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2022 2nd Conference on High Performance Computing and Communication Engineering, HPCCE 2022

作者： Yang, Chaochao Liu, Anjun Liu, Weifeng Hou, Jie Guo, Meng Shandong Computer Science Center Qilu University of Technology China Jinan Key Laboratory of High Performance Industrial Software China Institute of Applied Physics and Computational Mathematics China Jinan Institute of Supercomputing Technology China

ISBN: (纸本)9781510663374

The Davidson method is a traditional large-scale iterative diagonalization method in computational quantum chemistry. The Blocked-Davidson method is a classical version of the Davidson method, which is an important part of VASP software, occupying 22.9% of the calculation time. When VASP is transplanted to the new Sunway supercomputer, it is incompatible with the many-core heterogeneous environment of Sunway processor. The Blocked-Davidson method does not use slave-core accelerators. This paper designs collaborative computing, double buffer, store variables in slave-core LDM, LDM Level 2 Access, and segmented transmission methods of Blocked-Davidson method based on Sunway many-core architecture. The test results showed that the function in the Blocked-Davidson method accelerated 30.65 times with a single core group in the silica test case. However, negative optimization of the Blocked-Davidson method happens in some test cases such as ZrTiAlVSiN5 and Hg50. Therefore, an adaptive algorithm of automatic selection of less time-consuming optimization paths is designed to solve the negative optimization. The maximum acceleration is 23.6 times compared with not using the adaptive algorithm. © 2023 SPIE.

关键词： Supercomputers

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The effect of external magnetic field on projectile in the stopping power of warm dense deuterium for electrons

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The European Physical Journal Special Topics 2025年 1-16页

作者： Chen, Yuzhu Mo, Chongjie Xue, Quanxi Fu, Zhenguo Liu, Hao Department of Applied Physics School of Physics and Electronics Hunan University Changsha China Beijing Computational Science Research Center Beijing China State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Northwest Institute of Nuclear Technology Xi’an China Institute of Applied Physics and Computational Mathematics Beijing China

The stopping power of warm dense plasmas for electrons is a critical aspect in the study of hot electron transport. An externally applied strong magnetic field can significantly influence electron transport behavior due to various factors. However, the impact of external magnetic fields on the motion of incident particles is often overlooked. Through molecular dynamics simulations using the electron force field (eFF) method, this study investigates the stopping process of individual hot electrons in warm dense deuterium plasma under an applied longitudinal magnetic field. Results show that, at typical laboratory magnetic field intensities, the magnetic field significantly alters electron trajectories without notable effects on average stopping power, trajectory length, or scattering angle. Even with increased magnetic field intensity beyond 500 kT, it doesn’t affect the total kinetic energy loss of incident electrons but reduces stopping power by compressing the scattering angle distribution width. Due to the increase in the scattering angle distribution width with intensified fluctuations in high-temperature targets, the impact of the additional magnetic field on stopping power becomes more pronounced with an increase in target temperature.

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Mathematical Analysis of a Non-Smooth Mosquitoes Control Model

Mathematical Analysis of a Non-Smooth Mosquitoes Control Mod...

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2023 International Conference on Fractional Differentiation and Its Applications, ICFDA 2023

作者： Fawzy, Doaa M. Arafa, Ayman A. Elsaid, A. Zahra, W.K. Institute of Basic and Applied Sciences Egypt Japan University of Science and Technology Alexandria Egypt Fayoum University Faculty of Engineering Department of Engineering Mathematics and Physics Fayoum Egypt Sohag University Faculty of Science Department of Mathematics Sohag Egypt Mansoura University Faculty of Engineering Department of Mathematics and Engineering Physics Mansoura Egypt Tanta University Faculty of Engineering Department of Engineering Physics and Mathematics Tanta Egypt

ISBN: (纸本)9798350321685

The sterilization method (SM) is a promising strategy for preventing the escalation of dengue fever, zika and malaria through controlling mosquitoes. A fractional-order SM non-smooth Filippov system with threshold policy control is proposed, which entails sterile mosquitoes releasing to control the population of wild mosquitoes. If the density of the wild population falls below a certain threshold, sterile release is prohibited. However, if the wild population exceeds the threshold, sterile mosquitoes are released. The dynamics of this model, including various types of equilibria existence and their stability, are investigated analytically and numerically. Sliding mode dynamics and pseudo-equilibrium are obtained by using the Filippov convex method;moreover, boundary node and boundary saddle bifurcations are discovered. © 2023 IEEE.

关键词： Bifurcation (mathematics)

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Modeling dynamic elasticity on intraday volatility and volume by finding PDEs using machine learning

Modeling dynamic elasticity on intraday volatility and volum...

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AI IoT Congress (AIIoT), World

作者： David D. Li Angela Li Rodger Mensing Zy Li Data Science New Jersey Institute of Technology Newark NJ Applied Mathematics & Physics Stony Brook University Stony Brook NY Computer Science Seattle University Seattle WA

ISBN: (数字)9798350387803

ISBN: (纸本)9798350387810

The study proposes a methodology to identify a PDE describing the relationship between trading volume and volatility in securities, focusing on the SPDR S& P 500 ETF (SPY) as a case study. By integrating ML exploration with domain expertise, the study uncovers a simple and interpretable PDE, providing insights into market behavior and enhancing market monitoring capabilities for traders and investors. The approach emphasizes the importance of combining ML methods with domain knowledge to derive meaningful insights and practical applications in financial markets.

关键词： Solid modeling Focusing Machine learning Elasticity Security Monitoring

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Effect of ablation on the nonlinear spike growth for the single-mode ablative Rayleigh-Taylor instability

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Matter and Radiation at Extremes 2023年第1期8卷 53-62页

作者： J.Y.Fu H.S.Zhang H.B.Cai P.L.Yao S.P.Zhu Institute of Applied Physics and Computational Mathematics Beijing 100088People’s Republic of China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100088People’s Republic of China Graduate School China Academy of Engineering PhysicsP.O.Box 2101Beijing 100088People’s Republic of China Science and Technology on Plasma Physics Laboratory Laser Fusion Research CenterCAEPMianyang 621900People’s Republic of China

The effect of ablation on the nonlinear spike growth of single-mode ablative Rayleigh–Taylor instability(RTI)is studied by two-dimensional numerical *** is shown that the ablation can reduce the quasi-constant velocity and significantly suppress the reacceleration of the spike in the nonlinear *** is also shown that the spike growth can affect the ablation-generated vorticity inside the bubble,which further affects the nonlinear bubble *** vorticity evolution is found to be correlated with the mixing width(i.e.,the sum of the bubble and spike growths)for a given wave number and ablation *** considering the effects of mass ablation and vorticity,an analytical model for the nonlinear bubble and spike growth of single-mode ablative RTI is developed in this *** is found that the nonlinear growth of the mixing width,induced by the single mode,is dominated by the bubble growth for small-scale ablative RTI,whereas it is dominated by the spike growth for classical RTI.

关键词： phase nonlinear bubble

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PDHG-unrolled learning-to-optimize method for large-scale linear programming 24

PDHG-unrolled learning-to-optimize method for large-scale li...

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Proceedings of the 41st International Conference on Machine Learning

作者： Bingheng Li Linxin Yang Yupeng Chen Senmiao Wang Haitao Mao Qian Chen Yao Ma Akang Wang Tian Ding Jiliang Tang Ruoyu Sun Michigan State University School of Data Science The Chinese University of Hong Kong Shenzhen China and Shenzhen International Center For Industrial and Applied Mathematics Shenzhen Research Institute of Big Data Shenzhen International Center For Industrial and Applied Mathematics Shenzhen Research Institute of Big Data School of Data Science The Chinese University of Hong Kong Shenzhen China Shenzhen International Center For Industrial and Applied Mathematics Shenzhen Research Institute of Big Data and School of Science and Engineering The Chinese University of Hong Kong Shenzhen China Rensselaer Polytechnic Institute

Solving large-scale linear programming (LP) problems is an important task in various areas such as communication networks, power systems, finance, and logistics. Recently, two distinct approaches have emerged to expedite LP solving: (i) First-order methods (FOMs); (ii) Learning to optimize (L2O). In this work, we propose a FOM-unrolled neural network (NN) called PDHG-Net, and propose a two-stage L2O method to solve large-scale LP problems. The new architecture PDHG-Net is designed by unrolling the recently emerged PDHG method into a neural network, combined with channel-expansion techniques borrowed from graph neural networks. We prove that the proposed PDHG-Net can recover PDHG algorithm, thus can approximate optimal solutions of LP instances with a polynomial number of neurons. We propose a two-stage inference approach: first use PDHG-Net to generate an approximate solution, and then apply the PDHG algorithm to further improve the solution. Experiments show that our approach can significantly accelerate LP solving, achieving up to a 3× speedup compared to FOMs for large-scale LP problems.

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Node-line Dirac semimetal manipulated via Kondo mechanism in nonsymmorphic CePt2Si2

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Physical Review B 2023年第7期107卷 075124-075124页

作者： Hao-Tian Ma Xing Ming Xiao-Jun Zheng Jian-Feng Wen Yue-Chao Wang Yu Liu Huan Li College of Science Guilin University of Technology Guilin 541004 China Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing 100088 China

Dirac node lines (DNLs) are characterized by Dirac-type linear crossings between valence and conduction bands along one-dimensional node lines in the Brillouin zone (BZ). Spin-orbit coupling (SOC) usually shifts the degeneracy at the crossings thus destroys DNLs, and so far the reported DNLs in a few materials are noninteracting type, making the search for robust interacting DNLs in real materials appealing. Here, via first-principle calculations, we reveal that Kondo interaction together with nonsymmorphic lattice symmetries can drive a robust interacting DNLs in a Kondo semimetal CePt2Si2, and the feature of DNLs can be significantly manipulated by Kondo behavior in different temperature regions. Based on the density functional theory combining with dynamical mean-field theory (DFT+DMFT), we predict a transition to Kondo-coherent state at coherent temperature Tcoh≈80 K upon cooling, verified by temperature dependence of Ce−4f self-energy, Kondo resonance peak, magnetic susceptibility, and momentum-resolved spectral function. Below Tcoh, well-resolved narrow heavy-fermion bands emerge near the Fermi level, constructing clearly visualized interacting DNLs locating at the BZ boundary, in which the Dirac fermions have strongly enhanced effective mass and reduced velocity. In contrast, above a crossover temperature TKS≈600 K, the destruction of local Kondo screening drives noninteracting DNLs, which are comprised by light conduction electrons at the same location. These DNLs are protected by lattice nonsymmorphic symmetries thus robust under intrinsic strong SOC. Our proposal of DNLs, which can be significantly manipulated according to Kondo behavior provides an unique realization of interacting Dirac semimetals in real strongly correlated materials, and serves as a convenient platform to investigate the effect of electronic correlations on topological materials.

关键词： First-principles calculations Topological materials Dirac semimetal Heavy-fermion systems Density functional theory Dynamical mean field theory Electron-correlation calculations

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Comparison of Simulation and Measurements of Time-Domain Field-to-Line Coupling in Bounded wave Simulator

Comparison of Simulation and Measurements of Time-Domain Fie...

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2022 International applied Computational Electromagnetics Society Symposium, ACES-China 2022

作者： Zhong, Longquan Lin, Jiangchuan Qin, Feng Yang, Chun Liu, Chang Huang, Hua Complicated Electromagnetic Environment Laboratory of Caep Institute of Applied Electronics Mianyang China Software Center for High Performance Numerical Simulation of Caep Institute of Applied Physics and Computational Mathematics Beijing China Science and Technology on High Power Microwave Laboratory Institute of Applied Electronics Mianyang China

ISBN: (纸本)9781665452366

This paper presents an analysis of time-domain electromagnetic pulse coupling to single wire. A field-to-line coupling model was established. The simulation is performed using the uniform plane wave excitation defined by measured high-altitude nuclear electromagnetic pulse (HEMP) field signal, the induced currents of two load terminals are simulated. The validation measurement of single wire above the grounding plate is conducted in the bounded wave simulator. The frequency response of the actual coupled current signal monitoring system is considered in the data preprocessing. The comparison between simulation and measurement results show that the peak amplitude and waveform can coincide well. © 2022 IEEE.

关键词： Electromagnetic simulation

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Multi-Scale Electromagnetic Simulation Through Parallel Adaptive Mesh Refinement FDTD Method with Symmetric Positive Semi-Definite Subgridding Scheme

Multi-Scale Electromagnetic Simulation Through Parallel Adap...

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2023 International applied Computational Electromagnetics Society Symposium, ACES-China 2023

作者： Li, Hanyu Zhou, Haijing Bao, Xianfeng Chen, Xiaojie School of Physical Science and Technology Southwest Jiaotong University Chengdu China Institute of Applied Physics and Computational Mathematics Beijing China Software Center for High Performance Numerical Simulation Caep Beijing China

ISBN: (纸本)9781733509657

FDTD method is a common approach for electromagnetic propagation, scattering and coupling simulation. Conventional FDTD with universal mesh requires numerous computations to represent solve problems with multi-scale structures. In this paper, adaptive mesh refinement (AMR) strategy is performed to reduce the calculations along with symmetric positive semi-definite subgridding scheme to guarantee stability. Numerical example of a missile seeker coupling simulation shows that the computation time decrease down to 2% while preserving excellent precision. © 2023 applied Computational Electromagnetics Society (ACES).

关键词： Finite difference time domain method

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Periodic and chaotic dynamics in a map-based neuron model

Periodic and chaotic dynamics in a map-based neuron model

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作者： Trujillo, Frank Llovera Signerska-Rynkowska, Justyna Bartlomiejczyk, Piotr Doctoral School Gdańsk University of Technology Gdańsk Poland Faculty of Applied Physics and Mathematics and BioTechMed Centre Gdańsk University of Technology Gdańsk Poland Dioscuri Centre in Topological Data Analysis Institute of Mathematics of the Polish Academy of Sciences Warsaw Poland

Map-based neuron models are an important tool in modeling neural dynamics and sometimes can be considered as an alternative to usually computationally costlier models based on continuous or hybrid dynamical systems. However, due to their discrete nature, rigorous mathematical analysis might be challenging. We study a discrete model of neuronal dynamics introduced by Chialvo in 1995. In particular, we show that its reduced one-dimensional version can be treated as an independent simple model of neural activity where the input and the fixed value of the recovery variable are parameters. This one-dimensional model still displays very rich and varied dynamics. Using the fact that the map whose iterates define voltage dynamics is S-unimodal, we describe in detail both the periodic behavior and the occurrence of different notions of chaos, indicating corresponding regions in parameter space. Our study is also complemented by a bifurcation analysis of the mentioned dynamical model. © 2023 John Wiley & Sons, Ltd.

关键词： Neurons

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