几何的

The stealth warplane for the microwave radar usually have complicated structures with the coating of wave absorption. On the base of calculation and modeling of the geometrical structure of the warplane in real size, the HF RCS of the air crafts under two different polarizations in different direction have been calculated with the FDTD. The result shows that the above mentioned stealth warplane have the obvious characterstics of frequency resonance, polarization and the relatively large RCS in HF Band 10-30dBm2, which can be used as the theoretical reference for selection of working frequency for sky wave OTH Radar and it also means that the sky wave OTH radar has good capability of anti-stealth targets quantitatively.

对微波雷达具有隐身作用的飞机，其形体较为复杂且表面涂敷有强吸波材料在对一种具有隐身几何外形结构实际尺寸飞机进行计算建模的基础上，文中采用FDTD技术得到了两种极化状态下该飞机无涂敷时不同方向上的短波雷达截面RCS值其结果显示了这种隐身几何外形飞机在短波波段有明显的频率谐振特性、极化特性和较大的RCS10-30dBm2，可为天波超视距雷达在选择工作频率时提供理论参考，并定量地说明天波超视距雷达具有较优的反隐身目标能力

First, this thesis introduces basic theory of CBR , and studies many aspects of typical part design case , such as case representation, case retrieval, retain etc. Second, regards design code as case code in order to integrate the case with geometrical and non- geometrical information, and realizes the parametric modifying function for 3D solid model in the condition of Pro/E. Third, for the purpose of making true of system's aided design requirement, this thesis brings forward to create part design knowledge base with AI language CLIPS, and integrates the rule based KB into the system; finally, collects and summarizes the knowledge of shaft,gear,sleave, and a sample with ladder—shaft is shown in order to verify the correction of theory research.

首先，本文介绍CBR技术的基础理论，并重点研究典型零件案例的表示、检索、修改等功能；其次，以零件设计编号为案例编号实现对案例的几何与非几何信息的集成，并实现了三维实体模型在Pro／E环境下的参数化修改功能；再次，从系统辅助设计功能要求出发，提出将基于规则的知识库嵌入到系统内部，用人工智能语言CLIPS建立零件设计知识库；最后，对轴类、齿轮类、盘套类零件案例知识进行收集、总结，并通过阶梯轴设计实例验证了理论研究的正确性。

Our conclusion is : For general transport equation and some special transport equations (slab geometry, spherical symmetry, pillar symmetry) we can evaluate some relevant physical quantities and geometrical properties from the exiting photon flux. The method we will use is to transform the transport equation into integral equation by integrating it along its characteristics, then we prove the nonlinear operator K is monotone and continuous with respect to its arguments and obtain the existence of K~-1. Consequently, we can evaluate some relevant physical quantities and geometrical property of the medium.

我们得到的结论是：无论对于一般的迁移方程，还是当介质具有某种对称性时(板对称、球对称、柱对称)的迁移方程，我们都可以根据泄漏的光子流估计介质各种相关物理量和几何特性，所用方法都是将迁移方程通过沿特征线积分转化为积分方程的形式，然后证明非线性算子K关于自变量的单调性和连续性，从而得到逆算子K~(-1)存在，进而达到估计介质各种相关物理量和几何特性的目的。

The results shows that die pressure of extruder, relaxation time of polymer and geometrical parameters of die have significant effect on stress tensor in extruder die. By changing the geometrical parameters in the flowing channel, the pressure can be controlled.

模拟结果表明：机头压力、材料的松弛时间以及口模流道的几何尺寸对高聚物在机头中的应力张量的变化影响较大；通过改变挤出流道的几何尺寸，完全可以控制高聚物的熔体压力。

Researchment on Cable Dome begin with the Concept Design, which including geometric stability, ratio of rise to span, space between struts, height of struts, space between strop, inclination between ridge cable, etc.

对索穹顶结构设计技术的研究首先从概念设计开始，概念设计包括结构的几何稳定性判断、跨度和矢高的关系、压杆的间距、压杆的高度、环索的间距、脊索间夹角等，后面几个部分其实也可以归结为结构几何参数的优化问题。

For example, we study the properties of the"centroid curve" and the"auxiliary curve", and identify two planes in which these two curves are defined respectively; we also use the idea of homotopy method to prove a fact that the orbit of a differential system has no triple contact point with the line we considered. Another key technique, which we use several times, is deformation argument.

例如研究由Abel积分之比定义的"质心曲线"和"辅助曲线"的几何性质，并把这两条在不同平面上定义的曲线放在同一坐标系中考虑；利用拓扑中同伦的思想来证明微分系统的轨线不可能与某条直线三重相切；利用几何方法与分析计算相结合证明了某一曲线是正则的；以及连续变动参数的技巧。

But with the change of circumstances, the uncertainness of investment projects increases and these traditional decision approaches are challenged.

在第一章中，本文讨论在风险中性世界中的投资项目决策实物期权的价值评估问题，并假设投资项目的未来收益变化率S t服从如下的几何布朗运动：其中r为无风险利率，此时等于银行利率，σ为投资项目未来收益的波动率，随机过程Wt是上的几何布朗运动。

A stereo pair of SPOT-5 imagery acquired in across-track mode is selected and used. The empirical results have shown that the proposed geometric model, compared with the original model which considers the CCD line-scanner side watch angle as a constant, can improve the x-coordinate accuracy of image points, and can also raise the height accuracy of object space coordinates significantly while maintain the same level of the planimetric accuracy.

经对一SPOT-5异轨立体像对的试验表明，利用改进的几何模型和视CCD线阵列侧视角为常数的仿射变换模型对立体影像进行几何处理，前者较后者的像点x坐标精度有一定的改善，物点的高程精度有所提高，平面精度两者基本一致。

4Have done a great deal of research work, while on the stiffened ones, Wanget al. [5, 6, 7] have also done a series of research work. But up to now, tothe author's best knowledge, there have been no papers reported in the openliterature on the stability analysis of the laminated composite shells of revo-lution, both unstiffened and stiffened, by the finite element method.

在SABA族元素[1]的基础上，把复合材料各向异性的弹性性质考虑进去，把纵向筋条处理成为空间梁，计入梁偏心的影响，由梁的基本弹性和几何刚度矩阵出发，经过一系列变换，推导出与SABA元素相协调的新的弹性和几何刚度矩阵，从而较为精确地得到了复合材料叠层及加筋的稳定性分析结果。

After verification of the program, the mathematical models of the suspension bridges were studied by means of the program, as well as the determination of the main cable's shapes and its internal forces at different stages, the calculation of the cable's unstrained length and the analysis of the construction processes, of which some new approaches were presented in the mean time. Thus makes the structural analysis results of suspension bridges more reliable and in accordance with reality.

在用算例验证了程序分析结果正确性的基础上，应用该程序对悬索桥的数学模型、各阶段缆索几何形状及内力状态的确定以及缆索无应力长度的计算和施工过程分析进行了研究，提出了确定缆索在成桥状态下的几何形状及其内力状态以及缆索无应力长度计算的新方法，使悬索桥的结构分析结果更加符合实际情况。

The labia have now been sutured together almost completely.The drains and the Foley catheter come out at the top.

此刻阴唇已经几乎完全的缝在一起了，排除多余淤血体液的管子和Foley导管从顶端冒出来。

To get the business done, I suggest we split the difference in price.

为了做成这笔生意，我建议我们在价格上大家各让一半。