查询词典 method of approximation

A new method for reservoir identification is proposed which is based on the combination of the approximation principle of BP network and the technology of preprocessing.

根据BP神经网络的逼近原理，提出了基于滑动平均预处理的BP神经网络储层识别方法。

This approach was to replace the derivative operator in the continuous time model by an approximation and estimation of the physical parameters of structures by the least-squares method.

讨论了导数近似值的选择方法，并分析了算法的收敛性。

The book is divided into 14 chapters, including Introduction, continuous control system theory, process and discrete sampling, Z transform, sampled-data systems, discrete approximation of continuous system the equivalent, based on mathematical transform the classical design method, based on state space pole placement design methodology, multi-variable system of quadratic optimal control, quantitative effects, the choice of sampling period, the digital control system modeling, digital control system for a variety of design methods, variables quadratic optimal control systems, sampling cycle of selection, non-linear control of the problem, as well as digital control system, a typical application - Disk drive servo control design.

全书共分14章，内容包括概论、连续控制系统理论、采样过程和离散化、Z变换、采样数据系统、连续系统的近似离散等效、基于数学变换的经典设计方法、基于状态空间的极点配置设计方法、多变量系统的二次型最优控制、量化效应、采样周期的选择、数字控制系统的建模问题、数字控制系统的各种设计方法、变量系统的二次型最优控制、采样周期的选择、非线性控制的有关问题，以及数字控制系统的一个典型应用——磁盘驱动器的伺服控制设计等。

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。

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。

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。

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。

The boundary value problem for first-order differential equations with a parameter refers to the finite solution condition of equation which includes unknown quantity and its first-order derivative that not only relies on interval value but also relies on the parameter of the equation,which is always settled by fixed point theory or successive approximation method.

含一个参数的一阶微分方程边值问题是指：含有未知量及它的一阶导数的方程的定解条件不仅依赖于在区间端点的取值，而且依赖于方程中的参数。通常它用不动点定理或逐步逼近法来解决。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。