共查询到20条相似文献,搜索用时 46 毫秒
1.
ZHAOXiao-Wei CHENTian-Lun 《理论物理通讯》2003,40(3):363-368
Based on the standard self-organizing map (SOM) neural network model and an integrate-and-fire mecha-nism, we introduce a kind of coupled map lattice system to investigate scale-invariance behavior in the activity of model neural populations. We find power-law distribution behavior of avalanche size in our model. But more importantly, we find there are different avalanche distribution behaviors in different specific areas of our system, which are formed by the topological learning process of the SOM net. 相似文献
2.
Based on the standard self-organizing map neural network model and an integrate-and-fire mechanism, we introduce a kind of coupled map lattice system to investigate scale-invariance behavior in the activity of model neural populations. We let the parameter β, which together with α represents the interactive strength between neurons, have different function forms, and we find the function forms and their parameters are very important to our model‘s avalanche dynamical behaviors, especially to the emergence of different avalanche behaviors in different areas of our system. 相似文献
3.
ZHAOXiao-Wei ZHOULi-Ming CHENTian-Lun 《理论物理通讯》2003,40(5):607-613
Based on the standard self-organizing map neural network model and an integrate-and-fire mechanism, we introduce a kind of coupled map lattice system to investigate scale-invariance behavior in the activity of model neural populations. We let the parameter β, which together with α represents the interactive strength between neurons, have different function forms, and we find the function forms and their parameters are very important to our model‘‘s avalanche dynamical behaviors, especially to the emergence of different avalanche behaviors in different areas of our system. 相似文献
4.
The dynamical behavior in the cortical brain network of macaque
is studied by modelling each cortical area with a subnetwork of
interacting excitable neurons. We find that the avalanche of our
model on different levels exhibits power-law. Furthermore the
power-law exponent of the distribution and the average avalanche
size are affected by the topology of the network. 相似文献
5.
LINMin CHENTian-Lun 《理论物理通讯》2004,42(3):373-378
We introduce the Olami-Feder-Christensen (OFC) model on a square lattice with some “rewired“ longrange connections having the properties of small world networks. We find that our model displays the power-law behavior, and connectivity topologies are very important to model‘s avalanche dynamical behaviors. Our model has some behaviors different from the OFC model on a small world network with “added“ long-range connections in our previous work [LIN Min, ZHAO Xiao-Wei, and CHEN Tian-Lun, Commun. Theor. Phys. (Beijing, China) 41 (2004) 557.]. 相似文献
6.
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
7.
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
8.
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
9.
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
10.
Li W Cai X 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》2000,61(1):771-775
A quantity &fmacr; denoting the average fitness of an ecosystem is introduced in the Bak-Sneppen model. Through this quantity, a different hierarchy of avalanches, &fmacr;(0) avalanche, is observed in the evolution of Bak-Sneppen model. An exact gap equation, governing the self-organization of the model, is presented in terms of &fmacr;. It is found that self-organized threshold &fmacr;(c) can be exactly obtained. Two basic exponents of the new avalanche tau, avalanche distribution, and D, avalanche dimension are given through simulations of one- and two-dimensional Bak-Sneppen models. It is suggested that &fmacr; may be a good quantity in determining the emergence of criticality. 相似文献
11.
We study the driving-rate and temperature dependence of the power-law exponents that characterize the avalanche distribution in first-order phase transitions. Measurements of acoustic emission in structural transitions in Cu-Zn-Al and Cu-Al-Ni are presented. We show how the observed behavior emerges within a general framework of competing time scales of avalanche relaxation, driving rate, and thermal fluctuations. We confirm our findings by numerical simulations of a prototype model. 相似文献
12.
Effects of vertex activity have been analyzed on a weighted
evolving network. The network is characterized by the probability
distribution of vertex strength, each edge weight and evolution of
the strength of vertices with different vertex activities. The model exhibits self-organized criticality behavior. The
probability distribution of avalanche size for different network sizes is also shown. In addition, there is a power law relation between the size and the duration of an avalanche and the average of avalanche size has been studied for different vertex activities. 相似文献
13.
LIN Min WANG Gang CHEN Tian-Lun 《理论物理通讯》2007,47(4):759-764
Based on an integrate-and-fire mechanism, we investigate self-organized criticality of a simple neuron model on a modified BA scale-free network with aging nodes. In our model, we find that the distribution of avalanche size follows power-law behavior. The critical exponent τ depends on the aging exponent α. The structures of the network with aging of nodes change with an increase of α. The different topological structures lead to different behaviors in models of integrate-and-fire neurons. 相似文献
14.
Based on the LISSOM model and the OFC earthquake model, we introduce a selforganized neural network model, in which the distribution of the avalanche sizes (unstable neurons) shows power-law behavior. In addition, we analyze the influence of various factors of the model on the power-law behavior of the avalanche size distribution. 相似文献
15.
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
16.
It is shown that the cortical brain network of the macaque
displays a hierarchically clustered organization and the neuron
network shows small-world properties. Now the two factors will be
considered in our model and the dynamical behavior of the model
will be studied. We study the characters of the model and find
that the distribution of avalanche size of the model follows
power-law behavior. 相似文献
17.
LIN Min WANG Gang CHEN Tian-Lun 《理论物理通讯》2006,46(8)
A simple model for a set of interacting idealized neurons in scale-free networks is introduced. The basic elements of the model are endowed with the main features of a neuron function. We find that our model displays powerlaw behavior of avalanche sizes and generates long-range temporal correlation. More importantly, we find different dynamical behavior for nodes with different connectivity in the scale-free networks. 相似文献
18.
LIN Min WANG Gang CHEN Tian-Lun 《理论物理通讯》2006,46(2):362-366
A simple model for a set of interacting idealized neurons in scale-free networks is introduced. The basic elements of the model are endowed with the main features of a neuron function. We find that our model displays powerlaw behavior of avalanche sizes and generates long-range temporal correlation. More importantly, we find different dynamical behavior for nodes with different connectivity in the scale-free networks. 相似文献
19.
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
20.
We consider the earthquake model on a random graph. A detailed analysis of the probability distribution of the size of the avalanches will be given. The model with different inhomogeneities is studied in order to compare the critical behavior of different systems. The results indicate that with the increase of the inhomogeneities, the avalanche exponents reduce, i.e., the different numbers of defects cause different critical behaviors of the system. This is virtually ascribed to the dynamical perturbation. 相似文献