A Pseudo-Kinetic Approach for Helmholtz Equation Radjesvarane ALEXANDRE Jie LIAO A lattice Boltzmann type pseudo-kinetic model for a non-homogeneous Helmhol-tz equation is derived in this paper.Numerical results for s...A Pseudo-Kinetic Approach for Helmholtz Equation Radjesvarane ALEXANDRE Jie LIAO A lattice Boltzmann type pseudo-kinetic model for a non-homogeneous Helmhol-tz equation is derived in this paper.Numerical results for some model problems show the robustness and efficiency of this lattice Boltzmann type pseudo-kinetic scheme.The computation at each site is determined only by local parameters,and can be easily adapted to solve multiple scattering problems with many scatterers or wave propagation in non-homogeneous medium without increasing the computational cost.展开更多
On the Error Estimate of the Harmonic Bz Algorithm in MREIT from Noisy Magnetic Flux FieldQun CHEN Jijun LIUMagnetic resonance electrical impedance tomography （MREIT, for short） is a new medical imaging technique de...On the Error Estimate of the Harmonic Bz Algorithm in MREIT from Noisy Magnetic Flux FieldQun CHEN Jijun LIUMagnetic resonance electrical impedance tomography （MREIT, for short） is a new medical imaging technique developed recently to visualize the cross-section conductivity of biologic tissues A new MREIT image reconstruction method called harmonic Bz algorithm was proposed in 2002 with the measurement of Bz that is a single component of an induced magnetic flux density subject to an injection current. The key idea is to solve a nonlinear integral equation by some iteration process. This paper deals with the convergence analysis as well as the error estimate for noisy input data Bz, which is the practical situation for MREIT. By analyzing the iteration process containing the Laplacian operation on the input magnetic field rigorously, the authors give the error estimate for the iterative solution in terms of the noisy level 5 and the regularizing scheme for determining AB approximately from the noisy input data. The regularizing scheme for computing the Laplacian from noisy input data is proposed with error analysis. Our results provide both the theoretical basis and the implementable scheme for evaluating the reconstruction accuracy using harmonic Bz algorithm with practical measurement data containing展开更多
H^2-Stabilization of the Isothermal Euler Equations:a Lyapunov Function Approach Martin GUGAT Giinter LEUGERING Simona TAMASOIU Ke WANG The authors consider the problem of boundary feedback stabilization of the 1D Eul...H^2-Stabilization of the Isothermal Euler Equations:a Lyapunov Function Approach Martin GUGAT Giinter LEUGERING Simona TAMASOIU Ke WANG The authors consider the problem of boundary feedback stabilization of the 1D Euler gas dynamics locally around stationary states and prove the exponential stability with respect to the H^2-norm.To this end,an explicit Lyapunov function as a weighted and squared H^2-norm of a展开更多
Nash and Stackelberg Difierential Games Alain BENSOUSSAN Jens FREHSE Jens VOGELGESANG A large class of stochastic differential games for several players is considered in this paper.The class includes Nash differential...Nash and Stackelberg Difierential Games Alain BENSOUSSAN Jens FREHSE Jens VOGELGESANG A large class of stochastic differential games for several players is considered in this paper.The class includes Nash differential games as well as Stackelberg differential games.A mix is possmle.展开更多
Partial and Spectral-Viscosity Models for Geophysical Flows Qingshan CHEN Max GUNZBURGER Xiaoming WANG Two models based on the hydrostatic primitive equations are proposed.The first model is the primitive equations wi...Partial and Spectral-Viscosity Models for Geophysical Flows Qingshan CHEN Max GUNZBURGER Xiaoming WANG Two models based on the hydrostatic primitive equations are proposed.The first model is the primitive equations with partial viscosity only,and is oriented towards large-scale wave structures in the ocean and atmosphere.The second model is the viscous primitive equations with spectral eddy viscosity,and is oriented towards turbulent geophysical flows.For both models,the existence and uniqueness of global strong solutions are established.For the second model,the convergence of the solutions to the solutions of the classical primitive equations as eddy viscosity parameters tend to zero is also established.展开更多
A Mathematical Model with Delays for Schistosomiasis Japonicum Transmission Yu YANG Dongmei XIAO A dynamic model of schistosoma japonicum transmission is presented that incorporates effects of the prepatent periods of...A Mathematical Model with Delays for Schistosomiasis Japonicum Transmission Yu YANG Dongmei XIAO A dynamic model of schistosoma japonicum transmission is presented that incorporates effects of the prepatent periods of the different stages of schistosoma into Barbour's model.The model consists of four delay differential equations.Stability of the disease free equilibrium and the existence of an endemic equilibrium for this model are stated in terms of a key threshold parameter The展开更多
文摘A Pseudo-Kinetic Approach for Helmholtz Equation Radjesvarane ALEXANDRE Jie LIAO A lattice Boltzmann type pseudo-kinetic model for a non-homogeneous Helmhol-tz equation is derived in this paper.Numerical results for some model problems show the robustness and efficiency of this lattice Boltzmann type pseudo-kinetic scheme.The computation at each site is determined only by local parameters,and can be easily adapted to solve multiple scattering problems with many scatterers or wave propagation in non-homogeneous medium without increasing the computational cost.
文摘On the Error Estimate of the Harmonic Bz Algorithm in MREIT from Noisy Magnetic Flux FieldQun CHEN Jijun LIUMagnetic resonance electrical impedance tomography （MREIT, for short） is a new medical imaging technique developed recently to visualize the cross-section conductivity of biologic tissues A new MREIT image reconstruction method called harmonic Bz algorithm was proposed in 2002 with the measurement of Bz that is a single component of an induced magnetic flux density subject to an injection current. The key idea is to solve a nonlinear integral equation by some iteration process. This paper deals with the convergence analysis as well as the error estimate for noisy input data Bz, which is the practical situation for MREIT. By analyzing the iteration process containing the Laplacian operation on the input magnetic field rigorously, the authors give the error estimate for the iterative solution in terms of the noisy level 5 and the regularizing scheme for determining AB approximately from the noisy input data. The regularizing scheme for computing the Laplacian from noisy input data is proposed with error analysis. Our results provide both the theoretical basis and the implementable scheme for evaluating the reconstruction accuracy using harmonic Bz algorithm with practical measurement data containing
文摘H^2-Stabilization of the Isothermal Euler Equations:a Lyapunov Function Approach Martin GUGAT Giinter LEUGERING Simona TAMASOIU Ke WANG The authors consider the problem of boundary feedback stabilization of the 1D Euler gas dynamics locally around stationary states and prove the exponential stability with respect to the H^2-norm.To this end,an explicit Lyapunov function as a weighted and squared H^2-norm of a
文摘Nash and Stackelberg Difierential Games Alain BENSOUSSAN Jens FREHSE Jens VOGELGESANG A large class of stochastic differential games for several players is considered in this paper.The class includes Nash differential games as well as Stackelberg differential games.A mix is possmle.
文摘Partial and Spectral-Viscosity Models for Geophysical Flows Qingshan CHEN Max GUNZBURGER Xiaoming WANG Two models based on the hydrostatic primitive equations are proposed.The first model is the primitive equations with partial viscosity only,and is oriented towards large-scale wave structures in the ocean and atmosphere.The second model is the viscous primitive equations with spectral eddy viscosity,and is oriented towards turbulent geophysical flows.For both models,the existence and uniqueness of global strong solutions are established.For the second model,the convergence of the solutions to the solutions of the classical primitive equations as eddy viscosity parameters tend to zero is also established.
文摘A Mathematical Model with Delays for Schistosomiasis Japonicum Transmission Yu YANG Dongmei XIAO A dynamic model of schistosoma japonicum transmission is presented that incorporates effects of the prepatent periods of the different stages of schistosoma into Barbour's model.The model consists of four delay differential equations.Stability of the disease free equilibrium and the existence of an endemic equilibrium for this model are stated in terms of a key threshold parameter The
