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Joint density of hitting time and point to an ellipse for Brownian motion

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Chinese Science Bulletin 1997年第24期42卷 2054-2058页

作者： YIN Chuancun ZHAO Xuelei department of Mathematics, Qufu Normal university, Qufu 2.3165, China 2. Institute of Mathematics,{2., shantou 515063, China department of Mathematics Qufu Normal University Qufu China Institute of Mathematics Shantou University Shantou China

IT is well known that the distribution of hitting time, hitting point, last exiting time, and lastexiting point for Brownian motion to balls has been extensively studied. A similar investi-gation of rectangles or cubes has also been well done. However, analogous questions for Brow-nian motion to ellipsoid are rarely concerned. Bai and Cai obtained the distribution of

关键词： Brownian motion hitting time hitting point ellipse.

GENUINE-OPTIMAL CIRCULANT PRECONDITIONERS FOR WIENER-HOPF EQUATIONS

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Journal of Computational Mathematics 2001年第6期19卷 629-638页

作者： Fu-rong Lin (department of Mathematics, shantou university,{2.,China) 汕头大学广东汕头 515063

Discusses the genuine-optimal circulant preconditioner for finite-section Wiener-Hopf equations. Definition of the genuine-optimal circulant preconditioner; Use of the preconditioned conjugate gradient method; Numeric... 详细信息

关键词： Wiener-Hopf equations circulant preconditioner preconditioned conjugate gradient method quadrature rules Hilbert-Schmidt norm

Necessary and sufficient condition of C^0 flows on closed surfaces with isolated singular points having the pseudo-orbit tracing property

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Chinese Science Bulletin 1997年第3期42卷 259-260页

作者： MAI Jiehua and GU Rongbao1.Institute of Mathematics, shantou university, shantou 515063, China 2. {2. of Mathematics, Anhui university, Hefei 2.0039, China Institute of Mathematics Shantou University Shantou China department of Mathematics Anhui University Hefei China

IN this letter we discuss the necessary and sufficient condition of C^0 flows on closed surfaces with isolated singular points having the pseudo-orbit tracing property. According to ref. [1], on a closed surface, every minimal set of a C^r(r≥2. flow is trivial, but it is possible for a C^0 flow to contain non-trivial minimal sets. Thus C^0 flows on closed surfaces are more complicated than C^r(r≥2. flows.

关键词： Necessary and sufficient condition of C^0 flows on closed surfaces with isolated singular points having the pseudo-orbit tracing property

A class of compactly supported symmetric/antisymmetric B-spline wavelets

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Progress in Natural Science:Materials International 2005年第2期15卷 31-36页

作者： YANG Shouzhi* and LOU Zengjian(department of Mathematics, shantou university,{2., China) Dept. of Mathematics Shantou Univ. Shantou 515063 China

An algorithm for constructing a class of compactly supported symmetric/antisymmetric B-spline wavelets is presented. For any mth order and kth order cardinal B-spline Nm(x), Nk(x), if m+k is an even integer, the corresponding mth order B-spline wavelets ψkm(x) can be constructed, which are compactly supported symmetric/antisymmetric. In addition, if ψkm(x), m>1 is mth B-spline wavelet associated with two spline functions Nm(x) and Nk(x), then (ψkm(x))′(x) is m-1th B-spline wavelet associated with N m-1(x) and N k+1(x), i.e. (ψkm(x))′(x)=2.ψ k+1 m-1(x). Similarly, ∫x0ψkm(t)dt, k>1 is m+1th B-spline wavelet associated with N m+1(x) and N k-1(x). Using this method, we recovered Chui and Wang’s spline wavelets. Since a class of B-spline wavelets are symmetric/antisymmetric, their linear phase property is assured. Several examples are also presented.

关键词： compactly supported B-spline function B-spline wavelet symmetric antisymmetric

Two-dimensional Riemann problems of simplified Euler equation

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Chinese Science Bulletin 1998年第6期43卷 441-444页

作者： YANG Xiaozhou 1,2.and HUANG Feimin+1 1. Institute of Applied Mathematics, Chinese Academy of Sciences, Beijing 100080, China 2. department of Mathematics, shantou university, Guangdong {2., China Institute of Applied Mathematics Chinese Academy of Sciences Beijing China department of Mathematics Shantou University Guangdong China

The two-dimensional Riemann problem of simplifed Euler equation is discussed, in which initial value contains two different constant states that are separated by a smooth curve. This problem is a natural description of realistic phenomena, but it is hard to study by conventional idea. So a new approach is proposed. Some new properties about two-dimensional rarefaction wave, shock wave and intermediate state of solutions are disclosed.

关键词： D Riemann problem implicit functions cylindrical surface pencil of cylindrical surface.

Commuting double Ockham algebras

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Science China Mathematics 2008年第2期51卷 185-194页

作者： FANG Jie department of Mathematics,shantou {2.,shantou 515063,China department of Mathematics Shantou University Shantou China

In this paper,we study a certain class of double Ockham algebras (L;∧,∨,f,k,0,1), namely the bounded distributive lattices (L;∧,∨,0,1) endowed with a commuting pair of unary op- erations f and k,both of which are dual *** characterize the subdirectly irreducible members,and also consider the special case when both (L;f) and (L;k) are de Morgan *** show via Priestley duality that there are precisely nine non-isomorphic subdirectly irreducible members, all of which are simple.

关键词： subdirectly irreducible double Ockham algebra Priestley duality 06D15 06D30

Global smooth solution of multi-dimensional non-homogeneous conservation laws

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Progress in Natural Science:Materials International 2004年第10期14卷 15-22页

作者： YANG Xiaozhou 1 and ZHANG Tong 2. (1.department of Mathematics,shantou {2.,shantou515063,China 2.Institute of Mathematics,Chinese Academy of Sci-ences,Beijing100080,China) Dept. of Math. Shantou Univ. Shantou 515063 China Inst. of Math. Chinese Acad. of Sci. Beijing 100080 China

The initial value problem of multi-dimensional non-homogeneous conservation laws is studied and a sufficient condition of the existence of its global smooth solution is ***,three equivalent propositions of the existence of global smooth solution for multi-dimensional homogeneous scalar conservation laws are also *** global smooth solution is uniquely expressed by the global implicit function that is determined by a scalar equation,not by a system as usual methods do.

关键词： conservation laws global smooth solution global implicit function diffeomorphism

Multiwavelet sampling theorem in Sobolev spaces

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Science China Mathematics 2010年第12期53卷 3197-3214页

作者： LI YouFa 1,2.& YANG ShouZhi 1, 1 department of Mathematics, shantou university,{2., China 2.College of Mathematics and Information Sciences, Guangxi university, Nanning 530004, China department of Mathematics Shantou University Shantou China College of Mathematics and Information Sciences Guangxi University Nanning China

This paper is to establish the multiwavelet sampling theorem in Sobolev spaces. Sampling theorem plays a very important role in digital signal communication. The most classical sampling theorem is Shannon sampling theorem, which works for bandlimited signals. Recently, sampling theorems in wavelets or multiwavelets subspaces are extensively studied in the literature. In this paper, we firstly propose the concept of dual multiwavelet frames in dual Sobolev spaces (H s (R) , H-s (R)). Then we construct a special class of dual multiwavelet frames, from which the multiwavelet sampling theorem in Sobolev spaces is obtained. That is, for any f ∈ H s (R) with s > 1/2. it can be exactly recovered by its samples. Especially, the sampling theorem works for continuous signals in L 2.(R), whose Sobolev exponents are greater than 1 /2.

关键词： Sobolev spaces refinable function vectors dual multiwavelet frames delta function sampling theorem

Two-dimensional water-filling power allocation algorithm for MIMO-OFDM systems

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Science China(Information Sciences) 2010年第6期53卷 1242-1250页

作者： JIANG YongQuan 1 , SHEN MinFen 1 & ZHOU YuanPing 2.1 department of Electronic Engineering, shantou university,{2., China 2.department of Electronic Engineering, Sichuan university, Chengdu 610064, China department of Electronic Engineering Shantou University Shantou China department of Electronic Engineering Sichuan University Chengdu China

Departing from the narrowband channel model, more and more researchers have recently considered the application of multiple-input multiple-output(MIMO) systems over frequency-selective fading channels in combination with the orthogonal frequency-division multiplexing(OFDM) *** this paper, we focus on the capacity of MIMO-OFDM systems and how to increase the *** has been proved that the capacity of a MIMO system with space-dimensional water-filling power allocation is greater than that of the system with uniform power *** MIMO-OFDM systems, there is an additional degree of freedom to allocate power with respect to MIMO systems:the OFDM sub-channels in *** the singular value decomposition(SVD) applied to the channel frequency response matrix, the two-dimensional water-filling power allocation algorithm for MIMO-OFDM systems is proposed based on the Lagrange method, and the corresponding capacity analysis formula is *** results show that the capacity of a MIMO-OFDM system with the proposed two-dimensional water-filling power allocation is greater than that of the system with uniform power allocation and also greater than that of the system with the one-dimensional water-filling power allocation.

关键词： MIMO-OFDM two-dimensional water-filling power allocation capacity analysis singular value decomposition(SVD)