Understanding of spatiotemporal congestion patterns: A lattice model with predictive effect and density integral

2021 ◽  
pp. 2150206
Author(s):  
Tao Wang ◽  
Sainan Zhang ◽  
Zhen Li ◽  
Shubin Li ◽  
Jing Yuan ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Lattice Model ◽  
Traffic Congestion ◽  
Development Process ◽  
Mkdv Equation ◽  
Traffic Model ◽  
Critical Stability ◽  
Continuous Density ◽  
Simulation Results ◽  
Predictive Effect

To further enhance the adaptability of traffic model in actual traffic flow, this paper puts forward a lattice model with considering both the predictive effect and the continuous density of historical information. The critical stability condition is derived from linear stability analysis, and the phase diagram clearly shows that considering the predictive effect and the continuous historical density information is beneficial to reduce traffic congestion. Then, a mKdV equation is obtained by nonlinear analysis, which enable to depict the development process of blocked flow. Finally, the numerical simulation results are confirmed that the predictive effects and continuous historical density information have the ability to suppress traffic congestion.

Study on Numerical Simulation of Fire and Evacuation for a Supermarket

2015 ◽  
Vol 744-746 ◽  
pp. 1736-1740 ◽  
Author(s):  
Si Hui Dong ◽  
Min Li ◽  
Yu Han Lin
Keyword(s):  
Numerical Simulation ◽  
Physical Model ◽  
Development Process ◽  
Fire Danger ◽  
Actual Situation ◽  
Study Results ◽  
Simulation Results ◽  
Fire Scene ◽  
Safety Evacuation

3D physical model of a supermarket was constructed with Pyrosim software, and the fire scene was set according to the actual situation. The fire development process and personnel evacuation process were simulated with FDS. The fire danger time of the fire scene was analyzed according to the smoke temperature and visibility of different time. The personnel evacuation process to the supermarket was simulated with the evacuation software Evac, and the required safety egress time was calculated. By comparing the fire danger time and the required safety egress time, the conclusion was drawn that the supermarket can not meet the requirement for safety evacuation. After changing the conditions for safety evacuation, the required safety egress time was simulated again. And the simulation results showed that the changed evaluation conditions can meet the requirement for safety evacuation. The study results provide a basis to improve the safety evacuation conditions of the supermarket.

Nonlinear analysis of lattice model with the consideration of multiple optimal current differences for two-lane freeway

2015 ◽  
Vol 29 (04) ◽  
pp. 1550006 ◽  
Author(s):  
Guanghan Peng
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Nonlinear Analysis ◽  
Traffic Flow ◽  
Linear Stability ◽  
Lattice Model ◽  
Mkdv Equation ◽  
Traffic System ◽  
Optimal Current ◽  
The Stability

In this paper, a new lattice model is proposed with the consideration of the multiple optimal current differences for two-lane traffic system. The linear stability condition and the mKdV equation are obtained with the considered multiple optimal current differences effect by making use of linear stability analysis and nonlinear analysis, respectively. Numerical simulation shows that the multiple optimal current differences effect can efficiently improve the stability of two-lane traffic flow. Furthermore, the three front sites considered, is the optimal state of two-lane freeway.

The effect of interruption probability in lattice model of two-lane traffic flow with passing

2016 ◽  
Vol 27 (05) ◽  
pp. 1650050 ◽  
Author(s):  
Guanghan Peng
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Traffic Flow ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Stability Condition ◽  
Lattice Model ◽  
Mkdv Equation ◽  
Reaction Coefficient ◽  
The Stability

A new lattice model is proposed by taking into account the interruption probability with passing for two-lane freeway. The effect of interruption probability with passing is investigated about the linear stability condition and the mKdV equation through linear stability analysis and nonlinear analysis, respectively. Furthermore, numerical simulation is carried out to study traffic phenomena resulted from the interruption probability with passing in two-lane system. The results show that the interruption probability with passing can improve the stability of traffic flow for low reaction coefficient while the interruption probability with passing can destroy the stability of traffic flow for high reaction coefficient on two-lane highway.

A NEW LATTICE MODEL OF TWO-LANE TRAFFIC FLOW WITH THE CONSIDERATION OF MULTI-ANTICIPATION EFFECT

2013 ◽  
Vol 24 (07) ◽  
pp. 1350048 ◽  
Author(s):  
GUANGHAN PENG
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Traffic Flow ◽  
Linear Stability ◽  
Lattice Model ◽  
Mkdv Equation ◽  
Stable Region ◽  
Lane Changing ◽  
Traffic Jam ◽  
Anticipation Effect

In this paper, a new two-lane lattice model of traffic flow is proposed with the consideration of multi-anticipation effect. The linear stability condition of two-lane traffic is derived with the multi-anticipation effect term by linear stability analysis, which shows that the stable region enlarges with the number of multi-anticipation sites increasing. Nonlinear analysis near the critical point is carried out to obtain kink–antikink soliton solution of the mKdV equation with the multi-anticipation effect term. Numerical simulation also shows that the multi-anticipation effect can suppress the traffic jam efficiently with lane changing in two-lane system.

The driver’s anticipation effect with passing in lattice model for two-lane freeway

2015 ◽  
Vol 29 (28) ◽  
pp. 1550174 ◽  
Author(s):  
Guanghan Peng
Keyword(s):  
Numerical Simulation ◽  
Linear Stability ◽  
Lattice Model ◽  
Mkdv Equation ◽  
Lane Changing ◽  
Traffic System ◽  
Driver’S Anticipation Effect ◽  
The Stability ◽  
Anticipation Effect ◽  
Anticipation Effects

In this paper, a new lattice model is proposed with the consideration of the driver’s anticipation effect with passing for two-lane traffic system. The linear stability condition and the mKdV equation which are correlative to the driver’s anticipation effect with passing are derived from linear stability analysis and nonlinear analysis, respectively. Numerical simulation shows that the driver’s anticipation effects with passing can efficiently enhance the stability of traffic flow under lane changing on two-lane highway.

Numerical Simulation on Failure Process of Concrete-Filled Rectangular Steel Tube Column

2009 ◽  
Vol 417-418 ◽  
pp. 365-368
Author(s):  
Guang Ping Zou ◽  
Pei Xiu Xia ◽  
Xue Dong Zhang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Bearing Capacity ◽  
Development Process ◽  
Process Analysis ◽  
Failure Process ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Axial Loads ◽  
Simulation Results

Realistic Failure Process Analysis (RFPA3D) was used to simulate the concrete-filled rectangular steel tube columns which are subjected to axial loads. The ultimate bearing capacity and the load-strain figures were presented. The Numerical simulation results were verified by experimental data of the paper [5]. Meanwhile, the development process of crack in the specimen was described. The whole failure process of rectangular steel tube columns was reproduced. The failure principles of concrete-filled rectangular steel tube column were discussed deeply.

The new car following model considering vehicle dynamics influence and numerical simulation

2015 ◽  
Vol 26 (07) ◽  
pp. 1550081 ◽  
Author(s):  
Dihua Sun ◽  
Hui Liu ◽  
Geng Zhang ◽  
Min Zhao
Keyword(s):  
Numerical Simulation ◽  
Traffic Congestion ◽  
Vehicle Dynamics ◽  
Velocity Difference ◽  
Car Following ◽  
Car Following Model ◽  
Simulation Results ◽  
Starting Process ◽  
The Stability ◽  
Real Traffic

In this paper, the car following model is investigated by considering the vehicle dynamics in a cyber physical view. In fact, that driving is a typical cyber physical process which couples the cyber aspect of the vehicles' information and driving decision tightly with the dynamics and physics of the vehicles and traffic environment. However, the influence from the physical (vehicle) view was been ignored in the previous car following models. In order to describe the car following behavior more reasonably in real traffic, a new car following model by considering vehicle dynamics (for short, D-CFM) is proposed. In this paper, we take the full velocity difference (FVD) car following model as a case. The stability condition is given on the base of the control theory. The analytical method and numerical simulation results show that the new models can describe the evolution of traffic congestion. The simulations also show vehicles with a more actual acceleration of starting process than early models.

Avalanche Features in Silicon Schottky-FETs in Accordance with Numerical Simulation Results

2006 ◽  
Vol 65 (16) ◽  
pp. 1533-1546
Author(s):  
Yu. Ye. Gordienko ◽  
S. A. Zuev ◽  
V. V. Starostenko ◽  
V. Yu. Tereshchenko ◽  
A. A. Shadrin
Keyword(s):  
Numerical Simulation ◽  
Simulation Results

Tail shapes lead to different propulsive mechanisms in the body/caudal fin undulation of fish

2020 ◽  
pp. 095440622096768
Author(s):  
Jialei Song ◽  
Yong Zhong ◽  
Ruxu Du ◽  
Ling Yin ◽  
Yang Ding
Keyword(s):  
Numerical Simulation ◽  
Aspect Ratio ◽  
High Efficiency ◽  
The Body ◽  
Caudal Fin ◽  
Fish Model ◽  
Swimming Efficiency ◽  
Simulation Results ◽  
Propulsive Mechanism ◽  
High Depth

In this paper, we investigate the hydrodynamics of swimmers with three caudal fins: a round one corresponding to snakehead fish ( Channidae), an indented one corresponding to saithe ( Pollachius virens), and a lunate one corresponding to tuna ( Thunnus thynnus). A direct numerical simulation (DNS) approach with a self-propelled fish model was adopted. The simulation results show that the caudal fin transitions from a pushing/suction combined propulsive mechanism to a suction-dominated propulsive mechanism with increasing aspect ratio ( AR). Interestingly, different from a previous finding that suction-based propulsion leads to high efficiency in animal swimming, this study shows that the utilization of suction-based propulsion by a high- AR caudal fin reduces swimming efficiency. Therefore, the suction-based propulsive mechanism does not necessarily lead to high efficiency, while other factors might play a role. Further analysis shows that the large lateral momentum transferred to the flow due to the high depth of the high- AR caudal fin leads to the lowest efficiency despite the most significant suction.

Limitation of Erlang B Traffic Model in Elastic Optical Network for Blocking Probability Estimation

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Ujjwal ◽  
Jaisingh Thangaraj
Keyword(s):  
Blocking Probability ◽  
Optical Network ◽  
Constant Load ◽  
Traffic Model ◽  
Service Rate ◽  
Service Provisioning ◽  
Connection Request ◽  
Elastic Optical Network ◽  
Simulation Results ◽  
Single Path

Abstract In this paper, an algorithm for multipath connection provisioning in elastic optical network (EON) has been proposed. Initially, the algorithm prefers the single-path routing for service provisioning. But when single-path routing is not adequate to serve a dynamic connection, the algorithm switches to the connection request fragmentation. Its computation is based on the parameters such as capacity_constant and capacity_allowed to fragment the connection request on disjoint paths. Simulation results clearly state that the proposed algorithm performs well in service provisioning as compared to the traditional single-path routing algorithms and improves the average network throughput. Thereafter, we have investigated the limitation of Erlang B traffic model in EON for calculation of link blocking probability using routing and spectrum assignment (RSA) algorithm. It is verified by the following two ways: (i) effect on the blocking probability in case of constant load and (ii) effect of slot width on the blocking probability. Our simulation results indicate that in EON due to dynamic RSA, blocking probability is not constant in case of proportionate varying of call arrival and service rate giving constant load and blocking probability depends on the number of slots per link, but in Erlang B traffic model blocking probability is always constant in case of constant load and it considers wavelength per link instead of slots per link. This is attributed to the fact that Erlang B traffic model fails to calculate blocking probability accurately in EON. We have computed the carried traffic on 14 nodes, 21-link National Science Foundation Network (NSFNET) topology.

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