共查询到20条相似文献,搜索用时 15 毫秒
1.
K. Bhattacharya 《Physica A》2007,384(1):15-20
In this paper we briefly review few self-organized critical (SOC) models of the phenomenon of earthquakes. For example, the two-dimensional non-conservative SOC model of Olami, Feder and Christensen (OFC) has been described. It is known that the effect of the fixed boundary on this model is very strong. It has been recently observed that imposition of a moving boundary condition helps to remove the strong non-uniformity originated from the fixed boundary. A generalized spatio-temporal scaling for the recurrence time distribution was proposed by Bak et al. which was later confirmed by Corral. We studied the same scalings on the conservative OFC model with moving boundary condition. 相似文献
2.
G. Q. Zhang U. Tirnakli L. Wang T. L. Chen 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,82(1):83-89
A modified version of the Olami-Feder-Christensen model
has been introduced to consider avalanche size differences. Our
model well demonstrates the power-law behavior and finite size
scaling of avalanche size distribution in any range of the adding
parameter p
a
d
d
of the model. The probability density
functions of the avalanche size differences at consecutive
time steps (defined as returns) appear to be well approached, in
the thermodynamic limit, by q-Gaussian shape with appropriate
q values which can be obtained a priori from the avalanche size
exponent τ. For small system sizes, however, return
distributions are found to be consistent with the crossover
formulas proposed recently in Tsallis and Tirnakli [J. Phys.
Conf. Ser. 201, 012001 (2010)]. Our results strengthen
recent findings of Caruso et al. [Phys. Rev. E
75, 055101(R) (2007)] on the real earthquake data
which support the hypothesis that knowing the magnitude of
previous earthquakes does not make the magnitude of the next
earthquake predictable. 相似文献
3.
ZHANG Duan-Ming SUN Fan YU Bo-Ming PAN Gui-Jun SUN Hong-Zhang YIN Yan-Ping LI Rui SU Xiang-Ying 《理论物理通讯》2006,45(2):293-296
A simplified Olami-Feder-Christensen model on a random network has been studied. We propose a new toppling rule — when there is an unstable site toppling, the energy of the site is redistributed to its nearest neighbors randomly not averagely. The simulation results indicate that the model displays self-organized criticality when the system is conservative, and the avalanche size probability distribution of the system
obeys finite size scaling. When the system is nonconservative, the model
does not display scaling behavior. Simulation results of our model with
different nearest neighbors q is also compared, which indicates that the
spatial topology does not alter the critical behavior of the system. 相似文献
4.
We numerically investigate the Olami-Feder-Christensen model on a quenched random graph. Contrary to the case of annealed random neighbors, we find that the quenched model exhibits self-organized criticality deep within the nonconservative regime. The probability distribution for avalanche size obeys finite size scaling, with universal critical exponents. In addition, a power law relation between the size and the duration of an avalanche exists. We propose that this may represent the correct mean-field limit of the model rather than the annealed random neighbor version. 相似文献
5.
ZHANG Duan-Ming SUN Hong-Zhang LI Zhi-Hua PAN Gui-Jun YU Bo-Ming YIN Yan-Ping SUN Fan 《理论物理通讯》2005,44(8)
A one-dimensional sand-pile model (Manna model), which has a stochastic redistribution process, is studied both in discrete and continuous manners. The system evolves into a critical state after a transient period. A detailed analysis of the probability distribution of the avalanche size and duration is numerically investigated. Interestingly,contrary to the deterministic one-dimensional sand-pile model, where multifractal analysis works well, the analysis based on simple finite-size scaling is suited to fitting the data on the distribution of the avalanche size and duration. The exponents characterizing these probability distributions are measured. Scaling relations of these scaling exponents and their universality class are discussed. 相似文献
6.
ZHANG Duan-Ming SUN Hong-Zhang LI Zhi-Hua PAN Gui-Jun YU Bo-Ming YIN Yan-Ping SUN Fan 《理论物理通讯》2005,44(2):316-320
A one-dimensional sand-pile model (Manna model), which has a stochastic redistribution process, is studied both in discrete and continuous manners. The system evolves into a critical state after a transient period. A detailed analysis of the probability distribution of the avalanche size and duration is numerically investigated. Interestingly,contrary to the deterministic one-dimensional sand-pile model, where multifractal analysis works well, the analysis based on simple finite-size scaling is suited to fitting the data on the distribution of the avalanche size and duration. The exponents characterizing these probability distributions are measured. Scaling relations of these scaling exponents and their universality class are discussed. 相似文献
7.
A two-variable earthquake model on a quenched random graph is established
here. It can be seen as a generalization of the OFC models. We numerically study the critical behavior of the model when the system is nonconservative: the result indicates that the model exhibits self-organized criticality deep within the nonconservative regime. The probability distribution for avalanche size obeys finite size scaling. We compare our model with the model introduced by Stefano Lise and Maya Paczuski [Phys. Rev. Lett. 88 (2002) 228301], it is proved that they are not in the same universality class. 相似文献
8.
K. E. Lee J. W. Lee 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):271-275
We study a simple model for a neuron function in a collective brain
system. The neural network is composed of an uncorrelated
configuration model (UCM) for eliminating the degree correlation
of dynamical processes. The interaction of neurons is assumed to
be isotropic and idealized. These neuron dynamics are similar to
biological evolution in extremal dynamics with locally isotropic
interaction but has a different time scale. The functioning of
neurons takes place as punctuated patterns based on avalanche
dynamics. In our model, the avalanche dynamics of neurons exhibit
self-organized criticality which shows power-law behavior of the
avalanche sizes. For a given network, the avalanche dynamic
behavior is not changed with different degree exponents of
networks, γ≥2.4 and various refractory periods
referred to the memory effect, Tr. Furthermore, the avalanche
size distributions exhibit power-law behavior in a single scaling
region in contrast to other networks. However, return time
distributions displaying spatiotemporal complexity have three
characteristic time scaling regimes Thus, we find that UCM may be
inefficient for holding a memory. 相似文献
9.
ZHANGDuan-Ming SUNHong-Zhang LIZhi-Hua PANGui-Jun YUBo-Ming LIRui YINYan-Ping 《理论物理通讯》2005,44(1):99-102
The moment analysis is applied to perform large scale simulations of the rice-pile model. We find that this model shows different scaling behavior depending on the driving mechanism used. With the noisy driving, the rice-pile model violates the finite-size scaling hypothesis, whereas, with fixed driving, it shows well defined avalanche exponents and displays good finite size scaling behavior for the avalanche size and time duration distributions. 相似文献
10.
ZHANG Duan-Ming SUN Hong-Zhang LI Zhi-Hua PAN Gui-Jun YU Bo-Ming LI Rui YIN Yan-Ping 《理论物理通讯》2005,44(7)
The moment analysis is applied to perform large scale simulations of the rice-pile model. We find that this model shows different scaling behavior depending on the driving mechanism used. With the noisy driving, the rice-pile model violates the finite-size scaling hypothesis, whereas, with fixed driving, it shows well defined avalanche exponents and displays good finite size scaling behavior for the avalanche size and time duration distributions. 相似文献
11.
Ping Wang Zhe Chang Huanyu Wang Hong Lu 《The European Physical Journal B - Condensed Matter and Complex Systems》2017,90(11):214
Earthquakes are obviously complex phenomena associated with complicated spatiotemporal correlations, and they are generally characterized by two power laws: the Gutenberg-Richter (GR) and the Omori-Utsu laws. However, an important challenge has been to explain two apparently contrasting features: the GR and Omori-Utsu laws are scale-invariant and unaffected by energy or time scales, whereas earthquakes occasionally exhibit a characteristic energy or time scale, such as with asperity events. In this paper, three high-quality datasets on earthquakes were used to calculate the earthquake energy fluctuations at various spatiotemporal scales, and the results reveal the correlations between seismic events regardless of their critical or characteristic features. The probability density functions (PDFs) of the fluctuations exhibit evidence of another scaling that behaves as a q-Gaussian rather than random process. The scaling behaviors are observed for scales spanning three orders of magnitude. Considering the spatial heterogeneities in a real earthquake fault, we propose an inhomogeneous Olami-Feder-Christensen (OFC) model to describe the statistical properties of real earthquakes. The numerical simulations show that the inhomogeneous OFC model shares the same statistical properties with real earthquakes. 相似文献
12.
In critical phenomena, many of the characteristic features encountered in higher dimensions such as scaling, data collapse and associated critical exponents are also present in one dimension. Likewise for systems displaying self-organised criticality. We show that the one-dimensional Bak–Tang–Wiesenfeld sandpile model, although trivial, does indeed fall into the general framework of self-organised criticality. We also investigate the Oslo ricepile model, driven by adding slope units at the boundary or in the bulk. We determine the critical exponents by measuring the scaling of the kth moment of the avalanche size probability with system size. The avalanche size exponent depends on the type of drive but the avalanche dimension remains constant. 相似文献
13.
We introduce a sandpile model driven by degree on scale-free networks, where the perturbation is triggered at nodes with the same degree. We numerically investigate the avalanche behaviour of sandpile driven by different degrees on scale-free networks. It is observed that the avalanche area has the same behaviour with avalanche size. When the sandpile is driven at nodes with the minimal degree, the avalanches of our model behave similarly to those of the original Bak-Tang-Wiesenfeld (BTW) model on scale-free networks. As the degree of driven nodes increases from the minimal value to the maximal value, the avalanche distribution gradually changes from a clean power law, then a mixture of Poissonian and power laws, finally to a Poisson-like distribution. The average avalanche area is found to increase with the degree of driven nodes so that perturbation triggered on higher-degree nodes will result in broader spreading of avalanche propagation. 相似文献
14.
We report a universal scaling behavior of the first arrival time of a traveling magnetic domain wall into a finite space-time observation window of a magneto-optical microscope enabling direct visualization of a Barkhausen avalanche in real time. The first arrival time of the traveling magnetic domain wall exhibits a nontrivial fluctuation and its statistical distribution is described by universal power-law scaling with scaling exponents of 1.34+/-0.07 for CoCr and CoCrPt films, despite their quite different domain evolution patterns. Numerical simulation of the first arrival time with an assumption that the magnetic domain wall traveled as a random walker well matches our experimentally observed scaling behavior, providing an experimental support for the random-walking model of traveling magnetic domain walls. 相似文献
15.
Two cellular automata models with directed mass flow and internal time scales are studied by numerical simulations. Relaxation
rules are a combination of probabilistic critical height (probability of toppling p) and deterministic critical slope processes with internal correlation time tc equal to the avalanche lifetime, in model A, and ,in model B. In both cases nonuniversal scaling properties of avalanche distributions are found for , where is related to directed percolation threshold in d=3. Distributions of avalanche durations for are studied in detail, exhibiting multifractal scaling behavior in model A, and finite size scaling behavior in model B,
and scaling exponents are determined as a function of p. At a phase transition to noncritical steady state occurs. Due to difference in the relaxation mechanisms, avalanche statistics
at approaches the parity conserving universality class in model A, and the mean-field universality class in model B. We also
estimate roughness exponent at the transition.
Received: 29 May 1998 / Revised: 8 September 1998 / Accepted: 10 September 1998 相似文献
16.
Unified scaling law for earthquakes 总被引:2,自引:0,他引:2
We show that the distribution of waiting times between earthquakes occurring in California obeys a simple unified scaling law valid from tens of seconds to tens of years. The short time clustering, commonly referred to as aftershocks, is nothing but the short time limit of the general hierarchical properties of earthquakes. There is no unique operational way of distinguishing between main shocks and aftershocks. In the unified law, the Gutenberg-Richter b value, the exponent -1 of the Omori law for aftershocks, and the fractal dimension d(f) of earthquakes appear as critical indices. 相似文献
17.
Timothy M. Crowder Vasu Sethuraman Thomas B. Fields Anthony J. Hickey 《Particle & Particle Systems Characterization》1999,16(4):191-196
Previous studies of the flow of granular materials in a rotating drum have described the observed time sequences of angle of repose or time to avalanche. The time between avalanches approach has been incorporated into a commercially available powder flow analysis tool. In the present study, the time to avalanche analysis was complemented with a Fourier Transform power spectrum and phase space analysis of the angle of repose time series and avalanche size variability determination. The avalanche size variability approach was found to most readily differentiate between the flow properties of powders across material types. A model was constructed to provide an explanation for the utility of this method. 相似文献
18.
F. Caruso V. Latora A. Pluchino A. Rapisarda B. Tadić 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):243-247
We investigate numerically the Self Organized Criticality (SOC)
properties of the dissipative Olami-Feder-Christensen model on
small-world and scale-free networks. We find that the small-world
OFC model exhibits self-organized criticality. Indeed, in this
case we observe power law behavior of earthquakes size
distribution with finite size scaling for the cut-off region. In
the scale-free OFC model, instead, the strength of disorder
hinders synchronization and does not allow to reach a critical
state. 相似文献
19.
By analyzing the Japan Meteorological Agency (JMA) seismic catalog for different tectonic settings, we have found that the probability distributions of time intervals between successive earthquakes-interoccurrence times-can be described by the superposition of the Weibull distribution and the log-Weibull distribution. In particular, the distribution of large earthquakes obeys the Weibull distribution with the exponent α1<1, indicating the fact that the sequence of large earthquakes is not a Poisson process. It is found that the ratio of the Weibull distribution to the probability distribution of the interoccurrence time gradually increases with increase in the threshold of magnitude. Our results infer that Weibull statistics and log-Weibull statistics coexist in the interoccurrence time statistics, and that the change of the distribution is considered as the change of the dominant distribution. In this case, the dominant distribution changes from the log-Weibull distribution to the Weibull distribution, allowing us to reinforce the view that the interoccurrence time exhibits the transition from the Weibull regime to the log-Weibull regime. 相似文献
20.
Drossel B 《Physical review letters》2002,89(23):238701
The Olami-Feder-Christensen earthquake model is often considered the prototype dissipative self-organized critical model. It is shown that the size distribution of events in this model results from a complex interplay of several different phenomena, including limited floating-point precision. Parallels between the dynamics of synchronized regions and those of a system with periodic boundary conditions are pointed out, and the asymptotic avalanche size distribution is conjectured to be dominated by avalanches of size 1, with the weight of larger avalanches converging towards zero as the system size increases. 相似文献