查询词典 simple iterative method

In this article, a new multigrid method for solving p-Laplacian equations is proposed based on the existing multigrid method: FAS multigrid method and Cascade multigrid method. This method is a combination of Cascade method and a new method named "back" method.

本文主要研究现有的几种求解p-Laplace方程的多重网格方法：FAS多重网格方法和Cascade多重网格法，并在此基础上提出了一种新的求解p-Laplace方程的多重网格方法：Cascade-back方法。

This thesis investigates the profile extraction and shape optimization on the result of topology optimization of planar compliant mechanisms. The main context includes the following work:(1) summarizing and analyzing the recent research status, some harvest and unsolved problems;(2) analyzing the conceptual design of planar path-generating compliant mechanisms and its mathematical model and tools;(3) Modifying the method of density contour as the method of profile extraction, and developing a method to optimize the density function in the profile extraction according to the requirement of the design of compliant mechanism;(4) developing a method to abstract the compliant mechanism into a form of links and joints by using the principle of connectivity on topology;(5) developing a method of shape optimization of planar path-generating compliant mechanisms, by representing the profile of the abstracted compliant mechanism as simple curves such as straight lines and arcs, establishing the models of the size optimization of the parameters of these curves, so that the compliant mechanism has a machinable shape;(6) At last, proving the feasibleness and effectiveness of the design method by making simulation design and validating it in FEA software.

主要工作包括：(1)分析了柔顺机构拓扑优化和形状优化的研究现状，分析了目前柔顺机构的研究重点、主要成果和尚未解决的问题；(2)分析了基于SIMP的柔顺机构概念设计方法及其相关工具和模型；(3)针对柔顺机构轮廓提取的特殊要求，提出了密度等值线法的改进方案，对密度函数插值点密度值进行优化，提出优化模型和选择优化算法；(4)根据轨迹输出平面全柔顺机构自身的形状特点，提出了轨迹输出平面全柔顺机构的抽象方法，即应用拓扑学上的连通性原理将柔顺机构抽象成杆件和结点形式，并对相应的数学原理进行了证明；(5)提出了平面全柔顺机构的形状还原和尺寸优化方法，对抽象的柔顺机构进行还原，将其轮廓还原成简单曲线的连接，从而建立尺寸优化模型，对机构进行尺寸优化设计，在得到可加工的机构轮廓的同时又能对关键部位进行特别处理；(6)进行了柔顺机构的数值仿真设计，并将所得设计结果导入商用有限元软件中进行仿真实验，证明了设计方法的可行性和有效性。

The research of both theories and practices of gridding in the dissertation shows that: Linear interpolation based on triangulation is simple computationally and fast, but its gridding results isn't smooth and its precision is low; Multiquardric method is also simple computationally with high precision and good effect, but its gridding is slow because it is based on global calculation; Minimum curvature method is fast with high precision and good effect, but its gridding quickly degrades over areas with sparse data control when grid spacing smaller than the actual grid spacing is used; Ordinary Kriging method is high-precision, but its gridding is slow because of large calculation; Inverse interpolation is a computationally fast, efficient and robust method with high accuracy and perfect effect, and its gridding results of different gridding orientations are basically identical. Inverse interpolation is suitable for thegridding of geophysical irregular data, especially for large-scale geophysical irregular data.

本文的方法研究和数据试验分析表明：基于三角网的线性插值法计算简单，速度快，但其网格化结果不光滑，精度不够；多元二次函数法计算简单，网格化精度高，效果良好，但它是基于全局计算的，计算速度较慢；最小曲率法计算速度快，网格化精度高，效果良好，但其在稀疏控制点的网格化容易出现振荡现象；普通克里格法网格化精度高，效果良好，但其计算量较大，一般计算速度慢；反插值法网格化计算稳定，速度快，精度高，效果好，而且在网格化方向不同的情况下其网格化精度效果都达到基本一致，适合于地球物理不规则分布数据的网格化，特别是大规模地球物理不规则分布数据的网格化。

The material job and main conclusion are as follows:(1)A simple boundary orthogonalization procedure independence grids generation method is put forward on the base of algebraic grid generation method; Data structure and computational model on interface are established aiming at blocks of structured grids.(2) SIMPLE procedure is established in nonorthogonal grids by use of the finite volume method and in-depth discusses on special topic such as boundary condition in nonorthogonal grids, deferred correction method and grads compute on calculational nodes, and so on.

本文完成的具体工作和主要结论如下： 1以代数网格生成方法为基础提出了一种简单的、可独立于网格生成方法之外的边界正交化技术；针对分区结构网格系统建立了分区交界面处的数据结构与计算模型； 2利用有限体积方法在非正交同位网格系统中建立了SIMPLE求解算法，对非正交网格系统中的边界条件、延迟修正技术及计算节点的梯度计算等专题进行了深入讨论。

In the process of smart structure's uncoupled properties recognition, the new recognition method which is combined by initial-value search method and nonlinear Alternating iterative Method has been established.

在智能结构的非耦合物性识别中，建立了由初值搜索法与非线性交错迭代法；相组合的新的物性识别统一性解法。

At the same time, combining with the actual condition of delivery pipeline of our country and some prevalent leak detection and location methods, this paper raised a method, which is based on wavelet analysis and negative- pressure-wave to detect and locate the leakage. Jobs in the paper are as follows:As affected by gas density, pressure, specific heat and pipe material, the velocity of negative-pressure-wave improved depending on the energy conservation. At one time, taking the affection of velocity of gas flow, the location formula was modified in some degree.When locating the leaks with location formula, the iterative approach algorithm was adopted as a new method to increase the location accuracy level of system.Multi-scale decomposition and reconstruction of wavelet transform is utilized to filter the noise of negative-pressure-wave, which was brought by leakage. With the capacity to detect the signal singularity fast and accurately, wavelet transform was used to catch the break point of pressure signal. The work improved the accuracy of At in location formula, accordingly improved the location accuracy.Wavelet is a suitable tool for signal analysis. The distinct character is that the mother-wavelet is of optional. That means choosing different mother-wavelet will get different analysis result. So we studied how to choose mother-wavelet and its scale for signal singularity detection. The method is to choose a wavelet by regularities of the wavelet and the signal.Finally, a plan, which bases on SCADA system for inspection and detection of natural gas leakage, is proposed in the article.

其中，主要进行了以下几方面的工作：针对泄漏产生的负压波在管道中的传播速度受媒介的密度、压力、比热及材质等因素的影响，而非声波在空气中传播的速度，本文利用能量守恒原理，对其进行了修正；考虑到管内气体流速对压力波速的影响，对原始的负压波定位公式进行了一定程度的改进，并在利用定位公式进行泄漏点定位时采用逐步迭代逼近算法，提高了系统的定位精度；利用小波变换的多分辨率分解和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行了降噪处理；并利用小波变换技术对信号奇异点的快速、准确的识别能力，对经上述消噪后的负压波信号进行了奇异点捕捉，精确捕捉的结果提高了定位公式中上下游站点采集到的负压波奇异点的时间差△t的精度，从而进一步提高了定位的精度；考虑到小波变换是一种基波可变的信号分析工具，也就是说，不同的小波基波对信号分析的结果将有很大差别，这势必影响最终的处理结果，因此，我们又对比分析了本课题中小波基及尺度的选择问题，依据规则性系数相似性原理对母小波的选择进行了探索性研究；最后，还提出了基于SCADA的泄漏检测与定位系统的软件开发构想及系统的嵌入方案。

The examples indicate that the algorithm has strong pertinence and high efficiency, hi the discrete variable optimization, the problem is solved in the relative quotient method On the base of analyzing the relative quotient method, the conjugate gradient direction is used to modify the old search directions, the iterative matrix of the algorithm, and the method to resolve the discrete variable optimization, the relative conjugate difference quotient algorithm is presented.

离散变量优化算法是从相对差商法开始的，在详细分析相对差上法的基础上，用共轭梯度方向修正原有的搜索方向，并对算法的迭代矩阵进行相关的修改，最终形成一种用于求解离散变量优化问题的RCDQ法。

The method based upon semi-infinite slopes is intended to approximate the prescribed transfer function. In order to minimize the error function, the least square method is adopted. The method of correction with term by term is used to avoid the divergent difficulties in iterative design.

本文提出以折线法来构造网络的逼近函数，并利用最小二乘法和逐项修正法相结合的办法来达到最优逼近，然后依据网络综合的理论，用RC网络的综合步骤来计算出实际元件值。

Brief the; of commonly used method that narrated research to sort solid coupling problem discussed iterative method of dry mode law, across and LS-DYNA finite yuan of software analysis law, the theoretical calculation that is problem of coupling drifting solid offerred new method and train of thought, the analysis of problem of convection solid coupling has fair referenced value.

简要叙述了探究流固耦合新问题的常用方法；讨论了干模态法、交叉迭代法以及LS-DYNA有限元软件分析法，为流固耦合新问题的理论计算提供了新的方法和思路，对流固耦合新问题的分析有一定的参考价值。

The alternate iterative method in the nonlinear minimizing process has been presented, on the base of finite element method and the least square method.

摘 要：对混凝土框架结构的局部刚度缺损反问题进行了动力学方法研究，在采用有限元最小二乘法的基础上，提出并利用了非线性最小化过程的交错迭代法。

The dissecting of samples in group2 were difficult. The root of pulmonary artery and ascending aorta failed to be unfolded because fibrous tissue was tough, right and left fibrous trigone were too firm to be solved by hand. Cardiac muscle fibers couldn't be stripped along myofibrillar trajectory since they were prone to break because of their friability.

组2的心脏解剖困难，表现为纤维组织坚韧，游离肺动脉非常困难；徒手无法松解左、右纤维三角，肺动脉和主动脉根部的游离非常困难；心肌纤维坚硬、质脆，解剖时容易断离成碎块，无法沿纤维走行方向剥离。

We have battled against the odds in a province that has become increasingly violent.

我们对在一个争夺日益激烈省的可能性。