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A new characterization of Willmore submanifolds

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Applied Mathematics(A Journal of Chinese Universities) 2011年第4期26卷 453-463页

作者： XU hong-wei yang Deng-yun Center of Mathematical Sciences Zhejiang University Hangzhou 310027 China.

Let M^n be a compact Willmore submanifold in the unit sphere Sn＋p. In this note, we investigate the first eigenvalue of the SchrSdinger operator L = -△ - q on M, where q is some potential function on M, and present... 详细信息

关键词： Willmore submanifolds Schrodinger operator eigenvalue fiat normal bundle Willmore torus.

ON AN EFFICIENT IMPLEMENTATION OF THE FACE ALGORITHM FOR LINEAR PROGRAMMING＊

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Journal of Computational Mathematics 2013年第4期31卷 335-354页

作者： Lei-hong Zhang wei hong yang Li-Zhi Liao Department of Applied Mathematics Shanghai University of Finance and Economics Shanghai 200433 China School of Mathematical Sciences Fudan University Shanghai 200433 China Department of Mathematics and Institute of Computational and Theoretical Studies Hong Kong Baptist University Hong Kong China

In this paper, we consider the solution of the standard linear programming [Lt＇）. A remarkable result in LP claims that all optimal solutions form an optimal face of the underlying polyhedron. In practice, many real-world problems have infinitely many optimal solutions and pursuing the optimal face, not just an optimal vertex, is quite desirable. The face algorithm proposed by Pan [19] targets at the optimal face by iterating from face to face, along an orthogonal projection of the negative objective gradient onto a relevant null space. The algorithm exhibits a favorable numerical performance by comparing the simplex method. In this paper, we further investigate the face algorithm by proposing an improved implementation. In exact arithmetic computation, the new algorithm generates the same sequence as Pan＇s face algorithm, but uses less computational costs per iteration, and enjoys favorable properties for sparse problems.

关键词： Linear programming Level face Optimal face Rank-one correction.

Analysis of the rogue waves in the blood based on the high-order NLS equations with variable coefficients

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Chinese Physics B 2021年第11期30卷 151-169页

作者： Ying yang Yu-Xiao Gao hong-wei yang College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China Qingdao West Coast New Area Hospital of Traditional Chinese Medicine Qingdao 266590China

The research of rogue waves is an advanced field which has important practical and theoretical significances in mathematics,physics,biological fluid mechanics,oceanography,*** the reductive perturbation theory and long wave approximation,the equations governing the movement of blood vessel walls and the flow of blood are transformed into high-order nonlinear Schrodinger(NLS)equations with variable *** third-order nonlinear Schrodinger equation is degenerated into a completely integrable Sasa–Satsuma equation(SSE)whose solutions can be used to approximately simulate the real rogue waves in the *** the first time,we discuss the conditions for generating rogue waves in the blood vessels and effects of some physiological parameters on the rogue *** on the traveling wave solutions of the fourth-order nonlinear Schrodinger equation,we analyze the effects of the higher order terms and the initial deformations of the blood vessel on the wave propagation and the displacement of the tube *** results reveal that the amplitude of the rogue waves are proportional to the initial stretching ratio of the *** high-order nonlinear and dispersion terms lead to the distortion of the wave,while the initial deformation of the tube wall will influence the wave amplitude and wave steepness.

关键词： rogue wave variable-coefficients high-order nonlinear Schrodinger equation deformable blood vessels Sasa-Satsuma equation

Health and Economic Impacts of Air Pollution in China: A Comparison of the General Equilibrium Approach and Human Capital Approach

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Biomedical and Environmental Sciences 2005年第6期18卷 427-441页

作者： YUE WAN hong-wei yang TOSHIHIKO MASUI Department of Social Engineering Tokyo Institute of Technology Japan Center for Energy Environment ＆ Climate Change Energy Research Institute National Development ＆ Reform Commission China Social ＆ Environmental Systems Division National Institute for Environmental Studies Japan

In China, combustion of fossil fuels and biomass has produced serious air pollution that does harm to human health. Based on dose-response relationships derived from epidemiological studies, the authors calculated the number of deaths and people with health problems which were thought to be attributable to China＇s air pollution in the year of 2000. In order to estimate the corresponding economic impacts from the national point of view, the general equilibrium approach was selected as an analysis tool for this study. A computable general equilibrium （CGE） model was constructed involving 39 sectors and 32 commodities. The human capital approach （HCA） was also used for comparison. The economic burden of disease for people estimated by HCA was equivalent to 1.26‰ （ranging from 0.44‰ to 1.84‰） of China＇s gross domestic product （GDP）. China＇s GDP loss estimated by the general equilibrium approach reached 0.38‰ （ranging from 0.16‰ to 0.51‰）. The difference between the two approaches and the implications of the results were discussed.

关键词： Air pollution Health Economic impact CGE model Human capital approach

A particle-linkage model for non-axisymmetric elongated asteroids

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Research in Astronomy and Astrophysics 2018年第7期18卷 101-112页

作者： hong-wei yang Shuang Li Cong Xu College of Astronautics Nanjing University of Aeronautics and Astronautics Advanced Space Technology Laboratory Nanjing University of Aeronautics and Astronautics College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

This paper investigates a simplified model for describing the gravitational fields of non- axisymmetric elongated asteroids. The connection between the simplified model and the target aster-oid is built by considering the positions of equilibrium points. To improve the performance of po-sition matching for the equilibrium points associated with these non-axisymmetric asteroids, a non-axisymmetric triple-particle-linkage model is proposed based on two existing axisymmetric particle- linkage models. The unknown parameters of the simplified model are determined by minimizing the matching error using the nonlinear optimization method. The proposed simplified model is applied for three realistic elongated asteroids, 243 Ida, 433 Eros and （8567） 1996 HW1. The simulation re-sults verify that the current particle-linkage model has better matching accuracy than the two existing particle-linkage models. The comparison, between the simplified model and the polyhedral model, on the topological cases of the equilibrium points and the distribution of gravitational potential further validate the rationality and accuracy of the simplified model.

关键词： asteroids individual (243 Ida 433 Eros (8567) 1996 HW1) - celestial mechanics -gravitation

Considerations in Applying the General Equilibrium Approach to Environmental Health Assessment

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Biomedical and Environmental Sciences 2005年第5期18卷 356-361页

作者： YUE WAN hong-wei yang AND TOSHIHIKO MASUI Department of Social Engineering Tokyo Institute of Technology Japan Center for Energy Environment ＆ Climate Change Energy Research Institute National Development ＆ Reform Commission China Social ＆ Environmental Systems Division National Institute for Environmental Studies Japan

There are currently two commonly used approaches to assessing economic impacts of health damage resulting from environmental pollution： human capital approach （HCA） and willingness-to-pay （WTP）. WTP can be further divided into averted expenditure approach （AEA）, hedonlc wage approach （HWA）, contingent valuation approach （CVA） and hedonlc price approach （HPA）. A general review of the principles behind these approaches by the authors indicates that these methods are incapable of unveiling the mechanism of health impact from the point of view of national economy. On a basis of economic system, the shocks brought about by health effects of environmental pollution change the labor supply and medical expenditure, which in turn affects the level of production activity in each sector and the total final consumption pattern of the society. The general equilibrium approach within the framework of macroeconomic theory is able to estimate the health impact on national economy comprehensively and objectively. Its mechanism and applicability are discussed in detail by the authors.

关键词： Human capital approach Willingness-to-pay General equilibrium approach

Evaluation of different Krylov subspace methods for simulation of the water faucet problem

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Nuclear Science and Techniques 2021年第5期32卷 1-16页

作者： hong-yang wei Kevin Briggs Victor Quintanilla Yi-Tung Chen Department of Mechanical Engineering University of NevadaLas VegasNV 89154USA

In this study,a one-dimensional two-phase flow four-equation model was developed to simulate the water faucet *** performance of six different Krylov subspace methods,namely the generalized minimal residual(GMRES),transpose-free quasi-minimal residual,quasi-minimal residual,conjugate gradient squared,biconjugate gradient stabilized,and biconjugate gradient,was evaluated with and without the application of an incomplete LU(ILU)factorization preconditioner for solving the water faucet *** simulation results indicate that using the ILU preconditioner with the Krylov subspace methods produces better convergence performance than that without the ILU *** the GMRES demonstrated an acceptable convergence performance under the Krylov subspace methods without the *** velocity and pressure distribution in the water faucet problem could be determined using the Krylov subspace methods with an ILU preconditioner,while GMRES could determine it without the need for a ***,there are significant advantages of using an ILU preconditioner with the GMRES in terms of *** different Krylov subspace methods showed similar performance in terms of computational efficiency under the application of the ILU preconditioner.

关键词： Water faucet problem Krylov subspace methods ILU preconditioner

Feasible region and stability analysis for hovering around elongated asteroids with low thrust

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Research in Astronomy and Astrophysics 2015年第9期15卷 1571-1586页

作者： hong-wei yang Xiang-Yuan Zeng Hexi Baoyin School of Aerospace Engineering Tsinghua University

This paper investigates properties of low-thrust hovering, including the feasible region and stability, in terms of the dynamical parameters for elongated asteroids. An approximate rotating mass dipole model, by which the description of the rotational gravitational field is reduced to two independent parameters, is employed to construct normalized dynamical equations. The boundaries of the feasible region are determined by contours representing the magnitude of the active control. The effects of a rotating gravitational field and maximal magnitude of the low thrust on the feasible hovering regions are analyzed with numerical results. The stability conditions are derived according to the forms of the eigenvalues of the linearized equation near the hovering position. The stable regions are then determined by a grid search and the effects of the relevant parameters are analyzed in a parametric way. The results show that a close hovering can be easier to realize near the middle of the asteroid than near the two ends in the sense of both required control magnitude and stability.

关键词： space vehicles -- celestial mechanics -- cosmology -- observations

The research of vasoconstriction effect on the solitary waves in stenotic arterial vessel

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Communications in Theoretical Physics 2023年第5期75卷 38-51页

作者： Xue Sang Zongguo Zhang hong-wei yang Lei Fu College of Mathematics and System Science Shandong University of Science and TechnologyQingdao 266590China School of Mathematics Statistics Qilu University of Technology(Shandong Academy of Sciences)Jinan250200China

Vascular stenosis is a common cardiovascular disease,and the in-depth study of its biomechanical mechanism will help to explore the occurrence mechanism and law of the disease,which is of great significance in the prevention and diagnosis of cardiovascular *** from previous studies,radial and axial motions are considered in the realistic configuration of the wall,and the wall equation of the stenotic artery is *** the basis of the wall equation and fluid equation,the KdV-Burgers equation is obtained by scale analysis and perturbation *** effects of axial displacement and wall initial conditions on the propagation of solitary waves in stenotic arteries are *** is shown that with the increase of the axial and radial tension ratios,the amplitude and width of the solitary wave increase,and the solitary wave becomes steeper and more *** results of this study provide a theoretical value for detecting the shape change of solitary wave in blood vessel to predict vascular stenosis.

关键词： solitary waves stenosis arterial vessel KdV-Burgers equation steeping and peaking