With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation wind...With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation window period is crucial for navigating in the Arctic route,which is of great significance to the selection of the route and the optimization of navigation.This paper introduces the establishment of a risk index system,determination of risk index weight,establishment of a risk evaluation model,and prediction algorithm for the window period.In addition,data sources of both environmental factors and ship factors are introducted,and their shortcomings are analyzed,followed by introduction of various methods involved in window prediction and analysis of their advantages and disadvantages.The quantitative risk evaluation and window period algorithm can provide a reference for the research of polar navigation window period prediction.展开更多
The periodic window is researched by means of the symbolic dynamics and formal language.Firstly,the proper sampling period is taken and the orbital points of periodic motion are obtained through Poincar6 mapping.Secon...The periodic window is researched by means of the symbolic dynamics and formal language.Firstly,the proper sampling period is taken and the orbital points of periodic motion are obtained through Poincar6 mapping.Secondly,according to the method of symbolic dynamics of one-dimensional discrete mapping,the symbolic sequence describing the periodic orbit is obtained.Finally,based on the symbolic sequence,the corresponding model of minimal finite automation is constructed and the entropy is obtained by calculating the maximal eigenvalue of Stefan matrix.The results show that the orbits in periodic windows can be strictly marked by using the method of symbolic dynamics,thus a foundation for control of switching between target orbits is provided.展开更多
The periodic windows in weakly coupled map lattices with both diffusive and gradient couplings are studied. By using the mode analysis method, which reduces the behavior of the coupled systems to a few numbers of inde...The periodic windows in weakly coupled map lattices with both diffusive and gradient couplings are studied. By using the mode analysis method, which reduces the behavior of the coupled systems to a few numbers of independent modes, we theoretically analyze the detailed structures of the periodic windows. We find that the gradient coupling greatly enlarges the width of the periodic windows, compared with the diffusive coupling.展开更多
At present,the AI field is in a golden window period,which provides a historic opportunity for establishing new AI standards.Over the years,sensing enhanced AI technology has constantly developed,promoting the develop...At present,the AI field is in a golden window period,which provides a historic opportunity for establishing new AI standards.Over the years,sensing enhanced AI technology has constantly developed,promoting the development and progress of industries.With the development of new technologies,the demand for standards has become more prominent.The Global Center for Sensing Enhanced AI(GCSEA)is expected to integrate domestic and foreign resources and make joint efforts to promote the development of relevant sensing standards.展开更多
文摘With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation window period is crucial for navigating in the Arctic route,which is of great significance to the selection of the route and the optimization of navigation.This paper introduces the establishment of a risk index system,determination of risk index weight,establishment of a risk evaluation model,and prediction algorithm for the window period.In addition,data sources of both environmental factors and ship factors are introducted,and their shortcomings are analyzed,followed by introduction of various methods involved in window prediction and analysis of their advantages and disadvantages.The quantitative risk evaluation and window period algorithm can provide a reference for the research of polar navigation window period prediction.
基金This project is supported by National Natural Science Foundation of China(No.50075070).
文摘The periodic window is researched by means of the symbolic dynamics and formal language.Firstly,the proper sampling period is taken and the orbital points of periodic motion are obtained through Poincar6 mapping.Secondly,according to the method of symbolic dynamics of one-dimensional discrete mapping,the symbolic sequence describing the periodic orbit is obtained.Finally,based on the symbolic sequence,the corresponding model of minimal finite automation is constructed and the entropy is obtained by calculating the maximal eigenvalue of Stefan matrix.The results show that the orbits in periodic windows can be strictly marked by using the method of symbolic dynamics,thus a foundation for control of switching between target orbits is provided.
基金supported by National Natural Science Foundation of China under Grants Nos.10675161,10405018,and 70571053
文摘The periodic windows in weakly coupled map lattices with both diffusive and gradient couplings are studied. By using the mode analysis method, which reduces the behavior of the coupled systems to a few numbers of independent modes, we theoretically analyze the detailed structures of the periodic windows. We find that the gradient coupling greatly enlarges the width of the periodic windows, compared with the diffusive coupling.
文摘At present,the AI field is in a golden window period,which provides a historic opportunity for establishing new AI standards.Over the years,sensing enhanced AI technology has constantly developed,promoting the development and progress of industries.With the development of new technologies,the demand for standards has become more prominent.The Global Center for Sensing Enhanced AI(GCSEA)is expected to integrate domestic and foreign resources and make joint efforts to promote the development of relevant sensing standards.
