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Strong uniqueness of best approximations in spaces of bounded linear operators

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Science china Mathematics 2004年第3期47卷 339-351页

作者： LI Chong HE Jinsu Department of Mathematics, zhejiang university hangzhou 310027, china Department of Mathematics, zhejiang Normal university Jinhua 321004, china 1. Department of Mathematics Zhejiang University 310027 Hangzhou China 2. Department of Mathematics Zhejiang Normal University 321004 Jinhua China

The present paper is concerned with problems of the strong uniqueness of the best approximation and the characterization of a uniqueness element in operator *** results on the strong uniqueness of the best approximation operatorfrom RS-sets are proved and the uniqueness element of a sun in the compactoperator space from c0 to c0 is characterized by the strict Kolmogorov's *** recent results due to Lewicki and others are extended and improved.

关键词： best approximation operator, RS-set, sun, strong uniqueness, uniqueness element.

CHEMOENZYMATIC SYNTHESIS OF BIODEGRADABLE POLY(1’-O-VINYLADIPOYL-SUCROSE)

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Chinese Journal of Polymer Science 2002年第6期20卷 579-584页

作者： De-shui Lu Qi Wu Xian-fu Lin Department of Chemistry zhejiang university hangzhou 310027, china zhejiang Univ Dept Chem Hangzhou 310027 Peoples R China

A novel polymer containing the sucrose group was synthesized by radical polymerization from an enzymatically prepared monomer, 1'-O-vinyladipoyl-sucrose (VAS). Transesterification reaction of sucrose with divinyl adipate in anhydrous pyridine catalyzed by an alkaline protease from Bacillus subtilis at 60degreesC for 7 days gave VAS (yield 55%) without any blocking/deblocking steps. The vinyl sucrose ester could be polymerized with potassium persulfate and H2O2 as initiator to give poly(1'-O-vinyladipoyl-sucrose) with M-n = 33,000 and M-w = 53,200, M-w/M-n = 1.61. The polymer was biodegradable. After 6 days in aqueous buffer (pH 7), this alkaline protease could degrade poly(1'-O-vinyladipoyl-sucrose) to M. of ca. 1080, M-w/M-n = 3.30 (37degreesC), and M-n of ca. 5200, M-w/M-n = 2.44 (4degreesC). The polymer containing the sucrose branch would be a functional material in various application fields.

关键词： divinyladipate sucrose alkaline protease polymerization biodegradation

Empirical Euclidean likelihood for general estimating equations under association dependence

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Applied Mathematics(A Journal of Chinese Universities) 2010年第4期25卷 437-446页

作者： CHEN You-you ZHANG Li-xin Department of Mathematics, zhejiang university, hangzhou 310027, china Department of Mathematics Zhejiang University Hangzhou China

Empirical Euclidean likelihood for general estimating equations for association dependent processes is investigated. The strong consistency and asymptotic normality of the blockwise maximum empirical Euclidean likelihood estimator are presented. We show that it is more efficient than estimator without blocking. The blockwise empirical Euclidean log-likelihood ratio asymptotically follows a chi-square distribution.

关键词： Empirical Euclidean likelihood blockwise positive association negative association.

Estimation for nearly unit root processes with GARCH errors

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Applied Mathematics(A Journal of Chinese Universities) 2010年第3期25卷 297-306页

作者： YUAN Yu-ze ZHANG Rong-mao Department of Mathematics, zhejiang university, hangzhou 310027, china Department of Mathematics Zhejiang University Hangzhou China

In this paper the limiting distribution of the least square estimate for the autoregressive coefficient of a nearly unit root model with GARCH errors is derived. Since the limiting distribution depends on the unknown variance of the errors, an empirical likelihood ratio statistic is proposed from which confidence intervals can be constructed for the nearly unit root model without knowing the variance. To gain an intuitive sense for the empirical likelihood ratio, a small simulation for the asymptotic distribution is given.

关键词： Nearly unit root GARCH error least square estimation Ornstein-Uhlenbeck process empirical likelihood.

LEAST-SQUARES METHOD-BASED FEATURE FITTING AND EXTRACTION IN REVERSE ENGINEERING

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Chinese Journal of Mechanical Engineering 2003年第2期16卷 163-166页

作者： Ke YinglinSun QingLu ZhenCollege of Mechanical andEnergy Engineering,zhejiang university,hangzhou 310027, china College of Mechanical and Energy Engineering Zhejiang University Hangzhou 310027 China

The main purpose of reverse engineering is to convert discrete data pointsinto piecewise smooth, continuous surface models. Before carrying out model reconstruction it issignificant to extract geometric features because the quality of modeling greatly depends on therepresentation of features. Some fitting techniques of natural quadric surfaces with least-squaresmethod are described. And these techniques can be directly used to extract quadric surfaces featuresduring the process of segmentation for point cloud.

关键词： reverse engineering feature extraction least-squares method segmentationand surface fitting

Surface electromagnetic modes contribution to the anomalous terahertz transmission through double-layered metal hole array

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Science china(Information sciences) 2012年第1期55卷 90-97页

作者： RAO Lei1&YANG DongXiao1,2 1Department of Information Science and Electronic Engineering,zhejiang university,hangzhou 310027,china 2Research center for Terahertz Technology,zhejiang university,hangzhou 310027,china 1. Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China2. Research Center for Terahertz Technology Zhejiang University Hangzhou 310027 China

Terahertz transmission spectra through both single-layered and double-layered sub-wavelength metal hole arrays were calculated using rigorous mode-matching *** dispersion relations of the single-layered and double-layered metal hole arrays were obtained by FDTD *** are three anomalous peaks in the spectrum of the double-layered metal hole array,which arise from the three surface electromagnetic modes appearing in the dispersion *** comparing the transmission spectra and the dispersion relations of the single-layered and double-layered metal hole arrays,it was found that the two surface electromagnetic modes at higher frequencies are introduced by the single-layered metal hole array,while the one at lower frequencies is introduced by the double-layered metal hole *** validity of the analysis was qualitatively verified by the experimental *** structure can be finely designed for potential applications,such as wideband filtering.

关键词： surface electromagnetic modes double-layered metal hole array terahertz

Online uniform machine covering with the known largest size

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Progress in Natural Science:Materials International 2007年第11期17卷 1271-1278页

作者： Cao Shunjuan1,2 and Tan Zhiyi1,3(1. Department of Mathematics, zhejiang university, hangzhou 310027, china 2. Department of Mathematics, zhejiang Forestry university, hangzhou 311300, china 3. State Key Laboratory of CAD & CG, zhejiang university, hangzhou 310027, china) Department of Mathematics Zhejiang University Hangzhou 310027 China Department of Mathematics Zhejiang Forestry University Hangzhou 311300 China State Key Laboratory of CAD & CG Zhejiang University Hangzhou 310027 China

This paper investigates the semi-online scheduling problem with the known largest size on two uniform machines. The objective is to maximize the minimum machine completion time. Both lower bounds and algorithms are given. Algorithms are optimal for the majority values of s≥1, where s is the speed ratio of the two machines. The largest gap between the competitive ratio and the lower bound is about 0.064. Moreover, the overall competitive ratio 2 matches the overall lower bound.

关键词： scheduling and covering uniform machine design and analysis of algorithm online competitive ratio

On Holomorphic Automorphisms of a Class of Non-homogeneous Rigid Hypersurfaces in C^(N+1)

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Chinese Annals of Mathematics,Series B 2010年第2期31卷 201-210页

作者： Qingyan WU Department of Mathematics,Linyi Normal university,Linyi 276005,Shandong,china Department of Mathematics,zhejiang university,hangzhou 310027,china Department of Mathematics Linyi Normal University Linyi 276005 Shandong China Department of Mathematics Zhejiang University Hangzhou 310027 China

The author determines the real-analytic infinitesimal CR automorphisms of a class of non-homogeneous rigid hypersurfaces in CN+1 near the origin,and the connected component containing the identity transformation of al... 详细信息

关键词： Real-analytic infinitesimal CR automorphisms Rigid hypersurfaces Holomorphic automorphisms

Energy functionals and killing transform

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Chinese Science Bulletin 1997年第19期42卷 1593-1596页

作者： YING JiangangDepartment of Mathematics, zhejiang university, hangzhou 310027, china Istitute of Applied Mathematics, Chinese Academy of sciences, Beijing 100080, china Department of Mathematics Zhejiang University Hangzhou China Istitute of Applied Mathematics Chinese Academy of Sciences Beijing China

LET X=（Xt,Px） be a right Markov process with state space （E,ε）, semigroup （P1） andresolvent （Uq）. As in ref.[1, 2], we denote by Excq（X ）, Disq（X） and Conq（X） thecones of excessive, dissipative, conservative measures of X, respectively, and by Sq（X） thecone of excessive functions of X. By convention we drop the superscript q when it is zero. LetMF be the set of all exact multiplicative functional of X. For any given M∈MF, writeEM:= {x∈E:PM0 = 1 = 1} and SM: = inf} t>0: M1= 0 } for the set of

关键词： right processes multiplicative functionals Revuz measures energy functional capacity.