This research develops a comparative study between different multiplicative weights that are assigned to the covariance matrix that represents the background error in two hybrid assimilation schemes: 3DEnVAR and 4DEnV...This research develops a comparative study between different multiplicative weights that are assigned to the covariance matrix that represents the background error in two hybrid assimilation schemes: 3DEnVAR and 4DEnVAR. These weights are distributed between the static and time-invariant matrix and the matrix generated from the perturbations of a previous ensemble. The assigned values are 25%, 50%, and 75%, always having as a reference the ensemble matrix. The experiments are applied to the short-range Prediction System (SisPI) that works operationally at the Institute of Meteorology. The impact of Tropical Storm Eta on November 7 and 8, 2020 was selected as a study case. The results suggest that by giving the main weight to the ensemble matrix more realistic solutions are achieved because it shows a better representation of the synoptic flow. On the other hand, it is observed that 3DEnVAR method is more sensitive to multiplicative weight change of the first guess. More realistic results are obtained with 50% and 75% relations with 4DEnVAR method, whereas with 3DEnVAR a weight of 75% for the ensemble matrix is required.展开更多
Further developments in the hybrid multiscale energy density method are proposed on the basis of our previous papers. The key points are as follows. （i） The theoretical method for the determination of the weight par...Further developments in the hybrid multiscale energy density method are proposed on the basis of our previous papers. The key points are as follows. （i） The theoretical method for the determination of the weight parameter in the energy coupling equation of transition region in multiscale model is given via constructing underdetermined equations. （ii） By applying the developed mathematical method, the weight parameters have been given and used to treat some problems in homogeneous charge density systems, which ,＇ire directly related with multiscale science. （iii） A theoretical algorithm has also been presented for treating non-homogeneous systems of charge density. The key to the theoretical computational methods is the decomposition of the electrostatic energy in the total energy of density functional theory for probing the spanning characteristic at atomic scale, layer by layer, by which the choice of chemical elements and the defect complex effect can be understood deeply. （iv） The＇numerical computational program and design have also been presented.展开更多
目的优化羌芩颗粒的干法制粒成型工艺,并对颗粒进行质量控制。方法以颗粒成型率、吸湿率(H)、溶化率和休止角(α)的综合评分为指标,采用Box-Behnken设计-响应面法结合AHP-CRITIC混合加权法建立干法制粒关键工艺参数(critical process pa...目的优化羌芩颗粒的干法制粒成型工艺,并对颗粒进行质量控制。方法以颗粒成型率、吸湿率(H)、溶化率和休止角(α)的综合评分为指标,采用Box-Behnken设计-响应面法结合AHP-CRITIC混合加权法建立干法制粒关键工艺参数(critical process parameters,CPPs)和关键质量属性(critical quality attributes,CQAs)的数学模型,通过该模型构建干法制粒的设计空间,并进行蒙特卡洛验证。采用单形格子设计对满足制粒工艺的甘露醇、麦芽糊精、糊精进行辅料配比筛选,确定最佳辅料配比并进行验证。采用粉体学评价方法对羌芩颗粒各项物理质量属性指标进行综合表征,建立由松装密度(Da)、振实密度(Dc)、α、豪斯纳比(IH)、H、含水量(HR)、颗粒间孔隙率(Ie)、卡尔指数(IC)、比表面积(SSA)、粒径<50μm百分比(Pf)、分布宽度(span)、分布范围(width)、均匀性(HG)共13个二级物理质量指标构成的颗粒物理指纹图谱,评价不同批次间颗粒质量的一致性。结果羌芩颗粒干法制粒CPPs的设计空间为送料频率37~45 Hz,滚轮频率8.0~11.8 Hz,滚轮压力40~50 kg/cm^(2)。最佳辅料配比为甘露醇86%,糊精14%。15批样品物理指纹图谱的相似度均大于0.95。结论优选后的羌芩颗粒干法制粒成型工艺稳定可行,中间体物理性质质量评价科学合理,可为中药新药的开发及工业化放大生产提供参考。展开更多
A total variation diminishing-weighted average flux （TVD-WAF）-based hybrid numerical scheme for the enhanced version of nonlinearly dispersive Boussinesq-type equations was developed. The one-dimensional governing e...A total variation diminishing-weighted average flux （TVD-WAF）-based hybrid numerical scheme for the enhanced version of nonlinearly dispersive Boussinesq-type equations was developed. The one-dimensional governing equations were rewritten in the conservative form and then discretized on a uniform grid. The finite volume method was used to discretize the flux term while the remaining terms were approximated with the finite difference method. The second-order TVD-WAF method was employed in conjunction with the Harten-Lax-van Leer （HLL） Riemann solver to calculate the numerical flux, and the variables at the cell interface for the local Riemann problem were reconstructed via the fourth- order monotone upstream-centered scheme for conservation laws （MUSCL）. The time marching scheme based on the third-order TVD Runge- Kutta method was used to obtain numerical solutions. The model was validated through a series of numerical tests, in which wave breaking and a moving shoreline were treated. The good agreement between the computed results, documented analytical solutions, and experimental data demonstrates the correct discretization of the governing equations and high accuracy of the proposed scheme, and also conforms the advantages of the proposed shock-capturing scheme for the enhanced version of the Boussinesq model, including the convenience in the treatment of wave breaking and moving shorelines and without the need for a numerical filter.展开更多
从智能效益、经济效益、绿色效益和安全效益4个维度构建了智能变电站建设项目综合效益评价指标体系。其中评价指标的属性值为包含语言变量、精确数和正态分布区间数的混合信息。在此基础上,基于直觉模糊集和组合赋权法,构建了一种面向...从智能效益、经济效益、绿色效益和安全效益4个维度构建了智能变电站建设项目综合效益评价指标体系。其中评价指标的属性值为包含语言变量、精确数和正态分布区间数的混合信息。在此基础上,基于直觉模糊集和组合赋权法,构建了一种面向混合信息的混合多准则决策模型。该模型首先用不同的转换规则将混合信息一致化为直觉模糊数的形式。然后采用基于合作博弈模型的群组决策特征根法-直觉模糊熵(group eigenvalue method intuitionistic fuzzy entropy,GEM-IFE)组合赋权法来确定指标的综合权重,并基于直觉模糊集建立了改进的逼近理想解排序方法(technique for order preference by similarity to ideal solution,TOPSIS)评价模型。最后,以10个智能变电站建设项目作为案例进行分析,并将该模型与传统的TOPSIS方法和单一赋权法进行比较。结果证明该混合多准则决策模型具有良好的鲁棒性。展开更多
文摘This research develops a comparative study between different multiplicative weights that are assigned to the covariance matrix that represents the background error in two hybrid assimilation schemes: 3DEnVAR and 4DEnVAR. These weights are distributed between the static and time-invariant matrix and the matrix generated from the perturbations of a previous ensemble. The assigned values are 25%, 50%, and 75%, always having as a reference the ensemble matrix. The experiments are applied to the short-range Prediction System (SisPI) that works operationally at the Institute of Meteorology. The impact of Tropical Storm Eta on November 7 and 8, 2020 was selected as a study case. The results suggest that by giving the main weight to the ensemble matrix more realistic solutions are achieved because it shows a better representation of the synoptic flow. On the other hand, it is observed that 3DEnVAR method is more sensitive to multiplicative weight change of the first guess. More realistic results are obtained with 50% and 75% relations with 4DEnVAR method, whereas with 3DEnVAR a weight of 75% for the ensemble matrix is required.
基金supported by the National Basic Research Program of China(Grant No.2011CB606402)the National Natural Science Foundation of China(Grant No.51071091)
文摘Further developments in the hybrid multiscale energy density method are proposed on the basis of our previous papers. The key points are as follows. （i） The theoretical method for the determination of the weight parameter in the energy coupling equation of transition region in multiscale model is given via constructing underdetermined equations. （ii） By applying the developed mathematical method, the weight parameters have been given and used to treat some problems in homogeneous charge density systems, which ,＇ire directly related with multiscale science. （iii） A theoretical algorithm has also been presented for treating non-homogeneous systems of charge density. The key to the theoretical computational methods is the decomposition of the electrostatic energy in the total energy of density functional theory for probing the spanning characteristic at atomic scale, layer by layer, by which the choice of chemical elements and the defect complex effect can be understood deeply. （iv） The＇numerical computational program and design have also been presented.
基金supported by the National Natural Science Foundation of China(Grant No.51579034)the Open Fund of the Key Laboratory of Ocean Circulation and Waves,Chinese Academy of Sciences(Grant No.KLOCW1502)
文摘A total variation diminishing-weighted average flux （TVD-WAF）-based hybrid numerical scheme for the enhanced version of nonlinearly dispersive Boussinesq-type equations was developed. The one-dimensional governing equations were rewritten in the conservative form and then discretized on a uniform grid. The finite volume method was used to discretize the flux term while the remaining terms were approximated with the finite difference method. The second-order TVD-WAF method was employed in conjunction with the Harten-Lax-van Leer （HLL） Riemann solver to calculate the numerical flux, and the variables at the cell interface for the local Riemann problem were reconstructed via the fourth- order monotone upstream-centered scheme for conservation laws （MUSCL）. The time marching scheme based on the third-order TVD Runge- Kutta method was used to obtain numerical solutions. The model was validated through a series of numerical tests, in which wave breaking and a moving shoreline were treated. The good agreement between the computed results, documented analytical solutions, and experimental data demonstrates the correct discretization of the governing equations and high accuracy of the proposed scheme, and also conforms the advantages of the proposed shock-capturing scheme for the enhanced version of the Boussinesq model, including the convenience in the treatment of wave breaking and moving shorelines and without the need for a numerical filter.
文摘从智能效益、经济效益、绿色效益和安全效益4个维度构建了智能变电站建设项目综合效益评价指标体系。其中评价指标的属性值为包含语言变量、精确数和正态分布区间数的混合信息。在此基础上,基于直觉模糊集和组合赋权法,构建了一种面向混合信息的混合多准则决策模型。该模型首先用不同的转换规则将混合信息一致化为直觉模糊数的形式。然后采用基于合作博弈模型的群组决策特征根法-直觉模糊熵(group eigenvalue method intuitionistic fuzzy entropy,GEM-IFE)组合赋权法来确定指标的综合权重,并基于直觉模糊集建立了改进的逼近理想解排序方法(technique for order preference by similarity to ideal solution,TOPSIS)评价模型。最后,以10个智能变电站建设项目作为案例进行分析,并将该模型与传统的TOPSIS方法和单一赋权法进行比较。结果证明该混合多准则决策模型具有良好的鲁棒性。
