二阶非线性椭圆型微分方程解的振动比较定理

建立几个微分不等式,讨论了一类二阶非线性椭圆型微分方程解的振动性,得到几个新的振动比较定理．     

具连续变量的非线性时滞差分方程的振动性

本文研究了一类具有连续变量的非线性时滞差分方程的振动性,给出了该类方程振动的几个充分条件。     

时标上一类三阶中立型动力方程的振动准则

利用广义Riccati代换给出了时标上一类三阶中立型动力方程的振动准则,其结果不仅得到了几个振动解存在的条件,也拓展了一些已有的结论,在最后还给出了几个例子来验证结论.     

高阶非线性脉冲泛函微分方程的振动性

研究了一类广义的高阶非线性脉冲泛函微分方程的振动性,得到关于解振动的几个充分条件.     

具连续变量的偶数阶中立型差分方程的振动性

研究具有连续变量的偶数阶中立型时滞差分方程的解的振动性,给出了有界解振动的几个充分条件.     

二阶非线性泛函微分方程解的振动性质

研究了一类二阶非线性泛函微分方程解的振动性以及非振动解的有界性.在一定条件下,建立了几个新的振动性和有界性定理,其结果推广和改进了已有的一些结果.     

一类具有欧拉形式的中立型微分方程的振动性

研究具有欧拉形式的无界时滞中立型微分方程解的振动性，给出了方程振动的几个充分条件。     

具多偏差变元的一阶泛函微分方程的振动性

本文首先考虑多时滞泛函微分方程的振动性,给出了方程振动的几个新的充分条件.然后,把这些结果推广到微分不等式,并应用于多时滞中立型方程的振动性.     

一类偶数阶中立型非线性阻尼泛函微分方程的振动准则

本文用不同于原有文献的方法研究了一类偶数阶中立型非线性微分方程的振动性,得到了方程振动的几个新的充分条件。     

具有连续变量的非线性差分方程的强迫振动

本文讨论了一类具有连续变量的非线性差分方程的振动问题 ,给出了方程存在最终正解和最终负解的充要条件及强迫项对解振动的影响 ,得到了几个充分条件 .     

KKM技巧及其应用

本文介绍KKM技巧,并用以建立了新的抉择定理和重合定理,它们是[2,10,11,15,16]等近期文献中一些重要结果的推广.     

Stability of impulsive infinite delay differential equations

In this work, we consider the stability of impulsive infinite delay differential equations. By using Lyapunov functions and the Razumikhin technique, we get some results that are more general than ones given before. And in using the Razumikhin technique, we use a new technique that has been given by Shunian Zhang; we extend this technique to study impulsive systems. An example is also discussed in this work to illustrate the advantage of the results obtained.     

A note on the primal-dual column generation method for combinatorial optimization

In this paper, we address the primal-dual column generation technique, which relies on well-centred suboptimal solutions of the restricted master problems. We summarize new theoretical developments and present computational results for two classical combinatorial optimization problems, in which this technique has not been tested before. The results show that the primal-dual column generation technique usually leads to substantial reductions in the number of iterations and CPU time when compared to two other well-established approaches: the classical column generation technique and the analytic centre cutting plane method.     

Theoretical-experimental investigation of frequencies of free vibrations of circular cylindrical shells

We consider a holographic interferometry technique for the determination of frequencies of free vibrations of isotropic circular cylindrical shells and compare the experimental results with results of calculation of frequencies of these shells on the basis of the spline collocation technique.     

三阶非线性中立型变时滞动力方程的渐近性与振动性(英文)

考虑了时标上三阶非线性中立型变时滞动力方程的渐近性和振动性.利用广义Ric-cati技巧与完全平方技巧,获得了方程所有解渐近和振动的准则.所得结果推广了已有三阶动力方程的结果,给出了一些例子加以说明本文的主要结论.     

An efficient technique for finding the eigenvalues of fourth-order Sturm–Liouville problems

In this paper, we will develop a numerical technique for finding the eigenvalues of fourth-order non-singular Sturm–Liouville problems. We used the variational iteration methods as a basis for this technique. Numerical results and conclusions will be presented. Comparison results with others will be presented.     

Calculation of stress intensity using multimesh extrapolation

This paper illustrates a technique described as “multimesh extrapolation” where a number of less detailed models are used to extrapolate to more accurate results. It is shown that modeling error can be predicted using multimesh extrapolation for cases where no theoretical solution exists. The multimesh extrapolation technique is demonstrated with the analysis of a fracture toughness test specimen having a theoretically infinite stress at the crack tip. A technique based on elastic strain energy is used in conjunction with the multimesh extrapolation technique to evaluate the applied stress intensity K_I for a compact tension specimen. As a result of this analysis, it is shown that the multimesh extrapolation technique can lead to excellent results which approach the theoretically correct solution.     

二阶矩阵微分系统的区间振动准则

本文利用矩阵Riccati技巧,平均技巧及矩阵不等式,建立形如[P(t)Y']' Q(t)Y=0的二阶矩 阵微分系统的一些新的区间振动准则.所得结果推广,改进和包含一系列已有的结论,并能应用于已知 准则不能适用的若干情形.     

Chaotic Behavior in Slowly Varying Systems of Nonlinear Differential Equations

A technique is developed to find parameter regions of chaotic behavior in certain systems of nonlinear differential equations with slowly varying periodic coefficients. The technique combines previous results on how to find branches of periodic solutions which terminate with a homoclinic orbit and results on how to find chaotic trajectories in the neighborhood of homoclinic trajectories of the autonomous system. The technique is applied to the continuous stirred tank reaction A → B, for which it is shown that a slowly varying periodic flow rate can yield aperiodic temperature fluctuations.     

A wavelet filtering based estimation of output gap

Accurate estimation of output gap is an important and challenging problem for any economy. We consider here the problem of estimating the output gap for the Indian economy. The estimation of output gap involves a hypothetical variable, the potential output of the economy. In this paper, we propose a wavelet filtering based technique for estimation of output gap using monthly the Index of Industrial Production (IIP) series. We compare the results obtained using the proposed wavelet based technique with the widely used Hodrick-Prescott filtering and Seasonal ARIMA modeling based techniques. In order to compare the output gap estimated using the proposed technique with the other techniques, we explore the causal relationship between the estimates of output gap and the growth rate of an equity market indicator. It is observed that the wavelet filtering technique gives better results than the more popular econometric and standard time-series modeling techniques.