检索结果-南通市图书馆

Method of sequential mesh on Koopman-Darmois distributions

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2010年第4期53卷 917-926页

作者： LI Yan & PU XiaoLong school of finance and statistics,East china Normal {4.,Shanghai 20024.,china 1. school of finance and statistics East China Normal University Shanghai 200241 China

For costly and/or destructive tests,the sequential method with a proper maximum sample size is *** on Koopman-Darmois distributions,this paper proposes the method of sequential mesh,which has an acceptable maximum sample *** comparison with the popular truncated sequential probability ratio test,our method has the advantage of a smaller maximum sample size and is especially applicable for costly and/or destructive tests.

关键词： method of sequential mesh sequential probability ratio test (SPRT) Koopman-Darmois distributions maximum sample size

The steady-state solution of dendritic growth from the undercooled binary alloy melt with the far field flow

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2009年第8期52卷 2280-2287页

作者： CHEN MingWen1,2, WANG ZiDong2 & XU JianJun2,3,4.1 school of Applied Sciences, university of Science and Technology Beijing, Beijing 100083, china 2 school of Materials Science and Engineering, university of Science and Technology Beijing, Beijing 100083, china 3 school of Mathematical Sciences, Nankai university, Tianjin 300071, china 4.Department of mathematics and statistics, McGill university, Montreal H3A 2K6, Canada school of Applied Sciences University of Science and Technology Beijing Beijing 100083 China school of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China school of Mathematical Sciences Nankai University Tianjin 300071 China Department of mathematics and statistics McGill University Montreal H3A 2K6 Canada

The steady-state dendritic growth from the undercooled binary alloy melt with the far field flow is considered. By neglecting the interface energy, interface kinetics and buoyancy effects in the system, we obtaine the steady-state solution for the case of the large Schmidt number, in terms of the multiple variable expansion method. The changes of the temperature and concentration fields, the morphology of the interface, the normalization parameter and the Peclet number of the system induced by uniform external flow are derived. The results show that, compared with the system of dendritic growth from undercooled pure melt, the convective flow in the system of growth from undercooled binary alloy has stronger effects on the morphology of the interface. Nevertheless, the shape of the interface still remains nearly a paraboloid.

关键词： binary alloy melt convection dendritic growth interfaces steady-state solution multiple variable expansion method

MULTI-DIMENSIONAL REFLECTED BACKWARD STOCHASTIC DIFFERENTIAL EQUATIONS AND THE COMPARISON THEOREM

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2010年第5期30卷 1819-1836页

作者：吴臻消华 school of mathematics Shandong University school of mathematics and statistics Shandong University at Weihai

In this article, we study the multi-dimensional reflected backward stochastic differential equations. The existence and uniqueness result of the solution for this kind of equation is proved by the fixed point argument where every element of the solution is forced to stay above the given stochastic process, i.e., multi-dimensional obstacle, respectively. We also give a kind of multi-dimensional comparison theorem for the reflected BSDE and then use it as the tool to prove an existence result for the multi-dimensional reflected BSDE where the coefficient is continuous and has linear growth.

关键词： backward stochastic differential equations comparison theorem local time

Equivalence problem for Bishop surfaces

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2010年第3期53卷 687-700页

作者： HUANG XiaoJun 1, & YIN WanKe 2 1 Department of mathematics, Rutgers university, New Brunswick, NJ 08902, USA 2 school of mathematics and {4., Wuhan university, Wuhan 4.0072, china 1. Department of mathematics Rutgers University New Brunswick NJ 08902 USA2. School of Mathematics and Statistics Wuhan University Wuhan 430072 China

The paper has two parts. We first briefly survey recent studies on the equivalence problem for real submanifolds in a complex space under the action of biholomorphic transformations. We will mainly focus on some of the recent studies of Bishop surfaces, which, in particular, includes the work of the authors. In the second part of the paper, we apply the general theory developed by the authors to explicitly classify an algebraic family of Bishop surfaces with a vanishing Bishop invariant. More precisely, we let M be a real submanifold of C 2 defined by an equation of the form w = zz + 2Re(z s + az s+1 ) with s≥ 3 and a a complex parameter. We will prove in the second part of the paper that for s≥ 4.two such surfaces are holomorphically equivalent if and only if the parameter differs by a certain rotation. When s = 3, we show that surfaces of this type with two different real parameters are not holomorphically equivalent.

关键词： equivalence problem Bishop surface Chern-Moser theory elliptic and hyperbolic complex tangents normal form and modular space

Beurling's theorem and invariant subspaces for the shift on Hardy spaces

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2008年第1期51卷 131-142页

作者： QIU ZhiJian school of Economic mathematics, Southwestern university of finance and Economics, Chengdu 610074. {4. 1. school of Economic mathematics Southwestern University of Finance and Economics Chengdu 610074 China

Let G be a bounded open subset in the complex plane and let H 2(G) denote the Hardy space on G. We call a bounded simply connected domain W perfectly connected if the boundary value function of the inverse of the Riemann map from W onto the unit disk D is almost 1–1 with respect to the Lebesgue measure on ?D and if the Riemann map belongs to the weak-star closure of the polynomials in H ∞(W). Our main theorem states: in order that for each M ∈ Lat (M z ), there exist u ∈ H ∞(G) such that M = ∨{uνH 2(G)}, it is necessary and sufficient that the following hold:each component of G is a perfectly connected domainthe harmonic measures of the components of G are mutually singularthe set of polynomials is weak-star dense in H ∞(G).Moreover, if G satisfies these conditions, then every M ∈ Lat (M z ) is of the form uH 2(G), where u ∈ H ∞(G) and the restriction of u to each of the components of G is either an inner function or zero.

关键词： Hardy space invariant subspace shift operator 4.B20 30H05 30E10 4.E15

Split-plot designs with general minimum lower-order confounding

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2010年第4期53卷 939-952页

作者： WEI JiaLin 1,4.YANG JianFeng 1,LI Peng 3 & ZHANG RunChu 1,2,1 school of Mathematical Sciences and LPMC,Nankai university,Tianjin 300071,china 2 KLAS and school of {4. and statistics,Northeast Normal university,Changchun 130024.china 3 school of Mathematical Sciences,Capital Normal university,Beijing 100037,china 4.school of Sciences,Tianjin university of Commerce,Tianjin 300134.china 1. school of Mathematical Sciences and LPMC Nankai University Tianjin 300071 China4. School of Sciences Tianjin University of Commerce Tianjin 300134 China3. School of Mathematical Sciences Capital Normal University Beijing 100037 China2. KLAS and School of Mathematics and Statistics Northeast Normal University Changchun 130024 China

Split-plot designs have been widely used in industrial *** to now,most methods for choosing this kind of designs are based on the minimum aberration (MA) ***,by introducing a new pattern,called aliased effect-number pattern (AENP),Zhang et *** a general minimum lowerorder confounding (denoted by GMC for short) criterion and established a general minimum confounding (also denoted by GMC for saving notations) *** is proved that,the GMC criterion selects optimal designs in a more elaborate manner than the existing ones,and when an experimenter has a prior about the importance ordering of factors in experiments the GMC designs are better than other optimal *** this paper we extend the GMC criterion to the split-plot design case and give a GMC-FFSP criterion for ranking split-plot *** comparisons of the new criterion with the MA-MSA-FFSP criterion are given,and the optimal 32-run split-plot designs up to 14.factors under the two criteria are tabulated for comparison and application.

关键词： fractional factorial design GMC criterion minimum aberration split-plot

The restricted EM algorithm under linear inequalities in a linear model with missing data

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2005年第6期48卷 819-828页

作者： ZHENG Shurong, SHI Ningzhong & GUO Jianhua school of mathematics and statistics, Northeast Normal university, Changchun 130024. {4. Institute of mathematics, Jilin university, Changchun 130012, {4. 1. school of mathematics and statistics Northeast Normal University 130024 Changchun China 2. Institute of mathematics Jilin University 130012 Changchun China

This paper discusses the maximum likelihood estimate of β under linear inequalities A0β≥ a in a linear model with missing data, proposes the restricted EM algo rithm and proves the convergence.

关键词： EM algorithm, linear model, maximum likelihood estimate, missing data.

Weak martingale Hardy spaces and weak atomic decompositions

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2006年第7期49卷 912-921页

作者： HOU Youliang & REN Yanbo school of mathematics and statistics, Wuhan university, Wuhan 4.0072, {4. Department of mathematics & Physics, Henan university of Science and Technology, Luoyang 4.1003, {4. 1. school of mathematics and statistics Wuhan University Wuhan 430072 China 2. Department of mathematics & Physics Henan University of Science and Technology Luoyang 471003 China

In this paper we define some weak martingale Hardy spaces and three kinds of weak atoms. They are the counterparts of martingale Hardy spaces and atoms in the classical martingale Hp-theory. And then three atomic decomposition theorems for martingales in weak martingale Hardy spaces are proved. With the help of the weak atomic decompositions of martingale, a sufficient condition for a sublinear operator defined on the weak martingale Hardy spaces to be bounded is given. Using the sufficient condition, we obtain a series of martingale inequalities with respect to the weak Lp-norm, the inequalities of weak (p ,p)-type and some continuous imbedding relationships between various weak martingale Hardy spaces. These inequalities are the weak versions of the basic inequalities in the classical martingale Hp-theory.

关键词： martingale, weak Hardy space, weak atom, atomic decomposition.

Weighted Profile Least Squares Estimation for a Panel Data Varying-Coefficient Partially Linear Model

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of mathematics,Series B 2010年第2期31卷 247-272页

作者： Bin ZHOU Jinhong YOU Qinfeng XU Gemai CHEN school of finance and statistics East China Normal University Shanghai 200241 China. Department of statistics Shanghai University of Finance and Economics Shanghai 200433 China. Corresponding Author. school of Management Fudan University Shanghai 200433 China. Department of mathematics and statistics University of Calgary Calgary Alberta T2N 1N4 Canada.

This paper is concerned with inference of panel data varying-coefficient partially linear models with a one-way error structure. The model is a natural extension of the well-known panel data linear model （due to Baltagi 1995） to the setting of semiparametric regressions. The authors propose a weighted profile least squares estimator （WPLSE） and a weighted local polynomial estimator （WLPE） for the parametric and nonparametric components, respectively. It is shown that the WPLSE is asymptotically more efficient than the usual profile least squares estimator （PLSE）, and that the WLPE is also asymptotically more efficient than the usual local polynomial estimator （LPE）. The latter is an interesting result. According to Ruckstuhl, Welsh and Carroll （2000） and Lin and Carroll （2000）, ignoring the correlation structure entirely and ＂pretending＂ that the data are really independent will result in more efficient estimators when estimating nonparametric regression with longitudinal or panel data. The result in this paper shows that this is not true when the design points of the nonparametric component have a closeness property within groups. The asymptotic properties of the proposed weighted estimators are derived. In addition, a block bootstrap test is proposed for the goodness of fit of models, which can accommodate the correlations within groups illustrate the finite sample performances of the Some simulation studies are conducted to proposed procedures.

关键词： Semiparametric Panel data Local polynomial Weighted estimation Block bootstrap