
A. R. Lima, P. M. C. de Oliveira, T. J. P. Penna
We discuss the conceptual differences between the Broad Histogram (BHM) and reweighting methods in general, and particularly the so-called Multicanonical (MUCA) approaches. The mai…