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Optimality Conditions for Strictly Efficient Solutions in Set-valued Optimization

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Acta Mathematicae Applicatae Sinica 2020年第4期36卷 891-901页

作者： Yi-hong xu Department of Mathematics School of SciencesNanchang UniversityNanchang 330031China

A new kind of tangent derivative,M-derivative,for set-valued function is introduced with help of a modified Dubovitskij-Miljutin *** generalized pseudoconvex set-valued functions are *** both the objective function and constraint function are M-derivative,under the assumption of near conesubconvexlikeness,by applying properties of the set of strictly efficient points and a separation theorem for convex sets,Fritz John and Kuhn-Tucker necessary optimality conditions are obtained for a point pair to be a strictly efficient element of set-valued optimization *** the assumption of generalized pseudoconvexity,a Kuhn-Tucker sufficient optimality condition is obtained for a point pair to be a strictly efficient element of set-valued optimization problem.

关键词： strict efficiency near cone-subconvexlikeness set-valued optimization cone

Typhoon hazard assessment at the site-specific scale based on the probability density evolution method and its application on the southeast coast of China

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Science China(Technological Sciences) 2023年第1期66卷 86-100页

作者： hong xu LI Jie Collegeof Civil Engineering Tongji UniversityShanghai 200092China

Herein, a typhoon hazard assessment method at the site-specific scale is proposed. This method integrates the nonlinear threedimensional wind field model and the probability density evolution method. At the site-specific scale, the track of a typhoon near the engineering site is approximated via a straight line. The wind field model is utilized to calculate the wind speed at the surface given the gradient wind field at the top of the boundary layer. A comparison between the simulated and observed wind histories for Typhoon Hagupit that made landfall in Guangdong Province demonstrates the fidelity of the wind field model. The probability density evolution method is utilized to calculate the propagation of the randomness from the basic random variables toward the extremities of the typhoon surface wind. To model the probability distribution of the basic random variables, several candidate distributions are considered to fit the observations. Akaike information criterion and Anderson-Darling distance are used for selecting the preferred probability distribution model. The adequacy of the probability density evolution method in assessing typhoon hazards is verified by comparing the results with those generated by Monte Carlo simulations. The typhoon wind hazards estimated by the present study are compared with those proposed by other studies and the design code, and the differences are analyzed and discussed. The results of the proposed method provide the reasonable probabilistic model for the assessment of the structural reliability and the improvement of community resilience in the typhoon-prone areas.

关键词： typhoon hazard Akaike information criterion Anderson-Darling distance boundary-layer wind field probability density evolution method

Recent Progress in Arabidopsis Research in China： A Preface

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Journal of Integrative Plant Biology 2006年第1期48卷 1-4页

作者： Zhi-hong xu College of Life Sciences Peking University Beijing 100871 China Shanghai Institute of Plant Physiology and Ecology the Chinese Academy of Sciences Shanghai 200032 China

In 2002, a workshop on Arabidopsis research in China was held in Shanghai, when a small group of Chinese plant scientists was working on this model species. Since then, we have witnessed the rapid growth of Arabidopsis research in China. This special issue of Journal of Integrative Plant Biology is dedicated exclusively to the Fourth Workshop on Arabidopsis Research in China, scheduled on November 30, 2005, in Beijing. In addition to reports collected in this special issue, the Chinese Arabidopsis community has been able to make significant contributions to many research fields. Here, I briefly summarize recent advances in Arabidopsis research in China.

关键词： PREFACES & forewords BOTANY

MILP-Based Linear Attacks on Round-Reduced GIFT

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Chinese Journal of Electronics 2022年第1期31卷 89-98页

作者： CUI Yaxin xu hong QI Wenfeng Information Engineering University

GIFT is a lightweight block cipher with an substitution-per mutation-net work（SP N） structure proposed in CHES *** has two different versions whose block sizes are 64 and 128 *** RSA 2019,Zhu et *** some differential characteristics of GIFT with mixed integer linear programming（MILP） method and presented corresponding differential *** this paper,we further find some linear characteristics with MILP *** GIFT-64,we find two 11-round linear characteristics with correlation 2;,and use one of them to present a 16-round linear attack on GIFT-64 by adding4 rounds before and one round after the linear *** GIFT-128,we find a 16-round linear characteristic with correlation 2;.As far as we know,it is the longest linear characteristic found for *** the 16-round linear characteristic,we present a 20-round linear attack on GIFT-128 by adding 2 rounds before and2 rounds after the linear characteristic.

关键词： GIFT-128 RSA 2019 16-round linear attack substitution-permutation-network structure lightweight block cipher GIFT-64 public key cryptography 20-round linear attack CHES 2017 MILP-based linear attacks linear programming integer programming mixed integer linear programming method

Deviating from the nanorod shape： Shape-dependent plasmonic properties of silver nanorice and nanocarrot structures

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Frontiers of physics 2016年第2期11卷 45-55页

作者： hong-Yan Liang hong Wei hong-Xing xu Center for Nanoscience and Nanotechnology School of Physics and Technology and Institute for Advanced Studies Wuhan University Wuhan 430072 China Institute of Physics Chinese Academy of Sciences and Beijing National Laboratory for Condensed Matter Physics Beijing 100190 China

Noble metallic nanostructures exhibit special optical properties resulting from excitation of surface plasmons. Among the various metallic nanostructures, nanorods have attracted particular attention because of their unique and intriguing shape-dependent plasmonic properties. Nanorods can sup- port transverse and longitudinal plasmon modes, the latter ones depending strongly on the aspect ratio of the nanorod. These modes can be routinely tuned from the visible to the near-infrared spectral regions. Although nanorods have been investigated extensively, there are few studies de- voted to nanostructures deviating from the nanorod shape. This review provides an overview of recent progress in the development of two kinds of novel quasi-one-dimensional silver nanostruc- tures, nanorice and nanocarrot, including their syntheses, crystalline characterizations, plasmonic property analyses, and performance in plasmonic sensing applications.

关键词： electron energy loss spectroscopy (EELS) localized surface plasmon resonance (LSPR),multipolar longitudinal plasmon mode nanocarrot nanorice plasmonic sensing

A FEASIBLE DIRECTION ALGORITHM WITHOUT LINE SEARCH FOR SOLVING MAX-BISECTION PROBLEMS

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Journal of Computational Mathematics 2005年第6期23卷 619-634页

作者： Feng-min xu Cheng-xian xu hong-gang xue Department of Mathematics of Faculty of Science Xi'an Jiaotong University Xi'an 710049 China

This paper concerns the solution of the NP-hard max-bisection problems. NCP functions are employed to convert max-bisection problems into continuous nonlinear programming problems. Solving the resulting continuous nonlinear programming problem generates a solution that gives an upper bound on the optimal value of the max-bisection problem. From the solution, the greedy strategy is used to generate a satisfactory approximate solution of the max-bisection problem. A feasible direction method without line searches is proposed to solve the resulting continuous nonlinear programming, and the convergence of the algorithm to KKT point of the resulting problem is proved. Numerical experiments and comparisons on well-known test problems, and on randomly generated test problems show that the proposed method is robust, and very efficient.

关键词： Max-Bisection problem Feasible direction algorithm NCP function Convergence

Disturbance rejection control based on acceleration projection method for walking robots

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第11期9卷 1531-1538页

作者： xu-yang WANG Zhao-hong xu Tian-sheng LU School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China

This paper presents a disturbance rejection scheme for walking robots under unknown external forces and moments. The disturbance rejection strategy, which combines the inverse dynamics control with the acceleration projection onto the ZMP (zero moment point)-plane, can ensure the overall dynamic stability of the robot during tracking the pre-computed trajectories. Under normal conditions, i.e., the system is dynamically balanced, a primary inverse dynamics control is utilized. In the case that the system becomes unbalanced due to external disturbances, the acceleration projection control (APC) loop, will be activated to keep the dynamic stability of the walking robot through modifying the input torques. The preliminary experimental results on a robot leg demonstrate that the proposed method can actually make the robot keep a stable motion under unknown external perturbations.

关键词： Inverse dynamics Disturbance reiection ZMP (zero moment point)-plane Orthogonal projection Walking robot

Properties and Iterative Methods for the Lasso and Its Variants

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Chinese Annals of Mathematics,Series B 2014年第3期35卷 501-518页

作者： hong-Kun xu Department of Applied Mathematics National Sun Yat-Sen University Department of Mathematics King Abdulaziz University

The lasso of Tibshirani （1996） is a least-squares problem regularized by the l1 norm. Due to the sparseness promoting property of the l1 norm, the lasso has been received much attention in recent years. In this paper some basic properties of the lasso and two variants of it are exploited. Moreover, the proximal method and its variants such as the relaxed proximal algorithm and a dual method for solving the lasso by iterative algorithms are presented.

关键词： Lasso Elastic net Smooth-lasso l1 regulaxization Sparsity Proximalmethod Dual method Projection Thresholding

Hydrothermal Synthesis and Crystal Structure of Iron Molybdophosphate Fe[Mo_6O_(12)(OH)_3(H_2PO_4)(HPO_4)_2(PO_4)]_2- [Fe(2,2′-bipy)(H_2O)_2]_2[Fe(2,2′-bipy)_3]_2·6H_2O

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Chinese Journal of Structural Chemistry 2005年第10期24卷 1117-1122页

作者： GUO hong-xu LIU Shi-Xiong Department of Chemistry Fuzhou University Fuzhou 350002 China Department of Chemistry Zhangzhou Teachers College Zhangzhou 363000 China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences Fuzhou Fujian 350002 China

A molybdenum（V） phosphate supported by iron coordination complexes, Fe[Mo6O12（OH）3（H2PO4）（HPO4）2（PO4）]2[Fe（2,2′-bipy）（H2O）2]2[Fe（2,2′-bipy）3]2·6H2O （bipy = 2,2′-bipyridine） 1, has been synthesized by hydrothermal synthesis and characterized. The title complex crystallizes in the monoclinic system, space group P21/c with a = 14.0005（8）, b = 25.5229（12）, c = 17.9956（9） A, β = 103.470（2）°, V= 6253.5（6） A^3, Z= 2, Mr = 4114.03, Dc = 2.185 g/cm^3, F（000） = 4040, μ = 1.931 mm^-1, R = 0.0438 and wR = 0. 1168. The structure of the title polyoxometalate anion is based on a centrosymmetrical cluster Fe[Mo6O2（OH）3（H2PO4）（HPO4）2（PO4）]2 supported by two [Fe（2,2′-bipy）（H2O）2] subunits. The 2D network is formed through intermolecular hydrogen bonds.

关键词： molybdophosphate iron complex hydrothermal synthesis crystal structure