检索结果-南通市图书馆

Error analysis of the semi-discrete local discontinuous Galerkin method for semiconductor device simulation models

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2010年第12期53卷 3255-3278页

作者： LIU YunXian 1, & SHU Chi-Wang 2 1 school of mathematics, shandong university, jinan 2.0100, china 2 Division of Applied mathematics, Brown university, Providence, RI 02912, USA 1. school of mathematics Shandong University Jinan 250100 China2. Division of Applied Mathematics Brown University Providence RI 02912 USA

In this paper we continue our effort in Liu-Shu (2004) and Liu-Shu (2007) for developing local discontinuous Galerkin (LDG) finite element methods to discretize moment models in semiconductor device simulations. We consider drift-diffusion (DD) and high-field (HF) models of one-dimensional devices, which involve not only first derivative convection terms but also second derivative diffusion terms, as well as a coupled Poisson potential equation. Error estimates are obtained for both models with smooth solutions. The main technical difficulties in the analysis include the treatment of the inter-element jump terms which arise from the discontinuous nature of the numerical method, the nonlinearity, and the coupling of the models. A simulation is also performed to validate the analysis.

关键词： local discontinuous Galerkin method error estimate semiconductor

Image denoising and deblurring: non-convex regularization, inverse diffusion and shock filter

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第6期54卷 1184-1198页

作者： FU ShuJun 1,2,3 , ZHANG CaiMing 2 & TAI XueCheng 3,4 1 school of mathematics, shandong university, jinan 2.0100, china 2.school of Computer Science and Technology, shandong university, jinan 250101, china 3 school of Physical and Mathematical Sciences, Nanyang Technological university, Singapore 639798, Singapore 4 Department of mathematics, university of Bergen, Bergen 5008, Norway 1. school of mathematics Shandong University Jinan 250100 China2. School of Computer Science and Technology Shandong University Jinan 250101 China3. School of Physical and Mathematical Sciences Nanyang Technological University Singapore 639798 Singapore4. Department of Mathematics University of Bergen Bergen 5008 Norway

A large number of applications in image processing and computer vision depend on image quality. In this paper, main concerns are image denoising and deblurring simultaneously in a restoration task by three types of methodologies: non-convex regularization, inverse diffusion and shock filter. We discuss their relations in the context of image deblurring: the inverse diffusion implied by the non-convex regularization, and the superior ability of deblurring edge of the shock filter to that of the inverse diffusion, both in 1D and 2D cases. Finally, we propose a region-based adaptive anisotropic diffusion with shock filter method, which shows advantages of deblurring edges, denoising and smoothing contours in experiments, compared with some related methods. Therein an idea of "divide and rule" is introduced.

关键词： image denoising image deblurring non-convex regularization inverse diffusion shock filter adaptive anisotropic diffusion

Stability for a class of nonlinear time-delay systems via Hamiltonian functional method

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(Information Sciences) 2012年第5期55卷 1218-1228页

作者： YANG RenMing 1,2 & WANG YuZhen 1 1 school of Control Science and Engineering,shandong university,jinan 250061,china 2 shandong Jiaotong university,jinan 250023,china 1. school of Control Science and Engineering Shandong University Jinan 250061 China2. Shandong Jiaotong University Jinan 250023 China

This paper investigates the stability of a class of nonlinear time-delay systems via Hamiltonian functional method,and proposes a number of new results on generalized Hamiltonian realization (GHR) and stability analysis for this class of ***,the concept of GHR of general nonlinear time-delay systems is proposed,and several new GHR methods are ***,based on the new GHR methods obtained,the stability of time-delay systems is investigated,and several delay-dependent sufficient conditions in term of matrix inequalities are derived for the stability analysis by constructing suitable Lyapunov-Krasovskii (L-K) ***,an illustrative example shows that the results obtained in this paper have less conservatism,and work very well in the stability analysis of some nonlinear time-delay Hamiltonian systems.

关键词： nonlinear time-delay systems stability Hamiltonian functional method generalized Hamiltonian realization

S-rough sets and knowledge separation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2005年第2期16卷 403-410页

作者： Shi Kaiquan 1,21. school of mathematics and System Sciences, Liaocheng university, Liaocheng 252059, P. R. china 2. school of mathematics and System Sciences, shandong university, jinan 2.0100, P. R. china school of mathematics and System Sciences Liaocheng University Liaocheng 252059 P. R. China school of mathematics and System Sciences Shandong University Jinan 250100 P. R. China

The conceptions of the knowledge screen generated by S-rough sets are given: f- screen and - screen , and then puts forward - filter theorem, - filter theorem of knowledge. At last, the applications of knowledge separ... 详细信息

关键词： S- rough sets f- screen - screen f-filter theorem - filter theorem knowledge separation.

A note on a result of Abercrombie

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第14期42卷 1151-1154页

作者： ZHAI WenguangDepartment of mathematics, shandong Normal university, jinan 250014, china Department of mathematics Shandong Normal University Jinan 250014 China

SUPPOSE θ∈[1,+ ∞) is any real number. The sequence B_θ={[nθ]|n∈N}is calledBeatty’s sequence determined by θ. Beatty sequences have been the subject of intensive inves-tigation in recent years on account of the... 详细信息

关键词： Bealty’s sequence divisor problem rational approximation.

Local derivation on triangular subalgebras of hyperfinite von Neumann algebras

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第9期43卷 716-719页

作者： JI Peisheng Department of mathematics, shandong university, jinan 2.0100, china Department of mathematics Shandong University Jinan China

It is proved that every σ-weakly continuous local derivation from triangular subalgebra A of hyperfinite von Neumann algebra B into A (or B) is a derivation. Morevoer, if A is also a σ-Dirichlet subalgebra, each loc... 详细信息

关键词： hyperfinite von Neumann algebra triangular algebra derivation local derivation inner derivation.

Morita contexts on the Hopf algebroid

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2005年第7期48卷 958-971页

作者： YIN Yanmin school of Mathematical Sciences, Peking university, Beijing 100871, china Department of mathematics, shandong Institute of Architecture and Engineering, jinan 250101, china 1. school of Mathematical Sciences Peking University 100871 Beijing China 2. Department of mathematics Shandong Institute of Architecture and Engineering 250101 Jinan China

We generalize the Morita theory to the Hopf algebroid and give the characterization of the surjectivity of one of the Morita context maps.

关键词： comodule algebra, generalized smash product, Morita context.

Characteristic finite difference fractional step methods for three-dimensional semiconductor device of heat conduction

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2000年第2期45卷 125-131页

作者： YUAN Yirang Institute of mathematics. shandong university, jinan 2.0100, china Institute of mathematics Shandong University Jinan China

The mathematical model of the semiconductor device of heat conduction has been described by a system of four equations. The optimal order estimates in L2 norm are derived for the error in the approximates solution, pu... 详细信息

关键词： semiconductor device three-dimensional heat conduction parallel characteristic tinite differences fractional steps L2 error estimate.

NONOVERLAPPING DOMAIN DECOMPOSITION METHOD WITH MIXED ELEMENT FOR ELLIPTIC PROBLEMS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 1996年第4期14卷 291-300页

作者： H.X. Rui(mathematics Department, shandong university, jinan) shandong UNIV DEPT MATHJINAN 250100PEOPLES R CHINA

In this paper we consider the nonoverlapping domain decomposition method based on mixed element approximation for elliptic problems in two dimentional space. We give a kind of discrete domain decomposition iterative algorithm using mixed finite element, the subdomain problems of which can be implemented parallelly. We also give the existence, uniqueness and convergence of the approximate solution.

关键词： Zhang NONOVERLAPPING DOMAIN DECOMPOSITION METHOD WITH MIXED ELEMENT FOR ELLIPTIC PROBLEMS EV