检索结果-南通市图书馆

Chinese Annals of Mathematics,Series B 2000年第4期21卷 479-488页

作者： WANG ZAIHONG (Department of Mathematics, capital normal university, beijing 100037, china.) Department of Mathematics Capital Normal University Beijing 100037 China

This paper deals with the existence and multiplicity of periodic solutions of Duffing equations x + g(x) = p(t). The author proves an infinity of periodic solutions to the periodically forced nonlinear Duffing equations provided that g(x) satisfies the globally lipschitzian condition and the time-mapping satisfies the weaker oscillating property.

关键词： Periodic solution Time mapping Poincare-Birkhoff twist theorem

Quenched moderate deviations principle for random walk in random environment

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2010年第8期53卷 1947-1956页

作者： HONG WenMing 1 & WANG HuaMing 1,2 1 Key Laboratory of Mathematics and Complex Systems of Ministry of Education & school of mathematical sciences,beijing normal university,beijing 100875,china 2 Department of Basic Courses,Business College,beijing Union university,beijing 100025,china Key Laboratory of Mathematics and Complex Systems of Ministry of Education & school of mathematical sciences Beijing Normal University Beijing China Department of Basic Courses Business College Beijing Union University Beijing China

We derive a quenched moderate deviations principle for the one-dimensional nearest random walk in random environment,where the environment is assumed to be stationary and *** approach is based on hitting time decompos... 详细信息

关键词： random walk in random environment moderate deviations principle hitting time

Real solution isolation with multiplicity of zero-dimensional triangular systems

在线全文

学校读者我要写书评

暂无评论

Science china(Information sciences) 2011年第1期54卷 60-69页

作者： ZHANG ZhiHai,FANG Tian & XIA BiCan LMAM,school of mathematical sciences,Peking university,beijing 100871,china LMAM School of Mathematical Sciences Peking University Beijing China

Existing algorithms for isolating real solutions of zero-dimensional polynomial systems do not compute the multiplicities of the *** this paper,we define in a natural way the multiplicity of solutions of zero-dimensional triangular polynomial systems and prove that our definition is equivalent to the classical definition of local(intersection)*** we present an effective and complete algorithm for isolating real solutions with multiplicities of zero-dimensional triangular polynomial systems using our definition. The algorithm is based on interval arithmetic and square-free factorization of polynomials with real algebraic *** computational results on some examples from the literature are presented.

关键词： real solution isolation local multiplicity local ring polynomial system solving

Balanced multiple description subband coding based on multifilter banks

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) 2011年第11期54卷 2359-2372页

作者： WANG Ning 1,LI BaoBin 2 & PENG LiZhong 1 1 LMAM,school of mathematical sciences,Peking university,beijing 100871,china 2 school of Information Science and Engineering,Graduate university of Chinese Academy of sciences,beijing 100190,china LMAM School of Mathematical Sciences Peking University Beijing China school of Information Science and Engineering Graduate University of Chinese Academy of Sciences Beijing China

Multiple description coding is one of the source coding techniques to alleviate the problems of packet loss in *** encoder generates several different descriptions of the source and the decoder can produce a useful reconstruction with any received subset of these *** of the earlier works concentrated on redundancy and the average distortion of the single-description reconstructions,which is insufficient to describe the *** this paper,a metric of the coding system,balance eccentric modulus,is defined to evaluate the difference in quality between the individual *** the discrete wavelet transform becomes trivial polyphase transform when setting the balance eccentric modulus at zero,we introduce a multiwavelet based scheme ***,a sufficient condition for balanced multiwavelet based multiple description coding is presented.

关键词： multiple description coding rate-distortion theory balance eccentric modulus balanced multiwavelet multifilter bank

Twistor bundle theory and its application

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 2004年第4期47卷 605-616页

作者： PENG Chia-Kuei & TANG ZizhouDepartment of Mathematics, Graduate school of Chinese Academy of sciences, beijing 100039, china Department of mathematical sciences, Tsinghua university, beijing 100084, china Department of Mathematics Graduate School of Chinese Academy of Sciences Beijing China Department of mathematical sciences Tsinghua University Beijing China

Over an oriented even dimensional Riemannian manifold(M 2m ,ds2 ), in terms of the Levi-Civita connection form Ω and the canonical form Θ on the bundle of positive orthonormal frames, we give a detailed description of the twistor bundle Гm = SO(2m)/U(m)? J +(@#@ M,ds2 ) →M. The integrability on an almost complex structureJ compatible with the metric and the orientation, is shown to be equivalent to the fact that the corresponding cross section of the twistor bundle is holomorphic with respect toJ and the canonical almost complex structureJ 1 onJ +(M,ds2 ), by using moving frame theory. Moreover, for various metrics and a fixed orientation onM, a canonical bundle isomorphism is established. As a consequence, we generalize a celebrated theorem of LeBrun.

关键词： almost complex structure, integrability, twistor bundle.

Modal identification of system driven by lévy random excitation based on continuous time AR model

在线全文

学校读者我要写书评

暂无评论

Science china(Technological sciences) 2009年第12期52卷 3649-3653页

作者： DU XiuLi 1,2 &WANG FengQuan 1 1 College of Civil Engineering,Southeast university,Nanjing 210096,china 2 school of mathematical sciences,Nanjing normal university,Nanjing 210097,china College of Civil Engineering Southeast University Nanjing China school of mathematical sciences Nanjing Normal University Nanjing China

Based on the continuous time AR model,this paper presents a new time-domain modal identification method of LTI system driven by the uniformly modulated lévy random *** structural dynamic equation is first transformed into the observation equation and the state equation(namely,stochastic differential equation).Based on the property of the strong solution of the stochastic differential equation,the uniformly modulated function is identified *** by virtue of the Girsanov theorem,we present the exact maximum likelihood estimators of ***,the modal parameters are identified by eigen *** results show that the method not only has high precision and robustness but also has very high computing efficiency.

关键词： modal identification uniformly modulated function CAR model lévy process exact maximum likelihood estimator

METHOD OF NONCONFORMING MIXED FINITE ELEMENT FOR SECOND ORDER ELLIPTIC PROBLEMS METHOD OF NONCONFORMING MIXED FINITE ELEMENT FOR SECOND ORDER ELLIPTIC PROBLEMS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2000年第5期18卷 449-456页

作者： Zhen-dong Luo (Department of Mathematics, capital normal university, beijing 100057, china) 首都师范大学北京 100037

In this paper, the method of non-conforming mixed finite element for second order elliptic problems is discussed and a format of real optimal order for the lowest order error estimate.

关键词： Non-conforming mixed finite element Error estimate Second order elliptic problems.

Attention and available long-term memory in an activation-based model

在线全文

学校读者我要写书评

暂无评论

Science china(Life sciences) 2010年第6期53卷 743-752页

作者： LIU ZhaoMin1,GUO ChunYan2,3 & LUO Liang4 1 school of Sociology,china university of Political Science and Law,beijing 102249,china 2 beijing Key Laboratory of Learning and Cognition,Department of Psychology,capital normal university,beijing 100048,china 3 Key Laboratory of Mental Health,Chinese Academy of sciences,beijing 100101,china 4 State Key Laboratory of Cognitive Neuroscience and Learning,beijing normal university,beijing 100875,china school of Sociology China University of Political Science and Law Beijing China beijing Key Laboratory of Learning and Cognition Department of Psychology Capital Normal University Beijing China Key Laboratory of Mental Health Chinese Academy of Sciences Beijing China State Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal University Beijing China

The influence of attention on memorizing related items and on available long-term memory (ALTM) was explored,showing that N400 of no-memory items was more negative than that of the memory *** results of the category comparison task indicated that information processing under attention-driven in WM determined the availability of related long-term memory,i.e.,specific content,which was formerly concerned or ignored,yielding different indirect semantic priming *** indicate that the orientation of conceptual attention leads the related representations of LTM to diverse activation patterns,supporting the activation-based model.

关键词： activation-based model attention available long-term memory event-related potentials

On the local wellposedness of 3-D water wave problem with vorticity

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2007年第8期50卷 1065-1077页

作者： Ping ZHANG~1 Zhi-fei ZHANG~2 1 Academy of Mathematics and Systems Science,Chinese Academy of sciences,beijing 100080,china 2 school of mathematical sciences,Peking university,beijing 100871,china Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China school of mathematical sciences Peking University Beijing China

In this article, we first present an equivalent formulation of the free boundary problem to 3-D incompressible Euler equations, then we announce our local wellposedness result concerning the free boundary problem in Sobolev space provided that there is no self-intersection point on the initial surface and under the stability assumption that $\frac{{\partial p}}{{\partial n}}(\xi )\left| {_{t = 0} } \right. \leqslant - 2c_0 < 0$ being restricted to the initial surface.

关键词： water-waves free boundary incompressible Euler equations primary 35Q35 76B03 secondary 35J67 35L80

On consensus protocols for high-order multiagent systems

在线全文

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2010年第4期8卷 406-412页

作者： Jing KUANG,Jiandong ZHU (school of mathematical sciences,Nanjing normal university,Nanjing Jiangsu 210097,china) school of mathematical sciences Nanjing Normal University Nanjing Jiangsu China

In this paper,the static consensus problem and the dynamic consensus problem are considered for a class of high-order multiagent *** the proposed consensus protocols,necessary and sufficient conditions for the consensus problems are *** the static consensus protocol,the desired consensus speed can be achieved by adjusting feedback *** show the effectiveness of the proposed consensus protocols.

关键词： Consensus Multiagent systems Graph theory