This paper extends the adaptive moving mesh method developed by Tang and Tang[36]to two-dimensional(2D)relativistic hydrodynamic(RHD)equations.The algorithm consists of two“independent”parts:the time evolution of th...This paper extends the adaptive moving mesh method developed by Tang and Tang[36]to two-dimensional(2D)relativistic hydrodynamic(RHD)equations.The algorithm consists of two“independent”parts:the time evolution of the RHD equations and the(static)mesh iteration redistribution.In the first part,the RHD equations are discretized by using a high resolution finite volume scheme on the fixed but nonuniform meshes without the full characteristic decomposition of the governing equations.The second part is an iterative procedure.In each iteration,the mesh points are first redistributed,and then the cell averages of the conservative variables are remapped onto the new mesh in a conservative way.Several numerical examples are given to demonstrate the accuracy and effectiveness of the proposed method.展开更多
A mutual information-based non-rigid medical image registration algorithm is presented. An approximate function of Hanning windowed sinc is used as kernel function of partial volume (PV) interpolation to estimate the ...A mutual information-based non-rigid medical image registration algorithm is presented. An approximate function of Hanning windowed sinc is used as kernel function of partial volume (PV) interpolation to estimate the joint histogram, which is the key to calculating the mutual information. And a new method is proposed to compute the gradient of mutual information with respect to the model parameters. The transformation of object is modeled by a free-form deformation (FFD) based on B-splines. The experiments on 3D synthetic and real image data show that the algorithm can converge at the global optimum and restrain the emergency of local extreme.展开更多
体视化技术主要研究包含物体内部信息的体数据的表示、变换、操作和显示等。土壤中元素空间分布的体视化对土壤中元素的空间分布规律及其污染评价、预测具有重要意义。对于理解土壤数据中蕴涵的土壤学信息,体视化比使用一组二维切片表...体视化技术主要研究包含物体内部信息的体数据的表示、变换、操作和显示等。土壤中元素空间分布的体视化对土壤中元素的空间分布规律及其污染评价、预测具有重要意义。对于理解土壤数据中蕴涵的土壤学信息,体视化比使用一组二维切片表示三维数据更自然、更清晰。文中基于Visual Studio 2005开发平台使用C#语言,引入三维可视化类库VTK,采用Kriging插值方法,实现了土壤中元素空间分布的体视化、三维交互以及任意剖切,同时给出了合肥市土壤的应用实例。展开更多
基金supported by the National Natural Science Foundation of China(No.10925101,10828101)the Program for New Century Excellent Talents in University(NCET-07-0022)and the Doctoral Program of Education Ministry of China(No.20070001036).
文摘This paper extends the adaptive moving mesh method developed by Tang and Tang[36]to two-dimensional(2D)relativistic hydrodynamic(RHD)equations.The algorithm consists of two“independent”parts:the time evolution of the RHD equations and the(static)mesh iteration redistribution.In the first part,the RHD equations are discretized by using a high resolution finite volume scheme on the fixed but nonuniform meshes without the full characteristic decomposition of the governing equations.The second part is an iterative procedure.In each iteration,the mesh points are first redistributed,and then the cell averages of the conservative variables are remapped onto the new mesh in a conservative way.Several numerical examples are given to demonstrate the accuracy and effectiveness of the proposed method.
基金Supported bythe National Basic Research Programof China ("973"Program) (No2003CB716103)Key Project of Shanghai Scienceand Technology Committee(No05DZ19509)
文摘A mutual information-based non-rigid medical image registration algorithm is presented. An approximate function of Hanning windowed sinc is used as kernel function of partial volume (PV) interpolation to estimate the joint histogram, which is the key to calculating the mutual information. And a new method is proposed to compute the gradient of mutual information with respect to the model parameters. The transformation of object is modeled by a free-form deformation (FFD) based on B-splines. The experiments on 3D synthetic and real image data show that the algorithm can converge at the global optimum and restrain the emergency of local extreme.
文摘体视化技术主要研究包含物体内部信息的体数据的表示、变换、操作和显示等。土壤中元素空间分布的体视化对土壤中元素的空间分布规律及其污染评价、预测具有重要意义。对于理解土壤数据中蕴涵的土壤学信息,体视化比使用一组二维切片表示三维数据更自然、更清晰。文中基于Visual Studio 2005开发平台使用C#语言,引入三维可视化类库VTK,采用Kriging插值方法,实现了土壤中元素空间分布的体视化、三维交互以及任意剖切,同时给出了合肥市土壤的应用实例。
