几何基础

In this topic, the dynamic analysis methods for piezoelectric vibrator are studied systematically based on the theoretical model, FEM numerical experimentation and FEM governing equation for given compound-mode vibrator, and some valuable conclusions are obtained. The main work accomplished is summarized as follows: 1.Elaborate the main modeling methods for piezoelectric vibrator and the significance and necessity to study the dynamic characteristics of piezoelectric vibrator which emphasize the urgency of this paper. 2.Take the bending deformation induced by piezoelectric ceramic as example, the energy transfer mechanism of electric energy to mechanical energy are analyzed; the motion and force transfer mechanism are analyzed for the longitudinal-bending vibrator. 3.Based on mode assumption and Hamilton principle, the coupling model of piezoelectric vibrator of linear USM is built; moreover, the equivalent circuit model is obtained and a coupling equation represents the relation between electric parameters and mechanical parameters is derived which provides foundation to match the vibrator and driving circuit. 4.Combine the constitutive equation of piezoelectric ceramic with elastic-dynamical equation, geometric equation in force field and the Maxwell equation in electric field and the corresponding boundary condition equation, the FEM control equation for piezoelectric vibrator of USM to solve dynamic electro-mechanical coupling field is established by employing the principle of virtual displacement. The equation lays the foundation to study the non-linear constitutive equation of piezoelectric ceramic driven by high-power. 5.Define the dynamic indexes of characteristic of vibrator and carry out variable parameters simulation by calculating the model parameters and the electric characteristics of vibrator are simulated according to the equivalent circuit model. By numerical experimentation, the working mode of vibration of vibrator and the shock excitation results of the working frequency band which provides the mode frequency to realize bimodal are analyzed. Detailed calculation of the electro-mechanical coupling field parameters is made by programming the FEM control equation.

本课题从理论模型、有限元数值试验、有限元控制模型等方面以复合振动模式振子为例对超声电机压电振子的动力学特性及其分析方法进行了全面系统地研究，得出了许多有价值的结论，主要概括如下： 1、阐述了目前针对超声电机压电振子的主要建模方法，对压电振子动态特性的研究意义和必要性进行了论述，突出了本文研究内容的迫切性； 2、以压电陶瓷诱发弹性体发生弯曲变形为例，分析了压电陶瓷通过诱发应变来实现机电能量转换的机理；对基于纵弯模式的压电振子的运动及动力传递机理进行了分析； 3、基于模态假定，利用分析动力学的Hamilton原理，建立了面向直线超声电机压电振子的机电耦合动力学模型，并据此建立了压电振子的等效电路模型，导出了电参量与动力学特性参量的耦合方程，为压电振子与驱动电路的匹配提供了依据； 4、从压电陶瓷的本构方程出发，综合力场的弹性动力学方程、几何方程、电场的麦克斯韦方程以及相应的边界条件方程，采用虚位移原理，建立了压电振子动态问题机电耦合场求解的有限元控制方程，为研究其大功率驱动下的非线性本构模型奠定了基础； 5、界定压电振子的动力学特性指标，对压电振子的机电耦合动力学模型参数进行计算及变参数仿真；依据等效电路模型，对压电振子的电学特性进行了仿真分析；通过有限元数值实验，对压电振子工作模态附近的模态振型及工作频率附近的频段进行了激振效果分析，找出了实现模态简并的激振频率；利用有限元控制方程，通过编程计算，对压电振子的力电耦合场参数进行了详细计算，得出了一些有价值的结论。

The management and quality analysis of the primitive images have been analyzed and studied in this paper, of which the content and structure are as follows:Firstly, the developing background and the meaning of the management and quality analysis of the primitive image, as well as the trends of the management and data quality of the image database studied both in and out of our country, have been discussed in detail.Secondly, the developing direction of the technology of the remote sensing image and the importance of the remote sensing images in the field of economy nowadays have been analyzed systematically. And it is pointed that the primitive image with the elements of interior and exterior orientation will become more and more important as a sort of image production.Thirdly, the hierarchical structure of database, especially the SQL Server adopted in this system, has been deep studied and analyzed in the aspects of Applying Program Interface, Internet Data Connector and ActiveX Data Object.Fourthly, the methods of assessing the quality of the remote sensing image have been put forward in the terms of geometry, construction and the integrality of the assistant information.Fifthly, the model of propagation of errors of the precision of the ground coordinates has been calculated in the steps of inner orientation, spatial resection and answering based on the deep analysis of the principles and processes of inner direction and space resection, which have also been experimented and analyzed in term of numerical value.Finally, the total design and the idiographic realization of the sub-modules have been introduced in detail, based on which the design and development of this system are realized in combination with the program languages such as VB6.0, VC6.0 and SQL.

本文针对原始影像的管理与质量分析进行了深入的研究与探讨，主要内容包括：(1)首先对原始影像管理与质量分析系统的研制背景和意义进行了详细论述，并对影像数据库管理和数据质量研究的国内外动态作了介绍；(2)对遥感影像技术目前的发展趋势以及遥感影像在国民经济生活中的地位进行了深入的分析，并指出附带有内外方位元素的原始影像作为一种影像产品将越来越会引起人们的重视；(3)对数据库的体系结构进行了深入的研究与分析，尤其是对SQL Server数据库的体系结构，从编程接口、Internet数据连接器和ActiveX数据对象三个方面进行了深入剖析；(4)从几何质量、构像质量和附属信息的完整性三个方面提出了对遥感影像质量的评定方法；(5)基于对内定向和空间后方交会原理及过程的深入分析，推导出了从内定向到空间后方交会再到最终求解地面坐标的误差传递模型，并对上述模型进行了数值实验和分析；(6)对原始影像管理与质量分析系统的总体设计和各模块功能的具体实现进行了详细的介绍，并在此基础上联合VB6.0、VC6.0和SQL等编程语言，实现了系统的设计与开发。

Nan; You are absolutely right, I have studied in pure abstract image and geometry mountain stone image for a dozen of years, they are the foundation of other images.

南溪：您说得很对，纯抽象的图像，几何山石图像，我研究十几年，这类作品实际是形成今天其它图像的基础。

The model of the received power is established based on the basic principles of geometry optics and radiometry. This model provides the principle of receiver-transmitter design and performance evaluation. On the basis of the received power model and APD noise model, the response of measurement signal after passed through the frequency difference circuit and the corresponding change of its SNR are studied.

研究了非合作目标测距时，发射视场与接收视场的重叠情况，以及视场重叠区域内光的探测情况，并以此为基础，根据几何光学和光度学的基本理论，建立了非合作目标测距中接收光功率的数学模型，为接收/发射器的结构设计，以及测距性能的预测提供了理论依据。

When the geometric similitude ratio of the model to the prototype was determined and the loading similitude condition was satisfied by using similitude theory in structure modeling and experimental techniques, the prototype soil parameters were derived according to the model test result. The vibrating wheel compelled by harmonic exciting force was treated as a lumped mass vibrating system by equation equity method. By using this mechanical model in vibrating compaction, soil parameters were identified according to the equivalence of vibrating differential equation. The curve fitting method of amplitude versus frequency response was used for dynamic simulation based on the systematic dynamic equation of vibrating roller-soil system.

用相似理论与模型试验法在确定了模型与原型之间的几何相似比并满足载荷相似条件后，根据模型试验结果推导出了原型土体参数；用方程对等法把受简谐激振力作用的振动轮等效为集中质量振动系统，以此作为振动压实过程的力学模型，根据振动微分方程的等效条件进行识别；用幅频特性曲线拟合法以振动压路机－土壤系统动力学方程为基础，用计算机进行动态仿真。

On the basis of total analysis and summarization on basic knowledge, principle and expert experience of injection mould feed system as well as further research on the computer-aided design of injection mould feed system, according to the geometrical model of the plastic, applying technologies including feature-based modeling and identifying, RBR, CBR, oriented-object and database technology VC++ 6.0, SQL Server 2000, Object ARX, the paper conceives general structure and primary function module of the intelligent design of injection mould feed system, develops user-systemic interface, constructs knowledge rule library and case library of injection mould feed system, researches denotative method of knowledge rule library and case library, designs the ratiocinative mechanism of intelligent system design, and realize the intelligent design of injection mould feed system partly.

本文在对注塑模具浇注系统设计的基本知识与原则及专家经验全面分析总结，以及对计算机辅助浇注系统设计方法深入研究的基础上，以塑件几何模型为依据，应用基于特征的建模与识别技术、RBR和CBR推理技术、面向对象和数据库技术，以及VC++6.0、SOL Server 2000和Object ARX二次开发工具，在AutoCAD 2002平台上，构建了注塑模具浇注系统智能化设计系统的总体结构及主要功能模块，开发了系统的用户界面，建立了浇注系统设计的知识与规则库和事例库，研究了设计知识与规则和事例的表示方法，设计了智能化设计系统的推理机制，部分实现了注塑模具浇注系统的智能化设计。

Based on this theory, this paper discusses its importance on the recognizability, standardization and fast modeling of building model, and emphases are loaded on the structure and classification of basic geometric units that constitute the 3D model of buildings and on how the model of intricate building is established in different levels of details.

文中基于这一理论，讨论了该理论在建筑物模型的可识别性、标准性以及快速建模中的意义，并在此基础上重点研究了构成建筑物三维模型的基本几何单元的构成与分类，以及复杂建筑物在不同细节层次下的模型构建。

Based on the differential geometry theories , two kinds of the regular polyhedron are selectedas the new shapes of grinding media .

以微分几何理论为基础，选择了两种正多面体作为研磨体的形状，与球形研磨体进行了研磨效果的比较。

Based on the process of establishing model, the theory and method of geometry model of establishing modern surveying data are discussed in this paper, including the establishing model technology of scalar quantity field data and vector field data.

从构造模型的一般过程入手，主要讨论了建立现代测量数据的几何模型的理论和方法，包括标量场数据与矢量场数据构模技术，提出了一些有益的结论，为测量数据可视化提供了技术基础。

Chapter 3 studies the representation method of a contour: CODON code that is stable under rotation, translation and scale transformation.

第三章着重研究了抗旋转、尺度和平移等几何失真的图像轮廓表示方法—CODON编码，为图像匹配和识别奠定基础。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。