The Experts below are selected from a list of 135255 Experts worldwide ranked by ideXlab platform
Younian Wang - One of the best experts on this subject based on the ideXlab platform.
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plasmon excitation in metal slab by fast point charge the role of additional boundary conditions in quantum Hydrodynamic Model
Physics of Plasmas, 2014Co-Authors: Zoran L. Mišković, Shengbai An, Naijing Kang, Yuan Hong Song, Yingying Zhang, Younian WangAbstract:We study the wake effect in the induced potential and the stopping power due to plasmon excitation in a metal slab by a point charge moving inside the slab. Nonlocal effects in the response of the electron gas in the metal are described by a quantum Hydrodynamic Model, where the equation of electronic motion contains both a quantum pressure term and a gradient correction from the Bohm quantum potential, resulting in a fourth-order differential equation for the perturbed electron density. Thus, besides using the condition that the normal component of the electron velocity should vanish at the impenetrable boundary of the metal, a consistent inclusion of the gradient correction is shown to introduce two possibilities for an additional boundary condition for the perturbed electron density. We show that using two different sets of boundary conditions only gives rise to differences in the wake potential at large distances behind the charged particle. On the other hand, the gradient correction in the quantum hy...
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quantum ion acoustic waves in single walled carbon nanotubes studied with a quantum Hydrodynamic Model
Physical Review B, 2007Co-Authors: Younian WangAbstract:The quantum ion-acoustic waves in single-wall carbon nanotubes are studied with the quantum Hydrodynamic Model, in which the electron and ion components of the nanotubes are regarded as a two-species quantum plasma system. An analytical expression of the dispersion relation is obtained for the linear disturbance. Numerical results show that the frequency of the ion-acoustic wave strongly depends on the nanotube's radius in the long-wavelength cases.
Rongjun Cheng - One of the best experts on this subject based on the ideXlab platform.
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an extended lattice Hydrodynamic Model considering the delayed feedback control on a curved road
Physica A-statistical Mechanics and Its Applications, 2019Co-Authors: Rongjun Cheng, Y G WangAbstract:Abstract In this paper, we investigate the effect of delayed feedback control on a curved road analytically and numerically. An extended lattice Hydrodynamic Model is derived on a single-lane road which includes more comprehensive information. The control method is used to obtain the stability of the new Model and the critical condition for the linear steady traffic flow is deduced. Moreover the numerical simulations are carried out to verify the advantage of the proposed Model with and without the delayed feedback control on a curved road and a straight road. The results are consistent with the theoretical analysis correspondingly.
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a new lattice Hydrodynamic Model based on control method considering the flux change rate and delay feedback signal
Physics Letters A, 2018Co-Authors: Shunda Qin, Rongjun ChengAbstract:Abstract In this paper, a new lattice Hydrodynamic Model is proposed by taking delay feedback and flux change rate effect into account in a single lane. The linear stability condition of the new Model is derived by control theory. By using the nonlinear analysis method, the mKDV equation near the critical point is deduced to describe the traffic congestion. Numerical simulations are carried out to demonstrate the advantage of the new Model in suppressing traffic jam with the consideration of flux change rate effect in delay feedback Model.
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the control method for the lattice Hydrodynamic Model
Communications in Nonlinear Science and Numerical Simulation, 2015Co-Authors: Yu Cui, Keqiang Zhu, Rongjun ChengAbstract:Abstract The delayed-feedback control method is applied for lattice Hydrodynamic Model of traffic flow. The linear stability condition with and without control signal are derived through linear and nonlinear analysis. Numerical simulation is carried out and the results confirm that the traffic congested can be suppressed efficiently by considering the control signal.
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tdgl equation in lattice Hydrodynamic Model considering driver s physical delay
Nonlinear Dynamics, 2014Co-Authors: Hongxia Ge, Pengjun Zheng, Siuming Lo, Rongjun ChengAbstract:Based on an extended lattice Hydrodynamic Model considering the delay of the driver’s response in sensing headway, we get the time-dependent Ginzburg–Landau (for short, TDGL) equation to describe the transition and critical phenomenon in traffic flow by applying the reductive perturbation method. The corresponding solutions are obtained. Numerical simulation is carried out to examine the performance of the Model and the results show coincidence with the analysis results.
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the backward looking effect in the lattice Hydrodynamic Model
Physica A-statistical Mechanics and Its Applications, 2008Co-Authors: Rongjun ChengAbstract:Abstract The novel lattice Hydrodynamic Model is presented by incorporating the “backward looking” effect. The stability condition for the the Model is obtained using the linear stability theory. The result shows that considering one following site in vehicle motion leads to the stabilization of the system compared with the original lattice Hydrodynamic Model and the cooperative driving lattice Hydrodynamic Model. The Korteweg–de Vries (KdV, for short) equation near the neutral stability line is derived by using the reductive perturbation method to show the traffic jam which is proved to be described by KdV soliton solution obtained from the KdV equation. The simulation result is consistent with the nonlinear analysis.
Duncan J Mowbray - One of the best experts on this subject based on the ideXlab platform.
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plasmon excitations on a single wall carbon nanotube by external charges two dimensional two fluid Hydrodynamic Model
Physical Review B, 2010Co-Authors: Duncan J Mowbray, Silvina Segui, J L Gervasoni, Z L Miskovic, N R AristaAbstract:We present a quantization of the Hydrodynamic Model to describe the excitation of plasmons in a single-walled carbon nanotube by a fast point charge moving near its surface at an arbitrary angle of incidence. Using a two-dimensional electron gas represented by two interacting fluids, which takes into account the different nature of the $\ensuremath{\sigma}$ and $\ensuremath{\pi}$ electrons, we obtain plasmon energies in near-quantitative agreement with experiment. Further, the implemented quantization procedure allows us to study the probability of exciting various plasmon modes, as well as the stopping force and energy loss spectra of the incident particle.
Taixiong Zheng - One of the best experts on this subject based on the ideXlab platform.
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a new lattice Hydrodynamic Model considering the effects of bilateral gaps on vehicular traffic flow
Nonlinear Dynamics, 2017Co-Authors: Yu Song, Taixiong Zheng, Bin Yang, Huizong FengAbstract:This study proposes a new lattice Hydrodynamic Model considering the effects of bilateral gaps on a road without lane discipline. In particular, a lattice Hydrodynamic Model is proposed to capture the impacts from the lateral gaps of the right-side and left-side sites of the considered lattice sites. Linear stability analysis of the proposed Model is performed using the perturbation method to obtain the stability condition. Nonlinear analysis of the proposed Model is performed using the reductive perturbation method to derive the modified Korteweg–de Vries (mKdV) equation to characterize the density wave propagation. Results from numerical experiments illustrate that the smoothness and stability of the proposed Model are improved compared with the Model that considers the effect of unilateral gap. Also, the proposed Model is able to more quickly dissipate the effect of perturbation occurring in the vehicular traffic flow.
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lattice Hydrodynamic Model based delay feedback control of vehicular traffic flow considering the effects of density change rate difference
Communications in Nonlinear Science and Numerical Simulation, 2015Co-Authors: Li Zhang, Taixiong ZhengAbstract:Abstract This study proposes a control strategy of vehicular traffic based on the lattice Hydrodynamic Model by taking the difference of density change rate as a feedback signal. In particular, a delay feedback control scheme is designed based on Nagatani's lattice Model considering the effects of density change rate difference under the open boundary condition. Stability analysis of the lattice Hydrodynamic Model with the control signal is performed using the small gains theorem to obtain the stability condition. Results from numerical experiments including the single perturbation and multiple perturbations illustrate that the proposed control strategy can suppress traffic jam effectively and make the vehicular traffic flow to move into a comparatively homogeneous state.
Reza Ahmadian - One of the best experts on this subject based on the ideXlab platform.
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representation and operation of tidal energy impoundments in a coastal Hydrodynamic Model
Renewable Energy, 2016Co-Authors: Athanasios Angeloudis, Roger Alexander Falconer, Samuel Bray, Reza AhmadianAbstract:Abstract A methodology associated with the simulation of tidal range energy projects through a coastal Hydrodynamic Model is discussed regarding its capabilities and limitations. Particular focus is directed towards the formulations imposed for the representation of hydraulic structures and the corresponding Model boundary conditions. Details of refinements are presented that would be applicable in representing the flow (and momentum flux) expected through tidal range turbines to inform the regional Modelling of tidal lagoons and barrages. A conceptual tidal lagoon along the North Wales coast, a barrage across the Severn Estuary and the Swansea Bay Lagoon proposal are used to demonstrate the effect of the refinements for projects of a different scale. The Hydrodynamic Model results indicate that boundary refinements, particularly in the form of accurate momentum conservation, have a noticeable influence on near-field conditions and can be critical when assessing the environmental impact arising from the schemes. Finally, it is shown that these Models can be used to guide and improve tidal impoundment proposals.
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representation and operation of tidal energy impoundments in a coastal Hydrodynamic Model
Renewable Energy, 2016Co-Authors: Athanasios Angeloudis, Roger Alexander Falconer, Samuel Bray, Reza AhmadianAbstract:A methodology associated with the simulation of tidal range projects through a coastal Hydrodynamic Model is discussed regarding its capabilities and limitations. Particular focus is directed towards the formulations imposed for the representation of hydraulic structures and the corresponding Model boundary conditions. Details of refinements are presented that would be applicable in representing the flow (and momentum flux) expected through tidal range turbines to inform the regional Modelling of tidal lagoons and barrages. A conceptual tidal lagoon along the North Wales coast, a barrage across the Severn Estuary and the Swansea Bay Lagoon proposal are used to demonstrate the effect of the refinements for projects of a different scale. The Hydrodynamic Model results indicate that boundary refinements, particularly in the form of accurate momentum conservation, have a noticeable influence on near-field conditions and can be critical when assessing the environmental impact arising from the schemes. Finally, it is shown that these Models can be used to guide and improve tidal impoundment proposals.
