A5101478755- Numerical methods for differential equations
- Electromagnetic Simulation and Numerical Methods
- Advanced Numerical Methods in Computational Mathematics
- Seismic Imaging and Inversion Techniques
- Gas Dynamics and Kinetic Theory
- Medical Imaging Techniques and Applications
- Magnetic confinement fusion research
- Computational Fluid Dynamics and Aerodynamics
- Fractional Differential Equations Solutions
- Numerical methods in inverse problems
- Fluid Dynamics and Turbulent Flows
- HVDC Systems and Fault Protection
- Particle Accelerators and Free-Electron Lasers
- Model Reduction and Neural Networks
- High-Voltage Power Transmission Systems
- Advanced Vision and Imaging
- Differential Equations and Numerical Methods
- Nonlinear Waves and Solitons
- Seismic Waves and Analysis
- Smart Grid and Power Systems
- Photoacoustic and Ultrasonic Imaging
- Advanced Mathematical Modeling in Engineering
- Advanced X-ray and CT Imaging
- Geophysical Methods and Applications
- Image and Video Stabilization
Shandong Transportation Research Institute
2023-2025
State Grid Corporation of China (China)
2010-2024
Ames Research Center
2023
Tsinghua Sichuan Energy Internet Research Institute
2023
Augusta University
2018-2022
University of Science and Technology Beijing
2016-2022
Augusta University Health
2021
Tianjin Research Institute of Electric Science (China)
2021
Chongqing Cancer Hospital
2020
University of Science and Technology of China
2014-2018
Particle-in-Cell (PIC) simulation is the most important numerical tool in plasma physics. However, its long-term accuracy has not been established. To overcome this difficulty, we developed a canonical symplectic PIC method for Vlasov-Maxwell system by discretizing Poisson bracket. A fast local algorithm to solve implicit time advance discovered without root searching or global matrix inversion, enabling applications of proposed very large-scale simulations with many, e.g., $10^{9}$, degrees...
Time domain fluorescence molecular tomography (TD-FMT) provides a unique dataset for enhanced quantification and spatial resolution. The time-gate can be divided into two temporal groups around the maximum counts gate, which are early gates late gates. It is well established that allow improved resolution essential fluorophore unmixing concentration quantification. However, inverse problem of FMT ill-posed typically underdetermined, makes image reconstruction highly susceptible to data...
Explicit high-order non-canonical symplectic particle-in-cell algorithms for classical particle-field systems governed by the Vlasov-Maxwell equations are developed. The conserve a discrete structure derived from Lagrangian of system, which is naturally in particles. electromagnetic field spatially discretized using method exterior calculus with interpolating differential forms cubic grid. resulting time-domain assumes structure. It also gauge invariant and conserves charge. system then...
A 220 kV/300 MVA saturated iron-core superconducting fault current limiter (SI-SFCL) has been successfully manufactured and installed at Shigezhuang substation in Tianjin, China. Because it is the first time SI-SFCL used such a high voltage level, extensive testing was carried out to assess safety functional performance of device HV power grid. Two categories tests were conducted factory before SFCL shipped installation site. One examine whether met relevant industrial standards, as...
Hamiltonian time integrators for the Vlasov-Maxwell equations are developed by a splitting technique. The functional is split into five parts, which produces exactly solvable subsystems. Each subsystem system equipped with Morrison-Marsden-Weinstein Poisson bracket. Compositions of exact solutions provide structure preserving/Hamiltonian methods arbitrary high order equations. They then accurate and conservative over long because Poisson-preserving nature.
Secular dynamics of relativistic charged particles has theoretical significance and a wide range applications. However, conventional algorithms are not applicable to this problem due the coherent accumulation numerical errors. To overcome difficulty, we develop volume-preserving algorithm (VPA) with long-term accuracy conservativeness via systematic splitting method. Applied simulation runaway electrons time-span over 10 magnitudes, VPA generates accurate results enables discovery new...
Dynamics of a charged particle in the canonical coordinates is Hamiltonian system, and well-known symplectic algorithm has been regarded as de facto method for numerical integration systems due to its long-term accuracy fidelity. For simulations with high efficiency, explicit algorithms are desirable. However, it generally believed that only available sum-separable Hamiltonians, this restriction limits application dynamics. To overcome difficulty, we combine familiar sum-split generating...
In this paper, we study the Vlasov-Maxwell equations based on Morrison-Marsden-Weinstein bracket. We develop Hamiltonian particle-in-cell methods for system by employing finite element in space and splitting time. order to derive semi-discrete that possesses a discrete non-canonical Poisson structure, present criterion choosing appropriate spaces. It is confirmed some conforming elements, e.g., Nédélec's mixed satisfy requirement. When method used discretize time, resulting algorithm...
Scanning synthetic aperture radar (ScanSAR) is the dominant imaging mode of existing SAR satellites. However, in this mode, a burst operation utilized, resulting scalloping problems that significantly impact quality ScanSAR images. In response to poor robustness and high complexity denoising algorithms, based on analysis causes scalloping, suppression method for images considers azimuthal correction errors range spatial variant characteristics proposed. First, estimating azimuth antenna...
Abstract The linear bi-flux diffusion equation extends the classical process by incorporating a bimodal flux distribution. In this paper, we address an inverse problem associated with model. Specifically, consider case where coefficient of lowest order term in u(x,t) is unknown and focus on recovering function alongside solution. To solve problem, propose homotopy analysis method. By reformulating as integro- differential equation, it using method, which transforms into infinite series...
We construct high order symmetric volume-preserving methods for the relativistic dynamics of a charged particle by splitting technique with processing. Via expanding phase space to include time $t$, we give more general construction that can be applied systems time-dependent electromagnetic fields. The newly derived provide numerical solutions good accuracy and conservative properties over long simulation. Furthermore, because use processing are explicit, cost less than from standard...
Stereo cameras can capture the rich image textures of a scene, while LiDAR obtain accurate 3D coordinates point clouds scene. They complement each other and achieve comprehensive environment perception through data fusion. The primary step in fusion is to establish relative positional relationship between stereo LiDAR, known as extrinsic calibration. Existing methods camera–LiDAR by constraints correspondence different planes images clouds. However, these depend on ignore multipath-closure...
An explicit high-order noncanonical symplectic algorithm for ideal two-fluid systems is developed. The fluid discretized as particles in the Lagrangian description, while electromagnetic fields and internal energy are treated discrete differential form on a fixed mesh. With assistance of Whitney interpolating forms, this scheme preserves gauge symmetry field, pressure field naturally derived from energy. whole system solved using Hamiltonian splitting method discovered by He et al., which...
In this paper, we consider the Lorentz force system based on its Hamiltonian formulation. We decompose into four subsystems which can be solved with help of coordinate transformations. Via transformations, three kinds explicit symplectic numerical methods have been established for simulating motion charged particles under time-independent electromagnetic field. generalize our to solve time-dependent external fields, and also a relativistic effect. experiments, computing efficiency accuracy...