共查询到18条相似文献,搜索用时 173 毫秒
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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。 相似文献
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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。 相似文献
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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。 相似文献
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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. 相似文献
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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。 相似文献
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目前软件体系结构动态演化的元胞自动机模型存在描述单一、元胞间关系不明确、没有详细阐述动态演化过程应用约束条件的缺点。针对这些不足进行相关的研究,重新定义了软件体系结构动态演化的扩展元胞自动机模型,基于扩展元胞自动机模型结合演化应用约束条件,分析了软件体系结构的动态演化过程,运用元胞间控制约束条件和行为相关约束条件来正确地指导SA动态演化。提出了动点稳态转移的概念,对演化程度和一致性进行定义分析,此方法比以往的元胞自动机模型更能准确指导SA动态演化,促进SA动态演化的进一步研究。通过案例验证了该方法的应用价值和可行性,可以更全面地应用于软件体系结构的动态演化。 相似文献
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Carlisle 2005 urban flood event simulation using cellular automata-based rapid flood spreading model
Yang Liu Gareth Pender 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2013,17(1):29-37
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. 相似文献
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Hamidou Kassogué Abdes Samed Bernoussi Mina Amharref Mustapha Ouardouz 《International Journal of Parallel, Emergent and Distributed Systems》2019,34(1):21-36
ABSTRACTIn 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. 相似文献
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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. 相似文献
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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。 相似文献
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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. 相似文献
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Julian Canto-Perello Jorge Curiel-Esparza Vicente Calvo 《Expert systems with applications》2013,40(11):4707-4714
A utility tunnel is defined as an underground structure containing one or more utilities, permitting the installation, maintenance and removal of the systems without the necessity of making street cuts or excavations. These underground facilities contain all essential utilities serving large urban areas collected together in a tunnel; therefore they are an inviting target for sabotage or vandalism. This paper proposes an expert system combining color-coded scales, Delphi and AHP methods to analyze criticality and threats on utility tunnels to support planning of security policies for utilities in urban subsurface. 相似文献