迭代计算

It solves the grid equations with domain decomposing multigrid parallel method and precondithoners as elimination method.From the discussion of the iterative property of Gauss elimination method,it can improve the parallel efficiency by overcoming the obstacle in the information passing.

对网格方程组作多重网格区域分裂并行计算，以消去法为预条件，讨论了Gauss消去法的迭代性质，指出该迭代法有效改善通常迭代在子域信息传递过程中的障碍性问题，提高多重网格区域分裂并行计算效率。

Firstly, the principle of the iteration method is presented, the characteristic of the method is analyzed. The downward continuation computation for model and practical data with noise of different variance is performed by means of iteration method.

首先介绍了迭代法的基本原理，分析迭代法的特点；然后利用迭代法对不同噪声水平的模型数据和实测数据进行向下延拓计算，研究噪声对迭代法的计算误差影响。

In order to speed up the convergence speed, the each one step of the Landwber iteration is discomposed into the matrix computation and solution and a quick iteration scheme is given for the matrix computation. The relevant accelerated algorithm is given too. Numerical example proves that the accelerated algorithm can quicken convergence speed, reduce the calculation burden, and overcome the obstacle of application of Landweber method of iterated regularization.

为了加快Landweber迭代收敛速度，将每一步Landweber迭代分解为矩阵计算和求解，对矩阵计算部分设计了一种快速迭代格式，并给出了相应的加速算法，通过数值实验验证了这种算法能够大大加快收敛速度，有效的减少计算量，解决了Landweber迭代正则化方法在实际应用中的障碍。

Charge example in whom five node form, 4 node adopt Newton - pressgang modest law go on trend calculate, another node to contain wind-driven generator adopt PQ change, take the place of model go on trend calculate, change, take the place of with ordinary trend computing method first, judge revision wind electrical machinery nodal voltage error go on for the second time changing and taking the place of in establishing range.

在五个节点构成的算例中，4个节点采用牛顿-拉夫逊法进行潮流计算，另外一个含有风力发电机的节点采用PQ迭代模型进行潮流计算，先用普通潮流计算法迭代，后经过修正风电机节点电压判定误差是否在设定范围内进行第二次迭代。

Some efforts were made to improve the computational efficiency of the mold filling simulation of die casting process. To speed up the convergence of the pressure field and speed field, the SOLA method was modified and a dynamic iteration direction method was put forward.

通过对SOLA算法中迭代方法的改进和采用"动态迭代方向"法，加速了流场计算的迭代收敛速度；通过引进"瞬态层"概念，大大简化了流场耦合温度场计算时的计算规模，提高了计算效率。

In the thesis, Bathes nonlinear elastic constitutive model is modified to avoid iterative calculation in updating constitutive model.

本文修正了Bathe的非线性弹性本构关系，使得修正该本构关系中的特征强度时不再需要进行迭代计算。

This model based on Brews's charge sheet model and the above non-iterative computation of surface potential also accounts for DIBL effect, kink effect, and channel-length modulation.

基于Brews的薄层电荷模型和上述非迭代计算表面势，本电流模型同时考虑了漏致势垒降低效应、kink效应和沟道长度调制效应。

The technique does not have any simplification of drainage holes. In this paper, discussions are mainly conducted on the substructure mesh dividing and its second time automatic dividing, the substructure shape, the continuity among substructures and general elements, the classification and definition of the integrated hydraulic model of drainage substructure, the iteration computation of water level inside drainage hole, the application of the technique in solving unsteady unsaturated seepage field, etc., therefore, the high efficient, precise and quantitative analysis of the complex seepage with densely distributed drainage holes is totally realized.

该技术不对排水孔幕作任何简化，本文着重从子结构网格划分模式及二次自动剖分、子结构单元形态、子结构与总体单元网格之间的连续性、排水子结构完整水力学模型分类及定义、排水孔内水位迭代计算、排水子结构法在非稳定非饱和渗流场中的推广应用等各个方面进行论述，实现了对工程复杂渗流场中密集排水孔幕的高效、精细、定量分析。

Simultaneously, the exports of ionization rate and nonionzed concentration are set up as a powerful tool for studying thoroughly the freeze-out effect. dN〓/dp and dN〓/dn are neglected in the linearized equation system of the iteration methods of Newton and Gummel, due to having lower 15 orders or more than dN〓/dn and dN〓/dp, thus the computing effort is cut down with no effect on precision. A new cut-off technique is adopted to accelerate the convergence speed, about twice reduced for Newton iteration method and six times or so for Gummel iteration method. The approximate formulae of Fermi-Dirac statistics are also put forward with simpler form and higher precision. 3. A term dependent on time is added to the electron and hole current succession equations respectively. It is only this model that conservation of charge in transient analysis and alternating small-signal analysis at low temperature can be kept by. 4. The performance of SE-PISCES is explained by the simulation example of PISCES-2B, diode.

研究了低温半导体器件模拟的数值方法：对载流子浓度进行了新的归一化；编制了不考虑掺杂所引进的内建电场时的电离率计算程序；由于低温杂质电离率随偏压状态而变化，为此编制了每次求解迭代时的电离浓度计算程序，并将其插入到求解迭代程序中；同时，设置了杂质电离率和未电离杂质浓度的出口点，为更深入地研究冻析效应提供了有力工具；在Newton迭代法和Gummel迭代法的线性化方程组中忽略了dN〓/dp、dN〓/dn，是因为它们比dN〓/dn、dN〓/dp低15个数量级以上，这样减小了计算量又不影响模拟精度；对Newton迭代法和Gummel迭代法采取了新的截断技术，提高了收敛速度，Newton法迭代法和两次左右，Gummel法减少六次左右；给出了表达式更简单而精度更高的Fermi-Dirac积分近似计算公式。

The quasi-3D S〓/S〓 streamfilaments iterative computation is used to analyse the flow field in centrifugal impellers compressing perfect gas and real gas respectively.

使用准三元S2/S1流面迭代计算，对压缩理想气体和实际气体的离心叶轮流场作了分析。

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。