数值算法

The convergence theorem of the neural networks algorithm and the theorem of numerical integration solution and its inferences are presented and proved.

摘要该文提出了一种基于三角基函数神经网络算法求解数值积分的新方法，提出并证明了神经网络算法的收敛定理和数值积分的求解定理及推论。

In this paper, we propose an algorithm for finding global minimization by discrete mean value-level set, the convergence of this algorithm is proved, a termination rule and some numerical examples are given.

西文提出了一个只需计算函数值的离散均值—水平集求全局最优的方法，给出了算法的终止准则，证明了算法的收敛性，并给出了某些数值例子。

In chapter 2 we propose a linear equality constraint optimization question , the new algorithm is combined with the new conjugate gradient method(HS-DY conjugate gradient method)and Rosen"s gradient projection method , and has proven it"s convergence under the Wolfe line search.In chapter 3 we have combined a descent algorithm of constraint question with Rosen"s gradient projection, and proposed a linear equality constraint optimization question"s new algorithm, and proposed a combining algorithm about this algorithm, then we have proven their convergence under the Wolfe line search, and has performed the numerical experimentation.

在第三章中我们将无约束问题的一类下降算法与Rosen投影梯度法相结合，将其推广到线性等式约束最优化问题，提出了线性等式约束最优化问题的一类投影下降算法，并提出了基于这类算法的混合算法，在Wolfe线搜索下证明了这两类算法的收敛性，并通过数值试验验证了算法的有效性。

The outflow fields of a simplified fastback car were studied with numerical methods of different turbulence models and diflerent discretization scheme s with the CFD code STARCD.

以简化的直背式轿车模型为研究对象，以商用计算流体力学软件STAR-CD为工具，应用不同的湍流模型和离散格式对轿车外流场进行了数值模拟，通过与试验结果的对比，研究了湍流模型和离散格式对直背式轿车外流场数值计算精度的影响，同时对SIMPLE算法及其两种修正方法PISO和SIMPISO算法的计算精度进行了比较。

In the process of discretization, the uniform grid is shifted half mesh away from the poles by using the symmetry constrain property of Fourier coefficient on the sphere.

上述分析可推广至三子域情形，同样也得到了算法的有限步终止性。本文通过数值实验对区域分解算法进行数值分析。

Key words:the three dimensional contact problem with friction;nonlinearcomplementary;nonsmooth equations;generalized derivative;nonsmoothmethod;convergence analysis

给出了三维摩擦接触问题的一个非光滑混合不动点模型及算法，这种算法无须求导数，没有引进任何额外变量，并且可视为一种三维摩擦接触问题的迭代法，利用非光滑分析和不动点理论对算法做了分析，给出了算法的不动点理论背景及算法的理论分析，为模型解的存在性及算法收敛性提供分析依据，最后给出了相应的数值算例。

The main results of this research are as follows:(1) A parallel algorithm for solving dense matrix linear equations on distributed-memory multi-computer is presented. Convergent velocity of this algorithm is better than parallel Jacobi method"s, and parallelism is better than Gauss-Seidel method"s. According to theoretical analysis, convergent conditions are given. Moreover numerical experiments indicate that results agree with theory.

主要完成了如下研究工作：(1)提出了一种求解系数矩阵为稠密矩阵的线性方程组的适合于MIMD分布式存储的并行迭代算法，该算法设计上兼取了Jacobi算法并行性好的优点和Gauss-Seidel算法收敛速度快的长处，并且在理论上给出了该算法成立的收敛性条件，并通过数值计算验证了此算法结果与理论相符合。

Theoretical analysis and numerical results show that the new reconstruction algorithm can reduce the computational complexity and greatly improve the numerical stability.

理论分析和数值试验都表明，这种新的重建算法较常用的Newton-Raphson类算法，不仅数值稳定性有较大的提高，而且计算量有所减少。

First,we proposes the acceleration of Monte Carlo EM Algorithm,which is based on Monte Carlo EM Algorithm and Newton-Raphson algorithm,to improve the convergence rate;Second,the it is shown that the accelerated EM algorithm we proposed has quadratic convergence rate in a neighborhood of the posterior mode;Finally,its excellent performance in convergence rate is illustrated by a classical example.

受Monte Carlo EM算法与EM加速算法启发，本文构造了一种新的EM算法，称为Monte Carlo EM加速算法；证明了该算法在似然函数/后验分布的众数的附近确实具有二次收敛速度，改进了Monte Carlo EM算法的收敛速度；并通过一个数值例子的计算结果说明了该算法的优良性，它兼具实现简单及收敛速度快的特点。

After summarizing the waveform relaxation methods and domain decomposition, we finish some research on optimal Schwarz waveform relaxation algorithm as follows: In the first part, we apply Schwarz waveform relaxation methods on telegraph equation system to get optimal transmission conditions to speed up the algorithm.

在对波形松弛算法以及区域分解进行了综述性介绍后，本文对Schwarz波形松弛迭代算法具体进行了以下研究：首先，本文将在电报方程系统上应用Schwarz波形松弛迭代算法，通过强制加入新的局部传输条件分别给出了两种加速算法并通过定理保证了其优化后的收敛性，进而得到优化Schwarz波形松弛算法，然后通过数值试验对传统Schwarz波形松弛算法与优化Schwarz波形松弛算法进行了比较，研究了收敛率与优化系数的关系，找到了使算法最优的系数取值；最后得出优化后的Schwarz波形松弛算法优于常规Schwarz波形松弛算法的结论。

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。