检索结果-南通市图书馆

Congruences on ideal nil-extension of completely regular semigroups

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第5期43卷 379-381页

作者： REN Xueming 1, 2.GUO Yuqi 2.and CEN Jiaping (Shum Kar-ping) 31. department of mathematics, Xi’an {2. of Architecture & Technology, Xi’an 710055, china 2. department of mathematics, Yunnan {2., Kunming 650091, china 3. department of department of mathematics Xi’an University of Architecture & Technology Xi’an China department of mathematics Yunnan University Kunming China department of mathematics Chinese University of Hong Kong Hong Kong

Let S be an ideal nil-extension of a completely regular semigroup K by a nil semigroup Q with zero. A concept of admissible congruence pairs (δ,ω) of S is introduced, where δ and ω are a congruence on Q and a congruence on K respectively. It is proved that every congruence on S can be uniquely respresented by an admissible congruence pair (δ,ω) of S. Suppose that ρ K denotes the Rees congruence induced by the ideal K of S. Then it is shown that for any congruence σ on S,a mapping Γ:σ|→(σ Q,σ K) is an order-preserving bijection from the set of all congruences on S onto the set of all admissible congruence pairs of S,where σ K is the restriction of σ to K and σ Q=(σ∨ρ K)/ρ K. Moreover,the lattice of congruences of S is also discussed. As a special case,every congruence on completely Archimedean semigroups S is described by an admissible quarterple of S. The following question is asked: Is the lattice of congruences of the completely Archimedean semigroup a semimodular lattice?

关键词： completely regular semigroups ideal nil-extension congruences.

Interpolating triangular meshes by Loop subdivision scheme

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2010年第9期53卷 1765-1773页

作者： DENG ChongYang1* & WANG GuoZhao2.1Institute of Applied mathematics and Engineering Computations,Hangzhou Dianzi university,Hangzhou {2.,china 2.4} of mathematics,zhejiang university,Hangzhou 31002.,china 1. Institute of Applied mathematics and Engineering Computations Hangzhou Dianzi University Hangzhou 310018 China2. Department of Mathematics Zhejiang University Hangzhou 310027 China

Using the limit point formula of the Loop subdivision scheme,we propose a very simple and efficient method for constructing interpolation surface of triangular meshes by Loop subdivision *** excellent properties of the method are:(1) Locality:the perturbation of a given vertex only influences the surface shape near this vertex.(2. Efficiency:the locations of new points can be computed with explicit formulae.(3) Easiness in implementation:only the geometric rule of the first step should be modified.(4) Freedom:for each edge,there is one degree of freedom to adjust the shape of the interpolation surface.(5) Easiness in generalization:it is easy to generalize our method to other approximation subdivision schemes with explicit formulae to compute limit point.

关键词： computer aided geometric design subdivision surface approximating subdivision scheme Loop surface surface interpolating

Bifurcations of travelling wave solutions for two generalized Boussinesq systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china mathematics 2008年第9期51卷 1577-1592页

作者： LI JiBin1,2.1 department of mathematics, {2. Normal university, Jinhua 32.004, china 2.department of mathematics, Kunming university of Science and Technology, Kunming 650093, china department of mathematics Zhejiang Normal University Jinhua 321004 China department of mathematics Kunming University of Science and Technology Kunming 650093 China

Using the methods of dynamical systems for two generalized Boussinesq systems, the existence of all possible solitary wave solutions and many uncountably infinite periodic wave solutions is obtained. Exact explicit parametric representations of the travelling solutions are given. To guarantee the existence of the above solutions, all parameter conditions are determined.

关键词： nonlinear wave bifurcation solitary wave exact explicit solution generalized Boussinesq system 34C37 34C2. 74J30 58Z05

Planar cubic hybrid hyperbolic polynomial curve and its shape classification

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2004年第1期14卷 42-47页

作者： WANG Guozhao 1,2. * and YANG Qinmin 1,2. (1. Institute of Computer Graphics and Image Processing, 2. department of mathematics,{2., Hangzhou 31002., china) zhejiang Univ Inst Comp Graph & Image Proc Hangzhou 310027 Peoples R China zhejiang Univ Dept Math Hangzhou 310027 Peoples R China

The planar cubic hybrid hyperbolic polynomial curves and cubic H Bézier curves are presented. The conditions leading to inflection points and singularities (cusps and loops) are investigated and the shape of these curves is classified. The conclusions enable us to detect inflection points and singularities and get an idea of how to preserve the fair shape when designing such curves.

关键词： hybrid hyperbolic polynomial curve H-Bézier curve shape classification inflection points singularities

Almost sure central limit theorems for random functions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china mathematics 2006年第12期49卷 1788-1799页

作者： LU Chuanrong, QIU Jin & XU Jianjun School of mathematics and Statistics, zhejiang university of Finance and Economics, Hangzhou {2., china department of mathematics, zhejiang university, Hangzhou 31002., china 1. School of mathematics and Statistics Zhejiang University of Finance and Economics Hangzhou 310018 China 2. department of mathematics Zhejiang University Hangzhou 310028 China

Let {Xn,-∞< n <∞} be a sequence of independent identically distributed random variables with EX1 = 0, EX12.= 1 and let Sn =∑k=1∞Xk, and Tn = Tn(X1,…,Xn) be a random function such that Tn = ASn + Rn, where supn E|... 详细信息

Let {Xn,-∞2.= 1 and let Sn =∑k=1∞Xk, and Tn = Tn(X1,…,Xn) be a random function such that Tn = ASn + Rn, where supn E|Rn| 2.) a.s., or Rn = O(n1/2.2.) a.s., 0 <γ< 1/8. In this paper, we prove the almost sure central limit theorem (ASCLT) and the function-typed almost sure central limit theorem (FASCLT) for the random function Tn. As a consequence, it can be shown that ASCLT and FASCLT also hold for U-statistics, Von-Mises statistics, linear processes, moving average processes, error variance estimates in linear models, power sums, product-limit estimators of a continuous distribution, product-limit estimators of a quantile function, etc.

关键词： statistics,random function,almost sure central limit theorem,logarithm average.

Lipschitz equivalence of generalized {1,3,5}-{1,4,5} self-similar sets

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2007年第11期50卷 1537-1551页

作者： Li-feng XI~(1+) Huo-jun RUAN~2.1 Institute of mathematics,zhejiang Wanli {2.,Ningbo 315100,china 2.department of mathematics,zhejiang {2.,Hangzhou 31002.,china Institute of mathematics Zhejiang Wanli University Ningbo 315100 China department of mathematics Zhejiang University Hangzhou 310027 China

This paper investigates the Lipschitz equivalence of generalized {1,3,5}-{1,4,5} self-similar sets D=(r_1D)∪(r_2.+(1+r_1-r_2.r_3)/2.∪(r_3D+1+r_3) and E=(r_1E)∪(r_2.+1-r_2. r_3)∪(r_3E+1-r_3),and proves that D and E... 详细信息

关键词： self-similar set overlap Lipschitz equivalence graph-directed construction ergodicity martingale

Biorthogonal multiple wavelets generated by vector refinement equation

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2007年第7期50卷 1015-1025页

作者： Song LI~(1+) Jun XIAN~2.1 department of mathematics,{2. university,Hangzhou 31002.,china 2.department of mathematics,Sun Yat-Sen university,Guangzhou 5102.5,china 1. department of mathematics Zhejiang University Hangzhou 310027 China 2. department of mathematics Sun Yat-Sen University Guangzhou 510275 China

Biorthogonal multiple wavelets are generated from refinable function vectors by using the multiresolution analysis. In this paper we provide a general method for the construction of compactly supported biorthogonal multiple wavelets by refinable function vectors which are the solutions of vector refinement equations of the form $$\varphi (x) = \sum\limits_{\alpha \in \mathbb{Z}^s } {a(\alpha )\varphi (Mx - \alpha ), x \in \mathbb{R}^s } ,$$ where the vector of functions ? = (? 1, …, ? r)T is in $(L_2.(\mathbb{R}^s ))^r ,a = :(a(\alpha ))_{\alpha \in \mathbb{Z}^s } $ is a finitely supported sequence of r × r matrices called the refinement mask, and M is an s × s integer matrix such that lim n→∞ M ?n = 0. Our characterizations are in the general setting and the main results of this paper are the real extensions of some known results.

关键词： refinement equation biorthogonal multiple wavelets refinable function vector 42.40 41A10 41A15 41A2.

Fuzzy controllers based on some fuzzy implication operators and their response functions

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2004年第1期14卷 16-21页

作者： LI Hongxing 1*, YOU Fei 1 and PENG Jiayin 2.1. department of mathematics, Beijing Normal {2., Beijing 100875, china 2. department of mathematics, Neijiang Teacher's College, Neijiang 641112. china) Beijing Normal Univ Dept Math Beijing 100875 Peoples R China

The fuzzy controllers constructed by 2. fuzzy implication operators based on CRI algorithm and their response functions are discussed. The conclusions show that the fuzzy controllers constructed by 9 fuzzy implication operators are universal approximators to continuous functions and can be used in practical fuzzy control systems. And these 9 fuzzy implication operators except for Einstein operator intersection are all the adjoint pairs of some fuzzy implication operators. Besides, there are 3 other fuzzy controllers formed by fuzzy implication operators being regarded approximately as fitted functions.

关键词： fuzzy implication operators CRI algorithm fuzzy controllers response functions universal approximators

Diagnostic checking for conditional heteroscedasticity models

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china mathematics 2010年第10期53卷 2773-2790页

作者： WU JianHong1,& ZHU LiXing2.1College of Statistics and mathematics,zhejiang Gongshang {2.,Hangzhou 310018,china 2.5} of mathematics,Hong Kong Baptist {2.,Kowloon Tong,Hong Kong,china 1. College of Statistics and mathematics Zhejiang Gongshang University Hangzhou 310018 China2. Department of Mathematics Hong Kong Baptist University Kowloon Tong Hong Kong China

We suggest the score type tests for goodness-of-fit of conditional heteroscedasticity models in both univariate and multivariate time *** tests can detect the alternatives converging to the null at a parametric *** functions are involved in the construction of the tests,which provides us with the flexibility to choose scores,especially under directional alternatives,for enhancing power ***,when the alternatives are not directional,we construct asymptotically distribution-free maximin tests for a large class of alternatives.A possibility to construct score-based omnibus tests is discussed when the alternative is *** power performance is also investigated.A simulation study is carried out and a real data is analyzed.

关键词： conditional heteroscedasticity model maximin test model checking score type test time series