The shortcomings of an adaptive Sage filter are analyzed in this paper.An improved adaptive Sage filter is developed by using a weighted average quadratic form of the historical residuals of observations and predicted...The shortcomings of an adaptive Sage filter are analyzed in this paper.An improved adaptive Sage filter is developed by using a weighted average quadratic form of the historical residuals of observations and predicted states to evaluate the covariance matrices of observations and dynamic model errors at the present epoch.The weight function is constructed based on the variances of observational residuals or predicted state residuals and the space distance between the previous and the present epoch.In order to balance the contributions of the measurements and the dynamic model information,an adaptive factor is applied by using a two-segment function and predicted state discrepancy statistics.Two applications,orbit determination of a maneuvered GEO satellite and GPS kinematic positioning,are conducted to verify the performance of the proposed method.展开更多
Self-assembly of nanocrystals can not only lead to a better understanding of inter-particle acting force, but also enable rational building of complex and functional materials for future nanodevices. Here by utilizing...Self-assembly of nanocrystals can not only lead to a better understanding of inter-particle acting force, but also enable rational building of complex and functional materials for future nanodevices. Here by utilizing polyvinylpyrrolidone （PVP） as the as capping and structure directing agents, hierarchical Mn304 architectures involving coil-like nanorings, hexagonal nanoframes, and nanodisks are conveniently synthesized by a one-pot solution method. The sophisticated assemblies are proven to be me- diated by the PVP soft templates formed at varied concentrations. The driving forces of self-assembled complex nanostructures and the unique role of PVP concentration are discussed. Magnetic properties of the as assembled Mn3O4 rings are also studied by a SQUID system, which shows the typical side effect of Curie temperature.展开更多
基金supported by the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No.2007B51)the National Natural Science Foundation of China (Grant Nos.41174008 and 41020144004)+1 种基金China Postdoctoral Science Foundation (Grant Nos.20080430148 and 200902444)the Junior Scientist Exchange Program between the China Scholarship Council and the Helmholtz Association of German Research Centers Council
文摘The shortcomings of an adaptive Sage filter are analyzed in this paper.An improved adaptive Sage filter is developed by using a weighted average quadratic form of the historical residuals of observations and predicted states to evaluate the covariance matrices of observations and dynamic model errors at the present epoch.The weight function is constructed based on the variances of observational residuals or predicted state residuals and the space distance between the previous and the present epoch.In order to balance the contributions of the measurements and the dynamic model information,an adaptive factor is applied by using a two-segment function and predicted state discrepancy statistics.Two applications,orbit determination of a maneuvered GEO satellite and GPS kinematic positioning,are conducted to verify the performance of the proposed method.
基金supported by the National Natural Science Foundation of China (Grant Nos. 20973019,50725208 and 50902007)the Fundamental Research Funds for the Central Universities (Grant No. YMF1002016)
文摘Self-assembly of nanocrystals can not only lead to a better understanding of inter-particle acting force, but also enable rational building of complex and functional materials for future nanodevices. Here by utilizing polyvinylpyrrolidone （PVP） as the as capping and structure directing agents, hierarchical Mn304 architectures involving coil-like nanorings, hexagonal nanoframes, and nanodisks are conveniently synthesized by a one-pot solution method. The sophisticated assemblies are proven to be me- diated by the PVP soft templates formed at varied concentrations. The driving forces of self-assembled complex nanostructures and the unique role of PVP concentration are discussed. Magnetic properties of the as assembled Mn3O4 rings are also studied by a SQUID system, which shows the typical side effect of Curie temperature.
