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服役动车组车轮踏面旋修周期跟踪研究
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作者 吴晨恺 刘保臣 《铁道机车车辆》 2016年第5期40-43,47,共5页
对某条线路服役的两列CRH_1型车进行了长期跟踪测试,获得了车轮外形及车辆振动性能的演变规律。研究发现,两列跟踪动车组在以30万km为旋修周期时,旋修前各项振动性能、磨耗情况均满足标准限值要求,且距标准限值均有较大冗余,因此建议LM... 对某条线路服役的两列CRH_1型车进行了长期跟踪测试,获得了车轮外形及车辆振动性能的演变规律。研究发现,两列跟踪动车组在以30万km为旋修周期时,旋修前各项振动性能、磨耗情况均满足标准限值要求,且距标准限值均有较大冗余,因此建议LMD踏面采用30万km作为其旋修周期。 展开更多
关键词 车轮外形 实测跟踪 旋修周期验证
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基于等效锥度的动车组三级修间隔周期研究 被引量:3
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作者 吴晨恺 陈进 林凤涛 《城市轨道交通研究》 北大核心 2018年第10期48-51,共4页
对某条线路服役的两列CRH2A型车进行了长期跟踪测试。基于等效锥度的要求,获得了车轮外形及车辆动力学性能的演变规律。研究发现,两列跟踪动车组在三级修间隔周期由60万km延长至120万km后,各项动力学性能、磨耗情况无明显变化,均满足标... 对某条线路服役的两列CRH2A型车进行了长期跟踪测试。基于等效锥度的要求,获得了车轮外形及车辆动力学性能的演变规律。研究发现,两列跟踪动车组在三级修间隔周期由60万km延长至120万km后,各项动力学性能、磨耗情况无明显变化,均满足标准限值要求,因此建议将CHR2型车三级修间隔周期延长60万km。 展开更多
关键词 动车组 实测跟踪 三级修间隔周期 等效锥度
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Real-Time Front Vehicle Detection Algorithm Based on Local Feature Tracking Method 被引量:1
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作者 Jae-hyoung YU Young-joon HAN Hern-soo HAHN 《Journal of Measurement Science and Instrumentation》 CAS 2011年第3期244-246,共3页
This paper proposes an algorithm that extracts features of back side of the vehicle and detects the front vehicle in real-time by local feature tracking of vehicle in the continuous images.The features in back side of... This paper proposes an algorithm that extracts features of back side of the vehicle and detects the front vehicle in real-time by local feature tracking of vehicle in the continuous images.The features in back side of the vehicle are vertical and horizontal edges,shadow and symmetry.By comparing local features using the fixed window size,the features in the continuous images are tracked.A robust and fast Haarlike mask is used for detecting vertical and horizontal edges,and shadow is extracted by histogram equalization,and the sliding window method is used to compare both side templates of the detected candidates for extracting symmetry.The features for tracking are vertical edges,and histogram is used to compare location of the peak and magnitude of the edges.The method using local feature tracking in the continuous images is more robust for detecting vehicle than the method using single image,and the proposed algorithm is evaluated by continuous images obtained on the expressway and downtown.And it can be performed on real-time through applying it to the embedded system. 展开更多
关键词 vehicle detection object tracking real-time algorithm Haarlike edge detection
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Preliminary Study of Sensitive Areas for Several Tropical Cyclone Track Prediction Cases in 2007 被引量:1
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作者 TAN Xiao-Wei WANG Dong-Liang 《Atmospheric and Oceanic Science Letters》 2010年第6期299-302,共4页
Conditional (CNOP) obtained by nonlinear optimal perturbation the ensemble-based calculation method is employed to find possible sensitive areas for improving 48-h or more than 48-h tropical cyclone (TC) track pr... Conditional (CNOP) obtained by nonlinear optimal perturbation the ensemble-based calculation method is employed to find possible sensitive areas for improving 48-h or more than 48-h tropical cyclone (TC) track predictions in several cases affecting China in 2007. These sensitive areas are examined by observing system simulation experiments (OSSEs). Results show that these sensitive areas improve TC track predictions for 48 h or more to different extents. Further analysis is performed to determine the distribution characteristics of sensitive areas in these cases. Results show that areas south of Luzon and over surrounding oceans are significant for 48-h or more than 48-h TC track predictions, especially 60-h to 72-h track predictions. Areas over oceans north or east to Taiwan Island seem to be secondary sensitive for 48-h or more than 48-h TC track predictions. 展开更多
关键词 CNOP sensitive areas tropical cyclone track prediction
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A robust system for real-time pedestrian detection and tracking 被引量:2
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作者 李琦 邵春福 赵熠 《Journal of Central South University》 SCIE EI CAS 2014年第4期1643-1653,共11页
A real-time pedestrian detection and tracking system using a single video camera was developed to monitor pedestrians. This system contained six modules: video flow capture, pre-processing, movement detection, shadow ... A real-time pedestrian detection and tracking system using a single video camera was developed to monitor pedestrians. This system contained six modules: video flow capture, pre-processing, movement detection, shadow removal, tracking, and object classification. The Gaussian mixture model was utilized to extract the moving object from an image sequence segmented by the mean-shift technique in the pre-processing module. Shadow removal was used to alleviate the negative impact of the shadow to the detected objects. A model-free method was adopted to identify pedestrians. The maximum and minimum integration methods were developed to integrate multiple cues into the mean-shift algorithm and the initial tracking iteration with the competent integrated probability distribution map for object tracking. A simple but effective algorithm was proposed to handle full occlusion cases. The system was tested using real traffic videos from different sites. The results of the test confirm that the system is reliable and has an overall accuracy of over 85%. 展开更多
关键词 image processing technique pedestrian detection tracking video camera
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The Discovery of Burst Topic and Its Intermittent Evolution in Our Real World
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作者 汤斯亮 张寅 +3 位作者 王翰琪 陈铭 吴飞 庄越挺 《China Communications》 SCIE CSCD 2013年第3期1-12,共12页
Nowadays, a considerably large number of documents are available over many online news sites (e.g., CNN and NYT). Therefore, the utilization of these online documents, for example, the discovery of a burst topic and i... Nowadays, a considerably large number of documents are available over many online news sites (e.g., CNN and NYT). Therefore, the utilization of these online documents, for example, the discovery of a burst topic and its evolution, is a significant challenge. In this paper, a novel topic model, called intermittent Evolution LDA (iELDA) is proposed. In iELDA, the time-evolving documents are divided into many small epochs. iELDA utilizes the detected global topics as priors to guide the detection of an emerging topic and keep track of its evolution over different epochs. As a natural extension of the traditional Latent Dirichlet Allocation (LDA) and Dynamic Topic Model (DTM), iELDA has an advantage: it can discover the intermittent recurring pattern of a burst topic. We apply iELDA to real-world data from NYT; the results demonstrate that the proposed iELDA can appropriately capture a burst topic and track its intermittent evolution as well as produce a better predictive ability than other related topic models. 展开更多
关键词 LDA time series iterative clustering model
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