细胞自动机语言Cellang的扩展与应用

并行执行与并行描述是并行计算的两个方面,后者是并行软件技术的一个日益重要的问题,目前主流的并行语言都是针对特定的需求设计的。细胞自动机对许多问题具有自然而贴切的描述并行性,作为动力学系统仿真工具与并行离散计算模型近来受到广泛关注。通过对某些细胞自动机语言进行扩展,可以使其成为并行数值计算的良好工具,方便地描述与求解一大类并行数值计算问题。本文介绍我们对细胞自动机语言Cellang的扩展及在并行数值计算上的应用。     

Multi swarm bare bones particle swarm optimization with distribution adaption

Bare bones PSO is a simple swarm optimization approach that uses a probability distribution like Gaussian distribution in the position update rules. However, due to its nature, Bare bones PSO is highly prone to premature convergence and stagnation. The characteristics of the probability distribution functions used in the update rule have a tense impact on the performance of the bare bones PSO. As a result, this paper investigates the use of different methods for estimating the probability distributions used in the update rule. Four methods or strategies are developed that are using Gaussian or multivariate Gaussian distributions. The choice of an appropriate updating strategy for each particle greatly depends on the characteristics of the fitness landscape that surrounds the swarm. To deal with issue, the cellular learning automata model is incorporated with the proposed bare bones PSO, which is able to adaptively learn suitable updating strategies for the particles. Through the interactions among its elements and the learning capabilities of its learning automata, cellular learning automata gradually learns to select the best updating rules for the particles based on their surrounding fitness landscape. This paper also, investigates a new and simple method for adaptively refining the covariance matrices of multivariate Gaussian distributions used in the proposed updating strategies. The proposed method is compared with some other well-known particle swarm approaches. The results indicate the superiority of the proposed approach in terms of the accuracy of the achieved results and the speed in finding appropriate solutions.     

细胞自动机及其在复杂系统研究中的应用

近年来,随着计算机技术的飞速发展,细胞自动机理论及其在复杂系统研究领域中应用的研究受到科学界的高度重视。由于细胞自动机具有结构简单、并行计算能力强和易于在计算机上实现系统的可视化模拟等特点,它已成为复杂系统研究领域一种具有广阔发展前景的新方法,在复杂系统(如:生物系统、交通系统、经济系统、环境系统、工程系统、社会系统和各种工业生产系统等)研究中得到了广泛的应用,并取得了令人瞩目的成果。文章在简要介绍复杂系统、细胞自动机概念及特点的基础上,分析了二者的相互关系,较详细地综述了细胞自动机在各种复杂系统研究领域的应用,最后结合笔者的研究指出了细胞自动机理论及其在复杂系统应用研究中有待进一步完善和深入研究的问题。     

Sand automata as cellular automata

In this paper, we exhibit a strong relation between the sand automata configuration space and the cellular automata configuration space. This relation induces a compact topology for sand automata, and a new context in which sand automata are homeomorphic to cellular automata acting on a specific subshift. We show that the existing topological results for sand automata, including the Hedlund-like representation theorem, still hold. In this context, we give a characterization of cellular automata which are sand automata, and study some dynamical behaviors such as equicontinuity. Furthermore, we deal with simple sand automata. We show that the classical definition of nilpotency is not meaningful for sand automata. Then, we introduce the suitable new notion of flattening sand automata. Finally, we prove that this simple dynamical behavior is undecidable.     

Alternation on cellular automata

In this paper we consider several notions of alternation in cellular automata: non-uniform, uniform and weak alternation. We study relations among these notions and with alternating Turing machines. It is proved that the languages accepted in polynomial time by alternating Turing machines are those accepted by alternating cellular automata in polynomial time for all the proposed alternating cellular automata. In particular, this is true for the weak model where the difference between existential and universal states is omitted for all the cells except the first one. It is proved that real time alternation in cellular automata is strictly more powerful than real time alternation in Turing machines, with only one read-write tape. Moreover, it is shown that in linear time uniform and weak models agree.     

Simulation of pedestrian flow through a “T” intersection: A multi-floor field cellular automata approach

There are several ways to study pedestrian dynamics, such as the macroscopic hydrodynamics, molecular dynamics with social force, and cellular automata (CA) with mean field approach. In recent years, the cellular automata approach has received growing interest from researchers. Because this approach is not only to save the computing time but also to reduce the complexity of the problem. In this presentation, we report the study of the conformation of congestion in a “T” intersection by using a cellular automata procedure with multi-floor fields. By using the multi-floor fields, we can mimic the pedestrian flow from several entrances to different exits firstly, and we can simulate the different pedestrian speed by changing the controlling parameter. Our results show, there are some kinds of phase transition in this system.     

A cellular learning automata-based deployment strategy for mobile wireless sensor networks

One important problem which may arise in designing a deployment strategy for a wireless sensor network is how to deploy a specific number of sensor nodes throughout an unknown network area so that the covered section of the area is maximized. In a mobile sensor network, this problem can be addressed by first deploying sensor nodes randomly in some initial positions within the area of the network, and then letting sensor nodes to move around and find their best positions according to the positions of their neighboring nodes. The problem becomes more complicated if sensor nodes have no information about their positions or even their relative distances to each other. In this paper, we propose a cellular learning automata-based deployment strategy which guides the movements of sensor nodes within the area of the network without any sensor to know its position or its relative distance to other sensors. In the proposed algorithm, the learning automaton in each node in cooperation with the learning automata in the neighboring nodes controls the movements of the node in order to attain high coverage. Experimental results have shown that in noise-free environments, the proposed algorithm can compete with the existing algorithms such as PF, DSSA, IDCA, and VEC in terms of network coverage. It has also been shown that in noisy environments, where utilized location estimation techniques such as GPS-based devices and localization algorithms experience inaccuracies in their measurements, or the movements of sensor nodes are not perfect and follow a probabilistic motion model, the proposed algorithm outperforms the existing algorithms in terms of network coverage.     

A cellular automaton model of particle motions and its applications

A natural object such as a flame with smoke is featured in terms of ambiguous boundaries and complex motion. One way of modeling natural objects is by particle systems, which need a large amount of computation time to calculate interactions among the particles. This paper deseribes another way of modeling particle motions based on a cellular automaton. Cellular automata are massively parallel computation models that can simulate complex phenomena. In our model, particle motions are simulated in a cellular space with a Margolus neighborhood, which has good conservation properties and collision detectability. This paper shows several applications in two-dimensional cellular space.     

基于多耦合元胞自动机的加密算法

提出了耦合系数的概念,构造了一个新的耦合元胞自动机模型,并分析了耦合系数对耦合元胞自动机时空演化的影响。针对已有的单耦合元胞自动机加密系统中存在的不足,提出了基于多耦合元胞自动机的加密算法,该算法将多个元胞进行耦合,增强了两个元胞自动机之间的作用,扩大了相互影响的范围,使得误差扩散更为快速。仿真结果表明,该算法具有更为理想的扩散和扰乱特性,可抵抗蛮力攻击和差分分析攻击。     

Garden of eden configurations for 2-D cellular automata with rule 2460 N

An important problem in cellular automata theory is the reversibility of a cellular automaton which is related to the existence of Garden of Eden configurations in cellular automata. In this paper, we study new local rules for two-dimensional cellular automata over the ternary field Z₃ (the set of integers modulo three) with some of their important characteristics. We obtain necessary and sufficient conditions for the existence of Garden of Eden configurations for two-dimensional ternary cellular automata. Also by making use of the matrix representation of two-dimensional cellular automata, we provide an algorithm to obtain the number of Garden of Eden configurations for two-dimensional cellular automata defined by rule 2460 N. We present an application of the reversible two-dimensional ternary cellular automata to cryptography.     

元胞自动机与软计算的集成及其应用

介绍了元胞自动机的思想来源和基本原理，对元胞自动机与敦计算的人工智能技术进行比较并加以集成，讨论了近年来它在混沌分形、图像处理、智能材料、机器学习、模拟复杂现象等领域中的应用成果，并对进一步研究进行展望。     

Bulking II: Classifications of cellular automata

This paper is the second part of a series of two papers dealing with bulking: a way to define quasi-order on cellular automata by comparing space-time diagrams up to rescaling. In the present paper, we introduce three notions of simulation between cellular automata and study the quasi-order structures induced by these simulation relations on the whole set of cellular automata. Various aspects of these quasi-orders are considered (induced equivalence relations, maximum elements, induced orders, etc.) providing several formal tools allowing to classify cellular automata.     

Models for quantitative distributed systems and multi-valued logics

We investigate weighted asynchronous cellular automata (wACAs) with weights in valuation monoids. These automata form a distributed extension of weighted finite automata (wFAs) and allow us to model concurrency. Valuation monoids are abstract weight structures that include semirings and (non-distributive) bounded lattices but also offer the possibility to model average behaviours. We prove that wACAs and wFAs which satisfy an I-diamond property are equally expressive. The main result of this paper gives a characterization of this expressiveness by weighted monadic second-order logic.     

Effects of cell size and configuration in cellular automata based prey–predator modelling

Cellular automata (CA) have shown to be a viable approach in ecological modelling, in particular when dealing with local interactions between species and their environment. In CA modelling complex patterns emerge on a global scale through the evolution of interactions at a local level. Although the validity of a cell-based approach has successfully been demonstrated in numerous cases, very few studies have been reported that address the effects of cell size and configuration on the behaviours of CA-based models. In this paper, the performance of a cellular automaton based prey–predator model (EcoCA) developed by the author was first calibrated against the classical Lotka–Volterra (LV) model. The model was then used to investigate effects of cell size and cellular configurations (viz. the ‘computational stencil’). By setting up systematic simulation scenarios it was observed that the choice of a particular cell size has a clear effect on the resulting spatial patterns, while different cellular configurations affect both spatial patterns and system stability. On the basis of these findings, it is proposed to use the principal spatial scale of the studied ecosystem as CA model cell size and to apply the Moore type cell configuration. Methods for identifying principal spatial scales have been developed and are presented here.     

细胞自动机置换群加密技术研究

1.引言信息技术的发展对信息安全提出了更高的要求,并使得作为信息安全核心的加密技术及其实现变得越来越复杂。所以,人们开始探索简化加密系统实现的新方法,以满足现代信息技术发展对全方位多层次信息安全的要求。1948年,Von Neumann在研究具有自组织特性的系统时引入了细胞自动机的概念,后经S.Wolfram对其结构进行简化,从而极大地推动了细胞自动机理论及其应用的发展。细胞自动机具有组成单元的简单性、单元之间作用的局部性和信息处理的高度     

一种基于元胞自动机的图像拼接方法

描述了一种基于元胞自动机的图像拼接方法,采用元胞自动机提取图像特征点,然后以特征点邻域灰度互相关法进行特征点匹配,最后根据匹配的特征点对得到图像间的变换参数。实验结果表明,本方法不仅准确实现了图像拼接,而且降低了图像重叠度的要求。     

On behavior of two-dimensional cellular automata with an exceptional rule

Several studies [A.R. Khan, P.P. Choudhury, K. Dihidar, S. Mitra, P. Sarkar, VLSI architecture of a cellular automata, Comput. Math. Appl. 33 (1997) 79-94; A.R. Khan, P.P. Choudhury, K. Dihidar, R. Verma, Text compression using two-dimensional cellular automata, Comput. Math. Appl. 37 (1999) 115-127; K. Dihidar, P.P. Choudhury, Matrix algebraic formulae concerning some exceptional rules of two-dimensional cellular automata, Inf. Sci. 165 (2004) 91-101] have explored a new rule convention for two-dimensional (2-D) nearest neighborhood linear cellular automata (CA) with null and periodic boundary conditions. A variety of applications of the rule convention have been illustrated, and the VLSI architecture of cellular automata machine (CAM) has been proposed. However, most of the studies address the issue of the kernel dimension of 2-D CA, and many other important characteristics of CA, such as Garden of Eden (GOE), maximal transient length, maximal cycle length, etc., have not been explored. In this paper, by exploiting matrix algebra in GF(2) (the Galois field with two elements), we attempt to characterize the behavior of a specific rule, which is not covered in existing work but accords with the same convention. A necessary and sufficient condition is given to ensure that a given configuration is a GOE. Meanwhile, we propose some algorithms to determine the number of GOEs, the maximal transient length, and the maximal cycle length in a 2-D CA.     

Structure and reversibility of 2D hexagonal cellular automata

Cellular automata are used to model dynamical phenomena by focusing on their local behavior which depends on the neighboring cells in order to express their global behavior. The geometrical structure of the models suggests the algebraic structure of cellular automata. After modeling the dynamical phenomena, it is sometimes an important problem to be able to move backwards in order to understand it better. This is only possible if cellular automata is reversible. In this paper, 2D finite cellular automata defined by local rules based on hexagonal cell structure are studied. Rule matrix of the hexagonal finite cellular automaton is obtained. The rank of rule matrices representing the 2D hexagonal finite cellular automata via an algorithm is computed. It is a well known fact that determining the reversibility of a 2D cellular automata is a very difficult problem in general. Here, the reversibility problem of this family of 2D hexagonal cellular automata is also resolved completely.     

Hyperspectral image segmentation through evolved cellular automata

Segmenting multidimensional images, in particular hyperspectral images, is still an open subject. Two are the most important issues in this field. On one hand, most methods do not preserve the multidimensional character of the signals throughout the segmentation process. They usually perform an early projection of the hyperspectral information to a two dimensional representation with the consequent loss of the large amount of spectral information these images provide. On the other hand, there is usually very little and dubious ground truth available, making it very hard to train and tune appropriate segmentation and classification strategies. This paper describes an approach to the problem of segmenting and classifying regions in multidimensional images that performs a joint two-step process. The first step is based on the application of cellular automata (CA) and their emergent behavior over the hyperspectral cube in order to produce homogeneous regions. The second step employs a more traditional SVM in order to provide labels for these regions to classify them. The use of cellular automata for segmentation in hyperspectral images is not new, but most approaches to this problem involve hand designing the rules for the automata and, in general, average out the spectral information present. The main contribution of this paper is the study of the application of evolutionary methods to produce the CA rule sets that result in the best possible segmentation properties under different circumstances without resorting to any form of projection until the information is presented to the user. In addition, we show that the evolution process we propose to obtain the rules can be carried out over RGB images and then the resulting automata can be used to process multidimensional hyperspectral images successfully, thus avoiding the problem of lack of appropriately labeled ground truth images. The procedure has been tested over synthetic and real hyperspectral images and the results are very competitive.     

元胞自动机在"数字油田"中的应用

“数字油田”要设计一个涵盖油田全部业务活动的综合信息系统指导性框架,当作今后油田信息化建设的指南。它作为一个复杂的开放系统,适于使用元胞自动机模型来进行研究。介绍了元胞自动机的产生与原理,作为复杂性研究的新途径,探讨了元胞自动机在“数字油田”中的应用并做了复杂性分析。