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基于视频的交通流参数测量方法研究 被引量:7
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作者 张学武 徐立中 +1 位作者 梁瑞宇 张卓 《仪器仪表学报》 EI CAS CSCD 北大核心 2010年第11期2542-2548,共7页
道路交通流参数是交通安全管理、交通状况态势评估和决策的重要基础信息。提出一种改进的具有一定自适应功能的高斯背景建模法,并采用基于透视变换的计算模型,建立车辆的几何尺寸的视觉测量模型,通过CCD传感器感知道路环境并形成视频流... 道路交通流参数是交通安全管理、交通状况态势评估和决策的重要基础信息。提出一种改进的具有一定自适应功能的高斯背景建模法,并采用基于透视变换的计算模型,建立车辆的几何尺寸的视觉测量模型,通过CCD传感器感知道路环境并形成视频流记录,利用图像处理和分析方法,对视频流实时处理、跟踪和分析车辆状态参数及道路状况,实现道路交通流基础信息准确实时获取和辨识。实验和现场试验结果表明,平均测量精度达到工程应用需求,可为交通管理部门进行交通管理和交通规划决策提供科学的基础参数信息。 展开更多
关键词 交通流量参数 背景建模 视觉测量 透视变换 机器视觉
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Impact of Convective Momentum Transport by Deep Convection on Simulation of Tropical Intraseasonal Oscillation 被引量:1
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作者 LING Jian LI Chongyin 《Journal of Ocean University of China》 SCIE CAS 2014年第5期717-727,共11页
This paper focuses on the impacts of convective momentum transport(CMT) on simulations of the tropical intraseasonal oscillation(TIO) in SAMIL. Two sets of experiments are performed, which give different reality of th... This paper focuses on the impacts of convective momentum transport(CMT) on simulations of the tropical intraseasonal oscillation(TIO) in SAMIL. Two sets of experiments are performed, which give different reality of the Madden-Julian Oscillation(MJO). The Tiedtke cumulus parameterization scheme is used for all experiments. It is found that simulations of the TIO can be influenced by CMT, and the impacts on the simulated TIO depend on the model capability in simulating the MJO. CMT tends to have large influences to the model that can simulate the eastward propagation of the MJO. CMT can further influence the long-term mean of zonal wind and its vertical shear. Zonal wind suffers from easterlies biases at low level and westerlies biases at upper level when CMT is introduced. Such easterlies biases at low level reduce the reality of the simulated tropical intraseasonal oscillation. When CMT is introduced in the model, MJO signals disappear but the model's mean state improves. Therefore, a more appropriate way is needed to introduce CMT to the model to balance the simulated mean state and TIO signals. 展开更多
关键词 Madden-Julian Oscillation(MJO) convective momentum transport(CMT) SAMIL
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