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With the goal of improving the real-time automatic generation of water routes and obtaining the optimal water routes, the study is based on automatic identification system (AIS) big data and electronic chart display and information system (ECDIS) water route automatic generation. The parallel AIS data processing technology of the distributed storage system is selected to realize the AIS big data processing that is automatically generated by the water route, the geodetic coordinates of the AIS information after the big data processing are transformed to Mercator projection, and the obtained Mercator coordinates are converted to the latitude and longitude of the sampling point to obtain the final sampling point. The Douglas-Peucker algorithm is selected to compress the sampling points and select the turning points from the compressed sampling points according to the fixed threshold set. The connection of the obtained turning points is the automatically generated initial water route. The ECDIS electronic chart is used to detect the generated route, and the final feasible route is the generated final water route. The experimental results show that the automatically generated water route mileage of this method is shorter, and the automatic generation time is within 300 ms, which has higher water route generation efficiency.

Flow around an oscillating cylinder in a subcritical region are numerically studied with a lattice Boltzmann method (LBM). The effects of the Reynolds number, oscillation amplitude and frequency on the vortex wake modes and hydrodynamics forces on the cylinder surface are systematically investigated. Special attention is paid to the phenomenon of resonance induced by the cylinder oscillation. The results demonstrate that vortex shedding can be excited extensively under subcritical conditions, and the response region of vibration frequency broadens with increasing Reynolds number and oscillation amplitude. Two distinct types of vortex shedding regimes are observed. The first type of vortex shedding regime (VSR I) is excited at low frequencies close to the intrinsic frequency of flow, and the second type of vortex shedding regime (VSR II) occurs at high frequencies with the Reynolds number close to the critical value. In the VSR I, a pair of alternately rotating vortices are shed in the wake per oscillation cycle, and lock-in/synchronization occurs, while in the VSR II, two alternately rotating vortices are shed for several oscillation cycles, and the vortex shedding frequency is close to that of a stationary cylinder under the critical condition. The excitation mechanisms of the two types of vortex shedding modes are analyzed separately.

Link-level congestion, such as link spillback and long intersection queues, should be avoided during emergency evacuation. The reason is that these local traffic incidents can cause traffic safety risks and hinder evacuation tasks. To determine reliable routes and departure times for the whole evacuation, we establish the link-congestion mitigation-based dynamic evacuation route planning (LCM-DERP) model. The distinct difference with the typical DERP model lies in the objective composition. The system cost objective in our model consists of not only total evacuation time but also external congestion cost. The penalization for link spillback and long intersection queues is used to represent external congestion cost. An improved cell transmission structure, composed of tail cell and head cell and approach cell, is proposed to simulate dynamic traffic flow. Specifically, tail cell and head cell can detect the information of link spillback and long intersection queue separately. This function enables the representation of external congestion cost expressed by multiplying link-level congestion vehicles with penalty parameter. A method of successive average, including a calculation of the local path marginal cost, is used to solve the model. We applied the LCM-DERP model on a road network around Olympic Stadium in Nanjing, China, to test its effectiveness in the aspect of link-congestion control. Compared with the typical DERP model, our method can improve system cost, especially in the high demand range, wherein the reduced external congestion cost is larger than this reduced system cost.