离散地

The advantages of this new method are:(1) The field conductivity distribution function is fitter the actual condition than tradition methods:(2) On the condition of triangle elements cut of field, making the calculation speed increase in large degree than tradition methods.

与单元电导率重建算法相比，节点电导率重建算法的优点有：(1)使场域电导率分布函数更符合实际情况，克服了传统算法中对电导率作离散化处理的缺陷；(2)当场域采用三角形单元剖分方式时，在场域的剖分密度保持不变的情况下，可以大大提高重建计算的速度；(3)在场域采用三角形单元剖分方式时，场域的剖分密度可以比以前加大一倍，在不降低重建计算速度的前提下，可以改善重建计算的精度；(4)由于重建的是所有节点的电导率，避免了先前单元电导率重建图像中"阶梯"状边缘和"锯齿"状边缘的出现，明显地改善了图像的视觉效果。

ABSTRACT Based on the discussion of the characteristics of triangular Bezier patches, the theory and method of triangular Bezier surface m...

本文在分析Bezier三角曲面性质的基础上，系统地研究了离散数据的Be-zier三角曲面造型的理论、方法和应用。

ABSTRACT Based on the discussion of the characteristics of triangular Bezier patches, the theory and method of triangular Bezier surface modeling for 3-D scattered data points have been systematically studied.

本文在分析Bezier三角曲面性质的基础上，系统地研究了离散数据的Be-zier三角曲面造型的理论、方法和应用。

Firstly, according to the characteristic of STL file, the scattered data preprocessing and methods of triangulation are presented.

首先，根据RP技术中STL文件的特点，有针对性地提出了离散数据的预处理和网格划分的具体方法。

Since the lengths of the line segments and the angles between line segments are treated as representation parameters, it is convenient to construct energy function and to deal with displacement and length constraints. Based on this advantage, a parametrical model for human body is proposed, which can easily produce human body models with different feature sizes. The above method is just suitable for polylines. Therefore, a generic deformation method for both discrete curves and surfaces is presented. The energy function is constructed by analyzing the relationship of the points before and after deformation. Together with the displacement constraints, the deformation problem is converted to a convex quadratic programming. A necessary condition for constraint points and a sufficient condition for the uniqueness of solution are given. The proposed method can be combined with skeleton-driven animation to control the deformation.

将线段长度与线段之间的角度作为表示参数，既有利于能量函数的构造，又便于处理位移约束和长度内蕴约束条件，利用这一优势，将其应用于三维人体的参数化建模，可以方便地产生具有不同特征尺寸参数的人体模型，由于这种方法只适用于折线变形，具有较大局限性，因此，本文进一步提出一种较通用的离散曲线曲面变形方法，通过分析变形前后的位置关系来构造能量函数，再加上位移约束条件，将变形问题转化为一个凸二次规划问题，并且给出了约束点应满足的必要条件及模型解唯一的充分条件，这种方法还可以与骨架驱动变形的思想相结合，能更好的控制变形。

To avoid numerical diffusion caused by convection-dominated effect, the streamline upwind is introduced to modify the weighted function.

在有限元方程离散过程中，针对流动对流占优的问题，引入对权函数的流线迎风修正，有效地消除了高雷诺数流动计算中的数值震荡。

The thesis brings forward Random Number Sequence Shuffling Technology in a creative way,it can reduces the Linear Congruential Generator pertinency and discrete grid phenomena prominently.

创造性地提出在遗传算法中随机数序列处理的新方法——随机数序列洗牌技术，有效克服了线性同余发生器产生的随机数序列相关与离散网格现象。

The electronic structures of Dawson anion(S2Mo18O62)4- have been calculated by the discrete variational method coupled with the first principal density functional theory.And the comparison with Keggin anion(SMo12O40)2- has been made.The results show that the electrons delocalize around the all anion.But the difference of the electronic distributi on of polar and equator sites exists.

使用第一原理密度泛函理论中的离散变分方法对（S2Mo18O62）4-的电子结构进行了理论计算，并与Keggin结构（SMo12O40）2-的电子结构作了比较分析，结果表明，（S2Mo18O62）中的电子离域地分布在整个阴离子骨架中，但极位和赤道位原子的电荷分布有明显差异。

The 16 noded relative degree of freedom shell element is discussed and used to mesh the blades of the runner.

考虑到16结点相对自由度壳元能很好地描述薄壳和厚壳的性质，而且和三维实体单元的联接也相当方便，本文采用该种单元对水轮机叶片进行离散，并通过样条插值获得叶片有限元网格结点的三维坐标。

In the process of this item, after the mainly uncertainties affecting the network planning are detailedly researched, some flexible planning models such as Blind Number Method and Scenario Method are proposed. Because power network planning is a nonlinear, discrete, multi-peak, multi-objective and nondifferentiable problem, it is very hard to be solved. Ant Colony Algorithm is an advanced metaheuristic method and has potential to deal with network planning problems.

本项目的研究过程中，针对影响电网规划的不确定性因素做了深入的定性和定量分析，采用盲数理论和多场景技术建立了多种具有良好适应性和灵活性的电网规划模型；同时，针对电网灵活规划模型非线性、离散性、多目标及目标函数不可微等特点，对多种优化算法在处理此类问题时的性质进行了分析和对比，并最终采用蚁群算法较好地解决了电网灵活规划问题。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。