The piecewise linear recursive convolution （PLRC） finite-different time-domain （FDTD） method improves accuracy over the original recursive convolution （RC） FDTD approach and current density convolution （JEC） b...The piecewise linear recursive convolution （PLRC） finite-different time-domain （FDTD） method improves accuracy over the original recursive convolution （RC） FDTD approach and current density convolution （JEC） but retains their advantages in speed and efficiency. This paper describes a revised piecewise linear recursive convolution PLRC-FDTD formulation for magnetized plasma which incorporates both anisotropy and frequency dispersion at the same time, enabling the transient analysis of magnetized plasma media. The technique is illustrated by numerical simulations of the reflection and transmission coefficients through a magnetized plasma layer. The results show that the revised PLRC-FDTD method has improved the accuracy over the original RC FDTD method and JEC FDTD method.展开更多
Central discontinuous Galerkin（CDG）method is used to solve the Navier-Stokes equations for viscous flow in this paper.The CDG method involves two pieces of approximate solutions defined on overlapping meshes.Taking ...Central discontinuous Galerkin（CDG）method is used to solve the Navier-Stokes equations for viscous flow in this paper.The CDG method involves two pieces of approximate solutions defined on overlapping meshes.Taking advantages of the redundant representation of the solution on the overlapping meshes,the cell interface of one computational mesh is right inside the staggered mesh,hence approximate Riemann solvers are not needed at cell interfaces.Third order total variation diminishing（TVD）Runge-Kutta（RK）methods are applied in time discretization.Numerical examples for 1D and2 D viscous flow simulations are presented to validate the accuracy and robustness of the CDG method.展开更多
The objective of this paper is to design a microstrip patch antenna for the miniature electro-capsule communicating with external recorder at 915MHz located in Industry, Science, and Medical (ISM) bands. Microstrip an...The objective of this paper is to design a microstrip patch antenna for the miniature electro-capsule communicating with external recorder at 915MHz located in Industry, Science, and Medical (ISM) bands. Microstrip antenna design parameters, resonance characteristics and radiation patterns are evaluated using the finite-difference time-domain (FDTD) method. The effects of location of feed point and human body are analyzed, and the radiation performances of the proposed antenna are estimated in terms of radiation patterns. Finally, specific absorption rate (SAR) computations are also performed, and the peak 1-g and 10-g SAR values are calculated. According to peak SAR values, the maximum delivered power for the designed antenna was found so that the SAR values of the antennas satisfy ANSI limitations.展开更多
The electromagnetic properties of wire medium are studied by analyzing its transmission coefficient, and a homogeneous uniaxial effective permittivity tensor with one spatially dispersive component is obtained. In ord...The electromagnetic properties of wire medium are studied by analyzing its transmission coefficient, and a homogeneous uniaxial effective permittivity tensor with one spatially dispersive component is obtained. In order to evaluate the validity of the equivalent model for scattering problems, the bistatic and monostatic radar cross sections （RCS） of a block of wire medium are investigated with the finite-difference time-domain （FDTD） method. The difference of RCS from the physical wire medium and the corresponding equivalent model has been compared and analyzed under va- rious parameters of wire medium, which clearly demonstrates the accuracy of the equivalent model of wire medium.展开更多
The analysis of electromagnetic propagation in a dispersive medium is complicated in the time-domain because its dielectric constant is frequency-dependent. In this paper, the dielectric constant of the dispersive med...The analysis of electromagnetic propagation in a dispersive medium is complicated in the time-domain because its dielectric constant is frequency-dependent. In this paper, the dielectric constant of the dispersive medium is written as a rational polynomial function, and the relationship between D and E is derived in the time-domain. It is referred to as the shift operator finite-different time-domain （SO-FDTD） method. Compared to an analytical solution and a piecewise linear current density recursive convolution （PLJERC） solution, the high accuracy and efl%iency of this method is verified by calculating the reflectance of the electromagnetic wave through a cold plasma slab. As the electron density in plasma is distributed as the Epstein formula, the effect of distribution grads and electron collision frequency on the reflectance is calculated by using the SO-FDTD method. The result shows that the increase in the distribution grads coefficient affects the reflectance sharply. When it comes to a smaller distribution grads coelBcient, the increase of the collision frequency showed a significant effect on the reflectance, but on the contrary, there is actually less and less effect till it disappears.展开更多
This paper aims to discuss differences between human resource management （HRM） and strategic human resource management （SHRM）, and aims to discuss convergence or divergence between American and European HRM. There...This paper aims to discuss differences between human resource management （HRM） and strategic human resource management （SHRM）, and aims to discuss convergence or divergence between American and European HRM. Therefore, research question is what the similarities and differences are between European and American HRM. Research methodology is based on critical review of HRM literature. Therefore, this study aims to increase conceptual ability of human resource （HR） professionals. Major result is that HRM is related with employee performance, and SHRM is related with firm performance. Secondly, European HRM is becoming similar to American HRM. The difference between European and American HRM is social context and social partners. European HRM considers social partners in management of HR.展开更多
基金National Natural Science Foundation of China (No. 60471002) and the Natural Science Foundation ofJiangxi Province (No. 0412014)
文摘The piecewise linear recursive convolution （PLRC） finite-different time-domain （FDTD） method improves accuracy over the original recursive convolution （RC） FDTD approach and current density convolution （JEC） but retains their advantages in speed and efficiency. This paper describes a revised piecewise linear recursive convolution PLRC-FDTD formulation for magnetized plasma which incorporates both anisotropy and frequency dispersion at the same time, enabling the transient analysis of magnetized plasma media. The technique is illustrated by numerical simulations of the reflection and transmission coefficients through a magnetized plasma layer. The results show that the revised PLRC-FDTD method has improved the accuracy over the original RC FDTD method and JEC FDTD method.
基金Supported by the National Natural Science Foundation of China(11602262)
文摘Central discontinuous Galerkin（CDG）method is used to solve the Navier-Stokes equations for viscous flow in this paper.The CDG method involves two pieces of approximate solutions defined on overlapping meshes.Taking advantages of the redundant representation of the solution on the overlapping meshes,the cell interface of one computational mesh is right inside the staggered mesh,hence approximate Riemann solvers are not needed at cell interfaces.Third order total variation diminishing（TVD）Runge-Kutta（RK）methods are applied in time discretization.Numerical examples for 1D and2 D viscous flow simulations are presented to validate the accuracy and robustness of the CDG method.
文摘The objective of this paper is to design a microstrip patch antenna for the miniature electro-capsule communicating with external recorder at 915MHz located in Industry, Science, and Medical (ISM) bands. Microstrip antenna design parameters, resonance characteristics and radiation patterns are evaluated using the finite-difference time-domain (FDTD) method. The effects of location of feed point and human body are analyzed, and the radiation performances of the proposed antenna are estimated in terms of radiation patterns. Finally, specific absorption rate (SAR) computations are also performed, and the peak 1-g and 10-g SAR values are calculated. According to peak SAR values, the maximum delivered power for the designed antenna was found so that the SAR values of the antennas satisfy ANSI limitations.
基金Supported by the National Natural Science Foundation of China(61102022)the Fundamental Research Foundation of Beijing Institute of Technology of China(20120542014)
文摘The electromagnetic properties of wire medium are studied by analyzing its transmission coefficient, and a homogeneous uniaxial effective permittivity tensor with one spatially dispersive component is obtained. In order to evaluate the validity of the equivalent model for scattering problems, the bistatic and monostatic radar cross sections （RCS） of a block of wire medium are investigated with the finite-difference time-domain （FDTD） method. The difference of RCS from the physical wire medium and the corresponding equivalent model has been compared and analyzed under va- rious parameters of wire medium, which clearly demonstrates the accuracy of the equivalent model of wire medium.
基金supported by National Natural Science Foundation of China(Nos.60271005 and 60431010)the National Science Fund for Distinguished Young Scholars of China(No.60325103)
文摘The analysis of electromagnetic propagation in a dispersive medium is complicated in the time-domain because its dielectric constant is frequency-dependent. In this paper, the dielectric constant of the dispersive medium is written as a rational polynomial function, and the relationship between D and E is derived in the time-domain. It is referred to as the shift operator finite-different time-domain （SO-FDTD） method. Compared to an analytical solution and a piecewise linear current density recursive convolution （PLJERC） solution, the high accuracy and efl%iency of this method is verified by calculating the reflectance of the electromagnetic wave through a cold plasma slab. As the electron density in plasma is distributed as the Epstein formula, the effect of distribution grads and electron collision frequency on the reflectance is calculated by using the SO-FDTD method. The result shows that the increase in the distribution grads coefficient affects the reflectance sharply. When it comes to a smaller distribution grads coelBcient, the increase of the collision frequency showed a significant effect on the reflectance, but on the contrary, there is actually less and less effect till it disappears.
文摘This paper aims to discuss differences between human resource management （HRM） and strategic human resource management （SHRM）, and aims to discuss convergence or divergence between American and European HRM. Therefore, research question is what the similarities and differences are between European and American HRM. Research methodology is based on critical review of HRM literature. Therefore, this study aims to increase conceptual ability of human resource （HR） professionals. Major result is that HRM is related with employee performance, and SHRM is related with firm performance. Secondly, European HRM is becoming similar to American HRM. The difference between European and American HRM is social context and social partners. European HRM considers social partners in management of HR.
