任意约束边界条件下初始缺陷压杆的稳定性分析

对各种边界条件下初始缺陷压杆的稳定性进行了系统的研究,讨论了不同边界条件和初始挠度对压杆稳定性的影响,得出了求解弹性边界约束系数、端点转角、端点弯矩和压杆挠度的公式,为进一步的理论分析打下了基础。     

基于行为表达式的任意随机Petri网的品质分析

提出一种基于行为表达式的品质分析方法,可以做任意分布的有界或无界随机 Petri网的品质分析.该方法不仅拓广了分析范围,解决了文献[4]中没有解决的问题,而且 不必画出Petri网的可达标识图,使分析过程更为简洁.     

分割多边形成凸多边形的算法

提出将任意简单多边形分割成若干个凸多边形的一种算法，主要思想是：首先确定多边形的凹点，然后利用连接凹点与落入该点Ｂ域中顶点的方法，消去该凹点，从而分割原多边形成两个子多边形，最后对子多边形递归使用该方法，直至消去全部凹点该算法分割多边形成Ｏ（ｌ）个凸多边形，其时间复杂性是Ｏ（ｎ）次乘法，其中ｎ是多边形的顶点个数，ｌ为凹点数目     

多级旋转式倒立摆的建模与分析

运用刚体的动力学知识对多级旋转式倒立摆系统进行了动力学分析,归纳其规律性,并推导出旋臂及各级摆杆的运动微分方程,从而获得任意级旋转式倒立摆的非线性数学模型。文中还对旋转式倒立摆系统进行了能控性分析。最后利用MATLAB对一级、二级旋转式倒立摆的控制进行了仿真,并得到较好的仿真结果。     

任意分布参数的机械零件的可靠性稳健设计（一）：理论部分

 将可靠性优化设计理论、可靠性灵敏度技术和稳健设计方法相结合，讨论了具有任意分布参数的机械零件的可靠性稳健设计问题，提出了可靠性稳健设计的计算方法．把可靠性灵敏度融入可靠性优化设计模型之中，将可靠性稳健设计归结为满足可靠性要求的多目标优化问题．在基本随机参数的前四阶矩已知的情况下，通过计算机程序可以实现具有任意分布参数的机械零件的可靠性稳健设计，迅速准确地得到具有任意分布参数的机械零件的可靠性稳健设计信息。     

同步任意值计数器的设计

多值计数器的设计与二值计数器的设计不相同，因为一般多值触发器本身并不具有多值计数功能，所以多值计数器的设计首先要解决如何实现一位多值计数器的计数问题；另外要解决如何实现多位计数器的低位向高位的进位问题．此外，还介绍了几种具有代表性的四值计数器的设计，其方法可适用于任意值计数器的设计．     

Mixed convective heat transfer enhancement in a ventilated cavity by flow modulation via rotating plate

The present study numerically explores the mixed convection phenomena in a differentially heated ventilated square cavity with active flow modulation via a rotating plate. Forced convection flow in the cavity is attained by maintaining external fluid flow through an opening at the bottom of the left cavity wall while leaving it through another opening at the right cavity wall. A counter-clockwise rotating plate at the center of the cavity acts as an active flow modulator. Moving mesh approach is used for the rotation of the plate and the numerical solution is achieved using arbitrary Lagrangian-Eulerian finite element formulation with a quadrilateral discretization scheme. Transient parametric simulations have been performed for various frequency of the rotating plate for a fixed Reynolds number (Re) of 100 based on maximum inlet flow velocity while the Richardson number (Ri) is maintained at unity. Heat transfer performance has been evaluated in terms of spatially averaged Nusselt number and time-averaged Nusselt number along the heated wall. Power spectrum analysis in the frequency domain obtained from the fast Fourier transform analysis indicates that thermal frequency and plate frequency start to deviate from each other at higher values of velocity ratio (>4).     

Oscillation based test method of parameterization of open loop op amp and its authentication

The analytical design of differential amplifiers, the building blocks of an op-amp, requires an elegant, handy and computationally simple experimental method of measuring the d.c.super-gain of these blocks. This paper presents such an oscillation based test (OBT) by putting the Op.Amp. under test in the close loop of state variable filter. The oscillation frequency of the linearized system directly yields the d.c. open loop gain, the dominant pole and the second order non-dominant pole of test Op.Amp. The d.c. open loop gain of DUT is further authenticated by a novel method of frequency domain analysis using a super attenuator. The authentication is positive with 95 percent confidence level (ɛ, 0 percent, 9.64 percent) thereby establishing the validity of OBT method.     

Constructing hyperchaotic systems at will

Over the last two decades, chaotification has received increasing attention from various communities of science and engineering. This paper aims at developing a unified chaotification framework for generating desired higher‐dimensional dissipative hyperchaotic systems by using a single‐parameter controller. The main idea is to use a block diagonal matrix in the design of the nominal system, so as to construct a desired hyperchaotic system. Specifically, the proposed scheme is to assign desired closed‐loop poles to the controlled system, allocating the corresponding numbers of eigenvalues with positive real parts at two types of saddle‐focus equilibria. For the non‐degenerate case, the number of positive Lyapunov exponents of the controlled system is given by the largest number of positive Lyapunov exponents of the desired hyperchaotic system. Two representative examples are given to illustrate and verify the proposed design method. Finally, the digital signal processor is employed to implement the above 10‐dimensional hyperchaotic systems, and the experimental observation is also given. Copyright © 2015 John Wiley & Sons, Ltd.     

任意阶PDE降噪特性分析

通过对分数阶微积分原理的研究,提出了任意阶偏微分方程(partial differential equations,简称PDE)降噪的统一模型,实现了基于任意阶PDE降噪的数值化方法,并分析了任意阶PDE降噪特性。该数值化方法能够快速实现信号降噪,耗时少。通过仿真实验,分析了PDE降噪性能的影响因素,与其他去噪方法进行了对比分析,并对现场实测信号进行了降噪分析。结果表明,PDE数值求解降噪方法性能优良,算法简单。