de Queiroz S L A
Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Feb;77(2 Pt 1):021131. doi: 10.1103/PhysRevE.77.021131. Epub 2008 Feb 28.
We discuss the application of wavelet transforms to a critical interface model which is known to provide a good description of Barkhausen noise in soft ferromagnets. The two-dimensional version of the model (one-dimensional interface) is considered, mainly in the adiabatic limit of very slow driving. On length scales shorter than a crossover length (which grows with the strength of the surface tension), the effective interface roughness exponent zeta is approximately 1.20 , close to the expected value for the universality class of the quenched Edwards-Wilkinson model. We find that the waiting times between avalanches are fully uncorrelated, as the wavelet transform of their autocorrelations scales as white noise. Similarly, detrended size-size correlations give a white-noise wavelet transform. Consideration of finite driving rates, still deep within the intermittent regime, shows the wavelet transform of correlations scaling as 1/f(1.5) for intermediate frequencies. This behavior is ascribed to intra-avalanche correlations.
我们讨论小波变换在一个关键界面模型中的应用，该模型已知能很好地描述软铁磁体中的巴克豪森噪声。我们考虑该模型的二维版本（一维界面），主要是在驱动非常缓慢的绝热极限情况下。在比一个交叉长度（其随表面张力强度增长）短的长度尺度上，有效界面粗糙度指数ζ约为1.20，接近淬火爱德华兹 - 威尔金森模型普适类的预期值。我们发现雪崩之间的等待时间完全不相关，因为它们自相关的小波变换表现为白噪声。同样，去趋势化的大小 - 大小相关性给出白噪声小波变换。考虑仍处于间歇性区域深处的有限驱动速率，结果表明对于中频，相关性的小波变换按1/f(1.5)缩放。这种行为归因于雪崩内相关性。
