云南高校图书馆联盟文献共享服务平台- APPROXIMATION

APPROXIMATION: 作品数：1231被引量：1216H指数：13; 导出分析报告; 相关领域：理学更多>>; 相关作者：曹飞龙吴嘎日迪谢庭藩沈燮昌周颂平更多>>; 相关机构：北京大学宁夏大学西北工业大学中国计量学院更多>>; 相关期刊：更多>>; 相关基金：国家自然科学基金国家重点基础研究发展计划国家教育部博士点基金中国博士后科学基金更多>>

An improved δ-Eddington approximation被引量：1: 《Chinese Science Bulletin》1999年第4期304-309,共6页QIU JinhuanInstitute of Atmospheric Physics , Chinese Academy of Sciences , Beijing 100029, China; Based on an accuracy analysis of two-stream approximations, an improved δ-Eddington ap-proximation is developed. The approximation has much better accuracy than all exiting two-stream ap-proximations as the optical d...; 关键词：radiation FLUX FRACTIONAL FACTOR of δ-function EDDINGTON approximation.

Orthogonality in Banach spaces and orthogonal multiscale L^1-approximation: 《Chinese Science Bulletin》1999年第1期25-35,共11页YANG LihuaDepartment of Scientific Computing and Computer Applications, School of Mathematics and Computing Science, Zhongshan (Sun Yatsen) University, Guangzhou 510275, China Institute of Mathematics, Chinese Academy of Sciences, Beijing 100080, China; The orthogonality in Hilbert spaces is extended to the general Banach spaces and a concrete shift-invariant orthogonal family in L^1(R) is constructed. The corresponding projection approximation theorems and the algor...; 关键词：BANACH SPACES ORTHOGONALITY APPROXIMATION multiscale analysis.

Lipschitz continuity of best approximations and Chebyshev centers被引量：2: 《Chinese Science Bulletin》1998年第3期185-188,共4页LI Chong 1 and WANG Xinghua 2 1. Center for Mathematical Sciences, Zhejiang University, Hangzhou 310027, China 2. Department of Mathematics, Hangzhou University, Hangzhou 310028, China; ChinaMajorKeyProjectforBasicResearcher;NationalNaturalScienceFoundationofChina;partlysupportedbyZhejiangProvincialNaturalScienceFoundation ;ChinaPostdoctoralScienceFoundation; The Lipschitz continuity results are given for best approximations and Chebyshev centers. Consequently, the open problem presented by Septycki and Vleck is solved completely.; 关键词：best APPROXIMATION CHEBYSHEV CENTER UNIFORM convexity.

A remark on "an approximation condition and extremal quasiconformal extension被引量：8: 《Chinese Science Bulletin》1997年第21期1765-1767,共3页Chen, JX Chen, ZG; LET D be the unit disk in the complex plane C and f be a sense preserving quasisymmetrichomeomorphism of D onto itself. Denote by Q a quadrilateral D （z₁, z₂, z₃, z₄ ） wit...; 关键词：quasisymmetric function EXTREMAL quasiconformal MAPPING TEICHMÜLLER mapping.

On a conjecture in Moreau-Yosida approximation of a nonsmooth convex function: 《Chinese Science Bulletin》1997年第17期1423-1426,共4页Sun, DF Han, JY; CONSIDER minf(x) (1) where f: R^n→ [-∞, +∞] is an extended valued closed proper convex function. The Moreau-Yosida approximation F_λ of f is defined; 关键词：CONVEX function Moreau-Yosida APPROXIMATION PIECEWISE smooth.

A note on a result of Abercrombie: 《Chinese Science Bulletin》1997年第14期1151-1154,共4页ZHAI WenguangDepartment of Mathematics, Shandong Normal University, Jinan 250014, China; SUPPOSE θ∈[1,+ ∞) is any real number. The sequence B_θ={[nθ]|n∈N}is calledBeatty’s sequence determined by θ. Beatty sequences have been the subject of intensive inves-tigation in recent years on account of the...; 关键词：Bealty’s SEQUENCE DIVISOR problem RATIONAL approximation.

A minimization problem associated with gap phenomenon: 《Chinese Science Bulletin》1997年第13期1073-1076,共4页Shen, YT Yan, SS; This work was supported by the National Natural Science Foundation of China (Grant No. 19571028);the Guangdong Provincial Natural Science Foundation.; In this note, we consider （2） assuming that f satisfies the following conditions（f₁） and（f₂）. We will develop a method entirely different from that in ref. [2] to prove that for anyweak sol...; 关键词：APPROXIMATION ELLIPTIC SYSTEM HARMONIC map.

Characteristics of EM scattering on dielectric fractal surface: 《Chinese Science Bulletin》1997年第6期523-526,共4页Wang, MX Li, J Ren, L; The regular and smooth objects are always studied in conventional geometry. But very rough and irregular objects which have self-similarity, the fractal structure, are efficiently solved by fractal geometry. The self-...; 关键词：EM SCATTERING FRACTAL structure ROUGH surface KIRCHHOFF approximation.

Approximation problems in sigma-pi neural networks: 《Chinese Science Bulletin》1996年第13期1072-1074,共3页李纯明陈天平; Project supported in part by the Natural Science Foundation of Shanghai;the National Key Laboratory of Intelligent Technology and Systems of China.; Let the function n: R^R→R be defined by Recently, approximating continuous function of several variables by the composition and superposition 9oπ of the function π and a function of one variable g is arousing great...; 关键词：APPROXIMATION THEORY sigma-pi NEURAL NETWORKS denseness.

Approximation for multi-knapsack problem: 《Chinese Science Bulletin》1996年第12期1042-1045,共4页张立昂李路阳黄雄; Project supported in part by the National High-tech Project of China.; Suppose that ∏ is a maximization problem,and tha A is an approximation algorithmfor ∏.For every instance I of ∏,define R_A(I)=OPT(I)/A(I),where OPT(I)is the optimal value of I;A(I)is the value of approximate soluti...; 关键词：KNAPSACK PROBLEM APPROXIMATION algorithm for combinatorial PROBLEMS COMPUTATIONAL complexity.

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