Qing-Song Wu

University of Science and Technology of China, Luchow, Anhui Sheng, China

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Publications (112)148.46 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper studies a periodic one-dimensional exclusion process constituted by multiple diffusive channels and a common driven part. We have performed mean field analysis for the phase diagram, the density profiles, and the currents, which is in good agreement with the Monte Carlo simulations. In particular, in the special case that the diffusive channels are identical, the phase boundaries have been derived explicitly. It is shown that, in the driven part, the low density-high density region and the low density region shrink and will finally vanish with the increase of the number of diffusive channels. On the other hand, the high density region and the low density-high density region vanish if the total number of particles keeps constant. Numerical examples indicate that these features might be extended to general case in which the diffusive channels are not identical.
    Computer Physics Communications 11/2014; · 2.41 Impact Factor
  • Yu-Qing Wang, Rui Jiang, Qing-Song Wu, Hai-Yi Wu
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    ABSTRACT: This paper studies the periodic one-dimensional exclusion processes constituted by totally asymmetric simple exclusion process (TASEP) and two-lane simple exclusion processes (SEP). TASEP and SEP compete with each other. Complemented by Monte Carlo simulations, mean-field analysis has been performed. Varying current splitting parameter θ, diffusivity rate D1 (or D2) and the global particle density np, we have studied phase diagrams, typical density profiles and current diagrams.
    Modern Physics Letters B 02/2014; 28(8). · 0.48 Impact Factor
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    ABSTRACT: As a typical self-driven many-particle system far from equilibrium, traffic flow exhibits diverse fascinating non-equilibrium phenomena, most of which are closely related to traffic flow stability and specifically the growth/dissipation pattern of disturbances. However, the traffic theories have been controversial due to a lack of precise traffic data. We have studied traffic flow from a new perspective by carrying out large-scale car-following experiment on an open road section, which overcomes the intrinsic deficiency of empirical observations. The experiment has shown clearly the nature of car-following, which runs against the traditional traffic flow theory. Simulations show that by removing the fundamental notion in the traditional car-following models and allowing the traffic state to span a two-dimensional region in velocity-spacing plane, the growth pattern of disturbances has changed qualitatively and becomes qualitatively or even quantitatively in consistent with that observed in the experiment.
    PLoS ONE 01/2014; 9(4):e94351. · 3.53 Impact Factor
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    ABSTRACT: This paper studies the granular flow down a chute with two successive turnings, which play the role of bottlenecks for the granular flow system and determine the granular flow state in main section between them. With the increase of main section width D, phase transition from dilute to dense granular flow is observed: When the main section width D is small (large), the granular flow at upper (lower) bottleneck is dense and the granular flow is dilute (dense) in the main section. More interestingly, a bistable region is exhibited, in which either dilute flow or dense flow may occur and continue for the entire run. In this region, the packing in the reservoir will affect initial flow rate and then affect the flow pattern. This study can be viewed as a paradigm for the jamming and unjamming transitions under shear due to gravity.
    Physics Letters A. 01/2014;
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    ABSTRACT: This paper studies the Katz-Lebowitz-Spohn (KLS) process on lattices with a junction, where particles move on parallel lattice branches that combine into a single lattice at the junction. It is shown that 11 kinds of phase diagrams could be observed, depending on the two parameters ε and δ in the KLS process. We have investigated the phase diagrams as well as bulk density analytically based on flow rate conservation and the extremal current principle. Extensive Monte Carlo computer simulations are performed, and it is found that they are in excellent agreement with theoretical prediction.
    Physical Review E 06/2013; 87(6-1):062124. · 2.31 Impact Factor
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    ABSTRACT: This paper studies a periodic one-dimensional exclusion process composed of a driven part and a biased diffusive part in a mesoscopic limit. It is shown that, depending on the biased diffusion parameter δ, rich phase diagram structures appear in which diverse phases have been exhibited and the density profile in the diffusive part is qualitatively different. This is because the domain wall is behaving differently. Our analytical results are in good agreement with Monte Carlo simulations.
    Physical Review E 01/2013; 87(1-1):012107. · 2.31 Impact Factor
  • Qi-Hong Shi, Rui Jiang, Mao-Bin Hu, Qing-Song Wu
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    ABSTRACT: This Letter has firstly investigated three-lane PASEPs in which particles on lane i could move forward with rate pipi and backward with rate qiqi. Particles could also jump fully asymmetrically from lane i to lane i+1i+1. It is found that in the case that pi>qipi>qi and pi−qipi−qi are not equal to each other, the phase diagram in three-lane system has three different geometric structures. The principles of phase diagram structure have been generalized to multilane PASEPs. The case that pi−qipi−qi could be equal has also been studied. Unfortunately, the phase diagram structure is complex and generalization to multilane PASEPs is difficult. A vertical cluster mean-field analysis has been carried out, which shows good agreement with simulations.
    Physics Letters A 08/2012; 376(s 40–41):2640–2644. · 1.63 Impact Factor
  • The Twelfth COTA International Conference of Transportation Professionals; 07/2012
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    Qi-Hong Shi, Rui Jiang, Mao-Bin Hu, Qing-Song Wu
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    ABSTRACT: This paper studies a periodic driven diffusive system, which separates into two equal-sized parts with different values of hopping rates. Competition of the two different driven parts leads to various bulk-driven phase transitions, including shock and antishock. More interestingly, for the symmetric scenario, one can observe shock and antishock simultaneously in the system. We have explained the coexistence of shock and antishock via the effective boundary reservoir density. Theoretical analysis has been carried out to characterize the emerging nonequilibrium steady states, which is in good agreement with Monte Carlo simulations.
    Physical Review E 04/2012; 85(4 Pt 1):041131. · 2.31 Impact Factor
  • Lan Lin, Rui Jiang, Mao-Bin Hu, Qing-Song Wu
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    ABSTRACT: In this paper, we study traffic flow on a highway with three consecutive on-ramps by using the Nagel-Schreckenberg model, which is a generalization of our previous work concerning with highway with two ramps. We still focus on how to improve the system capacity by assigning traffic demand to the three ramps. It is shown that when all ramps are in free flow and the main road upstream of the ramps is in congestion, assigning a highest proportion of the demand to the upstream on-ramp, and lowest proportion of the demand to the downstream on-ramp could improve the overall flow. This is explained through studying the spatiotemporal patterns and analytical investigations. The conclusion could be generalized to highway with more on-ramps, i.e., the more downstream an on-ramp is, the lower the traffic demand should be assigned.
    Computational Sciences and Optimization (CSO), 2012 Fifth International Joint Conference on; 01/2012
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    ABSTRACT: This paper studies unidirectional pedestrian flow by using a lattice gas model with parallel update rules. Game theory is introduced to deal with conflicts that two or three pedestrians want to move into the same site. Pedestrians are either cooperators or defectors. The cooperators are gentle and the defectors are aggressive. Moreover, pedestrians could change their strategy. The fundamental diagram and the cooperator fraction at different system width W have been investigated in detail. It is found that a two-lane system exhibits a first-order phase transition while a multilane system does not. A microscopic mechanism behind the transition has been provided. Mean-field analysis is carried out to calculate the critical density of the transition as well as the probability of games at large value of W. The spatial distribution of pedestrians is investigated, which is found to be dependent (independent) on the initial cooperator fraction when W is small (large). Finally, the influence of the evolutionary game rule has been discussed.
    Physical Review E 09/2011; 84(3 Pt 2):036107. · 2.31 Impact Factor
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    ABSTRACT: A Comment on the Letter by Hauke Hinsch and Erwin Frey, Phys. Rev. Lett. 97, 095701 (2006). The authors of the Letter offer a Reply.
    Physical Review Letters 02/2011; 106(7):079601; author reply 079602. · 7.73 Impact Factor
  • Qing-yi Hao, Rui Jiang, Mao-Bin Hu, Qing-Song Wu
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    ABSTRACT: This paper studies unidirectional pedestrian flow in a channel by using a lattice gas model with parallel update rule. Game theory is introduced to deal with the conflict that several pedestrians intend to move to the same site. A pedestrian is either a co operator (C) or defector (D) when he or she wants to move into the same lattice as other pedestrians. Moreover, he or she could change the strategy (C or D) in the next conflict. The fundamental diagram of pedestrian flow in the channel has been investigated in details, and differences from the model with random sequential update rule have been observed. The co operators fraction is shown to exhibit an interesting non-monotonic dependence on pedestrian density. It is interesting to find that change of co operators fraction alters exponentially before the system comes to steady state. How the parameters p and q in the payoff matrix of game influence mean flow and co operators fraction is also investigated.
    01/2011;
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    Qing-Yi Hao, Rui Jiang, Mao-Bin Hu, Qing-Song Wu
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    ABSTRACT: This paper studies an extended parallel asymmetric exclusion process, in which the anticipation effect is taken into account. The fundamental diagram of the model has been investigated via cluster mean field analysis. Different from previous mean field analysis, in which the n -cluster probabilities P(σ{i},…,σ{i+n-1}) involve the (n+2) -cluster probabilities P(τ{i-1},…,τ{i+n}) , our mean-field analysis is asymmetric because the three-cluster probabilities P(σ{i},σ{i+1},σ{i+2}) involve the six-cluster probabilities P(τ{i-1},…,τ{i+4}) . We find an excellent agreement between Monte Carlo simulations and cluster mean field analysis, which indicates that the mean field analysis might give the exact expression.
    Physical Review E 08/2010; 82(2 Pt 1):022103. · 2.31 Impact Factor
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    ABSTRACT: This paper studies unidirectional pedestrian flow in a channel using the lattice gas model with parallel update rule. The conflict (i.e., several pedestrians intend to move to the same site) is solved by introducing probabilities as in floor field models. The fundamental diagram (FD) is investigated and it is found that when the drift strength D≲0.5, the FD is a concave curve. With the further increase in drift strength, a turning point appears on FD. The empirical findings show that both concave FD and FD with a turning point exist. Thus, the model might be able to reproduce both by tuning drift strength. It is also shown that in the special case D=1, two congested branches exist in the FD. We have carried out mean-field analysis of the FD and the mean-field results are in approximate agreement with simulations when the drift strength D is small. A comparison with random sequential update rule model is also made.
    Physical Review E 08/2010; 82(2 Pt 2):026113. · 2.31 Impact Factor
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    ABSTRACT: This paper studies a periodic asymmetric exclusion process composed of two equal parts. Particles are allowed to jump between these two parts. Shock formation has been revealed when the lane changing rates are asymmetric, in both strong and weak coupling situations. The density profiles and phase structure of the model are analyzed. Mean field analysis has been carried out and it is in agreement with the Monte Carlo simulations. The results have been compared with those arising from open boundaries and the differences are indicated and explained.
    Journal of Statistical Mechanics Theory and Experiment 06/2010; 2010(07):P07003. · 1.87 Impact Factor
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    ABSTRACT: In this paper, we study TASEPs on two intersected lattices. One TASEP has an open boundary (lattice 1) and the other has a periodic boundary (lattice 2). Extensive Monte Carlo simulations are carried out. It is found that the system phase diagram structure depends on the density ρ on lattice 2. Three critical densities ρc = 1/3, 1/2 and 2/3 are identified and four phase diagram structures are observed. The density profiles corresponding to all stationary phases and the phase boundaries are calculated using mean-field analysis. The analytic results are in good agreement with the simulation results.
    Journal of Statistical Mechanics Theory and Experiment 03/2010; 2010(03):P03014. · 1.87 Impact Factor
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    ABSTRACT: A network traffic system can be tuned by three factors: (i) the topology of underlying infrastructure; (ii) the distribution of traffic resources; (iii) the routing strategy. In this paper, we propose a model to study the optimization of network capacity based on complex network theory. We study the optimization method of network traffic in several situations corresponding to the real cases. The model is proposed mainly for the information traffic system. It can also be modified to characterize the behavior of an urban traffic system. Our study can benefit the modern communication networks, urban transportation systems, airline traffic, and power grids.
    Control and Automation, 2009. ICCA 2009. IEEE International Conference on; 01/2010
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    Zhi-Hu Sun, Rui Jiang, Mao-Bin Hu, Qing-Song Wu
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    ABSTRACT: This Letter presents an improved mean field analysis of a bidirectional two-lane asymmetric exclusion process with narrow entrances, which exhibits spontaneous symmetry breaking. The method takes into account the correlation of the vertical cluster at system boundaries, which shows better agreement with simulations than the simple mean field method.
    Physics Letters A 01/2010; 374(40):4080-4083. · 1.63 Impact Factor
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    Xiang Ling, Mao-Bin Hu, Rui Jiang, Qing-Song Wu
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    ABSTRACT: Traffic is essential for many dynamic processes on networks. The efficient routing strategy [G. Yan, T. Zhou, B. Hu, Z. Q. Fu, and B. H. Wang, Phys. Rev. E 73, 046108 (2006)] can reach a very high capacity of more than ten times of that with shortest path strategy. In this paper, we propose a global dynamic routing strategy for network systems based on the information of the queue length of nodes. Under this routing strategy, the traffic capacity is further improved. With time delay of updating node queue lengths and the corresponding paths, the system capacity remains constant, while the travel time for packets increases.
    Physical Review E 01/2010; 81(1 Pt 2):016113. · 2.31 Impact Factor

Publication Stats

790 Citations
148.46 Total Impact Points

Institutions

  • 2003–2014
    • University of Science and Technology of China
      • School of Engineering Science
      Luchow, Anhui Sheng, China
  • 2009
    • The University of Tokyo
      • Department of Aeronautics and Astronautics
      Tokyo, Tokyo-to, Japan
  • 2007–2009
    • Massey University
      • School of Engineering and Advanced Technology
      Palmerston North, Manawatu-Wanganui, New Zealand
  • 2004–2007
    • Beijing Jiaotong University
      • School of Traffic and Transportation
      Beijing, Beijing Shi, China
  • 2006
    • Curtin University Australia
      • Department of Mathematics and Statistics
      Bentley, Western Australia, Australia