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To make agents' route decision-making behaviours as real as possible, this paper proposes a layered navigation algorithm, emphasizing the coordinating of the global route planning at strategic level and the local route planning at tactical level. Specifically, by an improved visibility graph method, the global route is firstly generated based on static environment map. Then, a new local route planning (LRP) based on dynamic local environment is activated for multipath selection to allow pedestrian to respond changes at a real-time sense. In particular, the LRP model is developed on the basis of a passenger's psychological motivation. The pedestrians' individual preferences and the uncertainties existing in the process of evaluation and choice are fully considered. The suitable local path can be generated according to an estimated passing time. The LRP model is applied to the choice of ticket gates at a subway station, and the behaviours of gate choosing and rechoosing are investigated. By utilizing C++, the layered navigation algorithm is implemented. The simulation results exhibit agents' tendency to avoid congestion, which is often observed in real crowds., 1. Introduction Pedestrian simulation has engaged the attention of researchers over the past few decades. It is not only a simulation technology to reproduce the temporal and spatial changes of [...]

Turbulence near a free surface is of multi-layered nature and of fundamental significance in understanding vast marine and ocean processes. Direct numerical simulation of an open channel with the free surface modeled by a free-slip boundary is performed. Complex multi-layered turbulence (i.e., the blockage layer, the slip layer, and the Kolmogorov layer) under the free surface are first identified based on predefined anisotropy indices. Later on, statistical features of the anisotropic turbulence inside the three turbulence layers are presented. Most importantly, considering the drastic variation of both velocity and vorticity in near-surface layers, we revisit the complex multi-layered turbulence by the velocity–vorticity correlation structure (VVCS) method [Chen et al., J. Fluid Mech. 742, 291–307 (2014)]. It is found that the VVCS can physically depict evolution of the hairpin vortex inside the channel, including generation in the bottom wall region, expansion in the bulk flow, process of getting flattened in the blockage layer, and then distortion and breakdown in the slip layer and the Kolmogorov layer. Specifically, the correlation structures VVCS11 for streamwise velocity and streamwise vorticity reflect how the hairpin legs are spatially distributed, while the correlation structures VVCS13 for streamwise velocity and spanwise vorticity describe the evolution of the hairpin vortex head. In the end, a cradle-like structure model is proposed based on the VVCS results and the vortex ring collision model is introduced to improve the understanding of the multi-layered turbulence under free surface. Hopefully, this research can be of value in future turbulence modeling work on free surface flows. [ABSTRACT FROM AUTHOR]

An analytically based method is proposed to simulate the acoustic-gravity waves in the horizontally stratified atmosphere-Earth structure generated by a point force on the Earth's surface. The method solves the linear momentum, continuity and adiabaticity equations in the atmosphere and elastodynamic equations in the solid Earth in the frequency–wavenumber domain. The time-domain waveforms are obtained by wavenumber integration and fast Fourier transform with respect to the frequency. Numerical simulations are conducted to investigate the properties of the acoustic-gravity waves, including both the high-frequency acoustic-mode waves and low-frequency gravity-mode waves. Simulations of the high-frequency responses show that disturbances in the atmosphere with three apparent horizontal velocities can be identified. They are, namely, the direct acoustic-mode wave generated by source travelling with the sound speed, the head wave generated by the seismic P -wave travelling with apparent horizontal speed identical to the P velocity, and the head wave generated by the Rayleigh wave with a horizontal speed same to the Rayleigh wave velocity. Simulations of the low-frequency responses show that the gravity-mode wave and Lamb wave can be identified. The gravity-mode wave travels with a speed lower than the sound seed and does not reach everywhere, especially the area directly above the source. The Lamb wave travels along the Earth surface with a speed of about 310 m s–1 and its energy decays with the altitude. We also apply our method to explaining the Doppler sounding data observed in Taiwan area during the 2011 Tohoku M 9 earthquake, and find good agreement between the predicted signals and observed data in the arrival time and wave envelope associated with the Rayleigh wave. [ABSTRACT FROM AUTHOR]

Our previous studies demonstrated that peripheral overexpression of angiotensin II (ANG II) type 2 receptors ([AT.sub.2]R) prevents hypertension-induced cardiac hypertrophy and remodeling without altering high blood pressure. This, coupled with the observations that [AT.sub.2]R play a role in the antihypertensive actions of ANG II type 1 receptor ([AT.sub.1]R) blockers (ARBs), led us to propose that peripheral over-expression of [AT.sub.2]R would improve the antihypertensive action of losartan (Los) in Sprague-Dawley (SD) rats made hypertensive via chronic infusion of ANG II. Here we utilized adenoviral vector-mediated [AT.sub.2]R gene transfer to test this hypothesis. A single intracardiac injection of adenoviral vector containing genomic [AT.sub.2]R (G-[AT.sub.2]R) DNA and enhanced green fluorescent protein (EGFP) gene controlled by cytomegalovirus (CMV) promoters (Ad-G-[AT.sub.2]R-EGFP; 5 x [10.sup.9] infectious units) into adult SD rats produced robust [AT.sub.2]R overexpression in cardiovascular tissues (kidney, lung, heart, aorta, mesenteric artery, and renal artery) that persisted for 3-5 days postinjection. By 7 days post viral injection, the overexpressed [AT.sub.2]R are reduced toward basal values in certain tissues (lung, kidney, and heart) and are undetectable in others (kidney and blood vessels). In two separate protocols, we demonstrated that the hypotensive effect of Los (0.125, 0.5, and 1.0 mg/kg iv) was significantly greater in the [AT.sub.2]R-overexpressing animals (-40.7 [+ or -] 4.3, -41.8 [+ or -] 4.8, and -48.1 [+ or -] 2.6 mmHg, respectively) compared with control vector (Ad-CMV-EGFP)-treated rats (-12.4 [+ or -] 2.2, -20.2 [+ or -] 3.4, and -27.3 [+ or -] 3.4 mmHg, respectively). These results provide support for a depressor role of [AT.sub.2]R and the proposal that combined [AT.sub.2]R agonist and ARB treatment may be an improved therapeutic strategy for controlling hypertension. hypertension; angiotensin II; angiotensin receptor blocker; adenovirus; gene transfer

Movement of the conductive subsurface medium in the Earth's magnetic field can generate electromagnetic (EM) disturbances. This phenomenon is referred to as the motional induction (MI) effect and, though previously proposed as a possible mechanism for the generation of earthquake‐associated EM signals, has not yet been well understood. In this study, we present a semianalytical method to derive the EM response to an earthquake due to the MI effect in a 3D horizontally layered model. We solve the coupled elastodynamic and Maxwell's equations in the frequency–wavenumber domain through the global matrix method and then compute the seismic and EM responses in the time domain. We first verify the proposed method by comparing results to the analytical solution in a full‐space model and then conduct numerical simulations to investigate the properties of the EM fields and their sensitivities to the rock conductivity. Finally, we use the proposed method to model coseismic EM data observed during the 2008 Mw 6.1 Qingchuan earthquake. The results show that the simulated coseismic electric fields can fit the observed electric signals well in both arrival time and amplitude, suggesting that the MI effect is a possible mechanism for the generation of the observed electric signals. The simulated magnetic fields are 1 order of magnitude weaker in amplitude than the observed magnetic data, implying that the observed magnetic fields are mainly generated by other mechanisms. Plain Language Summary: Much observational evidence shows that anomalous electromagnetic (EM) signals are detected during earthquakes. These EM signals have attracted a lot of attention because they might be useful for earthquake early warning and disaster mitigation. But we lack sufficient understanding. Although the motional induction (MI) effect has been proposed, the precise mechanism by which earthquake (rupture) energy transforms to EM energy is unclear. MI effect results from motion of the conductive subsurface medium in the ambient geomagnetic field due to the Faraday's law. In this study, we present a method to simulate the EM fields generated by the earthquake due to MI effect. Our results show that earthquakes can produce two kinds of EM signals. One arrives before the seismic waves (called early EM signals) and the other arrives simultaneously with seismic waves (called coseismic EM signals). We also use our method to simulate the EM data recorded during a real earthquake (which happened in 2008 in Sichuan, China). The synthetic coseismic electric fields can explain the observed data well, indicating that MI effect is an effective mechanism to produce the earthquake‐associated EM signals. Key Points: We present a method to simulate electromagnetic field generated by an earthquake due to motional induction effect in 3D‐layered mediaNumerical simulations are conducted to investigate the character of the electromagnetic fields and their sensitivity to rock conductivityThe method is applied to the 2008 Qingchuan Mw 6.1 earthquake; synthetic electric signals can explain observed electric signals [ABSTRACT FROM AUTHOR]