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Hierarchical linear regression models for conditional quantiles

Science China Mathematics 2006年第12期49卷 1800-1815页

作者： TIAN Maozai & CHEN Gemai School of Statistics, Renmin university of China, Beijing 100872, China and Center for Applied Statistics, Renmin university of China, Beijing 100872, China Department of Mathematics and Statistics, university of Calgary, Canada School of Statistics Renmin University of China Beijing China Center for Applied Statistics Renmin University of China Beijing China Department of Mathematics and Statistics University of Calgary Canada

The quantile regression has several useful features and therefore is gradually developing into a comprehensive approach to the statistical analysis of linear and nonlinear response models,but it cannot deal effectively with the data with a hierarchical *** practice,the existence of such data hierarchies is neither accidental nor ignorable,it is a common *** ignore this hierarchical data structure risks overlooking the importance of group effects,and may also render many of the traditional statistical analysis techniques used for studying data relationships *** the other hand,the hierarchical models take a hierarchical data structure into account and have also many applications in statistics,ranging from overdispersion to constructing min-max ***,the hierarchical models are virtually the mean regression,therefore,they cannot be used to characterize the entire conditional distribution of a dependent variable given high-dimensional ***,the estimated coefficient vector (marginal effects)is sensitive to an outlier observation on the dependent *** this article,a new approach,which is based on the Gauss-Seidel iteration and taking a full advantage of the quantile regression and hierarchical models,is *** the theoretical front,we also consider the asymptotic properties of the new method,obtaining the simple conditions for an n1/2-convergence and an asymptotic *** also illustrate the use of the technique with the real educational data which is hierarchical and how the results can be explained.

关键词： hierarchical quantile regression models,EQ algorithm,fixed effects,random effects,regression quantile.

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HEAT ENERGY DISSIPATION IN FATIGUE DAMAGE PROCESS

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Acta Metallurgica Sinica(English Letters) 1992年第5期5卷 373-378页

作者： TUNG Xiaoyan Northwestern Polytechnical university,Xi’an,ChinaWANG Dejun XU Hao Northeast university of Technology,Shenyang,China Northwestern Polytechnical Univ Xi'an China

Using the dissipated energy as an essential parameter,the energy dissipative structure in pro- cess of fatigue damage of materials has been *** thermodynamic analysis for irreversible energy dissipation in fatigue damage process,the heat dissipative variations in cyclic loading process as well as in a cycle have been systematically studied on the basis of low cycle fatigue tests and infrared measurement of self-heating ***,the cyclic hysteresis energy and efficient energy dissipation (stored energy) have been proposed during fatigue damage process.

关键词： fatigue damage energy dissipation cycle loading process

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ANALYSIS OF THE THERMOPHYSICAL PARAMETERS OF MOIST WOOD PARTICLE MATERIAL IN A COUPLED HEAT AND MASS TRANSFER PROCESS OF FREEZING BY USING FINITE ELEMENT METHOD

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Journal of Northeast Forestry university 1991年第2期2卷 69-76页

作者： Shang DekuNortheast Forestry university Northeast Forestry university China

The coupled heat and moisture transfer in a freezing process of wood particle material was mathematically modeled in the paper. The models were interactively solved by using the numerical method(the finite element method and the finite difference method). By matching the theoretical calculation to an experiment, the nonlinear problem was analyzed and the variable thermophysical parameters concerned was evaluated. The analysis procedure and the evaluation of the parameters were presented in detail. The result of the study showed that by using the method as described in the paper, it was possible to determine the variable (with respect to temperature, moisture content and freezing state) thermophysical parameters which were unknown or difficult to measure as long as the governing equations for a considered process were available. The method can significantly reduces the experiment efforts for determining thermophysical parameters which arc very complicated to measure. The determined variable of the effective heat conductivity of wood particle material was given in the paper. The error of the numerical calculation was also estimated by the comparison with a matched experiment.

关键词： Finite element method Freezing process Coupled heat and mass transfer Variable thermophysical parameters

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Linear low-rank approximation and nonlinear dimensionality reduction

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Science China Mathematics 2004年第6期47卷 908-920页

作者： ZHANG Zhenyue & ZHA Hongyuan Department of Mathematics, Zhejiang university, Yuquan Campus, Hangzhou 310027, China Department of Computer Science and Engineering, The Pennsylvania State university, university Park, PA 16802, U.S.A. Department of Mathematics Zhejiang University Yuquan Campus Hangzhou China Department of Computer Science and Engineering The Pennsylvania State University University Park USA

We present our recent work on both linear and nonlinear data reduction methods and algorithms: for the linear case we discuss results on structure analysis of SVD of columnpartitioned matrices and sparse low-rank approximation; for the nonlinear case we investigate methods for nonlinear dimensionality reduction and manifold learning. The problems we address have attracted great deal of interest in data mining and machine learning.

关键词： singular value decomposition low-rank approximation sparse matrix nonlinear dimensionality reduction principal manifold subspace alignment data mining

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ANALYSIS OF SPATIAL COMPLIANCE BEHAVIOR OF COILED SPRINGS VIA SCREW THEORY

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Chinese Journal of Mechanical Engineering 2002年第4期15卷 293-297,318页

作者： Ding XilunRobotics Research Institute, Beijing university of Aeronautics and Astronautics,Beijing 100083, ChinaSelig J M South Bank university, UK Robotics Research Institute Beijing University of Aeronautics and Astronautics 北京 100083 South Bank university 英国

A new method is presented to describe and analyze the spatial compliance ofcoiled springs using screw theory. After an abbreviated description for the deformation of a beamelement using screw theory, the spatial compliance density for a beam element is derived based onthe fundamental material theory and reasonable assumptions, and the spatial compliance of the beamwith finite length is obtained by integral. The spatial compliance of coiled springs is furtheranalyzed using the spatial compliance density of the beam element. By calculating theeigencompliance and Ball's principle screws for the whole compliance of system, the complianceproperties varying with the basic physical parameters of the system are illustrated in detail. Thebasic ideas can be used for the design and application of the coiled springs and the other compliantmechanisms with spatial compliant beam element.

关键词： eigencompliance coiled springs screw theory mechanisms

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STUDY ON COMPONENTS OF FURFURAL RESIDUE FROM CORNCOB

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Journal of Northeast Forestry university 1991年第1期2卷 98-107页

作者： Zhang ShiNortheast Forestry university Northeast Forestry university China

In this paper, the components of furfural residue are analyzed. Total sugar content occupies 47.36% of absolute drying residue, and glucose occupies 83.23% of total sugar content. By combining the phcnyl nucleus exchange reaction with nitrobenzene oxidation, the quantity of structural units of phcnyl nuclei was determined, products from syringyl units occupy 50% of klason lignin. Especially, diphcnyl methane type syringyl units occupy 38.80%, and guaiacyl units 25%, other condensed guaiacyl units about 20%. The furfural residue is not a good material for the manufacture of adhcsivcs, but for active carbon. The yield of furfural residue may achieve about 350 thousand tons per year, but it has not been used in industry in China.

关键词： Hydrolysis of corncob Lignin Nucleus exchange reaction Alkaline nitrobenzene oxidation Guaiacyl nuclei Syringyl nuclei Glucose

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Synthesis and Crystal Structure of cis-Bis(3-hydroxy2-ethyl-4-pyranonato)dioxomolybdenum(Ⅵ)

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Chinese Journal of Structural Chemistry 2003年第5期22卷 573-576页

作者： LU Zai-Sheng② NIU De-Zhong LI Xiu-Ling (Department of university, Xuzhou Normal university, Xuzhou 221009, China) Department of university Xuzhou Normal University Xuzhou 221009

The complex MoO2(C7H7O3)2 has been prepared by the reaction of 3-hydroxy- 2-ethyl-4-pyranone with (NH4)6Mo7O244H2O. The single-crystal X-ray study shows that the coordination sphere about the molybdenum atom in the complex consists of six oxygen atoms arranged in a distorted octahedral geometry with the dioxo ligands in cis positions. The crystal is of monoclinic, space group P21/c with a = 8.3968(2), b = 12.7534(4), c = 14.5443(4) ? b = 96.277(1), V = 1548.18(7) ?, Z = 4, C14H14O8Mo, Mr = 406.19, Dc = 1.743g/cm3, m = 0.886mm-1, F(000) = 816, R = 0.0444 and wR = 0.1091 for 2336 observed reflections with I>2s(I). The average Mo=O bond length is 1.695(4) ? The two ketonic oxygen atoms of the pyranone moieties are trans to the oxo ligands and the hydroxy oxygen atoms are trans to each other. The average MoO bond lengths are 2.248(4) ?for the ketone oxygens and 2.005(3) ?for the hydroxy oxygens. The average ligand bite angle of OMoO is 75.2(2) and the bond angle between two Mo=O is 105.1(2). The dihedral angle is 79.16(2)?between two chelate ring planes.

关键词： crystal structure molybdenum(VI) complex 3-hydroxy-2-ethyl-4-pyranone

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Conduction Properties and Scattering Mechanisms in F-doped Textured Transparent Conducting SnO_2 Films Deposited by APCVD

引用

Journal of Materials Science & Technology 1997年第1期13卷 50-56页

作者： Deheng ZHANG(Dept. of Physics, Shandong university, Jinan 250100, China)Honglei MA(Institute of Optoelectronic Materials and Devices, Shandong university, Jinan 250100, China) Dept. of Physics Shandong University Jinan 250100 China Institute of Optoelectronic Materials and Devices Shandong University Jinan 250100 China

Transparent conducting F-doped texture SnO2 films with resistivity as low as 5× 10-4 Ω ·cm,with carrier concentrations between 3.5 × 1020 and 7× 1020 cm-3 and Hall mobilities from 15.7 to 20.1 cm2/(V/s) have been prepared by atmosphere pressure chemical vapour deposition (APCVD). These polycrystalline films possess a variable preferred orientation, the polycrystallite sizes and orientations vary with substrate temperature. The substrate temperature and fluorine flow rate dependence of conductivity, Hall mobility and carrier conentration fOr the resultingfilms have been obtained. The temperature dependence of the mobiity and carrier concentrationhave been measured over a temperature range 16～400 K. A systematically theoretical analysis on scattering mechanisms for the highly conductive SnO2 films has been given. Both theoretical analysis and experimental results indicate that for these degenerate, polycrystalline SnO2 ：F films in the low temperature range (below 100 K), ionized impurity scattering is main scattering mechanism. However, when the temperature is higher than 100 K, the lattice vibration scattering becomes dominant. The grain boundary scattering makes a small contribution to limit the mobility of the films.

关键词： SnO cm Conduction Properties and Scattering Mechanisms in F-doped Textured Transparent Conducting SnO2 Films Deposited by APCVD

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SOBOLEV INEQUALITY ON RIEMANNIAN MANIFOLDS

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Chinese Annals of Mathematics,Series B 2005年第4期26卷 651-658页

作者： WANG MENG Department of Mathematics, Zhejiang university, Hangzhou 310027, China School of Mathematical Sciences, Pudan university, Shanghai 200433, China. Department of Mathematics Zhejiang University Hangzhou 310027 China School of Mathematical Sciences Fudan University Shanghai 200433 China

Let M be an n dimensional complete Riemannian manifold satisfying the doublingvolume property and an on-diagonal heat kernel estimate. The necessary-sufficientcondition for the Sobolev inequality ‖f‖q ≤ Cn,,v,p,q(... 详细信息

关键词： Sobolev inequality Complete manifold Riesz transform Potential Heat kernel

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ON THE ESTIMATIONS OF BOUNDS FOR DETERMINANT OF HADAMARD PRODUCT OF H-MATICES

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Journal of Computational Mathematics 2001年第4期19卷 365-370页

作者： Yao-tang Li (Department of Mathemotics, Yuunan university, Kunming 650091, China) Ji-cheng Li (Department of Mathematics, Xian Jiaotong university, Xian 71049, China) 云南大学云南昆明 650091 西安交通大学陕西西安 710049

In this paper, some estimations of bounds for determinant of Hadamard product of H-matrices are given. The main result is the following: if A= (aij) and B=(bij) are nonsingular H-matrices of order n and ∏in=1, aiibii> 0, and Ak and Bk, k = 1, 2,…,n, are the k× k leading principal submatrices of A and B, respectively, then where M(Ak) denotes the comparison mains of Ak.

关键词： H-matrix Determinant Hadamard product.

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