热带气旋路径预报的MCE客观综合决策方法研究

采用MCE(Multi CriteriaEvaluation)方法 ,在台风路径客观综合预报方法研究与业务实验中 ,根据多家预报的主要结果进行综合评估分析 ,提出最佳客观综合预报结果以供决策者及预报员参照。取得初步结果 :(1)对 9711号台风进行了MCE客观综合决策方法的预报试验。结果表明 ,对于 9711号台风生命史中几个关键点的预报 ,即登陆预报、台风转向北上预报及出海转向预报等以及全程预报 ,MCE方法取得较佳预报结果。 (2 )在综合平台上对近 10年的疑难路径台风和 2 0 0 0年全年台风进行了MCE方法试验及多种预报结论的对比分析研究。MCE方法预报误差检验结果较好。 (3 )所提出的模拟预报员预报思维的联想智能模拟方法 ,以及可操作综合预警平台 ,为台风路径预报 ,包括分析、学习、回忆、对比、推理、联想直到形成综合预报结论提供了一个十分有用的工具。 (4 )

Correlation Functions of an Autonomous Stochastic System with Nonlinear Time Delays

The auto-correlation function and the cross-correlation of an autonomous stochastic system with nonlinear time-delayed feedback are investigated by using the stochastic simulation method. There are prominent differences be- tween the roles of quadratic time-delayed feedback and cubic time-delayed feedback on the correlations of an autonomous stochastic system. Under quadratic time-delayed feedback, the nonlinear time delay fails to improve the noisy state of the autonomous stochastic system, the auto-correlation decreases monotonously to zero, and the cross-correlation increases monotonously to zero with the decay time. Under cubic time-delayed feedback, the nonlinear time delay can improve the noisy state of the autonomous stochastic system; the auto-correlation and the cross-correlation show periodical oscillation and attenuation, finally tending to zero with the decay time. Comparing the correlations of the system between with nonfinear time-delayed feedback and linear time-delayed feedback, we find that nonlinear time-delayed feedback lowers the correlation strength of the autonomous stochastic system.