数值算法

In this paper a genetic algorithm four-dimension data assimilation system was applied to the more complex MM5 model, we verify the performance of the genetic algorithm assimilation system, we take the a heavy rainfall process during 04-05, July, 2003 as the experimental research object, and carry out data assimilation experiment of actual observation data, compare the experimental results of the genetic algorithm assimilation system and MM5 adjoint model assimilation system with the experimental results without assimilation, the following is the result:genetic algorithm assimilation system is used not only in a barotropic primitive equation but also in the complex model, MM5, for example, in the ideal experiment the result of the genetic algorithm assimilation system is better than the MM5 adjoint model assimilation system, in the assimilation experiment of actual observation data, whichever assimilation system is used, the initial field of numerical prediction model is effectively improved and the prediction effect of physical field and rainfall are somewhat enhanced.

本文将遗传算法的四维同化系统运用到更复杂的MM5模式中，在理想实验中验证遗传算法同化系统的性能，并以2003年7月4日"南京暴雨"作为研究对象，进行了实际观测资料的同化，并将遗传算法同化系统和MM5伴随模式同化系统得到的结果跟未同化的结果进行了比较，结果如下：遗传算法同化系统不仅可以用在正压原始方程模式上，同样也可以用在MM5等复杂模式上，理想实验证明了遗传算法同化系统优于MM5伴随同化系统，在实际观测资料同化中，采用两种方法的同化系统都能有效地改善数值预报模式的初始场，能在一定程度上提高物理量场和降水量的预报效果。

The main contributions of this dissertation are In chapter 2, we propose a scientific visualization system modal which is based on large-format display technology and Client-Commware-Server structure. In chapter 3 and chapter 4, we accomplish two large-scale scientific visualization systems. In chapter 5 and chapter 6, we propose HFFT on hexagon and parallel dodecahedron domains, and reduce the computational complexity from O and O to O and O . Lastly, we propose a parallel HFFT on distributed memory computers.

本文的主要贡献如下：提出了使用大屏幕显示技术、适用于大规模科学计算可视化系统的Client-Commware-Server模型；实现了油藏数值模拟和分子模拟两个大规模科学计算的可视化系统；给出了二维三方向六边形区域、三维四方向十二面体区域上的HFFT算法，将变换的计算复杂度分别从直接计算的O和O量级降到了快速算法的O和O量级；最后，本文给出了一种基于分布式存储的并行HFFT算法，并对影响、提高并行算法的若干因素进行了分析。

The reconstruction problem is ill-posed, so two optimal criterions, the least module and the smoothness criterion base on Tikhonov regularization technique, are introduced into reconstruction algorithm. Many regularization parameters choice strategies are investigated, and the TPA(Two—Parameter Algorithm) strategy which is based on the Morozov discrepancy principles, is implemented in two regularization reconstruction algorithms.Numerical experiment results show that the nonnegative and smoothness constraint condition can overcome the difficulty of iteration semiconvergent, preconditioned technique can improve convergence rate and reconstruction accuracy, smoothness regularization criterion can meliorate ill-posed problem of reconstruction and enhance iteration stability, and the TPA is an effective strategy of regularization parameters choice.

数值试验表明：在共轭梯度法中引入非负约束和光滑约束改善了迭代的"半收敛"性，非负约束保证了解的非负性，光滑约束抑制了重建解的振荡现象，约束算法的重建精度与无约束算法相比大幅度提高；在约束共轭梯度重建算法中引入预优技术，可以加快算法的收敛速度，提高迭代的稳定性和重建精度；引入光滑准则的正则化技术可以有效改善图像重建问题的不适定性，加快迭代的收敛速度，提高迭代的稳定性和图像重建质量，计算正则参数的TPA算法在闪光照相图像重建中是有效的。

This thesis is divided into six parts. The first chapter is preface, the current status of research in the inverse problems for parabolic partial differential equations is reported; the second chapter is "regularization methods for numerical differentiation and their applications ", in this chapter we investigate many regularization methods from a viewpoint of regularization theory and algorithm, some applications in the inverse problems for parabolic partial differential equations are given; the third chapter is "spectral regularization methods". Based on Fourier analysis, within the framework of regularization theory, we apply the spectral methods to some ill-posed problems. Many numerical experiments are done in order to show the validity of the methods; the fourth chapter is devoted to wavelet dual least squares method and a revised wavelet method; in the fifth chapter,we combine finite difference method with method of lines and apply it to the backward heat conduction problem in time; in the sixth chapter "identification problems for unknown source ", the essence and the degree of two problems related to source identification are pointed out, at the same time, some numerical methods are reported.

本文分为六个部分，第一章前言简要分析了国内外抛物型偏微分方程反问题的研究现状；第二章数值微分的正则化及其应用从正则化理论和算法的角度出发，考察了许多正则化方法，还给出了数值微分在抛物型偏微分方程反问题的一些应用；第三章谱正则化方法是在Fourier分析的基础上，在一般正则化理论的框架下，给出了这种方法在各种不适定问题中的应用，数值实验表明谱方法是有效的；第四章研究了小波对偶最小二乘方法和改进的小波方法；第五章主要研究了有限差分方法结合线方法在时间反向热传导问题中的应用；第六章是未知源识别问题，主要指出了两类未知源问题的不适定程度和不适定本质，同时报告了一些数值方法。

As a fast TDIE solver with high accuracy and efficiency, plane wave time domain algorithm is studied deeply in this thesis. The implementations of two-level and multilevel PWTD-enhanced MOT schemes are described and the numerical efficiency is presented.

论文还深入研究了一种高精度、高效率的TDIE加速算法——时域平面波算法的理论基础、数值实现的关键技术，以及两层、多层PWTD加速MOT的实现方案、程序流程以及数值性能。

Riemannian Space. The parameter space in blind source separation is Riemannian Space. Natural gradient has many better characters compared with normal gradient.

自适应盲分离算法中的系数空间是黎曼空间，本文将自然梯度下降法应用于Infomax算法可以改进算法的性能，有利于算法的数值稳定性和提高算法的收敛速度。

In the first chapter, the application background and the main algorithms of the complementarity problems is introduced. In Chapter 2, some basic definitions and theories of complementarity problems are introduced. The 3rd chapter is the most important part of this paper, in which a new class of smoothing Newton method is detailed, also the global and local superlinear convergence is established for the method. In the 4th chapter, we propose some numerical experiment, and the results show the effectiveness of the proposed algorithms.

全文共分为四章，各部分内容安排如下：第一章是绪论部分，介绍了互补问题的应用背景和近年来有关互补问题求解方法的研究成果；第二章介绍了与互补问题相关的一些定义以及相关的定理和推论；第三章是本文的重点，构造了求解互补问题的一类光滑牛顿法，从理论上证明了算法的全局收敛性和局部超线性收敛性；第四章是数值实验，通过数值试验的结果进一步证明了算法的可行性和有效性。

We also introduce a control function, prove the global convergence, and prove the local superlinear convergence under some conditions. Then we propose another new algorithm by using an existed approximation functions, which has the same characters as the first algorithms does. Finally, the result of the numerical experiments indicates the efficiency of the first algorithm. The paper contains four parts.

本文还引入了新的控制函数，并证明了算法具有全局收敛性和在一定的条件下具有局部超线性收敛性；然后，在第一个算法的基础上，本文利用已有的光滑逼近函数提出了另外一个新的算法，通过适当参数选取，证明了新的算法具有与第一个算法同样良好的收敛性质；最后，通过数值计算说明了算法的高效性。

Design Krylov subspace conjugate residual squared algorithm for nonsym-metric linear systems and the improved conjugate residual squared algorithm for distributed parallel computing based on biconjugate residual method algorithm, and give theoretical analysis and comparisons of algorithms for two algorithms.

基于BiCR算法设计了求解非对称线性方程组Krylov子空间平方共轭残差算法和适合分布式并行计算的改进的平方共轭残差算法，并对两种算法进行了理论分析和算法比较，串行和并行数值试验表明所提方法具有较好的收敛速度和并行性能。

The reconstruction problem is ill-posed, so two optimal criterions, the least module and the smoothness criterion base on Tikhonov regularization technique, are introduced into reconstruction algorithm. Many regularization parameters choice strategies are investigated, and the TPA(Two—Parameter Algorithm) strategy which is based on the Morozov discrepancy principles, is implemented in two regularization reconstruction algorithms.Numerical experiment results show that the nonnegative and smoothness constraint condition can overcome the difficulty of iteration semiconvergent, preconditioned technique can improve convergence rate and reconstruction accuracy, smoothness regularization criterion can meliorate ill-posed problem of reconstruction and enhance iteration stability, and the TPA is an effective strategy of regularization parameters choice.

数值试验表明：在共轭梯度法中引入非负约束和光滑约束改善了迭代的&半收敛&性，非负约束保证了解的非负性，光滑约束抑制了重建解的振荡现象，约束算法的重建精度与无约束算法相比大幅度提高；在约束共轭梯度重建算法中引入预优技术，可以加快算法的收敛速度，提高迭代的稳定性和重建精度；引入光滑准则的正则化技术可以有效改善图像重建问题的不适定性，加快迭代的收敛速度，提高迭代的稳定性和图像重建质量，计算正则参数的TPA算法在闪光照相图像重建中是有效的。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。