In this paper, Laplace decomposition method (LDM) and Pade approximant are employed to find approximate solutions for the Whitham-Broer-Kaup shallow water model, the coupled nonlinear reaction diffusion equations and ...In this paper, Laplace decomposition method (LDM) and Pade approximant are employed to find approximate solutions for the Whitham-Broer-Kaup shallow water model, the coupled nonlinear reaction diffusion equations and the system of Hirota-Satsuma coupled KdV. In addition, the results obtained from Laplace decomposition method (LDM) and Pade approximant are compared with corresponding exact analytical solutions.展开更多
A barrier option valuation model with stochastic barrier which was regarded as the main feature of the model was developed under the Hull-White interest rate model.The purpose of this study was to deal with the stocha...A barrier option valuation model with stochastic barrier which was regarded as the main feature of the model was developed under the Hull-White interest rate model.The purpose of this study was to deal with the stochastic barrier by means of partial differential equation methods and then derive the exact analytical solutions of the barrier options.Furthermore,a numerical example was given to show how to apply this model to pricing one structured product in realistic market.Therefore,this model can provide new insight for future research on structured products involving barrier options.展开更多
In this work we consider the problem of shape reconstruction from an unorganized data set which has many important applications in medical imaging, scientific computing, reverse engineering and geometric modelling. Th...In this work we consider the problem of shape reconstruction from an unorganized data set which has many important applications in medical imaging, scientific computing, reverse engineering and geometric modelling. The reconstructed surface is obtained by continuously deforming an initial surface following the Partial Differential Equation (PDE)-based diffusion model derived by a minimal volume-like variational formulation. The evolution is driven both by the distance from the data set and by the curvature analytically computed by it. The distance function is computed by implicit local interpolants defined in terms of radial basis functions. Space discretization of the PDE model is obtained by finite co-volume schemes and semi-implicit approach is used in time/scale. The use of a level set method for the numerical computation of the surface reconstruction allows us to handle complex geometry and even changing topology,without the need of user-interaction. Numerical examples demonstrate the ability of the proposed method to produce high quality reconstructions. Moreover, we show the effectiveness of the new approach to solve hole filling problems and Boolean operations between different data sets.展开更多
为了探究金融聚集对我国生猪产业高质量发展的影响及其空间溢出效应,本研究基于2013—2021年我国30个省份(自治区、直辖市,不包括西藏及港澳台地区)的面板数据,运用熵值法和TOPSIS(technique for order preference by similarity to an ...为了探究金融聚集对我国生猪产业高质量发展的影响及其空间溢出效应,本研究基于2013—2021年我国30个省份(自治区、直辖市,不包括西藏及港澳台地区)的面板数据,运用熵值法和TOPSIS(technique for order preference by similarity to an ideal solution)方法对我国各省份(自治区、直辖市)生猪产业高质量发展水平进行评价,并采用普通面板回归模型及空间计量模型分析金融聚集对生猪产业高质量发展的影响及空间溢出效应。结果表明:采用普通面板回归模型及空间计量模型分析时,金融聚集均在1%水平上显著正向促进生猪产业高质量发展,且权重矩阵(W)×金融聚集的估计系数为0.055,在5%水平上对生猪产业高质量发展存在显著正向的空间溢出效应。空间溢出效应分解发现,本省份(自治区、直辖市)及邻近省份(自治区、直辖市)的金融聚集在1%水平上显著促进了本省份(自治区、直辖市)的生猪产业高质量发展。通过稳健性检验及内生性检验发现结果稳健、可靠。鉴于此,本研究提出提升各省份(自治区、直辖市)金融聚集度,积极破除各省份(自治区、直辖市)间的金融壁垒,并充分激发金融在生猪产业创新发展、绿色转型中的积极作用等对策建议。展开更多
目的建立银杏叶片体外溶出度与空间分布均匀度评价方法,探究体外溶出行为对空间分布均匀度的影响,实现银杏叶片质量控制。方法首先,采用《中国药典》2020年版方法完成银杏叶片溶出度测定,并基于模型依赖法对银杏叶片体外溶出特性进行评...目的建立银杏叶片体外溶出度与空间分布均匀度评价方法,探究体外溶出行为对空间分布均匀度的影响,实现银杏叶片质量控制。方法首先,采用《中国药典》2020年版方法完成银杏叶片溶出度测定,并基于模型依赖法对银杏叶片体外溶出特性进行评价;其次,通过对称参数图像分析法(symetry parameterimage analysis,SPIA)和均匀度百分比指数法(percentage of homogeneity,H%)对银杏叶片空间分布均匀度进行评价;最后,建立偏最小二乘(partial least square,PLS)和标准正则变换(standardized normal variate,SVR)模型对银杏叶片体外溶出度与活性药物成分(active pharmaceutical ingredient,API)空间分布均匀度进行关联辨识研究。结果银杏叶片在45 min内完全溶出且累积溶出率大于70%,且不同批次溶出行为存在差异;银杏叶片API空间分布均匀度范围为64.09%~76.54%,其中5个批次银杏叶片质量差异较大;银杏叶片体外溶出度与API空间分布均匀度PLS和SVR模型R^(2)值分别为0.1110和0.2540,两者没有相关性。结论所建方法可客观评价中药固体制剂的溶出度与空间分布均匀度,实现银杏叶片与空间分布均匀度的关联辨识研究,为银杏叶片制造过程质量控制及提升提供了方向。展开更多
In this paper, we study the fractional-order biological population models （FI3PMs） with Malthusian~ Verhulst, and porous media laws. The fractional derivative is defined in Caputo sense. The optimal homotopy asympto...In this paper, we study the fractional-order biological population models （FI3PMs） with Malthusian~ Verhulst, and porous media laws. The fractional derivative is defined in Caputo sense. The optimal homotopy asymptotic method （OHAM） for partial differ- ential equations （PDEs） is extended and successfully implemented to solve FBPMs. Third-order approximate solutions are obtained and compared with the exact solutions. The numerical results unveil that the proposed extension in the OHAM for fractional- order differential problems is very effective and simple in computation. The results reveal the effectiveness with high accuracy and extremely efficient to handle most complicated biological population models.展开更多
文摘In this paper, Laplace decomposition method (LDM) and Pade approximant are employed to find approximate solutions for the Whitham-Broer-Kaup shallow water model, the coupled nonlinear reaction diffusion equations and the system of Hirota-Satsuma coupled KdV. In addition, the results obtained from Laplace decomposition method (LDM) and Pade approximant are compared with corresponding exact analytical solutions.
基金National Natural Science Foundations of China(Nos.11471175,11171221)
文摘A barrier option valuation model with stochastic barrier which was regarded as the main feature of the model was developed under the Hull-White interest rate model.The purpose of this study was to deal with the stochastic barrier by means of partial differential equation methods and then derive the exact analytical solutions of the barrier options.Furthermore,a numerical example was given to show how to apply this model to pricing one structured product in realistic market.Therefore,this model can provide new insight for future research on structured products involving barrier options.
基金supported by PRIN-MIUR-Cofin 2006,project,by"Progetti Strategici EF2006"University of Bologna,and by University of Bologna"Funds for selected research topics"
文摘In this work we consider the problem of shape reconstruction from an unorganized data set which has many important applications in medical imaging, scientific computing, reverse engineering and geometric modelling. The reconstructed surface is obtained by continuously deforming an initial surface following the Partial Differential Equation (PDE)-based diffusion model derived by a minimal volume-like variational formulation. The evolution is driven both by the distance from the data set and by the curvature analytically computed by it. The distance function is computed by implicit local interpolants defined in terms of radial basis functions. Space discretization of the PDE model is obtained by finite co-volume schemes and semi-implicit approach is used in time/scale. The use of a level set method for the numerical computation of the surface reconstruction allows us to handle complex geometry and even changing topology,without the need of user-interaction. Numerical examples demonstrate the ability of the proposed method to produce high quality reconstructions. Moreover, we show the effectiveness of the new approach to solve hole filling problems and Boolean operations between different data sets.
文摘为了探究金融聚集对我国生猪产业高质量发展的影响及其空间溢出效应,本研究基于2013—2021年我国30个省份(自治区、直辖市,不包括西藏及港澳台地区)的面板数据,运用熵值法和TOPSIS(technique for order preference by similarity to an ideal solution)方法对我国各省份(自治区、直辖市)生猪产业高质量发展水平进行评价,并采用普通面板回归模型及空间计量模型分析金融聚集对生猪产业高质量发展的影响及空间溢出效应。结果表明:采用普通面板回归模型及空间计量模型分析时,金融聚集均在1%水平上显著正向促进生猪产业高质量发展,且权重矩阵(W)×金融聚集的估计系数为0.055,在5%水平上对生猪产业高质量发展存在显著正向的空间溢出效应。空间溢出效应分解发现,本省份(自治区、直辖市)及邻近省份(自治区、直辖市)的金融聚集在1%水平上显著促进了本省份(自治区、直辖市)的生猪产业高质量发展。通过稳健性检验及内生性检验发现结果稳健、可靠。鉴于此,本研究提出提升各省份(自治区、直辖市)金融聚集度,积极破除各省份(自治区、直辖市)间的金融壁垒,并充分激发金融在生猪产业创新发展、绿色转型中的积极作用等对策建议。
文摘目的建立银杏叶片体外溶出度与空间分布均匀度评价方法,探究体外溶出行为对空间分布均匀度的影响,实现银杏叶片质量控制。方法首先,采用《中国药典》2020年版方法完成银杏叶片溶出度测定,并基于模型依赖法对银杏叶片体外溶出特性进行评价;其次,通过对称参数图像分析法(symetry parameterimage analysis,SPIA)和均匀度百分比指数法(percentage of homogeneity,H%)对银杏叶片空间分布均匀度进行评价;最后,建立偏最小二乘(partial least square,PLS)和标准正则变换(standardized normal variate,SVR)模型对银杏叶片体外溶出度与活性药物成分(active pharmaceutical ingredient,API)空间分布均匀度进行关联辨识研究。结果银杏叶片在45 min内完全溶出且累积溶出率大于70%,且不同批次溶出行为存在差异;银杏叶片API空间分布均匀度范围为64.09%~76.54%,其中5个批次银杏叶片质量差异较大;银杏叶片体外溶出度与API空间分布均匀度PLS和SVR模型R^(2)值分别为0.1110和0.2540,两者没有相关性。结论所建方法可客观评价中药固体制剂的溶出度与空间分布均匀度,实现银杏叶片与空间分布均匀度的关联辨识研究,为银杏叶片制造过程质量控制及提升提供了方向。
文摘In this paper, we study the fractional-order biological population models （FI3PMs） with Malthusian~ Verhulst, and porous media laws. The fractional derivative is defined in Caputo sense. The optimal homotopy asymptotic method （OHAM） for partial differ- ential equations （PDEs） is extended and successfully implemented to solve FBPMs. Third-order approximate solutions are obtained and compared with the exact solutions. The numerical results unveil that the proposed extension in the OHAM for fractional- order differential problems is very effective and simple in computation. The results reveal the effectiveness with high accuracy and extremely efficient to handle most complicated biological population models.
