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Yin L.,Southwest Jiaotong University | Zhu J.,Southwest Jiaotong University | Zhu J.,Sichuan Engineering Research Center for Emergency Mapping & Disaster Reduction | Wang J.,Royal Dutch Shell | And 4 more authors.
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/Geomatics and Information Science of Wuhan University | Year: 2015

Based on the natural similarity between the parallel computing features of cellular automata and the parallel computing architecture of the CUDA, a dam-break flood routing computing model based on GPU-CA is proposed. Key technologies including cellular automata (CA) model of dam-break flood routing, GPU model mapping method, calculation optimization method, and GPU/CPU collaborative implementation for dam-break flood routing simulation and analysis are discussed in detail. Finally, a prototype system was developed and a case study region selected for carrying out a preliminary experiment. As compared to the CPU-CA model computing, the experimental results showed that the dam-break flood routing computing based on GPU-CA model can greatly improve the computing efficiency, and also ensured the validity of the simulation results. Speedup can be improved by increasing the cellular grid resolution. When the cellular grid size was 10 m, the speedup of model calculation reached 15.9 times, which can support real-time simulation analysis and risk assessment for dam-break flood routing. Source


Zhang H.,Southwest Jiaotong University | Zhu J.,Southwest Jiaotong University | Zhu J.,Sichuan Engineering Research Center for Emergency Mapping and Disaster Reduction | Xu Z.,Southwest Jiaotong University | And 6 more authors.
Computers, Environment and Urban Systems | Year: 2016

A rule-based parametric modeling (RPM) method is proposed to dynamically generate virtual environments for simulation and analysis of the dynamics of coupled systems in high-speed trains. First, a precise and complete basic-element model base is built according to the modeling requirements of virtual simulation environments. Meanwhile, the classes of and relationships between the basic-element models are defined with respect to the geometrical, topological, semantical and appearance properties of these models. Then, multi-level semantic constraint rules and a parametric modeling method are designed to accurately analyze the simulation parameters and to rapidly integrate various basic-element models for automatic generation of virtual high-speed railway environments. Finally, after a prototype system is developed, various experiments are carried out for analysis of the advantages of the RPM method. The experimental results show that the RPM method can be used to normalize the error-prone modeling procedure and rapidly generate precise and realistic virtual environments. © 2015 Published by Elsevier Ltd. Source


Zhu J.,Southwest Jiaotong University | Zhu J.,HIGH-TECH | Zhang H.,Southwest Jiaotong University | Chen M.,Southwest Jiaotong University | And 11 more authors.
International Journal of Geographical Information Science | Year: 2015

A procedural modelling method based on model combination and spatial semantic constraint is proposed to realize the automatic modelling of high-speed railway scenes for management decisions and scientific experiments at different stages. The construction and description of basic-element models were first discussed in detail according to the fixed characteristics of the geometric appearances of and the spatial relationships between the components of high-speed railways. Then, spatial semantic constraint rules and scene mapping and instantiation methods were designed to accurately and rapidly integrate various basic-element models for automatically generating high-fidelity three-dimensional high-speed railway scenes. Finally, a prototype modelling system was developed to implement preliminary experiments. The experimental results show that the method proposed in this article is suitable for the automatic generation of virtual high-speed railway scenes by combining sophisticated basic-element models in a seamless manner. Modelling operations and professional knowledge are decoupled to reduce the complexity and difficulty of multidisciplinary collaborative modelling, which improves the modelling efficiency of virtual high-speed railway scenes. © 2015 Taylor & Francis. Source

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