基于改进边界条件的元胞自动机模型研究

元胞自动机方法在模拟过程中,必须用特殊的算法对边界进行处理才能避免边界出现杂质及失真.提出了基于Moore型邻接的改进边界条件算法并进行了模拟.通过与随机型边界条件模拟结果的对比,表明改进算法有利于模拟区域四角和四边的处理,可以应用于元胞自动机模拟中.     

求解声学问题的元胞自动机方法

为探究元胞自动机(cellular automata,CA)方法在求解声学问题中的适用性,结合CA原理与声波方程导出一维平面波场CA的局部演化规则,构建出一维声学CA模型,并计算不同边界条件下声管内的声压分布,同时对比解析解验证模型的正确性;以球坐标下的声波方程为基础,推导出脉动球源Y函数的CA局部演化规则,进而建立二...     

基于三维元胞自动机的烹饪状态曲线分析

本文是关于烤盘设计优化问题的研究,应用三维仿真来分析烤盘能量分布,通过优化烤盘形状降低烤焦率,得到令烤焦率最低的烤盘设计的相关原则。本文主要采用元胞自动机思想进行热传导过程的程序设计和指标设计。研究发现烹饪状态曲线有分光滑型和阶梯型,另外烤焦率与烤盘宽长比、烤盘圆角大小有关。最后提出烤盘形状设计的相关建议。     

基于元胞自动机的分布式水文模型研究

元胞自动机是一个时空离散的动力学模型,是复杂系统的研究方法之一。将元胞自动机这一新方法工具应用到分布式水文模型中,为分布式水文模型的发展提供一种新的思路。简要介绍元胞自动机的定义和构成等基本理论,针对水文研究领域的特殊性,扩展元胞自动机的定义,将元胞自动机和分布式水文模型相结合提出元胞自动机水文模型(CAHM),对元胞自动机水文模型的建模方法及模型结构进行阐述,并对元胞模型应用于分布式水文模型的优势及面临的问题进行分析。     

122号初等元胞自动机的周期性分析

自然界存在着许许多多的复杂系统,这些系统的每一部分结构可以非常简单,但由于各部分之间存在着一定的关联（耦合）,最后表现出的整体性态可以极其复杂。元胞自动机就是研究复杂系统的理想化的一种数学模型。90号初等元胞自动机时间序列的非周期性已经清楚[11],通过用122号和126号初等元胞自动机类比。证明122号初等元胞自动机规则下一类有限初始条件:s⁰=…0010^2k₁-110^2k₂-110^2k₃-11…0^2k_n-1100…产生的时间序列是周期的（其中k_i和n,i=1,2,…n是任意正整数）。除此类型以外的有限初始条件产生的时间序列是非周期的。     

122号初等元胞自动机的周期性分析

自然界存在着许许多多的复杂系统,这些系统的每一部分结构可以非常简单,但由于各部分之间存在着一定的关联（耦合）,最后表现出的整体性态可以极其复杂。元胞自动机就是研究复杂系统的理想化的一种数学模型。90号初等元胞自动机时间序列的非周期性已经清楚[11],通过用122号和126号初等元胞自动机类比。证明122号初等元胞自动机规则下一类有限初始条件：s^0=．．．0010^2k1-1 10^2k2-110^2k3-11…0^2kn-1100…产生的时间序列是周期的（其中ki和n,i=l…2．_n是任意正整数）。除此类型以外的有限初始条件产生的时间序列是非周期的。     

基于2.5维元胞自动机的人群疏散模型

在二维元胞自动机的基础上提出2.5维元胞自动机的新概念.以大型运动场馆为研究对象,研究和建立了基于2.5维元胞自动机的人群疏散网格模型.该模型兼顾考虑了场地客观因素及人员主观因素方面的影响,引入的高程因素对人群疏散情况分析是有效的.最后通过实例论证了提出的2.5维元胞自动机模型对人群疏散仿真效果的实用性及合理性.     

基于元胞自动机的陶瓷复合材料的设计与制备

基于元胞自动机理论对ZrB2/(W,Ti)C陶瓷复合材料进行了模拟,并对其进行了相关实验验证。模拟结果表明,随着(W,Ti)C含量的增加,晶粒的形貌不断地发生演化,(W,Ti)C加入的比例较合理时晶粒大小合适并分布比较均匀。实验结果表明,晶粒的尺寸随模拟的变化规律与实际情况较为吻合,利用元胞自动机理论进行复合材料的模拟,可以很好地模拟复合材料的微观组织演化。     

基于小波元胞自动机算法的引线键合去噪

本文针对引线键合过程中图像边缘要求性高的特点,提出一种基于小波与元胞自动机相结合的去噪算法。该算法对图像小波变换,根据像素点的方向信息和边缘有序性设定演化规则,使可能噪声像素进行元胞自动机演化,得到精确的噪声信息。     

元胞自动机：一种探索管理系统复杂性的有效工具

元胞自动机能利用简单的局部规则和离散方法描述复杂的全局的连续系统,已成为探索复杂系统的 一种有效工具。文章阐述了元胞自动机的发展历程、结构、特征及基本理论与方珐;介绍了元胞自动机在寡头 垄断行为、交通管理及工程运输、城市发展、市场营销、股票投资、企业战略等管理领域中的应用;指出元胞 自动机理论的优势与不足,并提出进一步的研究展望。     

Binary image encryption based on interference of two phase-only masks

Optical image encryption based on interference has attracted a lot of attention recently. The technique employs two pure phase masks derived from the complex field of the image in the Fresnel diffraction domain. The image decryption procedure can be carried out by inverse Fresnel transformation of the summation of two pure phase masks. However, the silhouette of the original image, which is recovered by either of the two phase-only masks, impedes the application of this technique. In this paper, a very simple method for binary image encryption based on interference of two phase-only masks is proposed without any silhouette problem. The binary image in combination with a random phase mask is separated into two phase-only masks directly, and the decryption by summation of the two masks can be performed digitally or optically. In this paper, the encryption and decryption processes are analyzed, after which both the optical simulation and the experimental results based on single-beam holography are given to demonstrate the feasibility of the encryption method. As information nowadays is mainly digitized into binary codes, the proposed encryption method may find applications in the information processing field.     

基于元胞自动机的薄膜磁滞回线的计算机模拟

利用Stoner-Wohlfarth模型,概率型元胞自动机的模型和算法,在考虑了退磁场和交换作用的情况下对薄膜的磁滞回线进行了模拟,比较了温度以及和易轴取向变化时磁化曲线以及剩磁矩形比和矫顽力的不同及变化趋势.退磁场和交换作用的引入对磁化翻转过程有显著的影响,剩磁矩形比和矫顽力都有不同程度的提高.     

A novel cellular automata based approach to storm sewer design

Optimal storm sewer design aims at minimizing capital investment on infrastructure whilst ensuring good system performance under specified design criteria. An innovative sewer design approach based on cellular automata (CA) principles is introduced in this paper. Cellular automata have been applied as computational simulation devices in various scientific fields. However, some recent research has indicated that CA can also be a viable and efficient optimization engine. This engine is heuristic and largely relies on the key properties of CA: locality, homogeneity, and parallelism. In the proposed approach, the CA-based optimizer is combined with a sewer hydraulic simulator, the EPA Storm Water Management Model (SWMM). At each optimization step, according to a set of transition rules, the optimizer updates all decision variables simultaneously based on the hydraulic situation within each neighbourhood. Two sewer networks (one small artificial network and one large real network) have been tested in this study. The CA optimizer demonstrated its ability to obtain near-optimal solutions in a remarkably small number of computational steps in a comparison of its performance with that of a genetic algorithm.     

Testing of quantum cellular automata

There has been considerable research on quantum dot cellular automata (QCA) as a new computing scheme in the nanoscale regimes. The basic logic element of this technology is the majority voter. In this paper, a detailed simulation-based characterization of QCA defects and study of their effects at logic level are presented. Testing of these QCA devices at logic level is investigated and compared with conventional CMOS-based designs. Unique testing features of designs based on this technology are presented and interesting properties have been identified. A testing technique is presented; it requires only a constant number of test vectors to achieve 100% fault coverage with respect to the fault list of the original design. A design-for-test scheme is also presented, which results in the generation of a reduced test set at 100% fault coverage.     

Modelling approaches for coastal simulation based on cellular automata: the need and potential

The paper summarizes the theoretical and practical needs for cellular automata (CA)-type models in coastal simulation, and describes early steps in the development of a CA-based model for estuarine sedimentation. It describes the key approaches and formulae used for tidal, wave and sediment processes in a prototype integrated cellular model for coastal simulation designed to simulate estuary sedimentary responses during the tidal cycle in the short-term and climate driven changes in sea-level in the long-term. Results of simple model testing for both one-dimensional and two-dimensional models, and a preliminary parameterization for the Blackwater Estuary, UK, are shown. These reveal a good degree of success in using a CA-type model for water and sediment transport as a function of water level and wave height, but tidal current vectors are not effectively simulated in the approach used. The research confirms that a CA-type model for the estuarine sediment system is feasible, with a real prospect for coupling to existing catchment and nearshore beach/cliff models to produce integrated coastal simulators of sediment response to climate, sea-level change and human actions.     

Micro-simulation of vehicle conflicts involving right-turn vehicles at signalized intersections based on cellular automata

At intersection, vehicles coming from different directions conflict with each other. Improper geometric design and signal settings at signalized intersection will increase occurrence of conflicts between road users and results in a reduction of the safety level. This study established a cellular automata (CA) model to simulate vehicular interactions involving right-turn vehicles (as similar to left-turn vehicles in US). Through various simulation scenarios for four case cross-intersections, the relationships between conflict occurrences involving right-turn vehicles with traffic volume and right-turn movement control strategies are analyzed. Impacts of traffic volume, permissive right-turn compared to red-amber-green (RAG) arrow, shared straight-through and right-turn lane as well as signal setting are estimated from simulation results. The simulation model is found to be able to provide reasonable assessment of conflicts through comparison of existed simulation approach and observed accidents. Through the proposed approach, prediction models for occurrences and severity of vehicle conflicts can be developed for various geometric layouts and traffic control strategies.     

陶瓷材料烧结致密化过程的元胞自动机模拟

为研究陶瓷材料烧结致密化过程,以晶界能和晶界曲率生长驱动力理论为基础,建立了含有气孔的二相晶粒生长的元胞自动机模型,对陶瓷材料烧结致密化过程进行了模拟,并与制备的Al2O3/TiN陶瓷材料进行对比.结果表明,模型可有效地模拟陶瓷材料烧结时晶粒的生长及气孔的湮灭情况,能较好地再现烧结致密化过程,模拟结果与制备的陶瓷材料微观形貌组织十分接近.     

Iris segmentation using an edge detector based on fuzzy sets theory and cellular learning automata

Iris-based biometric systems identify individuals based on the characteristics of their iris, since they are proven to remain unique for a long time. An iris recognition system includes four phases, the most important of which is preprocessing in which the iris segmentation is performed. The accuracy of an iris biometric system critically depends on the segmentation system. In this paper, an iris segmentation system using edge detection techniques and Hough transforms is presented. The newly proposed edge detection system enhances the performance of the segmentation in a way that it performs much more efficiently than the other conventional iris segmentation methods.     

Serial bit-stream analysis using quantum-dot cellular automata

Quasi-adiabatically switched quantum-dot cellular automata (QCA) devices present the opportunity to extend our efforts from the implementation of combinational logic devices to more useful sequential logic devices. One very important application of sequential logic is in the recognition of patterns in serial bit streams. This is important, for example, in Internet applications, where particular bit patterns are designated as "sentinel" characters that indicate a particular action should be taken. The foundation of a serial bit-stream analyzer is a shift register, which can be implemented very easily using quasi-adiabatically switched QCA devices. In addition to the shift register, the device will require a multiple-bit comparator, which has not yet been demonstrated in a QCA architecture. We will present a multiple-bit serial stream analyzer that combines the functions of the shift register and the comparator. This device will be analyzed first using behavioral and structural models developed specifically for this project, then its correct quasi-adiabatic behavior will be demonstrated using well established quantum mechanical models. We will show that the proposed device can be used to detect any arbitrary bit pattern appearing in a serial stream of data applied to its serial input. The bit pattern to be detected can be changed using device inputs, and a successful match will be indicated by asserting an output.