Cellular Automata Theory Research Articles

Subsidence through formation simulation with the use of cellular automata theory on the example of real, multi-longwall example

The paper presents an example of real subsequent underground hard coal mining (3 longwalls), which caused the formation of a subsidence trough on the surface of the mining area. Surface deformations were covered by systematic leveling measurements along the measurement line “1”. For the illustrated example of underground mining, numerical calculations were made using the theory of cellular automata. Calculated data were compared with the results of leveling. The aim of the article was to verify the theoretical assumptions of the model and to demonstrate the practical possibilities of applying the method to assess the subsidence of the mining area.

The continuous-discontinuous cellular automaton method for elastodynamic crack problems

In this paper, the recently proposed continuous-discontinuous cellular automaton method (CDCA) is further developed for elastodynamic problems in 2D elastic solids. A continuity-to-discontinuity enriched function technique is developed for elastodynamics and combined with a cellular automaton formulation; the cellular automaton theory for elastodynamics, in which fast adaptive updating rules for the cell and its neighbors are developed, and the time domain CDCA are proposed. In this method, the cracks are independent of the integral meshes, and no assembled global matrix is needed for the whole process. Time-dependent equations for the cells are discretized by the Newmark method, and rapidly solved by the cellular automaton method. To analyze the fracture behaviors of elastic solids with dynamic loads, mixed-mode dynamic stress intensity factors are obtained by the interaction integral method. Some numerical examples for elastodynamic problems are studied to validate the accuracy and efficiency of the present method, and solutions from analytical method and some other methods are employed to show the high accuracy of the CDCA.

A PROBABILISTIC CELLULAR AUTOMATON TO FORECAST PORT CHOICE DECISIONS

The port choice problem consists in predicting the selection of a port, made by an agent who has alternatives to choose from. Most of the literature has tackled this problem assuming a discrete choice model dependent on the ports’ characteristics and agents’ attributes. However, in practice the port choice decision depends also on the choices made by other agents as well as decisions made by these agents in the past. There are only a few examples that incorporate the complexity generated by spatio-temporal interactions between agents. However, those modelling structures are rather cumbersome, precluding their use in practical cases. This article presents a new modelling framework to predict port choice decisions, based on the theory of Cellular Automaton (CA), which is simple in structure and can be quickly calibrated and applied. This framework is a probabilistic CA intended to imitate the decision processes made from multiple shippers that interact with each other. These shippers face similar alternatives of seaports for exporting their products within a certain time span. The port choice here is a dynamic decision that depends on the ports’ characteristics and attributes of each shipper at a given time, as well as the decisions made by their neighbours. The outcome of the interaction is a discrete decision that evolves in time according to the dynamics of the system as a whole. The specified CA was applied to the case of vehicle exports from Brazil and the calibration was performed through a genetic algorithm. The results show that the probabilistic CA is able to replicate the historic behaviour of the port choice decisions in the Brazilian vehicle industry, with a high degree of success. The spatial component of the CA turned out to be of major relevance in the dynamic decision process along with the attributes and geographical location of ports.

A Cellular-automaton Model for Throughput Optimization at Airport Security Checkpoint

The purpose of throughput optimization is to optimize the passenger throughput at airport security checkpoint while still maintain the level of passenger safety. Queuing theory is frequently used to optimize the queuing efficiency. While in this paper, we apply cellular-automaton theory to simulate the passengerflow in the process and evaluate the performance of the airport security checkpoint. The simulation results show the validation of the cellular-automaton model.

Three-dimensional multi-species mathematical model of the aerobic granulation process based on cellular automata theory.

Aerobic granular sludge is a kind of microbial polymer formed by self-immobilization under aerobic conditions. It has been widely studied because of its promising application in wastewater treatment. However, the granulation process of aerobic sludge is still a key factor affecting its practical application. In this paper, a three-dimensional (3D) multi-species mathematical model of aerobic granular sludge was constructed using the cellular automata (CA) theory. The growth process of aerobic granular sludge and its spatial distribution of microorganisms were studied under different conditions. The simulation results show that the aerobic granules were smaller under high shear stress and that the autotrophic bacterial content of the granular sludge interior was higher. However, the higher the dissolved oxygen concentration, the larger the size of granular sludge and the higher the content of autotrophic bacteria in the interior of the granular sludge. In addition, inhibition of toxic substances made the aerobic granule size increase more slowly, and the spatial distribution of the autotrophic bacteria and the toxic-substance-degrading bacteria were mainly located in the outer layer, with the heterotrophic bacteria mainly existing in the interior of the granular sludge.

Traffic Flow Modeling on Road Networks Using Cellular Automata Theory

The paper deals with mathematical modeling of traffic flows on urban road networks. The original model is based on the cellular automata theory and presents a generalization of Nagel-Schreckenberg model to a multilane case.Numerical realization of the model is represented in a form of the program package that consists of two modules: User Interface and Visualization module (for setting initial conditions and modelling parameters and visual representation of calculations) and Computation module (for calculations).Computations are carried out for each element of the road (i.e. T or X type intersection, straight road fragment) separately and in parallel, that allows performing calculations on various complex road networks. Different kinds of average characteristics (e.g. the capacity of the crossroad) can be also obtained using the program package.

Fire and Heat Spreading Model Based on Cellular Automata Theory

The distinctive feature of the proposed fire and heat spreading model in premises is the reduction of the computational complexity due to the use of the theory of cellular automata with probability rules of behavior. The possibilities and prospects of using this model in practice are noted. The proposed model has a simple mechanism of integration with agent-based evacuation models. The joint use of these models could improve floor plans and reduce the time of evacuation from premises during fires.

Authorship attribution based on Life-Like Network Automata.

The authorship attribution is a problem of considerable practical and technical interest. Several methods have been designed to infer the authorship of disputed documents in multiple contexts. While traditional statistical methods based solely on word counts and related measurements have provided a simple, yet effective solution in particular cases; they are prone to manipulation. Recently, texts have been successfully modeled as networks, where words are represented by nodes linked according to textual similarity measurements. Such models are useful to identify informative topological patterns for the authorship recognition task. However, there is no consensus on which measurements should be used. Thus, we proposed a novel method to characterize text networks, by considering both topological and dynamical aspects of networks. Using concepts and methods from cellular automata theory, we devised a strategy to grasp informative spatio-temporal patterns from this model. Our experiments revealed an outperformance over structural analysis relying only on topological measurements, such as clustering coefficient, betweenness and shortest paths. The optimized results obtained here pave the way for a better characterization of textual networks.

An Iterated Local Search to find many solutions of the 6-states Firing Squad Synchronization Problem

This paper proposes an optimization approach for solving a classical problem in cellular automata theory: the 6-states Firing Squad Synchronization Problem (FSSP). To this purpose, we introduce an original optimization function which quantifies the quality of solutions according only to the main goal of the problem without taking into account any side information about cellular automata computations. This function is used for a dedicated Iterated Local Search algorithm which finds several hundreds of new solutions of the FSSP. Note, that up to present only one human-designed solution was known which is optimal in time. Most of the new solutions found by our algorithm have lower complexity (in terms of number of transitions rules used). An analysis of the fitness landscape for FSSP explains why, counter-intuitively, local search strategy can achieve good results for FSSP.

Phenomenology of coupled nonlinear oscillators.

A recently introduced model of coupled nonlinear oscillators in a ring is revisited in terms of its information processing capabilities. The use of Lempel-Ziv based entropic measures allows to study thoroughly the complex patterns appearing in the system for different values of the control parameters. Such behaviors, resembling cellular automata, have been characterized both spatially and temporally. Information distance is used to study the stability of the system to perturbations in the initial conditions and in the control parameters. The latter is not an issue in cellular automata theory, where the rules form a numerable set, contrary to the continuous nature of the parameter space in the system studied in this contribution. The variation in the density of the digits, as a function of time is also studied. Local transitions in the control parameter space are also discussed.

A Cellular Automata-Based Simulation Tool for Real Fire Accident Prevention

Many serious real-life problems could be simulated using cellular automata theory. There were a lot of fires in public places which kill many people. Proposed method, called Cellular Automata Evaluation (CAEva in short), is using cellular automata theory and could be used for checking buildings conditions for fire accident. The tests performed on real accident showed that an appropriately configured program allows obtaining a realistic simulation of human evacuation. The authors analyze some real accidents and proved that CAEva method appears as a very promising solution, especially in the cases of building renovations or temporary unavailability of escape routes.

Воспроизведение экспериментальных пространственно-временных структур в транспортных потоках при помощи математической модели на основе теории клеточных автоматов

Воспроизведение экспериментальных пространственно-временных структур в транспортных потоках при помощи математической модели на основе теории клеточных автоматов

Multilane Traffic Flow Modeling Using Cellular Automata Theory

The paper deals with the mathematical modeling of traffic flows on urban road networks using microscopic approach. The model is based on the cellular automata theory and presents a generalization of the Nagel-Schreckenberg model to a multilane case. The created program package allows to simulate traffic on various types of road fragments (T or X type intersection, strait road elements, etc.) and on road networks that consist of these elements. Besides that, it allows to predict the consequences of various decisions regarding road infrastructure changes, such as: number of lanes increasing/decreasing, putting new traffic lights into operation, building new roads, entrances/exits, road junctions.

Graph Cellular Automata with Relation-Based Neighbourhoods of Cells for Complex Systems Modelling: A Case of Traffic Simulation

A complex system is a set of mutually interacting elements for which it is possible to construct a mathematical model. This article focuses on the cellular automata theory and the graph theory in order to compare various types of cellular automata and to analyse applications of graph structures together with cellular automata. It proposes a graph cellular automaton with a variable configuration of cells and relation-based neighbourhoods (r–GCA). The developed mechanism enables modelling of phenomena found in complex systems (e.g., transport networks, urban logistics, social networks) taking into account the interaction between the existing objects. As an implementation example, modelling of moving vehicles has been made and r–GCA was compared to the other cellular automata models simulating the road traffic and used in the computer simulation process.

Towards a microscopic model for analyzing the pedestrian mobility in an urban infrastructure

PurposeUp-to-date, the simulation of pedestrian behavior is used to support the design and analysis of urban infrastructure and public facilities. The purpose of this paper is to present a microscopic model that describes pedestrian behavior in a two-dimensional space. It is based on multi-agent systems and cellular automata theory. The concept of layered-intelligent terrain from the video game industry is reused and concepts such as tracing, evasion and rejection effects related to pedestrian interactive behavior are involved. In a simulation scenario, an agent represents a pedestrian with homogeneous physical characteristics such as walking speed and height. The agents are moved through a discrete space formed by a lattice of hexagonal cells, where each one can contain up to one agent at the same time. The model was validated by using a test that is composed of 17 real data sets of pedestrian unidirectional flow. Each data set has been extracted from laboratory-controlled scenarios carried out with up to 400 people walking through a corridor whose configuration changed in form of the amplitude of its entrance doors and the amplitude of its exit doors from one experiment to another. Moreover, each data set contained different groups of coordinates that compose pedestrian trajectories. The scenarios were replicated and simulated using the proposed model, obtaining 17 simulated data sets. In addition, a measurement methodology based on Voronoi diagrams was used to compute the velocity, density and specific flow of pedestrians to build a time-series graphic and a set of heat maps for each of the real and simulated data sets.Design methodology/approachThe approach consists of a multi-agent system and cellular automata theory. The obtained results were compared with other studies and a statistical analysis based on similarity measurement is presented.FindingsA microscopic mobility model that describes pedestrian behavior in a two-dimensional space is presented. It is based on multi-agent systems and cellular automata theory. The concept of layered-intelligent terrain from the video game industry is reused and concepts such as tracing, evasion and rejection effects related to pedestrian interactive behavior are involved. On average, the simulated data sets are similar by 82 per cent in density and 62 per cent in velocity compared to the real data sets. It was observed that the relation between velocity and density from real scenarios could not be replicated.Research limitations/implicationsThe main limitations are presented in the speed simulations. Although the obtained results present a similar behavior to the reality, it is necessary to introduce more variables in the model to improve the precision and calibration. Other limitation is the dimension for simulating variables at this moment 2D is presented. So the resolution of cells, making that pedestrian to occupy many cells at the same time and the addition of three dimensions to the terrain will be a good challenge.Practical implicationsIn total, 17 data sets were generated as a case study. They contain information related to speed, trajectories, initial and ending points. The data sets were used to calibrate the model and analyze the behavior of pedestrians. Geospatial data were used to simulate the public infrastructure in which pedestrians navigate, taking into account the initial and ending points.Social implicationsThe social impact is directly related to the behavior analysis of pedestrians to know tendencies, trajectories and other features that aid to improve the public facilities. The results could be used to generate policies oriented toward developing more consciousness in the public infrastructure development.Originality/valueThe general methodology is the main value of this work. Many approaches were used, designed and implemented for analyzing the pedestrians’ behavior. In addition, all the methods were implemented in plug-in for Quantum GIS. The analysis was described with heat maps and statistical approaches. In addition, the obtained results are focused on analyzing the density, speed and the relationship between these features.

Optimal placement of fast cut back units based on the theory of cellular automata and agent

The thermal power generation units with the function of fast cut back could serve power for auxiliary system and keep island operation after a major blackout, so they are excellent substitute for the traditional black-start power sources. Different placement schemes for FCB units have different influence on the subsequent restoration process. Considering the locality of the emergency dispatching rules, the unpredictability of specific dispatching instructions and unexpected situations like failure of transmission line energization, a novel deduction model for network reconfiguration based on the theory of cellular automata and agent is established. Several indexes are then defined for evaluating the placement schemes for FCB units. The attribute weights determination method based on subjective and objective integration and grey relational analysis are combinatorically used to determine the optimal placement scheme for FCB unit. The effectiveness of the proposed method is validated by the test results on the New England 10-unit 39-bus power system.

Новые алгоритмы перестроения автомобилей для микроскопической модели транспортных потоков на основе теории клеточных автоматов

Новые алгоритмы перестроения автомобилей для микроскопической модели транспортных потоков на основе теории клеточных автоматов

基于种间竞争模型的毒杂草入侵空间分布模拟研究

PDF HTML阅读 XML下载 导出引用 引用提醒 基于种间竞争模型的毒杂草入侵空间分布模拟研究 DOI: 10.5846/stxb201604130679 作者: 作者单位: 西北民族大学数学与计算机科学学院,西北民族大学数学与计算机科学学院;西北民族大学实验中心,西北民族大学数学与计算机科学学院,西北民族大学数学与计算机科学学院,西北民族大学实验中心 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目（31260098，11361049，31560127）；甘肃省自然科学基金（145RJZA158，1506RJZA274）；国家民委中青年英才计划资助（〔2014〕121号）；西北民族大学研究生科研创新项目（YXM2014172，YXM2015178）；2013年西北民族大学创新团队项目资助 Spatial distribution of poisonous weed invasion based on inter-species competition models Author: Affiliation: School of Mathematics and Computer Science,Northwest University for Nationalities,Lanzhou,School of Mathematics and Computer Science,Northwest University for Nationalities,Lanzhou,;China;Experimental Center,Northwest University for Nationalities,Lanzhou,;China,School of Mathematics and Computer Science,Northwest University for Nationalities,Lanzhou,School of Mathematics and Computer Science,Northwest University for Nationalities,Lanzhou,Experimental Center,Northwest University for Nationalities,Lanzhou Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以天然草场中毒杂草与可食牧草为研究对象，在种间竞争的生态数学模型的基础上引入入侵扩散因素建立毒杂草入侵扩散模型。采用元胞自动机理论将竞争模型扩展到空间网络进行模拟研究，分析毒杂草属的空间分布类型，为毒杂草的控制提供数据支持。研究表明：（1）在入侵扩散作用下，毒杂草与可食牧草的共存平衡点由一个增加为两个，增加了共存的可能性；（2）入侵扩散作用影响了毒杂草种群的空间分布特征，减少了种群空间分布的聚集程度。 Abstract:In the present study, a spatial diffusion model of poisonous weed invasion by using inter-species competition model was developed based on poisonous weeds and edible forage in native pastures. Using the cellular automata theory, the competition model was extended to the spatial network to simulate and study the spatial distribution patterns of poisonous weeds, which will provide data supporting their control. The results showed that (1) under the influence of invasion and diffusion, the coexistence equilibrium point of the poisonous weeds and the edible grass could be increased by an increase of two, which increased the possibility of coexistence; and (2) the spatial distribution of the weed population was affected by invasion and diffusion, and the aggregation of the spatial distribution of the population was reduced. 参考文献 相似文献 引证文献

The Cellular Automata Theory in Fracture Mechanisms Predictions

In the presentation the cellular automata theory is applied to model the evolution of cleavage and ductile fracture mechanisms in front of the crack in three-point-bent specimens containing crack, made of Hardox-400 steel. The experimental and numerical results were used to define: dead elements, weakened elements and healthy elements. One element in the cellular automata model represents one grain. In some of elements large inclusions/interstitials are present. They are randomly distributed; however, to some degree the distribution of these inclusions depend on the strain level. Each element of the cellular automata can change the actual state due to the primary stress distribution, orientation of the cleavage planes {100} and the neighborhood of the fractured grain. The computer program allows for reproduction of the fractured surface as well as to simulate fracture mechanisms in various geometrical and temperature conditions.

Dynamic properties of a continuous stirred tank biofilm bioreactor for aerobic processes

A dynamic analysis of a continuous stirred tank bioreactor with biofilm was performed. The existence of gas, liquid, and biofilm were taken into account. The proposed heterogeneous model of such bioreactor takes into account dynamic biofilm growth and interphase transfer of substrates and biomass for a double‐substrate aerobic process. Simulations were performed to investigate the influence of important process parameters, i.e., toxic substrate concentration in the feed stream, detachment rate coefficient, mean residence time of the liquid and aeration intensity, on dynamic properties of the bioreactor. Dynamic behavior at conditions of anoxia of microorganisms were shown. A method was proposed to reduce bioreactor start‐up time significantly. The paper presents a mathematical model of the bioreactor that uses a discrete model of biofilm growth based on the theory of cellular automata. Dynamics of the bioreactor based on the continuous and discrete biofilm model was compared. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1818–1829, 2017