为进一步研究适用于风云三号(FY-3)土壤水分遥感产品的降尺度方法,分别将基于不规则三角形特征空间的Chauhan模型与Piles模型等土壤水分降尺度方法应用于低分辨率风云三号B星(FY-3B)土壤水分产品,得到高分辨率土壤水分,结合地面观测数据...为进一步研究适用于风云三号(FY-3)土壤水分遥感产品的降尺度方法,分别将基于不规则三角形特征空间的Chauhan模型与Piles模型等土壤水分降尺度方法应用于低分辨率风云三号B星(FY-3B)土壤水分产品,得到高分辨率土壤水分,结合地面观测数据,对不同降尺度方法进行对比分析。结果表明,不同降尺度方法后土壤水分与FY-3B土壤水分空间分布一致,其中,Chauhan模型降尺度后土壤水分与地面观测值相关性最好,均方根误差RMSE低于0.08 cm 3·cm-1,FY-3B土壤水分产品本身的精度以及降尺度模型是影响降尺度结果的重要因素。展开更多
In this paper, we mainly pay attention to the weighted sampling and reconstruction algorithm in lattice-invariant signal spaces. We give the reconstruction formula in lattice-invariant signal spaces, which is a genera...In this paper, we mainly pay attention to the weighted sampling and reconstruction algorithm in lattice-invariant signal spaces. We give the reconstruction formula in lattice-invariant signal spaces, which is a generalization of former results in shift-invariant signal spaces. That is, we generalize and improve Aldroubi, Groechenig and Chen＇s results, respectively. So we obtain a general reconstruction algorithm in lattice-invariant signal spaces, which the signal spaces is sufficiently large to accommodate a large number of possible models. They are maybe useful for signal processing and communication theory.展开更多
The chaotic nonlinear time series method is applied to analyze the sliver irregularity in textile processing.Because it unifies the system's determinacy and randomness,it seems more adaptive to describe the sliver...The chaotic nonlinear time series method is applied to analyze the sliver irregularity in textile processing.Because it unifies the system's determinacy and randomness,it seems more adaptive to describe the sliver irregularity than conventional methods.Firstly,the chaos character,i.e.fractal dimension,positive Lyapunov exponent,and state space parameters,including time delay and reconstruction dimension,are calculated respectively.As a result,a positive Lyapunov exponent and a fractal dimension are obtained,which demonstrates that the system is chaotic in fact.Secondly,both local linear forecast and global forecast models based on the reconstructed state are adopted to predict a segment part of the sliver irregularity series,which proves the validity of this analysis.Therefore,the sliver irregularity series shows the evidence of chaotic phenomena,and thus laying the theoretical foundation for analyzing and modeling the sliver irregularity series by applying the chaos theory,and providing a new way to understand the complexity of the sliver irregularity much better.展开更多
文摘为进一步研究适用于风云三号(FY-3)土壤水分遥感产品的降尺度方法,分别将基于不规则三角形特征空间的Chauhan模型与Piles模型等土壤水分降尺度方法应用于低分辨率风云三号B星(FY-3B)土壤水分产品,得到高分辨率土壤水分,结合地面观测数据,对不同降尺度方法进行对比分析。结果表明,不同降尺度方法后土壤水分与FY-3B土壤水分空间分布一致,其中,Chauhan模型降尺度后土壤水分与地面观测值相关性最好,均方根误差RMSE低于0.08 cm 3·cm-1,FY-3B土壤水分产品本身的精度以及降尺度模型是影响降尺度结果的重要因素。
文摘In this paper, we mainly pay attention to the weighted sampling and reconstruction algorithm in lattice-invariant signal spaces. We give the reconstruction formula in lattice-invariant signal spaces, which is a generalization of former results in shift-invariant signal spaces. That is, we generalize and improve Aldroubi, Groechenig and Chen＇s results, respectively. So we obtain a general reconstruction algorithm in lattice-invariant signal spaces, which the signal spaces is sufficiently large to accommodate a large number of possible models. They are maybe useful for signal processing and communication theory.
文摘The chaotic nonlinear time series method is applied to analyze the sliver irregularity in textile processing.Because it unifies the system's determinacy and randomness,it seems more adaptive to describe the sliver irregularity than conventional methods.Firstly,the chaos character,i.e.fractal dimension,positive Lyapunov exponent,and state space parameters,including time delay and reconstruction dimension,are calculated respectively.As a result,a positive Lyapunov exponent and a fractal dimension are obtained,which demonstrates that the system is chaotic in fact.Secondly,both local linear forecast and global forecast models based on the reconstructed state are adopted to predict a segment part of the sliver irregularity series,which proves the validity of this analysis.Therefore,the sliver irregularity series shows the evidence of chaotic phenomena,and thus laying the theoretical foundation for analyzing and modeling the sliver irregularity series by applying the chaos theory,and providing a new way to understand the complexity of the sliver irregularity much better.
