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arXiv 2017年

作者： Chen, Minghua Bu, Weiping Qi, Wenya Wang, Yantao School of Mathematics and Statistics Gansu Key Laboratory of Applied Mathematics and Complex Systems Lanzhou University Lanzhou730000 China School of Mathematics and Computational Science Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan University Xiangtan411105 China South University of Science and Technology of China Shenzhen518055 China

In this article a theoretical framework for the Galerkin finite element approximation to the time-dependent Riesz tempered fractional problem is provided without the fractional regularity assumption. Because the time-dependent problems should become easier to solve as the time step τ → 0, which correspond to the mass matrix dominant [R. E. Bank and T. Dupont, Math. Comp., 153 (1981), pp. 35-51]. Based on the introduced and analysis of the fractional τ-norm, the uniform convergence estimates of the V-cycle multigrid method with the time-dependent fractional problem is strictly proved, which means that the convergence rate of the V-cycle MGM is independent of the mesh size h and the time step τ. The numerical experiments are performed to verify the convergence with only O(NlogN) complexity by the fast Fourier transform method, where N is the number of the grid points. To the best of our knowledge, this is the first proof for the convergence rate of the V-cycle multigrid finite element method with τ → 0. Copyright © 2017, The Authors. All rights reserved.

关键词： Fast Fourier transforms

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Adaptive-multilevel BDDC algorithm for three-dimensional plane wave Helmholtz systems

arXiv

引用

arXiv 2019年

作者： Peng, Jie Shu, Shi Wang, Junxian Zhong, Liuqiang School of Mathematical Sciences South China Normal University Guangzhou510631 China School of Mathematics and Computational Science Xiangtan University Xiangtan411105 China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan University Xiangtan411105 China

In this paper we are concerned with the weighted plane wave least-squares (PWLS) method for three-dimensional Helmholtz equations, and develop the multi-level adaptive BDDC algorithms for solving the resulting discrete system. In order to form the adaptive coarse components, the local generalized eigenvalue problems for each common face and each common edge are carefully designed. The condition number of the two-level adaptive BDDC preconditioned system is proved to be bounded above by a user-defined tolerance and a constant that is only dependent on the maximum number of faces and edges per subdomain and the number of subdomains sharing a common edge. The effectiveness of these algorithms is illustrated on benchmark problem. The numerical results show the robustness of our two-level adaptive BDDC algorithms with respect to the wave number, the number of subdomains and the mesh size, and appear that our multi-level adaptive BDDC algorithm can reduce the number of dofs at the coarse problem and can be used to solving large wave number problems efficiently. Copyright © 2019, The Authors. All rights reserved.

关键词： Elastic waves

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Synthesis of 4-aryl-1,4-dihydropyridine-porphyrin Compounds

Synthesis of 4-aryl-1,4-dihydropyridine-porphyrin Compounds

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中国化学会第二十七届学术年会

作者： Fei Yao Hui Wang Rong-Jin Zeng Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan411201

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Design and Adaptive Finite Element simulation of Conformal Transformation Optics Devices with Isotropic Materials

SSRN

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SSRN 2022年

作者： Yang, Wei He, Bin Wang, Hao Department of Mathematics Lanzhou Jiaotong University Gansu Lanzhou730070 China School of Mathematics and Statistics Anhui Normal University Anhui Wuhu241000 China Hunan Key Laboratory for Computation and Simulation in Science and Engineering School of Mathematics and Computational Science Xiangtan University Hunan Xiangtan411105 China

Traditional transform optical devices are designed from anisotropic magnetic materials which are difficult to fabricate. In this paper, we design and simulate a conformal carpet invisible cloak and bending waveguide device with isotropic material. According to the existing conformal coordinate transformation, we deduce the perfect parameters required by the conformal device. And the finite element method and error analysis of the model equation and the basic process of adaptive algorithm are given. We first simulated a carpet cloak and bending waveguide device with perfect parameters;then we used the idea of parameter segmentation to design a carpet cloak that requires 35 isotropic materials and use the idea of layering to design the conformal bending waveguide device, and relevant numerical results are presented;finally, we designed the adaptive finite element algorithm to realize the numerical simulation of Maxwell's equations in isotropic material isotropic material. © 2022, The Authors. All rights reserved.

关键词： Error analysis

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The Control Design of Space Flying Net Robot System Based on RBF Network

The Control Design of Space Flying Net Robot System Based on...

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Chinese Automation Congress (CAC)

作者： Xu Zhang Yuanhe Liu Yan’gang Liang Kebo Li Hunan Key Laboratory of Intelligent Planning and Simulation for Aerospace Missions College of Aerospace Science and Engineering National University of Defense Technology Changsha China

ISBN: (纸本)9781665426480

Space Flying Net Robot System (SFNRS) is a new capture method of space debris. In this paper, the SFNRS dynamic equations are established by using the lumped mass method. The previous studies about controller design assumed that the mass of the maneuvering unit in SFNRS is known and a constant while it is unknown in fact. In addition, the upper boundary of tension in the space net is often assumed as a known constant, but it is difficult to get the value. In this paper, the radial basis function (RBF) network is used to design a controller in order to overcome the shortcomings above. Finally, the simulation is carried out to verify the effectiveness and the robustness of the proposed method.

关键词： Upper bound Control design Space debris simulation Radial basis function networks Aerospace electronics Robustness

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Financing strategy of SMEs based on the shortage of environmental protection funds

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Procedia Computer science 2022年 199卷 1521-1528页

作者： Wang Haiyang Zhuang Xiaohui College of Automation and Electronic Engineering Qingdao University of Science & Technology Qingdao 260061 China School of Management Shandong Key Laboratory of Social Supernetwork Computation and Decision Simulation Shandong University Jinan Shandong 250100 China

With the development of society, environmental protection issues have received increasing attention. The increase in environmental protection requirements has greatly affected small and medium-sized enterprises（SMEs）. Due to the poor credit status and imperfect systems of SMEs, financing is difficult and expensive, which makes environmental protection funds insufficient, leading to outstanding environmental protection problems. In the supply chain, in order to maintain the stability of the supply chain, the core enterprises will help SMEs to alleviate the funding difficulties. This article starts from the supply chain financing of SMEs, explores the specific ways that core enterprises can help SMEs in supply chain financing, and analyses the feasibility of financing methods. Through analysis and demonstration, it is found that core enterprises can help SMEs with supply chain financing through prepayments, help small and medium-sized suppliers solve the problem of insufficient environmental protection funds, and core enterprises can obtain benefits from it.

关键词： Supply Chain Finance Small medium-sized enterprises (SMEs) Prepayments

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Multifractal analysis of complex networks

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Chinese Physics B 2012年第8期21卷 080504-80504页

作者： Wang, Dan-Ling Yu, Zu-Guo Anh, V. School of Mathematical Sciences Queensland University of Technology GPO Box 2434 Brisbane QC 4001 Australia School of Mathematics and Physics University of Science and Technology Beijing Beijing 10083 China Hunan Key Laboratory for Computation and Simulation in Science and Engineering School of Mathematics and Computational Science Xiangtan University Xiangtan 411105 China

Complex networks have recently attracted much attention in diverse areas of science and technology. Many networks such as the WWW and biological networks are known to display spatial heterogeneity which can be characterized by their fractal dimensions. Multifractal analysis is a useful way to systematically describe the spatial heterogeneity of both theoretical and experimental fractal patterns. In this paper, we introduce a new box-covering algorithm for multifractal analysis of complex networks. This algorithm is used to calculate the generalized fractal dimensions Dq of some theoretical networks, namely scale-free networks, small world networks, and random networks, and one kind of real network, namely protein - protein interaction networks of different species. Our numerical results indicate the existence of multifractality in scale-free networks and protein - protein interaction networks, while the multifractal behavior is not clear-cut for small world networks and random networks. The possible variation of Dq due to changes in the parameters of the theoretical network models is also discussed. © 2012 Chinese Physical Society and IOP Publishing Ltd.

关键词： Small-world networks

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GLOBAL OPTIMIZATION FOR THE PORTFOLIO SELECTION MODEL WITH HIGH-ORDER MOMENTS

arXiv

引用

arXiv 2022年

作者： Yang, Liu Yang, Yi Zhong, Suhan Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan University School of Mathematics and Computational Sciences Xiangtan University Hunan Xiangtan411105 China School of Mathematics Hunan City University Hunan Yiyang413000 China Department of Mathematics Texas A&M University College StationTX77843-3368 United States

In this paper, we study the global optimality of polynomial portfolio optimization (PPO). The PPO is a kind of portfolio selection model with high-order moments and flexible risk preference parameters. We introduce a perturbation sample average approximation method, which can give a robust approximation of the PPO in form of linear conic optimization. The approximated problem can be solved globally with Moment-SOS relaxations. We summarize a semidefinite algorithm, which can be used to find reliable approximations of the optimal value and optimizer set of the PPO. Numerical examples are given to show the efficiency of the algorithm. Copyright © 2022, The Authors. All rights reserved.

关键词： Global optimization

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Global Exponential Stability of Fuzzy Cellular Neural Networks with Constant Delays

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通讯和计算机（中英文版） 2010年第4期7卷 30-34页

作者： Wei Luo Qianhong Zhang Guozheng Wang Changjin Xu Basic Science Department Hunan Institute of Technology Hengyang 421002 China Guizhou Key Laboratory of Economics System Simulation Guizhou College of Finance and Economics Guiyang 550004 China Faculty of Science Hunan Institute of Engineering Xiangtan 411004 China

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Design and Characterization of Low-Carbon Supersulfated Cement Prepared Using As-Received Electrolysis Manganese Dioxide Residue

SSRN

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SSRN 2023年

作者： Ma, Wenbo Bai, Tianwen Zhu, Wei Guo, Shuaicheng School of Mechanical Engineering and Mechanics Xiangtan University Xiangtan411105 China College of Civil Engineering Xiangtan University Xiangtan411105 China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan University Xiangtan411105 China Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan University Changsha410082 China International Science Innovation Collaboration Base for Green & Advanced Civil Engineering Materials of Hunan Province Hunan University Changsha410082 China Key Laboratory for Green & Advanced Civil Engineering Materials and Application Technology of Hunan Province College of Civil Engineering Hunan University Changsha410082 China

Utilizing electrolysis manganese dioxide residue (EMDR) to prepare the supersulfated cement can achieve effective waste recycling, and its application can reduce the carbon emission caused by Portland cement. This study aims to quantitatively build the correlation between the mechanical performance and cementitious matrix composition of EMDR-based supersulfated cement. The supersulfated cement containing clinker, slag and as received EMDR is designed and prepared based on the simplex centroid design method. The compressive strength, tensile strength and flexural strength of the EMDR based supersulfated cement paste were measured at 3-day, 7-day and 28-day ages. The compressive strength of the electrolysis manganese dioxide residue (EMDR) based supersulfated cement first increases and then decreases with the mass ratio between slag and EMDR. The added cement clinker can increase the compressive strength at 3-day and 7-day ages, but the 28-day age strength first decrease and then increase with the cement clinker content. Meanwhile, the flexural and tensile performances of the EMDR based supersulfated cement generally increase with the clinker content. The measured elastic modulus results indicated the added clinker could enhance the stiffness of the stiffness development. Then the strength development mechanisms of EMDR-based supersulfated cement are analyzed based on phase and microstructure characterization. It is found the clinker can accelerate the reaction rate between the slag and EMDR, and the consumption rate of the gypsum contained in EMDR. The calcium silicate hydrate (CSH) gel phase's contribution to tensile strength is more significant than that of ettringite phase. Based on the mechanism analysis, the index of [SO3]/[Al2O3] molar ratio is proposed for the matrix design of EMDR based SSC. This study can support the design and application of EMDR-based supersulfated cement. © 2023, The Authors. All rights reserved.

关键词： Aluminum oxide

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