问题分析法

This thesis contributed to the comprehensive study of the Finite-Difference Time-Domain method and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies. The work includes mainly three parts: the study on the performance of PML absorbing boundary condition applied to pseudo low frequency electromagnetic problems; the validation of the FDTD method with PML absorbing boundary conditions and the corresponding computer software based on the numerical study of the electromagnetic field of an electric dipole antenna, and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies; the development of an improved alternating direction implicit finite-difference time-domain method.

在综合前人工作基础上，本文对时域有限差分法及其在开关电源辐射电磁场数值计算中的应用进行了系统的分析和研究，其核心内容包括：伪低频电磁场数值计算中PML吸收边界条件性能的研究；基于基准问题—电偶极子天线三维辐射电磁场，验证了本文构造的基于PML吸收边界条件的三维FDTD法及其计算软件，并应用于高频开关电源辐射电磁场的数值分析；提出了一种改进的交替方向隐格式时域有限差分法。

First, For the coronary artery stent, two kinds of loads, including the pressure named 〓 derivatively from the balloon and the counterforce named 〓 on the wall edge of the stent, have been taken into account in the analysis of the stent.〓 and 〓 were changing as the stent expanding. So, the expansion process of the stent could be considered as the process composing of many extremely short equilibrium processes, where 〓 and 〓 could be regarded as constants and the stresses, the strains and the displacements were obtained using NFEA in every processes. Then, the stresses, the strains and the displacements obtained in every processes or steps were added up to get the final structure of the coronary stent.

首先，解决了支架有限元分析的载荷非线性问题，认为医用心血管支架受到两种载荷的作用：球囊直接传递的压力〓和球囊对不锈钢支架丝壁边缘的反作用力〓，这两种载荷在支架分析中必须都考虑进去；〓为非线性载荷，随着支架扩张不断变化，处理时将支架扩张的整个过程看成由37个很短的平衡过程组成，在每个过程中取〓为常量，采用有限元法获得应力、应变、位移，最后将各过程的应力、应变、位移迭加起来就获得了不锈钢支架总的应力、应变和位移；本研究用变分法和有限元法模拟杆件拉伸证明了上述方法是合理的。

In POT model, it used the technique of parameter estimator stability, making up for the limits of the currently popularly-used Mean Excess Function e, and the threshold quantitatively selected by Kurtosis Method has also been achieved, and solving the problem the illustration method couldn't be applied to.

特别是，在BMM模型中充分地考虑了子区间极值一般极限分布与极值序列极限分布之间的关系，测度了受子区间长度影响的极值VaR；在POT模型中运用参数估计量稳定性法弥补了目前普遍采用的样本平均超出量函数e法的不足，针对一些图解法无法适用的问题，实现了峰度法对阈值的定量选取，并对指数回归模型法、子样本自助法、序贯法等定量法进行了分析探讨。

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。

Boundary polynomial point interpolation mesh-free method and boundary radial point interpolation mesh-free method were presented, based on polynomial basis and radial basis respectively for transient eddy current analysis, and their interpolation shape functions satisfy the Kronecker delta function and the essential boundary conditions can be directly imposed on the boundary nodes. An example on analyzing transient eddy current of a square metal column was set to prove the validity of the proposed methods, and a comparison on accuracy between BPPIM and BRPIM was analyzed as well.

运用多项式点插值法和径向基点插值法构造形函数，推导了适合于工程电磁场瞬态涡流问题的多项式基点插值边界无单元方法和径向基点播值边界无单元方法，这两种方法的空间插值形函数满足Kronecker delta条件，从而强加边界条件可以直接施加在边界点上，以金属长方柱的瞬态涡流分析作为数值算例，证实了两种方法的正确性和有效性，并对两种基类的点插值法进行了精度分析和比较。

Based on the fundamental principles of the improved method mentioned above, multi-functional computation software package, which can be used to analyze effectively the interference effects of random flaws in plane problem, boundary problem and space problem, is compiled and a number of problems involved in the interference effects of different kinds of flaws such as random equal length through-cracks, random branched throughcracks, random unequal length through-cracks, random holes to through-cracks, unequal length edge cracks, equal length and distance multiple edge cracks, random notches with different aspect ratio, random notch to edge crack, non-coplanar surface cracks with different aspect ratio, staggered surface cracks, surface crack to embedded crack and embedded cracks near free boundary are analyzed and computed by the package.

依据上述改进法的基本原理，本文编制了能有效地分析平面问题，边界问题及空间问题的任意缺陷群相互干涉效应的多功能计算软件包。据此，本文分析计算了各类缺陷群。诸如，任意等长裂纹群。任意折裂纹群；任意不等长裂纹群，任意孔与裂纹群，不等长边裂纹群。等长等间距多裂纹群，任意形状比缺口群，任意缺口与边裂纹，非共面不同形状比表面裂纹群，交错型表面裂纹群，表面裂纹与埋藏裂纹群及自由边界附近埋藏裂纹群等的相互干涉效应问题。

Fourth, Based on sample data collected in Shenzhen city in 2003, the paper, from various perspectives, calculates nominal VAT rate for goods sold domestically or internationally. By the means of the calculation of the extent of indirect nominal tax burden shifting, we can get the economy tax burden from evaluating some trades'tax burden shifting range of Shenzhen VAT taxpayer. This paper also analyses the problems and the reasons of it and proved that the result of the separate calculation of domestic sales nominal tax burden and export sales tax burden can more realistically reflects the enterprises'nominal tax burden.. Enterprises with higher nominal tax burden can transfer their most parts of their nominal tax burden to the consumers, but the enterprises with lower nominal tax burden have to bear all nominal tax burden. Thus, when measuring the properness of tax burden from the VAT taxpayer, a comparison between economic tax burden and optimum tax burden should be considered.

第四，本文以2003年度深圳市数据为例，从不同的口径分别用经典名义税负测算法和内外销分别测算法测算了深圳市增值税纳税人的名义税负，运用间接税税负转嫁程度测算模型，测算了深圳市增值税纳税人部分行业税负转嫁的程度，进而得出其经济税负，并分析了深圳市增值税纳税人税负存在的问题以及成因，验证了内外销分别测算法得出的结果更能真实地反映企业的名义税负，得出以下结论：名义税负较高的行业，其经济税负不一定高，而名义税负较低的行业，其经济税负并不一定低，在衡量增值税纳税人的税收负担是否适度的问题上，不能简单的将名义税负与最优税负比较，而应将经济税负与最优税负比较。

Based on the proportion estimate and the mean estimate in sampling technology,the authors of this paper put forward the method of ratio estimator in sampling technology and makes a detailed analysis of method.

在抽样技术比例估计与均值估计的基础上，提出了抽样技术的比率估计法，并对其作了详细的分析，同时，通过具体问题的讨论，说明了比率估计法所具有的优越性；针对各个样本比值有比较大的差别时所产生的不稳定性，运用聚类分析的方法提出了具体的比率估计法的改进公式，减少了噪声数据的影响，得到了较高的准确度。

To solve the problem of instability when the ratio of samples differ greatly,an improved formula for the method of ratio estimator is put forward by means of clustering,which can reduce the ef.

在抽样技术比例估计与均值估计的基础上，提出了抽样技术的比率估计法，并对其作了详细的分析，同时，通过具体问题的讨论，说明了比率估计法所具有的优越性；针对各个样本比值有比较大的差别时所产生的不稳定性，运用聚类分析的方法提出了具体的比率估计法的改进公式，减少了噪声数据的影响，得到了较高的准确度

Moreover, this paper makes an effort in incorporating theCosserat theory in the VCFEM for the elastic-plastic analysis of heterogeneous materialsbased on the PVP. The chapters are divided as follows: In Chapter 1, the author summarizes the study on the equivalent mechanics properties ofheterogeneous materials (including the development of the universal relationship which isirrelevant to the micro structure, the discussion of the limitations of the effective moduli, thecomputation of the effective properties of heterogeneous materials with the micromechanicsmethod and the FEM, and the equivalence of the heterogeneous micropolar materials) and thepresentation, the evolution, the corresponding numerical studies of the Cosserat model and itsapplications in engineering.

本文基于参数变分原理，构建了Cosserat体弹塑性有限元分析模型并用于求解应力集中和应变局部化问题；利用Voronoi有限元法提出了适用于非均质材料宏观弹塑性性能计算的参数二次规划算法；进一步将Cosserat模型应用到Voronoi有限元法中，提出了基于Cosserat理论的Voronoi杂交有限元法，并采用参数变分原理进行新模型的分析计算。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。