With the development of mobile technology, Internet and GIS, LBS plays an important role in various applications. From the perspective of LBS, it is one of the main tasks of matching 3-dimensional spatial-temporal tra...With the development of mobile technology, Internet and GIS, LBS plays an important role in various applications. From the perspective of LBS, it is one of the main tasks of matching 3-dimensional spatial-temporal trajectories. We present an interpoiation based Modified Hausdorff Distance algorithm for 3-dimensional spatial-temporal Trajectory Matching （IMHD-ST）. It adopts interpolation algorithm to shield the impact to the distance between trajectories due to different position updating porices, sampling granularity, initial position and so on in Moving Object Database （MOD）. Besides, it uses MHD to deal with the implicit spatial information and structural information of weighted position updating points in various trajectories and reflects the discrepancy of moving results through the spatial distance between trajectories. In addition, it adopts temporal distance corresponding to the spatial distance between trajectories to reflect the differences including direction, speed and so on during moving process. The experimental results show that the algorithrn can reflect the trajectory similarity between 3-dimensional mobile objects more correctly, accurately and robustly.展开更多
Ten years （from 2005 to 2014） of satellite sea surface temperature （SST） data from the Advanced Very High Resolution Radiometer （AVHRR） are analyzed to reveal the monthly changes in surface cold patches （SCPs）...Ten years （from 2005 to 2014） of satellite sea surface temperature （SST） data from the Advanced Very High Resolution Radiometer （AVHRR） are analyzed to reveal the monthly changes in surface cold patches （SCPs） in the main areas of the Northern Yellow Sea （NYS）. The Canny edge detection algorithm is used to identify the edges of the patches. The monthly changes are de- scribed in terms of location, temperature and area. The inter-annual variations, including changes in the location and area of the SCPs from 2010 to 2014, are briefly discussed. The formation mechanisms of the SCPs in different periods are systematically analyzed using both in situ data and numerical simulation. The results show that from May to October, the location and area of the SCPs re- main stable, with a north-south orientation. The SCPs altogether cover about I° of longitude （124°E-125°E） in width and 2° of lati- tude （37.5°N-39.5°N） in length. In November, the SCP separates from the Jangsan Cape and forms a closed, isolated, and approxi- mately circular cold patch in the central NYS. From May to October, the upweUing that leads to the formation of the SCP is mainly triggered by the headland residual current, wind field, climbing movement of the current and secondary circulation at the tide front. In November, cyclonic circulation in the NYS is primarily responsible for generating the upwelling that leads to the formation of the closed and isolated SCE展开更多
文摘With the development of mobile technology, Internet and GIS, LBS plays an important role in various applications. From the perspective of LBS, it is one of the main tasks of matching 3-dimensional spatial-temporal trajectories. We present an interpoiation based Modified Hausdorff Distance algorithm for 3-dimensional spatial-temporal Trajectory Matching （IMHD-ST）. It adopts interpolation algorithm to shield the impact to the distance between trajectories due to different position updating porices, sampling granularity, initial position and so on in Moving Object Database （MOD）. Besides, it uses MHD to deal with the implicit spatial information and structural information of weighted position updating points in various trajectories and reflects the discrepancy of moving results through the spatial distance between trajectories. In addition, it adopts temporal distance corresponding to the spatial distance between trajectories to reflect the differences including direction, speed and so on during moving process. The experimental results show that the algorithrn can reflect the trajectory similarity between 3-dimensional mobile objects more correctly, accurately and robustly.
基金supported by the National Natural Science Foundation of China (No.41276041)the NSFC–Shandong Joint Fund for Marine Science Research Centers (No.U1406404)
文摘Ten years （from 2005 to 2014） of satellite sea surface temperature （SST） data from the Advanced Very High Resolution Radiometer （AVHRR） are analyzed to reveal the monthly changes in surface cold patches （SCPs） in the main areas of the Northern Yellow Sea （NYS）. The Canny edge detection algorithm is used to identify the edges of the patches. The monthly changes are de- scribed in terms of location, temperature and area. The inter-annual variations, including changes in the location and area of the SCPs from 2010 to 2014, are briefly discussed. The formation mechanisms of the SCPs in different periods are systematically analyzed using both in situ data and numerical simulation. The results show that from May to October, the location and area of the SCPs re- main stable, with a north-south orientation. The SCPs altogether cover about I° of longitude （124°E-125°E） in width and 2° of lati- tude （37.5°N-39.5°N） in length. In November, the SCP separates from the Jangsan Cape and forms a closed, isolated, and approxi- mately circular cold patch in the central NYS. From May to October, the upweUing that leads to the formation of the SCP is mainly triggered by the headland residual current, wind field, climbing movement of the current and secondary circulation at the tide front. In November, cyclonic circulation in the NYS is primarily responsible for generating the upwelling that leads to the formation of the closed and isolated SCE
