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Based on the elastic theory of large deflection and by taking into account the variation of the axial force and its effects on bending deformation of the drillstring in vertical section,the vibration of the drillstring induced by fluctuating weight-on-bit is described by a parametrically excited system.A Mathieu equation describing the system is established by Galerkin Method.By extending the solution into a Fourier series,the curves of dynamic bifurcation values and the dynamically unstable regions surrounded by the curves are presented.

基于弹性大变形理论，考虑到轴力沿钻柱轴线的变化及其对钻柱弯曲变形的影响等因素，将受自重作用的铅垂井段钻柱在波动钻压激励下的振动转化为一个参数激励系统，用Galerkin方法首次得到了描述此系统的Mathieu方程，并通过将方程的解展成富里叶级数的方法，得到了该振动系统的动力分岔值曲线及其所包围的动力不稳定区。

The study methods: Based on digital printing and offset printing technology principle, the basic parameters having effect on the ink-jet printing output quality were analyzed. And the mathematics models between the ink quantity and the solid density, and the relation between the gamma and printing contrast were established. The relation among the output dot area coverage, the original dot area coverage and the dot-gain percent was analyzed. And the mathematics models of printing characteristics curves and dot-gain curves were established. The factors influencing the dot-gain were analyzed, and then the dot-gain compensation function was acquired. All the models were verified by the method of regression analysis. And the precisions of the models were obtained by the correlation coefficient and multiple correlation coefficients.

研究方法：根据数码印刷以及胶版印刷的工艺原理，分析了影响喷墨印刷输出质量的基本参数，建立墨量与样张实地密度、γ与相对反差的数学模型；分析输出网点面积率、标定网点面积率以及网点扩大率三者之间的关系，建立网点扩大曲线和印刷阶调复制曲线的数学模型，并对网点扩大的影响因素进行了分析，导出了网点扩大补偿函数；运用回归分析方法分析模型，并用相关系数和复相关系数检验回归模型的显著性；使用灰平衡方程，结合回归法得出灰平衡控制曲线。

Around the topic, the weak points of the traditional platform is analyzed first, such as complex arithmetic, long calculating time, high needs of hardware and so on. A real time control method based on virtual simulation is suggested to separate the complex positive/negative calculation of space kinematic and real time motion control. And a"3-2-1"type 6DOF platform is designed with the reference of the MAST (Multi-Axis Shaking Table) of MTS. The kinematic and dynamic calculation of the platform is finished. According to the calculating result, the control system of the"3-2-1"type 6DOF platform including 6 linear servo electric cylinders is designed and constructed. And the professional software Pro/E is used to do the 3D model and 6DOF motion simulation of the platform. The motion curves of the pistons of the 6 cylinders are exported with the simulation. At last the control software is programmed with Microsoft Visual Basic 6.0 and realizes the functions with the commands of GE series motion controllers. When loading the motion curves exported with the simulation, every cylinder can follow the curve very well and the platform realizes the hoped 6DOF motion.

围绕选题，本论文首先分析了传统的运动平台控制方法所存在的算法复杂、解算耗时长、硬件需求高的缺点，提出了一种基于虚拟仿真的实时控制方法，该方法将复杂的空间运动学正、反解与实时运动控制相分离；之后，参考MTS公司的MAST多轴振动平台，设计了新型的"3-2-1"型六自由度平台，并进行了运动学及动力学计算，根据相关计算结果，设计与搭建了包括驱动6个直线伺服电动缸在内的"3-2-1"型六自由度平台控制系统；接着，使用Pro/E对"3-2-1"型六自由度平台进行了三维建模和六自由度运动学仿真，并由仿真直接获得了6个直线伺服电动缸的活塞杆的相应运动曲线；最后使用Microsoft Visual Basic 6.0编写了控制软件界面，通过调用GE系列运动控制卡的各种命令函数实现了控制系统的相关功能，而当加载仿真得到的各缸运动曲线后，每缸均能很好地跟踪输入曲线，使平台实现了期望的多自由度运动。

Since two curves have the same coordinates and unit normal vector at the contacting point, the problem of the mesh of two planar curves is transformed into an ordinary differential equation by vector analysis. We have the solution to the equation by numerical method and computer calculation. After repeating the way of computing the solution to the equation, we have the contacting points.

因两曲线於接触点的位置相同，单位法线向量相等，由向量分析使曲线接触问题转变为常微分方程式，藉助数值计算与电脑运算得到方程式解，重覆计算方程式的解即可得每一接触点的位置。

The critical point means such a state that all the differences between gas and liquid disappear completely,being a most important parameter of dividing the types of fluid and being widely verified in both theory and practice.Currently,four methods of determining critical point are summarized as follows:①laboratory measurement through examining critical opalescence or recording the bubble point and dew point curves;②empiric relation;③calculation of the bubble point and dew point curves by PVT software;and ④ direct calculation according to thermodynamic theories.

随后对临界点进行确定，临界点是气液一切性质差异均消失的状态，是区分流体类型最重要的参数，并得到了理论和工程应用的广泛验证，目前确定临界点大致有四种方法：①实验测定，通过观察临界乳光现象或记录流体的泡点和露点线；②经验关系式；③通过PVT软件计算流体的泡点和露点线；④利用热力学理论直接计算。

In this paper, mainly from the parallel curves, the definition of the parallel surface to start to discuss the legislation of their sentence, nature, and to study certain aspects of their applications, have been on parallel curves, parallel surfaces at some conclusions.

本文主要从平行曲线、平行曲面的定义入手，讨论了他们的判立、性质，并研究了他们在某些方面的应用，得到了关于平行曲线、平行曲面的一些结论。

Critical point detection of planar curves can be well applied in approaching of curves using poly lines,which has very important applications in image recognition,measurement and analysis.

平面曲线的关键点检测可用于数字曲线的直线段逼近，因此在很多图像识别、测量及分析的场合均有重要应用。

In this paper,we introduce a novel blending approach for both 2D and 3D curves with the discrete Poisson equation defined on piecewise linear curves as the theoretical foundation.

以定义在分段线性曲线上的离散Poisson方程为理论基础，提出了一种同时适用于平面和空间曲线形状渐变的方法。

In this paper, we survey the development of polynomial approximation of rational curves and state the knowledge of interval curves in the first chapter.

本论文中，第一章首先介绍了有理曲线曲面的多项式逼近研究工作的发展情况和区间曲线曲面一些相关知识。

A principal curve is used to represent the shape feature of every region. Then Hough transform is applied to these curves to detect a logarithm spiral equation which can match the curves well.

首先螺旋云带的提取建立在对云图恰当分割的基础上，从云团的骨架中提取出能够反映螺旋云带特征的局部螺旋线。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐