地下矿CA粒子系统火灾蔓延仿真

为了对火灾在地下矿巷道中的蔓延情况进行仿真,提出了一个元胞自动机理论和粒子系统理论相结合的地下矿巷道系统中火灾蔓延仿真方法。针对地下矿巷道这个特殊环境,采取可变邻域半径的元胞自动机模型来仿真火焰在巷道中蔓延的情景;同时,引入基于粒子系统的烟雾模型,把燃烧着的元胞作为烟雾模型的粒子发射器。整个仿真系统基于同一时钟运行,把时间、空间、火烟的物理行为有效地结合起来,不仅能非常直观地仿真出火势蔓延态势和烟雾扩散运动过程,并且通过在仿真过程中计算记录不同时刻火灾蔓延距离和入侵巷道烟雾粒子数量等数据,可以获取大量巷道环境相关信息,为逃生决策和火灾预防与控制提供依据。     

基于元胞自动机的洪泽湖洪水蔓延模型研究

分析了元胞自动机的基本原理和构成，利用元胞自动机原理建立了洪泽湖洪水蔓延模型。模型以栅格空间数据结构作为基础，采用二维元胞自动机模型，确定了元胞空间和元胞状态，建立了洪泽湖洪水蔓延的规则，并根据规则以9邻域方式进行元胞状态的更新。选择性地测试了洪水蔓延模型的计算结果，模型计算数据与实际数据的比较表明，二维元胞自动机模型能够更为简单、快速地模拟洪泽湖洪水的蔓延。     

基于元胞自动机的网络舆论激励模型

为了研究网络舆论的传播过程及发展趋势，建立了一个基于元胞自动机的网络舆论激励模型，用于模拟网络舆论形成过程中个体发表言论数的变化以及个体观点的变化。在模型中，将网络空间的个体抽象为以情感描述的元胞，用情感倾向度和情感倾向度门限来确定元胞发表言论的状态，用情感激励来描述元胞的移动规则。同时，该模型考虑了个体数量增减和社会突发事件对网络舆论传播的影响，从而更能准确地模拟网络现实事件。     

巷道热流蔓延及阻滞的分块耦合LBM仿真

为了掌握地下矿火灾发生后遇到易燃物蔓延、障碍物阻滞的规律,提出用分块耦合格子Boltzmann方法(LBM)进行巷道热流蔓延与阻滞的仿真方法.该方法使用分块耦合算法将巷道分为若干相对规则的块,并应用速度-温度双分布LBM对巷道热流蔓延及阻滞过程进行仿真.仿真时,在巷道随机设置多处易燃物,当热流流经巷道时采用热流蔓延模型使得易燃物在一定条件下被引燃,产生热流与原有热流共同传播;在巷道随机设置障碍物,采用热流阻滞模型分析热流遇到障碍物后其方向和温度变化状况.仿真结果表明,该仿真方法可得到关于热流流动速度、热流温度和压力的详细数据,获得关于巷道热流流态的直观信息,从而为制定有效的规避热流的方案提供依据.     

自行车CA模型的元胞长度动态修正

采用固定元胞单元尺寸建立自行车流元胞自动机(CA)模型会产生仿真偏差。为此，提出一种基于现场视频检测数据的元胞尺寸标定方法。通过统计分析车头间距、横向间距与车速的关系，设计一个动态修正元胞长度的函数。对比修正前后模型演化获得的宏观三参数值，可以发现，修正函数能较好地描述跟车距离与车速的动态关系，克服模型因采用定长度元胞单元而造成的面积密度与流率偏差。     

基于CA的离散粒子系统仿真和显示研究

综合考虑计算的效率,根据真实存在的离散粒子系统的特点,进行元胞自动机模型的建立和规则设计,并以一个三维螺旋空间为例进行仿真和分析。实例表明,该方法在三维复杂空间中运行,元胞自动机模型能定性地体现粒子之间的碰撞和摩擦现象。该方法可以用于动态显示三维离散粒子系统的演化过程,计算效率优于传统的离散单元法.     

基于数字地球的林火灾害建模

针对数字地球上林火灾害可视化问题,建立林火灾害仿真可视化框架。设计蔓延表现算法,采用Rothermel火行为计算模型和邻接单元蔓延模型。提出一种网格均匀划分的简化模型,进行仿真实验。结果表明,该方法能在数字地球上表达林火蔓延过程,较好地描述林火蔓延物理机理,为三维地理环境上的灾害分析提供辅助支持。     

基于元胞自动机的交通流计算机模拟

元胞自动机是把复杂系统量化为简单的个体,在元胞自动机模型中.空间、时间都被离散化,每一个相互作用的单元仅为有限的状态.以元胞自动机理论为基础,把车辆在路段上交通流中运动的变化规律表述为元胞自动机的演化规则,建立了基于元胞自动机理论的交通流模拟模型,标定了元胞长度和最大速度等参数,分析了元胞变换的原则;详细探讨了元胞自动机在道路交通模拟中的应用,设计出了交通元胞自动机的结构,分析了交通元胞自动机所采取的状态变换原则,建立了一维(单车道)交通流模拟模型;并利用C语言编程实现模拟.模拟结果符合实际交通流的特点.     

一种改进的NS元胞自动机模型

研究改进了基于元胞自动机的一维NS交通模型，细化了元胞长度和时间步长，对静止车辆的加速能力进行了约束，用简单的方法解决了该模型中车辆的速度演化规则与前车速度无关的缺点。同时，考虑了交通密度对随机慢化概率的影响。计算机仿真表明：改进模型不仅得到了一些与其他元胞自动机模型共有的性质，且得到的基本图更加接近实测数据。     

基于耦合触发元胞自动机的并行加密模型

介绍了耦合触发元胞自动机构造的一般方法，根据耦合触发元胞自动机的特性，提出了一种耦合触发元胞自动机并行加密模型．仿真实验表明：耦合触发元胞自动机并行加密模型与其迭代加密模型相比，大大提高了加密解密速度，具有更好的实时性、普适性．     

Carlisle 2005 urban flood event simulation using cellular automata-based rapid flood spreading model

In this study, we propose a new method to apply the rapid flood spreading model (RFSM) using cellular automata (CA) to multiple inflows of Carlisle, UK. The purpose of the RFSM is to generate predictions of water depth and flood extent using less computer resource than required by two-dimensional shallow water equation models (SWEMs). To be useful the RFSM must produce predictions that are comparable with those obtained from SWEMs. This paper reports a validation data available to the date on an urban flood, collected in January 2005 after a major event in the city of Carlisle, UK. This demonstrates an agreement between the proposed RFSM and measured data.     

Cellular automata approach for modelling climate change impact on water resources

ABSTRACT

In this work, we consider the cellular automata (CA) approach for modelling the climate change impact on water resources. This consists in: constructing a CA model that describes the water cycle dynamics taking into account physical terrain attributes and climatic constraints; coupling the CA model with climate projection scenarios for a considered region as input data; determining and analysing in output the variations of the underground, surface and evaporated water. We present these variations per time interval and per zone of influence. As an application, we consider simulation for a basin in northern Morocco using a simulation software we have designed in Java Object Oriented Programming.

We consider cellular automata (CA) approach for modelling climate change impact on water resources. This consists in, first constructing a CA model that describes the water cycle dynamics taking into account physical terrain attributes and climatic constraints, then coupling the CA model with climate projection scenarios for a considered region as input data, and we determine and analyze in output the variations of the water resources (groundwater and surface water). We present these variations per time interval and per zone of influence. The approach application is for a basin in northern Morocco for which we use simulation software that we have designed in Java Object Oriented Programming. Digital terrain model, geological map and satellites image are used for input data.     

基于演化硬件的交通流模型自适应优化

BML模型是用于研究城市路网结构中交通流特征的细胞自动机模型。基于软件的模拟及演化优化方式存在着运算效率低、优化速度慢等缺陷,极大地限制了交通流模型的实时应用能力。针对这一问题,提出将演化硬件与细胞自动机相结合,实现交通流模型的在线演化。同时对I3ML模型进行了改进,以便能够依据现实车流状况进行交通灯信号的自适应调节。实验结果表明,将演化硬件技术用于交通流模型的自适应优化,对于研制智能交通系统是一种可行的途径。     

A weighted cellular automata 2D inundation model for rapid flood analysis

To achieve fast flood modelling for large-scale problems, a two-dimensional cellular automata based model was developed. This model employs simple transition rules and a weight-based system rather than complex Shallow Water Equations. The simplified feature of cellular automata allows the model to be implemented in parallel environments, resulting in significantly improved modelling efficiency. The model has been tested using an analytical solution and four case studies and the outputs were compared to those from a widely-used commercial physically-based hydraulic model. Results show that the model is capable of simulating water-depth and velocity variables with reasonably good agreement with the benchmark model, using only a fraction of the computational time and memory. In the case of the real world example, the proposed model run times are up to 8 times faster. The rapid and accurate attributes of the model have demonstrated its applicability for quick flood analysis in large modelling systems.     

基于稀疏三维散点的地下巷道可视化重建方案

为了对地下巷道进行三维可视化重建,提出了一种基于稀疏三维散点的巷道可视化方案.根据地下巷道的形状规律,建立了梯形断面巷道的三维数学模型,将巷道分为多段,根据稀疏的三维散点得到每段巷道的中心线位置、长度数据和断面顶点,画出每段巷道的各个面,以完成整条巷道的重建.实验验证表明,该方法可视化巷道所需要的三维点数量很少,且有一定抗噪性,稳定性.     

隧道防汛监控预警系统设计

下穿式隧道是城市交通中快速通道的重要形式，但在雨季汛期容易发生积水现象，影响交通安全和效率。目前常用的隧道积水检测方法存在测量不准确、反应不及时、维护成本高等。为了实现下穿式隧道水位的实时监测预警，设计了一种基于STM32F103C8T6主控芯片、HC-SR04超声波传感器和nRF24L01通信模块的水位检测系统。从机位负责采集隧道口易积水地区的水位高度，并通过无线方式发送给主机位；主机位负责接收并处理水位信息，并在OLED12864显示屏上显示实时水位及相应警告。该系统具有测量精度高、响应速度快、功耗低、安装简便等特点。实验结果表明，该系统能够准确地测量隧道口易积水地区的水位高度，并在OLED12864显示屏上显示相应警告信息，达到了预期效果。为下穿式隧道积水检测提供了一种新颖有效的解决方案，并为其他类似场景中的水位监测提供了参考。     

一种改进CA高速公路隧道交通流仿真研究

应用元胞自动机理论,针对VDR单车道模型在仿真交通流时数值模拟结果偏小的情况,考虑前车相对运动对跟随车的影响,提出了虚拟车间距的概念,同时在一定条件下对后车进行了跟驰约束,建立改进的VDR绿波模型并应用该模型对高速公路隧道交通流进行了模拟仿真,分析了速度、密度、流量三参数之间的关系,得出车辆密度、车辆延迟刹车概率等因素对高速公路隧道交通流的影响规律,仿真结果表明改进的VDR绿波模型不仅具有基本慢启动模型的典型特性,而且对传统VDR元胞自动机模型数值模拟偏小的情况有合理的改善,对科学管理高速公路瓶颈隧道交通流具有一定的参考价值。     

Robophysical study of excavation in confined environments

Soil-dwelling social insects build complex nests. Nest excavation is performed by multiple animals simultaneously and is governed by local interactions of the workers with other nest-mates and their surroundings. To investigate collective confined excavation challenges, we built groups of robotic excavators capable of performing hours of autonomous tunnel excavation in a model cohesive granular medium. Excavator behavior was governed by a simple set of rules triggered by interactions with the surrounding environment and other robots. The rate of tunnel growth and energetic costs of excavation were measured for groups of different numbers operating in wide and narrow tunnels. To extend the results to systems with large numbers of robots, we developed a cellular automata model. Experiments and simulations showed that in sufficiently wide tunnels an increase in the size of the excavating group increased the excavation rates without a significant increase in the energy consumption per robot. A decrease in the tunnel width resulted in a decrease in the excavation rates and increase in the energetic costs of excavation. We attribute this effect to the emergence of multiple time-consuming interactions (clogs) among excavating robots in the confined spaces. Although in all situations clogs were resolvable, clog resolution took longer in the systems with larger number of robots and narrower tunnels. We expect that our robotic system can be used to investigate the behavior of social insects in confined spaces as well as inspire more sophisticated search-and-rescue robotics.