New conditions on absolute stability of uncertain Lur'e systems and the maximum admissible perturbed bound

Email: fhao{at}buaa.edu.cn Received on April 5, 2006; Accepted on September 10, 2006 The robust absolute stability problem for structured uncertainLur'e systems is considered in this paper by using Popov criterionand extended strictly positive real lemma. The conditions onrobust absolute stability for Lur'e systems with structureduncertainties are established in terms of multilinear matrixinequalities. An estimate of the maximum bound of all admissibleperturbations is given by a generalized eigenvalue problem.Finally, a numerical example is worked out to illustrate theefficiency of the main results.     

On the limiting behavior of the maximum partial sums for arrays of rowwise NA random variables

Let {Xni, 1 ≤ n,i ＜∞} be an array of rowwise NA random variables and {an, n ≥ 1} a sequence of constants with 0 ＜ an ↑∞. The limiting behavior of maximum partial sums 1/an max 1≤k≤n| kΣi=1 Xni| is investigated and some new results are obtained. The results extend and improve the corresponding theorems of rowwise independent random variable arrays by Hu and Taylor [1] and Hu and Chang [2].     

Potential theory of truncated stable processes

For any , a truncated symmetric α-stable process is a symmetric Lévy process in with a Lévy density given by for some constant c. In this paper we study the potential theory of truncated symmetric stable processes in detail. We prove a Harnack inequality for nonnegative harmonic functions of these processes. We also establish a boundary Harnack principle for nonnegative functions which are harmonic with respect to these processes in bounded convex domains. We give an example of a non-convex domain for which the boundary Harnack principle fails. The research of Panki Kim is supported by Research Settlement Fund for the new faculty of Seoul National University. The research of Renming Song is supported in part by a joint US-Croatia grant INT 0302167.     

Maximum number of colorings of (2k,k2)‐graphs

Let consist of all simple graphs on 2k vertices and edges. For a simple graph G and a positive integer , let denote the number of proper vertex colorings of G in at most colors, and let . We prove that and is the only extremal graph. We also prove that as . © 2007 Wiley Periodicals, Inc. J Graph Theory 56: 135–148, 2007     

Hapten heterology for a specific and sensitive indirect enzyme-linked immunosorbent assay for organophosphorus insecticide fenthion

Five haptens with different spacer-arm attachment sites on the structure of the organophosphorus insecticide fenthion were designed and synthesized. All of the haptens were conjugated with ovalbumin (OVA) for the coating antigen, and three haptens containing all or most of the structure of fenthion were conjugated with bovine serum albumin (BSA) for the immunogen. Six polyclonal antisera were raised against the three BSA conjugates, and 30 antibody/coating conjugate combinations were selected for studies of assay sensitivity and specificity for fenthion. The study revealed the best combination with high sensitivity (I₅₀ of 0.08 ng mL⁻¹) and high assay specificity, which indicated that when structural difference between the analyte and an immunizing hapten is less than that between a coating hapten and the immunizing hapten, a high sensitive enzyme-linked immunosorbent assay (ELISA) in the heterologous system may stand a good chance to be developed. The immunity results showed that heterology in the hapten spacer-arm attachment site of the immunogen could achieve a remarkable improvement in the quantity, sensitivity, and/or specificity of antibody, and that the moiety of an analyte, which is the same as the moiety near/on the immunizing spacer-arm hapten attachment site, contributes greatly to the interaction of antibody and hapten.     

利用激光并采用热释电探测器的实时测温系统的灵敏度

在介绍一种利用 In Ga As/I半导体激光器并采用钽酸锂 ( L i Ta O3)热释电探测器实时测温系统的基础上 ,着重分析了在该系统测量中和在高温度时的极限灵敏度 ,并导出了该系统极限灵敏度的数学表达式。给合其温度的测量误差 ,分析了系统的工作波长、被测温度、放大器带宽以及光学系统的相对孔径对极限灵敏度的影响 ,并进行了计算机模拟 ,得到了一系列有意义的结论     

用图形计算器和CBL系统测量物体间的静摩擦力

介绍图形计算器。CBL及力传感器。并用于测量两物体同的最大静摩擦力。     

A FINITE ELEMENT—MATHEMATICAL PROGRAMMING METHOD FOR ELASTOPLASTIC PROBLEMS BASED ON THE PRINCIPLE OF VIRTUAL WORK

By expanding the yielding function according to Taylor series and neglecting the high order terms, the elastoplastic constitutive equation is written in a linear complementary form. Based on this linear complementary form and the principle of virtual work, a finite element-complementary method is derived for elastoplastic problem. This method is available for materials which satisfy either associated or nonassociated flow rule. In addition, the existence and uniqueness of solution for the method are also discussed and some useful conclusions are given. The project is supported by the National Natural Science Foundation of China     

some general theorems and generalized and piecewise generalized variational principles for linear elastodynamics

From the concept of four-dimensional space and under the four kinds of time limit conditions, some general theorems for elastodynamics are developed, such as the principle of possible work action, the virtual displacement principle, the virtual stress-momentum principle, the reciprocal theorems and the related theorems of time terminal conditions derived from it. The variational principles of potential energy action and complementary energy action, the H-W principles, the H-R principles and the constitutive variational principles for elastodynamics are obtained. Hamilton's principle, Toupin's work and the formulations of Ref. [5], [17]-[24] may be regarded as some special cases of the general principles given in the paper. By considering three cases: piecewise space-time domain, piecewise space domain, piecewise time domain, the piecewise variational principles including the potential, the complementary and the mixed energy action fashions are given. Finally, the general formulation of piecewise variati     

入水冲击问题变分原理及其它

首先建立入水前后两个衔接阶段的较为严密的场方程.再得到与之对应的各类变分原理,界限定理,第二阶段问题的边界积分方程.证明了解的存在性并提供了求解实施方案.最后以船舶兴波阻力问题的算例,论证了第二阶段问题的一种特殊应用及其正确性.从而为求取较为精确的入水冲击问题基本方程的变分有限元及边界元方法奠定了严密的理论基础.