1 Introduction In the United States, the largest groups of acupuncture or traditional Chinese medicine （TCM） practitioners settled and still remain in California and New York, as these two states historically have...1 Introduction In the United States, the largest groups of acupuncture or traditional Chinese medicine （TCM） practitioners settled and still remain in California and New York, as these two states historically have the largest, most concentrated Asian populations. The TCM practitioners originally worked in a legal gray-zone, sometimes even being treated as illegal practitioners by the local governments, since TCM licensing laws did not exist until late 1973[1]. The first legal acupuncture clinic was established in Washington, D.C. in 1972[2], but Nevada was the first state that passed a full practicing law for acupuncture and TCM[3]. Under- standing the legal history of acupuncture in the U.S. will help us to see the road ahead more clearly.展开更多
In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell＇s equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not req...In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell＇s equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not require permittivity averaging so that better accuracy can be achieved. Our numerical results on optical force computation show that the standard FDTD method converges linearly, while the proposed method achieves quadratic convergence and better accuracy.展开更多
In this paper, a locally non-orthogonal overlapping Yee (OY) FDTD method is proposed in order to accurately calculates the optical force on dielectric and dispersive nanoparticles. It extends our previous work to geom...In this paper, a locally non-orthogonal overlapping Yee (OY) FDTD method is proposed in order to accurately calculates the optical force on dielectric and dispersive nanoparticles. It extends our previous work to geometries with sharp corners and dispersive materials. In addition to consistently achieving the smallest errors in comparison to the standard FDTD method, the OY approach is a stable non-orthogonal FDTD method that attains second-order convergence when sharp corners are present.展开更多
Professor Lau is currently Professor, Division of Hepato-Pancreato-Biliary Surgery, Department of Surgery, The Chinese University of Hong Kong; Honoarary Consultant in Hepato-pancreato-biliary Surgery in hospitals und...Professor Lau is currently Professor, Division of Hepato-Pancreato-Biliary Surgery, Department of Surgery, The Chinese University of Hong Kong; Honoarary Consultant in Hepato-pancreato-biliary Surgery in hospitals under the New Territories East Cluster （which includes Prince of Wales Hospital, Alice Ho Miu Ling Nethersole Hospital and North District Hospital） and Honorary Consultant Surgeon to the United Christian Hospital.展开更多
为了解决利用时域有限差分(finite difference timedomain,FDTD)方法实现凸体的电磁散射特性数值计算中,普遍遇到的Yee元胞建模问题,该文提出了关于凸体的一种新的Yee元胞建模方法。其主要思路是利用凸面几何学的理论判断空间任意一点...为了解决利用时域有限差分(finite difference timedomain,FDTD)方法实现凸体的电磁散射特性数值计算中,普遍遇到的Yee元胞建模问题,该文提出了关于凸体的一种新的Yee元胞建模方法。其主要思路是利用凸面几何学的理论判断空间任意一点和凸体每一个体元之间的位置关系,进而可以判断此点与整个凸体的位置关系,由此建立了凸体的Yee元胞建模方法。此种方法称为凸体的凸面几何学Yee元胞建模(convex geometry Yee cells model building of convexobject,CGYCMBCO)方法。CGYCMBCO方法给出了4个凸体的Yee元胞建模的实验结果,实验结果表明CGYCMBCO方法适用于任意凸体,能给出任意凸体的Yee元胞。展开更多
We utilize Fourier methods to analyze the stability of the Yee difference schemes for Berenger PML （perfectly matched layer） as well as the UPML （uniaxial perfectly matched layer） systems of two-dimensional Maxwel...We utilize Fourier methods to analyze the stability of the Yee difference schemes for Berenger PML （perfectly matched layer） as well as the UPML （uniaxial perfectly matched layer） systems of two-dimensional Maxwell equations. Using a practical spectrum stability concept, we find that the two schemes are spectrum stable under the same conditions for mesh sizes. Besides, we prove that the UPML schemes with the same damping in both directions are stable. Numerical examples are given to confirm the stability analysis for the PML method.展开更多
This paper is concerned with the fast iterative solution of linear systems arising from finite difference discretizations in electromagnetics. The sweeping preconditioner with moving perfectly matched layers previousl...This paper is concerned with the fast iterative solution of linear systems arising from finite difference discretizations in electromagnetics. The sweeping preconditioner with moving perfectly matched layers previously developed for the Helmholtz equation is adapted for the popular Yee grid scheme for wave propagation in inhomogeneous, anisotropic media. Preliminary numerical results are presented for typical examples.展开更多
In this paper,several new energy identities of metamaterial Maxwell’s equations with the perfectly electric conducting(PEC)boundary condition are proposed and proved.These new energy identities are different from the...In this paper,several new energy identities of metamaterial Maxwell’s equations with the perfectly electric conducting(PEC)boundary condition are proposed and proved.These new energy identities are different from the Poynting theorem.By using these new energy identities,it is proved that the Yee scheme on non-uniform rectangular meshes is stable in the discrete L2 and H1 norms when the Courant-Friedrichs-Lewy(CFL)condition is satisfied.Numerical experiments in twodimension(2D)and 3D are carried out and confirm our analysis,and the superconvergence in the discrete H1 norm is found.展开更多
文摘1 Introduction In the United States, the largest groups of acupuncture or traditional Chinese medicine （TCM） practitioners settled and still remain in California and New York, as these two states historically have the largest, most concentrated Asian populations. The TCM practitioners originally worked in a legal gray-zone, sometimes even being treated as illegal practitioners by the local governments, since TCM licensing laws did not exist until late 1973[1]. The first legal acupuncture clinic was established in Washington, D.C. in 1972[2], but Nevada was the first state that passed a full practicing law for acupuncture and TCM[3]. Under- standing the legal history of acupuncture in the U.S. will help us to see the road ahead more clearly.
基金supported by the Air Force Office of Scientific Research (AFOSR) under Grant numbers FA9550-04-1-0213 and FA9550-07-1-0010
文摘In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell＇s equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not require permittivity averaging so that better accuracy can be achieved. Our numerical results on optical force computation show that the standard FDTD method converges linearly, while the proposed method achieves quadratic convergence and better accuracy.
文摘In this paper, a locally non-orthogonal overlapping Yee (OY) FDTD method is proposed in order to accurately calculates the optical force on dielectric and dispersive nanoparticles. It extends our previous work to geometries with sharp corners and dispersive materials. In addition to consistently achieving the smallest errors in comparison to the standard FDTD method, the OY approach is a stable non-orthogonal FDTD method that attains second-order convergence when sharp corners are present.
文摘Professor Lau is currently Professor, Division of Hepato-Pancreato-Biliary Surgery, Department of Surgery, The Chinese University of Hong Kong; Honoarary Consultant in Hepato-pancreato-biliary Surgery in hospitals under the New Territories East Cluster （which includes Prince of Wales Hospital, Alice Ho Miu Ling Nethersole Hospital and North District Hospital） and Honorary Consultant Surgeon to the United Christian Hospital.
文摘为了解决利用时域有限差分(finite difference timedomain,FDTD)方法实现凸体的电磁散射特性数值计算中,普遍遇到的Yee元胞建模问题,该文提出了关于凸体的一种新的Yee元胞建模方法。其主要思路是利用凸面几何学的理论判断空间任意一点和凸体每一个体元之间的位置关系,进而可以判断此点与整个凸体的位置关系,由此建立了凸体的Yee元胞建模方法。此种方法称为凸体的凸面几何学Yee元胞建模(convex geometry Yee cells model building of convexobject,CGYCMBCO)方法。CGYCMBCO方法给出了4个凸体的Yee元胞建模的实验结果,实验结果表明CGYCMBCO方法适用于任意凸体,能给出任意凸体的Yee元胞。
文摘We utilize Fourier methods to analyze the stability of the Yee difference schemes for Berenger PML （perfectly matched layer） as well as the UPML （uniaxial perfectly matched layer） systems of two-dimensional Maxwell equations. Using a practical spectrum stability concept, we find that the two schemes are spectrum stable under the same conditions for mesh sizes. Besides, we prove that the UPML schemes with the same damping in both directions are stable. Numerical examples are given to confirm the stability analysis for the PML method.
文摘This paper is concerned with the fast iterative solution of linear systems arising from finite difference discretizations in electromagnetics. The sweeping preconditioner with moving perfectly matched layers previously developed for the Helmholtz equation is adapted for the popular Yee grid scheme for wave propagation in inhomogeneous, anisotropic media. Preliminary numerical results are presented for typical examples.
基金supported by the National Natural Science Foundation of China Grant No.11671233 and the Shandong Provincial Science and Technology Development Program Grant No.2018GGX101036.
文摘In this paper,several new energy identities of metamaterial Maxwell’s equations with the perfectly electric conducting(PEC)boundary condition are proposed and proved.These new energy identities are different from the Poynting theorem.By using these new energy identities,it is proved that the Yee scheme on non-uniform rectangular meshes is stable in the discrete L2 and H1 norms when the Courant-Friedrichs-Lewy(CFL)condition is satisfied.Numerical experiments in twodimension(2D)and 3D are carried out and confirm our analysis,and the superconvergence in the discrete H1 norm is found.
