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Improved social force model based on exit selection for microscopic pedestrian simulation in subway station

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Journal of Central South University 2015年第11期22卷 4490-4497页

作者：郑勋李海鹰孟令云许心越陈旭 State Key Laboratory of Rail Traffic Control and Safety (Beijing Jiaotong University) School of Traffic and Transportation Beijing Jiaotong University

An improved social force model based on exit selection is proposed to simulate pedestrians' microscopic behaviors in subway station. The modification lies in considering three factors of spatial distance, occupant density and exit width. In addition, the problem of pedestrians selecting exit frequently is solved as follows: not changing to other exits in the affected area of one exit, using the probability of remaining preceding exit and invoking function of exit selection after several simulation steps. Pedestrians in subway station have some special characteristics, such as explicit destinations, different familiarities with subway station. Finally, Beijing Zoo Subway Station is taken as an example and the feasibility of the model results is verified through the comparison of the actual data and simulation data. The simulation results show that the improved model can depict the microscopic behaviors of pedestrians in subway station.

关键词： exit selection social force model exit width micro

Effect of exit location on flow of mice under emergency condition

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Chinese Physics B 2019年第1期28卷 290-299页

作者：张腾黄申石张学林陆守香黎昌海 State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230027China School of Civil Engineering Chongqing Three Gorges UniversityChongqing 404000China

The evacuation of crowds in a building has always emerged as a vital issue in many accidents. The geometrical structure of a room, especially the exit design has a great influence on crowd evacuation under emergency conditions. In this paper, the effect of exit location of a room on crowd evacuation in an emergency is investigated with mice. Two different exits are set in a rectangular chamber. One is located in the middle of a wall(middle-exit) and the other is at the corner of the chamber(corner-exit). Arching and clogging are observed in the flow of mice. The result based on the escape trajectories of mice shows a dynamic balance in the arch near the exit wherever the exit is located. We demonstrate that the occupant position in the arch has an effect on the escape sequence of mice. At a low stimulation level, the narrow middle-exit is more effective in increasing the flow rate of mice than the narrow corner-exit. However, the opposite result appears when the exit becomes wider. At a high stimulation level, the effect of exit location on flow of mice tends to be weakened. The results suggest that the specific level of stimulation needs to be taken into account when optimizing the evacuation efficiency of a crowd through the geometrical structure of a room.

关键词： exit location evacuation mice stimulation level

Intelligent exit-Selection Behaviors during a Room Evacuation

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Chinese Physics Letters 2012年第1期29卷 291-294页

作者： Zarita Zainuddin 林永益 School of Mathematical Sciences Universiti Sains Malaysia11800 MindenPenangMalaysia Institut Matematik Kejuruteraan Universiti Malaysia Perlis02000 Kuala PerlisPerlisMalaysia

A modified version of the existing cellular automata (CA) model is proposed to simulate an evacuation procedure in a classroom with and without obstacles.Based on the numerous literature on the implementation of CA in modeling evacuation motions,it is notable that most of the published studies do not take into account the pedestrian's ability to select the exit route in their models.To resolve these issues,we develop a CA model incorporating a probabilistic neural network for determining the decision-making ability of the pedestrians,and simulate an exit-selection phenomenon in the simulation.Intelligent exit-selection behavior is observed in our model.From the simulation results,it is observed that occupants tend to select the exit closest to them when the density is low,but if the density is high they will go to an alternative exit so as to avoid a long wait.This reflects the fact that occupants may not fully utilize multiple exits during evacuation.The improvement in our proposed model is valuable for further study and for upgrading the safety aspects of building designs.

关键词： exit utilize automata

Absolute continuities of exit measures for superdiffusions

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Science China Mathematics 2000年第5期43卷 449-457页

作者：任艳霞 Center for Advanced Study Tsinghua University Beijing 100084 China Suppose X= | Xt Xr Pμ| is a superdiffusion in Rd with general branching mechanism ψand general branching rate f unction A. We discuss conditions on A to guarantee that the exit measures Xt of the superdiffusion X from bounded smooth domains in Rd have absolutely continuous states.

Suppose X= | Xt ,Xr, Pμ| is a superdiffusion in Rd with general branching mechanism ψ and general branching rate f unction A. We discuss conditions on A to guarantee that the exit measures Xt of the superdiffusion X... 详细信息

关键词： exit measure superdiffusion absolutely continuous state.

Numerical simulation of particle formation and evolution in a vehicle exhaust plume using the bimodal Taylor expansion method of moments

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Particuology 2019年第2期17卷 46-55页

作者： Shuyuan Liu Tat Leung Chan Huijie Liu Department of Mechanical Engineering The Hong Kong Polytechnic University Kowloon Hong Kong China

The bimodal Taylor expa nsion method of moments (B-TEMOM) model scheme was developed to simulate the formation and evolution of vehicle exhaust particles. Two independent types of log-normal particle size distributions were selected in the B-TEMOM model scheme, comprising large and small particles to represent background (i.e., the surrounding environment) and vehicle exhaust particles, respectively. Concentration distributions of exhaust and background particles derived using this model scheme were verified against results from a moving secti onal method and the bimodal quadrature method of moments, showing excellent agreement. The effects of vehicle tailpipe ex 让 cond 让 ions (e.g., exhaust particle concentrations and velocity), sulfurcontent, and relative humidity on the evoluti on of particles were investigated numerically. Both two-dimensional and three-dimensional numerical simulations showed that tailpipe exit velocity and relative humid让y did not greatly affect the steady-state concentrations or the diameters of particles in urban atmospheres. Although an increase in sulfur content had little effect on the particle concentration, it led to background particles with larger geometric average diameter entering the environment. This coupled CFD-B-TEMOM numerical model provides a simple but accurate and efficient method for studying bimodal aerosol dynamics.

关键词： Vehicle exhaust particles Bimodal Taylor expansi on method of moments Homogeneous nucleation Coagulation Tailpipe exit velocity Sulfur content and ambient relative humidity

Absolutely continuous states of exit measures for super-Brownian motions with branching restricted to a hyperplane

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Science China Mathematics 1998年第6期41卷 582-594页

作者：任艳霞王永进 Departrnt-nt of Mathematics Nankai University Tianjin China

The exit measures of super Brownian motions with branching mechanism ψ(z)=z α, 11+2α-1, they are singular. However, if the branching is restricted to a singular hyperplane, it is proved that they have absolutely ... 详细信息

关键词： exit measure super Brownian motion absolutely continuous state singular state.

Firm-Level TFP Growth in the Chinese Automobile Industry

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2020年第1期15卷 103-123页

作者： Xiaoheng Zhang Xu Tian College of Economics and Management Huazhong Agricultural UniversityWuhan 430070China College of Economics and Management Nanjing Agricultural UniversityNanjing 210095China

China has been the world’s largest automobile producer since 2009,but it still lags behind other countries in terms of productivity. Based on theNational Bureau of Statistics of China (NBSC) firm-level data and the improvedapproach proposed by Ackerberg et al. (2015), this paper investigates thecontribution of total factor productivity (TFP) growth to the Chinese automobileindustry and evaluates the impact of firm entry and exit on TFP growth. Theempirical results show that the TFP of the Chinese automobile industry grows at10.7% per year. Joint venture and foreign-owned firms have a significantly higherTFP growth rate than others. Large-scale firms have a higher TFP growth rate thando small-scale firms, but the latter have caught up after 2004. Moreover, the entryof new firms and exit of old firms significantly improve the aggregate TFP growthrate.

关键词： automobile industry total factor productivity(TFP)growth rate firm entry and exit ACF model ownership structure China National Bureau of Statistics of China(NBSC)database firm size

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exit

英语学习 1994年第7期 20-27页

作者：佚林 Harry Farjeon

"I say, we seem a bit gloomy, don’t we? exclaimed Todman.‘Who’ll do something to cheer us up on our last night?’ ‘Nothing’s going to cheer me up.’ said the pretty girl on thefootstool, transferring her dreamy eyes from the log fire to theyoung man standing by. ‘Christmas-Honeymoon-Dartmoor-it’s been too perfect! And tomorrow it will be all over!’ ‘Not over, Jessamy-just beginning,’ the young man cor-

关键词： exit

Two-Sided First exit Problem for Jump Diffusion Distribution Processes Having Jumps with a Mixture of Erlang

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Applied Mathematics 2013年第8期4卷 1142-1153页

作者： Yuzhen Wen Chuancun Yin School of Mathematical Sciences Qufu Normal University Qufu China

In this paper, we consider the two-sided first exit problem for jump diffusion processes having jumps with rational Laplace transforms. We investigate the probabilistic property of conditional memorylessness, and drive the joint distribution of the first exit time from an interval and the overshoot over the boundary at the exit time.

关键词： First exit Time Two-Sided Jumps Jump Diffusion Process Overshoot