正六边形自聚焦透镜折射率分布研究

针对离子交换实验的定源扩散,提出了一种求解正六边形自聚焦透镜折射率分布的理论模型.并在此基础上采用分离变量法和坐标变换,求得了正六边形自聚焦透镜折射率分布的解析解.通过Matlab对该解析解进行了模拟比较,定性、定量地证明了其正确性.     

Improved interpolation method based on singular spectrum analysis iteration and its application to missing data recovery

A novel interval quartering algorithm （IQA） is proposed to overcome insufficiency of the conventional singular spectrum analysis （SSA） iterative interpolation for selecting parameters including the number of the principal components and the embedding dimension. Based on the improved SSA iterative interpolation, interpolated test and comparative analysis are carried out to the outgoing longwave radiation daily data. The results show that IQA can find globally optimal parameters to the error curve with local oscillation, and has advantage of fast computing speed. The improved interpolation method is effective in the interpolation of missing data.