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Confidence Intervals of the Generalized Pareto Distribution Parameters Based on Upper Record values

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Acta Mathematicae Applicatae Sinica 2019年第4期35卷 909-918页

作者： Xu ZHAO Wei-hu CHENG Yang ZHANG Shao-jie WEI Zhen-hai YANG College of applied Sciences Beijing University of Technology China department of economics Rutgers University USA

In this paper, we proposed a new efficient approach to construct confidence intervals for the location and scale parameters of the generalized Pareto distribution(GPD) when the shape parameter is known. The superiority of our method is that the distributions of pivots are exact, but not approximate distributions. The proposed interval estimation provides the shortest interval for the GPD parameter whether or not the confident distribution of the pivot is symmetric. We first estimate the location and scale parameters of the GPD using least squares and then, construct confidence intervals based on the equal probability density principle. The results of various simulation studies illustrate that our interval estimators show the better performance than competing method.

关键词： generalized Pareto distribution upper record values least squares estimator equal probability density principle confidence interval

Effects of N/Z on Post-Saddle γ Emission as an Observable of Post-Saddle Nuclear Friction

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Communications in Theoretical Physics 2010年第4期53卷 731-734页

作者：陈娜叶巍 School of applied Mathematics Nanjing University of Finance & Economics department of Physics Southeast University

Based on a dynamical Langevin equation coupled with a statistical decay model, we calculate the variation of the post-saddle giant dipole resonance （GDR） q-ray multiplicity of the heavy nuclei 24^240Cf, ^246Cf, ^252Cf and ^240U with the post-saddle friction strength （13）. We find that the sensitivity of the post-saddle γ emission to β decreases considerably with increasing the neutron-to-proton ratio （N/Z） of the system. Moreover, for 240 U, the γ emission is no longer sensitive to 13. We suggest that to accurately obtain information of the post-saddle friction strength by measuring pre-scission GDR γ-ray multiplicities, it is optimal to choose among the various compound systems those with low N/Z.

关键词： nuclear dissipation pre-scission 7-ray multiplicity N/Z effect Langevin model

A FLEXIBLE PRECONDITIONED ARNOLDI METHOD FOR SHIFTED LINEAR SYSTEMS

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Journal of Computational Mathematics 2007年第5期25卷 522-530页

作者： G.-D. Gu X.-L. Zhou Lei Lin department of applied Mathematics Shanghai University of Finance and Economics Shanghai 200433 China department of Mathematics Shanghai University Shanghai 200436 China

We are interested in the numerical solution of the large nonsymmetric shifted linear system, （A ＋ αI）x -= b, for many different values of the shift a in a wide range. We apply the Saad＇s flexible preconditioning technique to the solution of the shifted systems. Such flexible preconditioning with a few parameters could probably cover all the shifted systems with the shift in a wide range. Numerical experiments report the effectiveness of our approach on some problems.

关键词： Shifted linear systems 65F10 65Y20. Arnoldi method Flexible preconditioning

Maximization of the sum of the trace ratio on the Stiefel manifold, I: Theory

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Science China Mathematics 2014年第12期57卷 2495-2508页

作者： ZHANG LeiHong LI RenCang department of applied Mathematics Shanghai University of Finance and Economics department of Mathematics University of Texas at Arlington

We are concerned with the maximization of tr（v T Av）/tr（v T Bv）＋tr（v T Cv） over the Stiefel manifold {v ∈ R m×l ｜ v T v = Il} （l 〈 m）, where B is a given symmetric and positive definite matrix, A and C are symmetric matrices, and tr（. ） is the trace of a square matrix. This is a subspace version of the maximization problem studied in Zhang （2013）, which arises from real-world applications in, for example, the downlink of a multi-user MIMO system and the sparse Fisher discriminant analysis in pattern recognition. We establish necessary conditions for both the local and global maximizers and connect the problem with a nonlinear extreme eigenvalue problem. The necessary condition for the global maximizers offers deep insights into the problem, on the one hand, and, on the other hand, naturally leads to a self-consistent-field （SCF） iteration to be presented and analyzed in detail in Part II of this paper.

关键词： trace ratio Rayleigh quotient Stiefel manifold nonlinear eigenvalue problem optimality condition eigenspace

An Existence Theorem of Solution for a Singular Third-order Two-point Boundary value Problem

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Chinese Quarterly Journal of Mathematics 2008年第1期23卷 61-66页

作者：姚庆六 department of applied Mathematics Nanjing University of Finance and Economics

By constructing suitable Banach space, an existence theorem is established under a condition of linear growth for the third-order boundary value problem u″′（t）＋f（t,u（t）,u′（t））=0,0〈t〈1,u（0）=u′（0）=u′（1）=0, where the nonlinear term contains first and second derivatives of unknown function. In this theorem the nonlinear term f（t, u, v, w） may be singular at t = 0 and t = 1. The main ingredient is Leray-Schauder nonlinear alternative.

关键词： singular ordinary differential equation boundary value problem existence theorem nonlinear alternative

Existence of solutions and positive solutions to a fourth-order two-point BvP with second derivative

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Journal of Zhejiang University-Science A(applied Physics & Engineering) 2004年第3期5卷 104-108页

作者：姚庆六 department of applied Mathematics Nanjing University of Finance and Economics

Several existence theorems were established for a nonlinear fourth-order two-point boundary value problem with second derivative by using Leray-Schauder fixed point theorem, equivalent norm and technique on system of integral equations. The main conditions of our results are local. In other words, the existence of the solution can be determined by considering the height of the nonlinear term on a bounded set. This class of problems usually describes the equilibrium state of an elastic beam which is simply supported at both ends.

关键词： Nonlinear fourth-order equation Two-point boundary value problem Solution and positive solution Existence Fixed point theorem

Multifunctional catalytic sites regulation of atomic-scale iridium on orthorhombic-CoSe_(2)for high efficiency dual-functional alkaline hydrogen evolution and organic degradation

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Journal of Energy Chemistry 2024年第5期92卷 271-281页

作者： Jingjing Huang Chenglin Zhong Yanjie Xia Jia Liu Guizhen Li Chao Yang Jiahong Wang Qian Wang Zhenbao Zhang Feng Yan Jianghua Wu Yu Deng Zhenjiang Zhou Xingchen He Paul K.Chu Woon-Ming Lau Xue-Feng Yu College of Chemistry and Chemical Engineering Linyi UniversityLinyi 276005ShandongChina Shenzhen Engineering Center for the Fabrication of Two-Dimensional Atomic Crystals Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055GuangdongChina National Laboratory of Solid State Microstructures Jiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093JiangsuChina College of Biosystems Engineering and Food Science Zhejiang UniversityHangzhou 310058ZhejiangChina department of Physics Department of Materials Science and EngineeringDepartment of Biomedical EngineeringCity University of Hong KongTat Chee AvenueKowloonHong KongChina

The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporating iridium(Ir)ions on the atomic scale into orthorhombic-CoSe2(Ir-CoSe_(2))was *** hydrogen evolution activity in alkaline media such as a low overpotential of 48.7 mv at a current density of 10 mA cm^(-2)and better performance than commercial Pt/C catalysts at high current densities were found in the Ir-CoSe_(2) *** the experiments and theoretical calculations,it was revealed that Ir enabled CoSe_(2)to form multifunctional sites to synergistically catalyze alkaline HER by promoting the adsorption and dissociation of H_(2)O(Ir sites)and optimizing the binding energy for H^(*)on Co *** was noticeable that the electrolytic system comprising the Ir-CoSe_(2)electrode not only produced hydrogen efficiently via HER,but also degraded organic pollutants(Methylene blue).The cell voltage of the dual-function electrolytic system was 1.58 v at the benchmark current density of 50 mA cm^(-2),which was significantly lower than the conventional water splitting *** was indicated that this method was a novel strategy for designing advanced HER electrocatalysts by constructing multifunctional catalytic sites for hydrogen production and organic degradation.

关键词： Orthorhombic-CoSe_(2) Multifunctional sites design Hydrogen evolution reaction Synergistically catalyze Methylene blue oxidation

Assessment of the impacts of land-use change and slope position on soil loss by magnetic susceptibility-based models

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International Journal of Sediment Research 2023年第3期38卷 455-468页

作者： Saidati Bouhlassa Naima Bouhsane Laboratory of applied Chemistry of Materials Department of Chemistry Faculty of Sciences Mohammed V University

Soil loss is a global environmental problem resulting from the erosion process caused by many factors,including land use and slope position. Estimation of total soil loss from agricultural fields is useful for understanding the consequences of historical and current erosion. The main purposes of the current study are to explore the application of magnetic measurements in the mapping and measuring soil redistribution in cultivated（MZ13） and forested（MZ17） transects in a Moroccan subcatchment, to develop a methodological approach correlating magnetic susceptibility（MS, denoted χ） variation to soil erosion/aggradation, and to discriminate the effects of land-use change and slope position on the total cumulative soil loss, assessed using three recently established erosion models based on an MS *** measurements were done on several soil cores collected at different slope positions including the summit（SU）, shoulder（SH）, back slope（BS）, foot slope（FS）, toe slope（TS） for Transects MZ13 and MZ17.A tillage homogenization（T-H） model, simple correlation model（SCM）, and simple proportional model（SPM） based on χlf（where lf indicates low frequency） were applied to estimate soil loss for each slope position in the two transects. The results show that the correlation between χlfand χfd（which is the frequency-dependent magnetic susceptibility percentage） is positive and high for the two transects（R2= 0.95; p ves that it is possible to trace and monitor soil erosion and deposition using magnetic parameters(χlfand χfd%) for different slope positions along cultivated and forested transects. The results confirm that the soil losses strongly depend on land use and slope position. Higher erosion depth（d） estimated using the three erosi

关键词： Magnetic susceptibility Soil loss Tillage homogenization Upper slope Lower slope Land use

STATE DERIvATIvE-FREE vARIABLE STRUCTURE MODEL REFERENCE ADAPTIvE CONTROL OF LINEAR PARABOLIC SYSTEMS

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Journal of Systems Science & Complexity 2013年第6期26卷 957-967页

作者： JIA Chaohua SHAO Zhi-Chao School of Mathematics and Systems Science Beihang University department of applied Mathematics School of StatisticsUniversity of International Business and Economics

The problem of constructing a model dimensional parabolic system is considered in this reference adaptive control law for an uncertain 1- article. The controller designed here involves only the plant state but no its derivatives. A priori bounds on the plant＇s uncertain parameters are used to propose switching laws which serve as an adaptive mechanism. The exponential decay to zero of the state error with any prescribed rate is guaranteed by choosing a controller parameter correspondingly. Numerical studies are also presented to illustrate the applicability of the control law.

关键词： Distributed parameter systems model reference adaptive control parabolicsystems.