查询词典 approximation method

The application of the lattice Boltzmann method in unsteady open channel flows was studied in detail in the paper. An existing lattice BGK model was mended; For the problem of negative local equilibrium and evolutionary distribution, we proposed a lattice Boltzmann model based on cell-population equilibrium, which is a direct non-negative approximation to the continuous Maxwell distribution. The model reduces the transport and collision, two basic evolution steps in the LB model, to transport of the non-equilibrium distribution.

本文系统的研究了格子Boltzmann 方法在明渠非恒定流中的应用问题，改进了一个现有的LB 模型，数值实验表明此改进是有效的；在平衡态分布函数及分布函数的非负性问题上，作者提出了一个基于单元均衡的格子Boltzmann 模型，通过直接对Maxwell 分布函数的离散化实现对速度分布函数的非负离散，这种方法将传统模型演化过程中的碰撞和输运两个步骤直接表现为粒子的输运。

In view of the tedious and mistakable manual calculation in measuring Gauss projection,coordinate zone transformation and meridian convergence,an itera-tive approximation method is adopted and programmed by BASIC to imple-ment the direct and converse calculation of Gauss projection and computer cal-culation of meridian convergence angle.

针对测量工作中人工进行高斯投影、坐标换带和平面子午线收敛角计算非常麻烦又容易出错的问题，采用迭代法趋近求值，用BASIC语言编制了相应的计算机程序，实现了上述计算。

Keywords Closed convex cone;gradient projection method;Least-squares solution;Inverse matrix problem;Inverse eigenvalue problem;Matrix completion problem;Optimal approximation

Article From 湖南大学；应用数学博士论文 2005年度闭凸锥；投影梯度法；最小二乘解；矩阵反问题；矩阵逆特征值问题；矩阵完全化；最佳逼近

Digital holography ; Microscopic digital holography ; Wave front reconstruction ; Fresnel approximation ; Convolution method ; Angular spectrum theorem

数字全息；显微数字全息；波前重建；菲涅耳近似；卷积法；角谱方法

In order to apply virtual reality technique into medical image processing, make convenient for surgeons to access virtual and mini invasive surgery, this paper, presents a full interactive virtual endoscopy system framework, analyzing and discussing system architecture and algorithm models. We explain some key procedures in virtual endoscopy system such as definition of world coordinate, virtual camera, surface detection, normal approximation, volume rendering and surface rendering, and also some interactive control method.

在综合利用各种计算机图形、图象技术的基础上，提出了完整的交互式虚拟内窥镜系统的框架，同时对系统结构和各种模型进行了分析和讨论，还针对系统的实时性和绘制结果的逼真性要求，提出了基于 Object Cache和扩展的区域增长方法，并将其应用到医学图象处理当中，得到了较好的效果。

A projection method is used to smooth out start and end points of the ruling line sets. With predefined Euclidean 6 space distances, the problem of ruled surface approximation from line sets in Euclidean 3 space can be converted into a least square B-spline curve fitting issue in Euclidean 6 space.

利用"投影"光顺法对齐直母线段族首末端点，再通过定义欧氏6空间下的距离函数，将欧氏3空间下的直线族逼近直纹面问题转换成欧氏6空间下B样条曲线最小二乘拟合问题。

In early 3rd century, the ancient Greek women had to body curve and the pursuit of the original "invented", the "model body underwear model body underwear" using the approximation method of modern three-dimensional cutting, and in the waist with metal waist clip plastic waist, then, in this kind of dress of women in society status for the priests, the performers and palace ladies - this is the earliest human research into the "model body".

早在公元三世纪之初，古希腊的女性便有了对身体曲线的追求，并发明了原始的"塑身内衣"，这种"塑身内衣"采用了近似现代立体裁剪的方法，并在腰部用金属腰夹塑腰，当时，穿着这类服装的女性均为处于上流社会地位的祭司、表演者和宫中女士--这是可以考证到的人类最早的"塑体内衣"。

Then,the arrangement method for pressure monitoring points was proposed according to the approximation degree of nodes'pressure changes.

最后，根据各节点压力变化的近似程度和特征，提出供水管网压力监测点的布置方案。

Taking the process of grooving as an example, the optimal solution is worked out with objective simplex method. The degree of approximation between every objective function and given corresponding target value is observed.

以切槽车刀的车削为实例，采用目标单纯形法求得其最优解，确定了每一个目标函数与事先给定的对应目标值的逼近程度。

This paper presents an improved variable stepsize BP learning algorithm by making use of the concept of model approximation degree and by taking advantages of the merits of simulated annealing method.

基于模型逼近度和接受概率的一个变步长快速BP学习算法叶东毅（福州大学计算机科学系福州350002）摘要本文给出模型逼近度的概念。

Many will continue to choose to live in duality and in conflict.

许多人将继续选择活在二元对立性和冲突中。

I find that students of the University of Physical Education all wear sportswear at first sight.

我发现：体育大学的学生乍一看，都是穿运动衣，大家都一样