自适应Fuzzy系统及其逼近性能分析

本文提出了一种新的Fuzzy推理方法——自适应Fuzzy推理方法,基于该方法构造了自适应Fuzzy系统,证明了该系统不但具有泛逼近性,而且具有光滑性.基于该方法也得到了一种构造Fuzzy系统推理前件Fuzzy集的方法.使用该前件,CRI方法也具有光滑性,这使得CRI方法具有更广泛的意义.     

具有优势机器的无空闲同顺序Flow Shop排序问题

本文讨论具有优势机器的无空闲同顺序Flow Shop排序问题的两种特殊情况,第一种情况是具有增减系列优势机器,第二种情况是具有减增系列优势机器．对于目标函数是最大完工时间,加权完工时间和,最大延误和延误工件数等问题,给出了求解最优排序的有效方法．     

具有模糊权限结构和模糊支付的合作对策

具有权限结构的合作对策可刻画合作者之间具有等级限制的情形,而具有模糊权限结构的合作对策是对经典情形的拓广.进一步考虑具有模糊权限结构和模糊支付的合作对策,利用联盟的自主度算子和模糊Choquet积分,定义了这种合作对策的限制对策.在此基础上给出了两种模糊权限值,分别证明了这两种值满足的一些性质.最后利用一个算例说明这两种值在企业协作生产收益分配中的应用.     

超幂模型与超闭映射

众所周知,拓扑空间的紧性具有可乘性而弱于紧性的可数紧性却不具有可乘性。于是存在着这样的问题:是否存在着一种介于紧性与可数紧性之间的另一种紧性,使其具有司乘性?1971年A.Bernstein利用超幂模型。给出了这样的一种紧性,即D-紧性([1])。1984年我国数学家李邦河与冯汉桥对这种紧性作了进一步的研究,给出了空间的     

具有混合时滞的脉冲合作系统正周期解的存在性

本文首先建立了具有变时滞和分布时滞的Lotka-Volterra两种群脉冲合作系统.然后通过应用Gaines和Mawhin叠合度定理,研究得到了具有变时滞和分布时滞的Lotka-Volterra两种群脉冲合作系统正周期解存在性的充分条件.     

三步五阶迭代方法解非线性方程组

本文根据求积公式, 给出了三种求解非线性方程组的迭代方法, 并证明了所提出的三步迭代方法具有五阶收敛性. 最后给出了四个数值实例, 将本文的实验结果与现有的几种迭代方法的实验结果作了比较分析, 表明本文所提出的方法具有明显的优越性.     

两种近似计算GM(1,1)参数的有效方法

给出了两种计算灰色模型参数的新方法,并证明通过这些方法所求的预测公式均具有白化指数律重合性,伸缩变换预测公式具有形式不变性,具有齐次性(或称具有伸缩变换一致性).并通过实例展示了方法的简易性和有效性.     

基于广义动态因子模型的中国出口周期分析与预测

研究出口周期的景气循环对于进一步扩大出口及推动整个国民经济的发展具有重要的意义.基于传统的先行指标体系和SW景气指数方法能够为出口周期的监测和预警提供参考,而近年来逐渐完善的广义动态因子模型基于频域分析方法,在处理高维数据方面比前两种方法更具有优势,同时该方法在拐点的探测方面也具有重要的作用.作者首先对三种指数构建方法进行了理论上的介绍;其次,分别运用三种方法构建了中国出口增长循环的一致及先行指数;最后,对三种方法在中国出口周期分析上的表现进行了比较与评价,得出了一些重要的结论.     

疫苗接种、媒体报道和治疗措施对传染病传播影响的数学模型研究

为了探讨疫苗接种、媒体报道和治疗措施对麻疹传播影响,首先建立了具有非线性发生率的SIR传染病模型,证明了无病平衡点和地方病平衡点的全局渐近稳定性.其次,建立了具有三种控制策略新的传染病模型,得到新的基本再生数R_1.最后,为了获得更好的控制效果,对这三种控制措施进行了最优化设计,得到了相应最优控制策略.数值模拟结果显示媒体报道和疫苗接种策略在抑制麻疹的传播方面比治疗措施具有更好的控制效果.     

Vague集上模糊熵的几点注记

V ague集上的不确定性度量有两种途径,一种是度量V ague集是模糊集的程度,一种是度量V ague集具有的模糊性的程度。后者将模糊集的模糊熵作为特例。本文基于“投票模型”分析了V ague集的熵应具有的特征,对国内作者提出的V ague集上的模糊熵进行了评述。     

夹层圆板的大幅度振动

本文利用哈密顿原理导出了夹层圆板轴对称大幅度自由振动的基本方程,并给出了表板很薄情况下的简化形式.作为算例,利用修正迭代法求出了具有滑动固定边界条件夹层圆板对轴称大幅度自由振动的一种解析解,并由此导出了夹层圆板振幅和振频的解析关系式.     

Load and frequency interaction in dynamic buckling of soft-core sandwich plates and shells

The present study is concerned with an analysis of load-frequency interaction effects in the dynamic buckling response of soft-core sandwich plates and shells. Based on a higher-order geometrically non-linear sandwich shell theory in conjunction with an extended Galerkin procedure, a mathematical model together with analytical solution for simply supported sandwich plates and shells with with rectangular projection is obtained. By linearization of the non-linear solution with respect to the oscillating parts, the interaction of the natural frequencies with static preloads can be analyzed. The results reveal that the transverse compressibility of soft sandwich cores might have distinct effects on the natural frequencies. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Buckling forms of homogeneous and sandwich plates in pure shear in tangential directions

The mathematical problem of the plane shear buckling form (BF) of sandwich plates and plates homogeneous across the thickness in pure shear is considered. The solution to this problem is compared with the solution to the problem of a flexural BF which is realized in these plates with the formation of oblique waves. It is established that, in the case of plates homogeneous across the thickness, the critical loads corresponding to the plane shear BF are maximum for isotropic ones. In real one-layer structural elements manufactured both of isotropic homogeneous and orthotropic composite materials, these critical loads cannot be reached since they exceed considerably the critical loads for the flexural BFs with oblique waves. The critical loads corresponding to the two BFs are comparable only for relatively thick plates. However, the plane shear BF can be realized in sandwich plates earlier than the flexural one even if the plates are thin. Translated from Mekhanika Kompozitnykh Materialov, Vol. 36, No. 2, pp. 215–228, 2000.     

Multi-dimensional deformation tests of sandwich plates

Sandwich-type plates are widely used in present technical structures. A variety of special sandwich theories and composite laminated plate theories (CLT, FSDT, HSDT) are available for calculating plate deflections. Since the problem of assessing these theories still exists, a new test apparatus for multilayered composite and sandwich plates was developed. Different types of sandwich plates were used in quasistatic multidimensional deformation tests. Deflections and thickness reductions are compared with the theoretical results obtained by sandwich theories, CLT-, FSDT-, HSDT-, and 3D-solutions.Submitted to the 10th International Conference on Mechanics of Composite Materials, Riga, April 20–23, 1998.Published in Mekhanika Kompozitnykh Materialov, Vol. 33, No. 5, pp. 612–625, September–October, 1997.     

周边面内压力作用下夹层圆板的非线性振动

基于von Krmn薄板理论,讨论了滑动固定基础上周边面内压力作用下夹层圆板的非线性振动问题,应用变分法导出了该问题的非线性特征方程和边界条件,给出了其精确静态解,并使用修正迭代法求解了该方程,导出了夹层圆板振幅和非线性振频的解析关系式．当周边面力使夹层圆板的最低固有频率为零时,就可获得临界载荷的值．     

Plane finite element for static and free vibration analysis of sandwich plates

Conclusions Triangular sandwich finite elements (MPLW30) with 30 DOF have been developed for the static and free vibration analysis of sandwich plates with thin faces and low core shear modules. The results of numerical examples presented here demonstrate the accuracy and suitability of the formulations for the analysis of sandwich plates with k_H > 25 and k_E > 200.Published in Mekhanika Kompozitnykh Materialov, Vol. 30, No. 2, pp 238–248, March–April, 1994.     

Electro-dynamic analysis of smart nanoclay-reinforced plates with integrated piezoelectric layers

Integrating engineering structures with piezoelectric layers as actuator and/or sensor offers smart sandwich structures with controllable static and dynamic deflections. In this paper, a smart sandwich plate consisting of a light nanoclay-reinforced composite core and two piezoelectric face sheets is considered. The static and dynamic behaviors of the proposed smart plate are obtained using their governing coupled electro-mechanical system of equations. In order to facilitate the governing equations, a mesh-free method based on moving least square (MLS) shape function and first order shear deformation (FSDT) is developed and implemented. Two morphologies of intercalated stack and exfoliated nanoclay dispersions are considered in the distribution of the nanoclay into the polymeric matrix. The effects of morphology and volume fraction of the nanoclay, time-dependent loading, and essential boundary condition on the static and dynamic behavior of the smart piezoelectric-integrated nanocomposite plates are examined. In the dynamic analysis, resonance and amplitude modulation phenomena are studied. It is observed that the use of nanoclay, especially with exfoliated morphology, improves the static and the free vibration responses of the smart sandwich plates. Moreover, the frequency of the applied mechanical load has a significant effect on the electro-dynamic response of the proposed smart sandwich plates.     

Free vibration of sandwich plates with impact-induced damage

Free vibrations of impact-damaged sandwich plates with honeycomb and foam cores are studied. It is assumed that damages caused by impact events are to exist before the vibration start and to be constant during oscillations. The influence of the impact damage modes involving the core crushing (planar damage), face sheets fracture (indentation) and the core to face sheets interface degradation (debonding) on the natural frequencies and associated mode shapes of the sandwich plates was investigated using commercially available finite element code ABAQUS. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

均布载荷作用下夹层圆板的非线性振动

给出了均布载荷作用下夹层圆板的大幅度振动方程.按假设的时间模态导出了该问题的非线性耦合的代数和微分特征方程组,并利用修正迭代法求出了该方程组的近似解析解,得到了周边固定夹层圆板振动的幅频-载荷特征关系.讨论了载荷对非线性振动性态的影响.     

关于一阶剪切板的Kármán型精化理论

依据Mindlin_Reissner理论 ,着重研究一阶剪切板的K rm n型精化理论 ,并推导出仅以挠度和应力函数为未知变量的广义K rm n型大挠度方程 ,适用于复合材料上复合构造剪切板的非线性分析·　在当前板的精化理论中 ,消去的两个转角以隐含形式作用于板的整体变形·　这一工程理论适用于各种计及横向剪切复合材料板、正交各向异性中厚板和夹层板等的线性和非线性分析·　容易发现 ,针对具体的工程应用 ,由该方程可直接获得相应的退化形式 ,并且与文献所载的一致·