A Novel Three-Dimensional Cellular Automaton Evacuation Model

2014 ◽  
Vol 472 ◽  
pp. 550-554
Author(s):  
Jun Hu ◽  
Lei You ◽  
Juan Wei ◽  
Wen Qian Wu ◽  
Di Zhou ◽  
...  
Keyword(s):  
Cellular Structure ◽  
Three Dimensional ◽  
Time Parameter ◽  
Calculation Formula ◽  
Key Factors ◽  
Evacuation Time ◽  
Cellular Automation ◽  
Evacuation Model ◽  
Dimensional Condition ◽  
Moving Speed

In order to effectively reduce evacuation time of pedestrians in emergencies, a novel evacuation model is proposed based on the three-dimensional cellular automation. The model, according to Moore cellular structure, firstly defines location income and estimates evacuation time parameter, and then gives calculation formula for moving probability of pedestrians at next moment. Meanwhile, in combination with the degree of fear and moving speed, evacuation strategies and cellular evolution rules suited to the three-dimensional condition are raised. At last, by establishing simulation model, the article profoundly analyses key factors that affect evacuation time of pedestrians, and finds that the evacuation time shows a negative correlation with the exit width, but a positive correlation with pedestrian density. Appropriate increase of pedestrians fear degree is good for reducing the whole evacuation time.

scholarly journals Simulation of the Texture Evolution During Annealing of Cold Rolled Bcc and Fcc Metals Using a Cellular Automation Approach

1997 ◽  
Vol 28 (3-4) ◽  
pp. 211-218 ◽  
Author(s):  
V. Marx ◽  
D. Raabe ◽  
O. Engler ◽  
G. Gottstein
Keyword(s):  
Static Recrystallization ◽  
Texture Evolution ◽  
Three Dimensional ◽  
Deformation Texture ◽  
Three Dimensional Model ◽  
Static Recovery ◽  
Fcc Metals ◽  
Cellular Automation ◽  
Texture Change ◽  
Cold Rolled

In this study both primary static recrystallization and static recovery of cold rolled bcc and fcc metals and alloys are numerically simulated using a three-dimensional model that is based on a modified cellular automaton approach. The model considers the influence of the initial deformation texture and microstructure on both static recovery and primary static recrystallization with a high spatial resolution. The cellular automat technique provides both local and statistical information about the kinetics, the morphology and the texture change during annealing. The influence of nucleation and growth can be studied in detail. The simulations are compared to experimental results obtained on fcc and bcc polycrystals.

Fast flow algorithm prioritizing the most time-consuming source point by using a multi-source evacuation model

2021 ◽  
Author(s):  
Jianfang Yang ◽  
Hao Lin ◽  
Junbiao Guan
Keyword(s):  
Optimal Solution ◽  
Single Source ◽  
Shopping Malls ◽  
Evacuation Time ◽  
Source Point ◽  
The People ◽  
Flow Algorithm ◽  
Evacuation Model ◽  
Fast Flow ◽  
Capacity Constrained

In many public spaces (e.g. colleges and shopping malls), people are frequently distributed discretely, and thus, single-source evacuation, which means there’s only one point of origin, is not always a feasible solution. Hence, this paper discusses a multi-source evacuation model and algorithm, which are intended to evacuate all the people that are trapped within the minimum possible time. This study presents a fast flow algorithm to prioritize the most time-consuming source point under the constraint of route and exit capacity to reduce the evacuation time. This fast flow algorithm overcomes the deficiencies in the existing global optimization fast flow algorithm and capacity constrained route planner (CCRP) algorithm. For the fast flow algorithm, the first step is to determine the optimal solution to single-source evacuation and use the evacuation time of the most time-consuming source and exit gate set as the initial solution. The second step is to determine a multi-source evacuation solution by updating the lower limit of the current evacuation time and the exit gate set continually. The final step is to verify the effectiveness and feasibility of the algorithm through comparison.

Cotton Picker Picks Roller Motion Simulation and Dynamics Analysis

2010 ◽  
Vol 34-35 ◽  
pp. 1765-1769 ◽  
Author(s):  
Wen Lei Sun ◽  
Xiao Li Li ◽  
Chang Bing Fu
Keyword(s):  
Simulation Model ◽  
Prototype Model ◽  
Dynamics Analysis ◽  
Motion Simulation ◽  
Key Factors ◽  
Road Speed ◽  
Cotton Picker ◽  
Cotton Picking ◽  
Movement Simulation ◽  
Moving Speed

The drum is the process of picking cotton, picking cotton picker cotton picker head of the key device, which controls the seat tube and Abstract Abstract ingot of movement, Abstract spindle picking of cotton is also directly affect the quality and efficiency of key factors. Therefore, by creating a virtual prototype model cotton picker roller, about picking cotton picker principle, and the movement simulation model to arrive at, dynamic model of the external force, the cotton picker spindles moving speed of the Summary Block pipe displacement, velocity and acceleration effects. Then summed up, cotton picker of road speed, picking rate and the net rate of mining.

scholarly journals Analysis of the Evacuation Capacity of Parallel Double Running Stairs in Different Merging Form Based on Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Xia-zhong Zheng ◽  
Xue-ling Xie ◽  
Dan Tian ◽  
Jian-lan Zhou ◽  
Ming Zhang
Keyword(s):  
Computer Simulation ◽  
Evaluation Model ◽  
Pedestrian Flow ◽  
Agent Based Model ◽  
Evacuation Time ◽  
Agent Based ◽  
Positive Correlation ◽  
Model Based ◽  
Evacuation Model ◽  
Merging Behavior

In order to analyze the evacuation capacity of parallel double running stairs, a dozen stairs merging forms are set by investigation and statistics, and the improved agent-based evacuation model that considers the merging behavior is used to simulate the process of merging and evacuation in the stairs. The stairs evacuation capacity is related to the evacuation time and the robustness of stairs, and the evacuation time can be calculated by using the improved agent-based model based on computer simulation. The robustness of each merging form can be obtained according to the fluctuation degree of evacuation time under the different pedestrian flow. The evaluation model of stairs evacuation capacity is established by fusing the evacuation time and the robustness of stairs. Combined with the specific example to calculate the evacuation capacity of each stairs form, it is found that every merging form has different evacuation time and different robustness, and the evacuation time has not positive correlation with the robustness for the same form stairs. Meanwhile, the evacuation capacity of stairs is not related to the number of the floor entrances. Finally, the results show that the evacuation capacity of stairs is optimal when the floor entrances are close to out stairs in parallel double running stairs and suitable to the case where pedestrian flow and the change of pedestrian flow are large.

scholarly journals Physiological State and Learning Ability of Students in Normal and Virtual Reality Conditions: Complexity-Based Analysis (Preprint)

2020 ◽  
Author(s):  
Mohammad H Babini ◽  
Vladimir V Kulish ◽  
Hamidreza Namazi
Keyword(s):  
Virtual Reality ◽  
Fractal Theory ◽  
Physiological State ◽  
Three Dimensional ◽  
Physiological Signals ◽  
Learning Ability ◽  
Two Dimensional ◽  
Reality Condition ◽  
Computer Mediated ◽  
Dimensional Condition

BACKGROUND Education and learning are the most important goals of all universities. For this purpose, lecturers use various tools to grab the attention of students and improve their learning ability. Virtual reality refers to the subjective sensory experience of being immersed in a computer-mediated world, and has recently been implemented in learning environments. OBJECTIVE The aim of this study was to analyze the effect of a virtual reality condition on students’ learning ability and physiological state. METHODS Students were shown 6 sets of videos (3 videos in a two-dimensional condition and 3 videos in a three-dimensional condition), and their learning ability was analyzed based on a subsequent questionnaire. In addition, we analyzed the reaction of the brain and facial muscles of the students during both the two-dimensional and three-dimensional viewing conditions and used fractal theory to investigate their attention to the videos. RESULTS The learning ability of students was increased in the three-dimensional condition compared to that in the two-dimensional condition. In addition, analysis of physiological signals showed that students paid more attention to the three-dimensional videos. CONCLUSIONS A virtual reality condition has a greater effect on enhancing the learning ability of students. The analytical approach of this study can be further extended to evaluate other physiological signals of subjects in a virtual reality condition.

scholarly journals A Multistory Building Evacuation Model Based on Multiple-Factor Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Yang Zhou ◽  
Tanghong Wu ◽  
Gaofan Zhang ◽  
Zichuan Fan
Keyword(s):  
Functional Relationship ◽  
Emergency Evacuation ◽  
Multiple Factor Analysis ◽  
Time Step ◽  
Evacuation Time ◽  
Building Evacuation ◽  
Access Path ◽  
Multistory Building ◽  
Evacuation Model ◽  
Evacuation Routes

Emergency evacuation is an important issue in public security. To make a considerate plan, various situations are presented including blocking the accident area and letting the emergency access path available. In order to offer dynamic evacuation routes due to different circumstances, a multistory building evacuation model is proposed. Firstly, to analyse the patency of the building, an evacuation formula is applied after binary processing. The function of evacuation time and some other parameters is given by means of regression analysis. Secondly, the cellular automata (CA) algorithm was applied to illustrate the effect of the bottleneck. The response of evacuation time could be approximately optimized through calculating time step of the CA simulation. Finally, the value of maximum evacuation population density could be determined according to the analysis of CA simulation results, which was related to the switch state of the emergency channel. The emergency evacuation model was simulated by using the Louvre museum as an example. The results of the simulation presented some feasible evacuation routes in all kinds of situations. Furthermore, the functional relationship would also be given among evacuation time with the diversity of tourists, pedestrian density, and width of exits. It can give a different perspective that the multistory building evacuation model shows excellent adaptability to different circumstances.

The Influence of Evacuation Signs on Evacuation for Bad Visibility

2014 ◽  
Vol 472 ◽  
pp. 574-578 ◽  
Author(s):  
Hai Tao Chen ◽  
Peng Yang ◽  
Run Cang Yu
Keyword(s):  
Programming Language ◽  
The Novel ◽  
Evacuation Time ◽  
Time Ratio ◽  
Pedestrian Evacuation ◽  
Calculation Results ◽  
Evacuation Model ◽  
Theoretical Results

In emergencies such as fire, pedestrian evacuation for bad visibility is significantly different to the evacuation for normal visibility. In the novel evacuation model, the strategies of pedestrian evacuation and the moving rules are proposed. Then the formulas of the evacuation time are achieved and the time ratio is 0.63. More, using the programming language, pedestrian evacuation is simulated and reproduced. The studies shows that the proposed evacuation model can well reflect the process of pedestrian evacuation; and the evacuation signs of reasonable design can significantly optimize the process. The calculation results also show that the ratio of evacuation time between considering evacuation signs and no evacuation signs is close to 0.63 that is the theoretical results.

Effects of Smoke on Evacuation

2014 ◽  
Vol 899 ◽  
pp. 539-542
Author(s):  
Martin Lopušniak
Keyword(s):  
National Standards ◽  
Evacuation Time ◽  
Evacuation Model

Smoke is often presents during a fire. It affects efficiency of evacuations in buildings. Slovakian national standards do not consider any fire products in evacuation calculations. The paper presents results of evacuation calculations with considerations of smoke. Calculations are done with the evacuation model buildingEXODUS on a hotel building. Results show that prolongation of evacuation time is up to 162%. Results show that the prolongation of evacuation time is up to 162 %, and also show the prolongation of evacuation time do not necessary depend on size, but on position of smoke.

scholarly journals Dynamic Crushing Analysis of a Three-Dimensional Re-Entrant Auxetic Cellular Structure

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 460 ◽  
Author(s):  
Tao Wang ◽  
Zhen Li ◽  
Liangmo Wang ◽  
Zhengdong Ma ◽  
Gregory Hulbert
Keyword(s):  
Energy Dissipation ◽  
Relative Density ◽  
Cellular Structure ◽  
Three Dimensional ◽  
Analytical Formula ◽  
Absorption Capacity ◽  
Plastic Energy ◽  
Theoretical Predictions ◽  
Auxetic Structure

Dynamic behaviors of the three-dimensional re-entrant auxetic cellular structure have been investigated by performing beam-based crushing simulation. Detailed deformation process subjected to various crushing velocities has been described, where three specific crushing modes have been identified with respect to the crushing velocity and the relative density. The crushing strength of the 3D re-entrant auxetic structure reveals to increase with increasing crushing velocity and relative density. Moreover, an analytical formula of dynamic plateau stress has been deduced, which has been validated to present theoretical predictions agreeing well with simulation results. By establishing an analytical model, the role of relative density on the energy absorption capacity of the 3D re-entrant auxetic structure has been further studied. The results indicate that the specific plastic energy dissipation is increased by increasing the relative density, while the normalized plastic energy dissipation has an opposite sensitivity to the relative density when the crushing velocity exceeds the critical transition velocity. The study in this work can provide insights into the dynamic property of the 3D re-entrant auxetic structure and provides an extensive reference for the crushing resistance design of the auxetic structure.

BONE BIOMECHANICAL MODELING BASED ON CELLULAR STRUCTURE: METHODS AND EVALUATION

2015 ◽  
Vol 15 (06) ◽  
pp. 1540046 ◽  
Author(s):  
MONAN WANG ◽  
SHUFENG WANG ◽  
XIANJUN AN
Keyword(s):  
Cellular Structure ◽  
Geometric Model ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Bone Modeling ◽  
Transverse Strain ◽  
Test Results ◽  
Cellular Mechanics ◽  
Compression Load ◽  
Mechanics Model

The aim of this study is to establish a biomechanical model of bone on the basis of cellular structure and then to evaluate its accuracy for the clinical application. The thighbone of swine was scanned by computed tomography (CT). The resulting sectional images were input into MIMICS10.01 to generate a three-dimensional geometric model. A biomechanical model of bone was built on the basis of cellular structure, and calculations of the model were implemented in MATLAB with the finite element method. With this cellular mechanics model, axial compression load was simulated, and load–axial and load–transverse strain at the measurement points were detected. To evaluate the model, a mechanics model derived from an empirical formula was simulated under the same conditions, and an actual biomechanical experiment was also conducted. The simulated results obtained from the two models were then compared with the test results, indicating that the simulated results for the cellular model were closer to the test results than those for the empirical mechanics model. Therefore, the proposed cellular mechanics model shows advantages in accuracy and scope of application for bone modeling.

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