This research aims to elucidate the navigational situation of ships during the massive tsunami that occurred in the Tohoku district of Japan on March 11,2011. In particular, it focuses on the time the massive tsunami ...This research aims to elucidate the navigational situation of ships during the massive tsunami that occurred in the Tohoku district of Japan on March 11,2011. In particular, it focuses on the time the massive tsunami encountered ships. AIS （automatic identification system）, which is required to be fitted aboard large ships for identifying and locating vessels, was used for the analysis of the navigational status of ships. It was confirmed that a group of ships sailing off the coast suddenly changed course. It was also verified that the ships had been struck by the tsunami, and the time of the strike was identified. The novelty and importance of this research are as follows. First, the behaviour of many ships that encountered the massive tsunami was clarified. There are no earlier instances of simultaneous and detailed recording of the behaviour of many ships encountering a massive tsunami. Second, the movement of the ships that encountered the tsunami was analysed, and the time of the maximum wave of the tsunami was verified. The research presents, for the first time in ship history, the status of a ship at the time of a tsunami using objective navigational data.展开更多
To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle＇s （AUV） motion controller, a six-degree of freedom （6-DOF） dynamic model for AUV controlled by thruster an...To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle＇s （AUV） motion controller, a six-degree of freedom （6-DOF） dynamic model for AUV controlled by thruster and fins with appendages is examined. Based on the dynamic model, a simulation system for the AUV＇s motion is established. The different kinds of typical motions are simulated to analyze the motion performance and the maneuverability of the AUV. In order to evaluate the influences of appendages on the motion performance of the AUV, simulations of the AUV with and without appendages are performed and compared. The results demonstrate the AUV has good maneuverability with and without appendages.展开更多
文摘This research aims to elucidate the navigational situation of ships during the massive tsunami that occurred in the Tohoku district of Japan on March 11,2011. In particular, it focuses on the time the massive tsunami encountered ships. AIS （automatic identification system）, which is required to be fitted aboard large ships for identifying and locating vessels, was used for the analysis of the navigational status of ships. It was confirmed that a group of ships sailing off the coast suddenly changed course. It was also verified that the ships had been struck by the tsunami, and the time of the strike was identified. The novelty and importance of this research are as follows. First, the behaviour of many ships that encountered the massive tsunami was clarified. There are no earlier instances of simultaneous and detailed recording of the behaviour of many ships encountering a massive tsunami. Second, the movement of the ships that encountered the tsunami was analysed, and the time of the maximum wave of the tsunami was verified. The research presents, for the first time in ship history, the status of a ship at the time of a tsunami using objective navigational data.
基金Supported by the National Natural Science Foundation of China under Grant No.50909025
文摘To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle＇s （AUV） motion controller, a six-degree of freedom （6-DOF） dynamic model for AUV controlled by thruster and fins with appendages is examined. Based on the dynamic model, a simulation system for the AUV＇s motion is established. The different kinds of typical motions are simulated to analyze the motion performance and the maneuverability of the AUV. In order to evaluate the influences of appendages on the motion performance of the AUV, simulations of the AUV with and without appendages are performed and compared. The results demonstrate the AUV has good maneuverability with and without appendages.
