检索结果-南通市图书馆

Modal parameter identification under non-stationary ambient 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10期52卷 3180-3187页

作者： DU XiuLi1,2 & WANG FengQuan1 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 210096 China school of mathematical sciences Nanjing Normal University Nanjing 210097 China

A new time-domain modal identification method of linear time-invariant system driven by the non-stationary Gaussian random excitation is introduced based on the continuous time AR model. The method can identify physical parameters of the system from response data. In order to identify the parameters of the system, the structural dynamic equation is first transformed into the continuous time AR model, and subsequently written into the forms of observation equation and state equation which is just a stochastic differential equation. Secondly, under the assumption that the uniformly modulated function is approximately equal to a constant matrix in a very short time period, the uniformly modulated function is identified piecewise. Then, we present the exact maximum likelihood estimators of parameters by virtue of the Girsanov theorem. Finally, the modal parameters are identified by eigenanalysis. Numerical results show that the method we introduce here not only has high precision and robustness, but also has very high computing efficiency. Therefore, it is suitable for real-time modal identification.

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

同方期刊数据库

A specific family of cyclotomic polynomials of order three

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2010年第9期53卷 2269-2274页

作者： JI ChunGang school of mathematical sciences,nanjing normal university,nanjing 210097,china 1. school of mathematical sciences Nanjing Normal University Nanjing 210097 China

Let A(n) be the largest absolute value of any coefficient of n-th cyclotomic polynomial Φn(x).We say Φn(x) is flat if A(n) = *** this paper,for odd primes p < q < r and 2r ≡±1(mod pq),we prove that Φpqr(x) is fla... 详细信息

Let A(n) be the largest absolute value of any coefficient of n-th cyclotomic polynomial Φn(x).We say Φn(x) is flat if A(n) = *** this paper,for odd primes p 2r ≡±1(mod pq),we prove that Φpqr(x) is flat if and only if p = 3 and q ≡ 1(mod 3).

关键词： cyclotomic polynomial flat cyclotomic polynomial ternary cyclotomic polynomial

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

Romanoff theorem in a sparse set

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2010年第9期53卷 2195-2202页

作者： CHEN Yong-Gao school of mathematical sciences,nanjing normal university,nanjing 210046,china 1. school of mathematical sciences Nanjing Normal University Nanjing 210046 China

Let A be any subset of positive integers,and P the set of all positive *** of our results are:(a) the number of positive integers which are less than x and can be represented as 2k + p(resp.p-2k) with k ∈ A and p ∈ P is more than 0.03A(log x/log 2)π(x) for all sufficiently large x;(b) the number of positive integers which are less than x and can be represented as 2q + p with p,q ∈ P is(1 + o(1))π(log x/log 2)π(x).Four related open problems and one conjecture are posed.

关键词： Romanoff theorem Polignac conjecture asymptotic density

Characterizations of α-Bloch functions on the unit ball without use of derivative

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2008年第11期51卷 1965-1981页

作者： CHEN HuaiHui school of Mathematics and Computer Science, nanjing normal university, nanjing 210097, china 1. school of Mathematics and Computer Science Nanjing Normal University Nanjing 210097 China

In this paper we establish characterizations of α-Bloch functions on the unit ball without use of derivative, which are stronger, more precise and general than those obtained by Nowak and Zhao.

关键词： α-Bloch function unit ball Bergman metric 32A18 32A37

ON TWO CONJECTURES OF THE QUADRATIC DIFFERENTIAL SYSTEMS

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 1997年第4期18卷 429-434页

作者： ZHANG XIANG Institute of Mathematics,nanjing normal university,nanjing 210097,china 南京师范大学数学所江苏南京

Two conjectures in the qualitative theory of quadratic differential systems are proved under certain conditions.

关键词： Quadratic system Limit cycle Dulac function

Some new results on planar harmonic mappings

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 597-604页

作者： CHEN HuaiHui Department of Mathematics, nanjing normal university, nanjing 210097, china 1. Department of Mathematics Nanjing Normal University Nanjing 210097 China

This survey paper contains some new results on the Landau theorem, Bloch theorem and Schwarz-Pick lemma for planar harmonic mappings.

关键词： harmonic mapping Landau theorem Bloch constant Schwarz-Pick lemma quasi-regularity

normal Functions and α-normal Functions

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2000年第3期16卷 399-404页

作者： Yan Xu Department of Mathematics,nanjing normal university,nanjing 210097 P.R.china Department of Mathematics Nanjing Normal University Nanjing 210097 P. R. China

This paper has studied two open questions about normal functions due to Lappan,and obtained two corresponding results for α-normal functions.

关键词： Spherical derivative normal function α-normal function

On the variational principle for the topological pressure for certain non-compact sets

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 1117-1128页

作者： PEI Yu 1 & CHEN ErCai 1,2,1 Department of Mathematics,nanjing normal university,nanjing 210097,china 2 Center for Nonlinear Science,nanjing university,nanjing 210093,china 1. Department of Mathematics Nanjing Normal University Nanjing 210097 China2. Center for Nonlinear Science Nanjing University Nanjing 210093 China

Let (X,d,T) be a dynamical system,where (X,d) is a compact metric space and T:X → X is a continuous *** assume that the dynamical system satisfies g-almost product property and the uniform separation *** compute the topological pressure of saturated sets under these two *** the uniform separation property does not hold,we compute the topological pressure of the set of generic *** give an application of these results to multifractal analysis and finally get a conditional variational principle.

关键词： uniform separation property g-almost product property topological pressure of non-compact sets variational principle BS-dinmension