数值方法

Meanwhile, it could be seen that there does not exist a confidence interval with width less than 0.5 because of the property of Poisson distribution. Based on these conditions, the author mainly carried out research into two aspects of this problem as follows. Firstly, by numerical and theoretical analysis, the author compares some existent confidence intervals, for example,"exact" confidence interval, Wald confidence interval and Bayesian confidence interval, and finds some deficiencies points of the confidence intervals, whose modification version has been proposed .Also, several better confidence intervals such asare also presented .Secondly, for given confidence coefficient and interval width, the author constructs a class of asymptotical two-stage interval estimate procedures. At the same time, under varies restriction of confidence coefflcientent interval width, the optional sample size of the first stage has been computed by numerical computation. The numerical computation shows that the method considered in this dissertation have good properties and applied value.

同时，由于Poisson分布的特性，我们知道不存在其参数区间长度小于0.5的置信区间，基于这些情况，我们主要展开了以下两个方面的研究：一是利用数值计算分析与理论分析的方法对现有的若干置信区间如"精确"置信区间，Wald置信区间，Bayes置信区间等进行分析比较，发现了一些缺陷，针对这些缺陷，我们进行适当的修正，并得到几种性质较好的置信区间如：修正大样本区间Jeffreys原则下置信区间二是针对已给定的置信系数与区间长度，我们提出了一种渐近的两阶段区间估计程序，并利用数值计算的方法，在各种置信系数与区间长度限定下，算出了最优的第一阶段观测次数，大量数据表明，本文考虑的方法性态良好，具有应用价值。

The coordinate transformation and numerical integration was executed on the discretized tetrahedral elements based on which the 3-D MT vector-finite element method was implemented. A whole computation framework for 3-D vector-finite element method with unstructured mesh was given. Based on this some typical models were tested which has demonstrated that our algorithm could distinctively avoid problems caused by the fake solution and both the accuracy and efficiency were enhanced which made our algorithm has a bright future for further application.3. According to theory of Sobolev vector space and the discretization of Helmholtz space, the error estimate which was suitable for 3-D MT vector-finite element modeling was deduced by which the procedure of adaptive technique was guaranteed.4. Based on the fully unstructured tetrahedralization and optical strategy, the 3-D magnetotelluric h-adaptive vector-finite element method was presented through combining the error estimate. With this work, the accuracy and creditableness for 3-D MT complicatedly modeling was guaranteed.5. The 3-D magnetotelluric h-adaptive vector-finite element algorithm with unstructured mesh was implemented.

针对非结构化的四面体单元，采用坐标变换和数值积分方法，实现了MT三维矢量有限单元分析，建立起基于非结构化网格的三维MT矢量有限元计算流程，并对典型模型和国际标准电磁模型进行了数值模拟，结果对比和分析表明，基于非结构化网格的三维MT矢量有限元不仅消除了节点型有限元的伪解，而且具有很高的计算精度和速度，有广阔的应用前景。3、根据Sobolev函数的向量空间和Hemlholtz空间的分解，推导出基于残差的三维大地电磁矢量有限元后验误差估计公式，为三维大地电磁自适应矢量有限元数值模拟的实现奠定了基础。4、在完全非结构化四面体单元剖分及优化基础上，结合三维大地电磁矢量有限元后验误差估计公式，提出了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算策略，保证了对复杂大地电磁模型数值计算的精度和可靠性。5、实现了基于非结构化网格的三维大地电磁h-型自适应矢量有限元计算流程，对典型模型和国际标准电磁模型进行了数值模拟。

This paper studies the main geometrical parameter such as angle, height, width, stagger and the upper width in dentation and trapezoid flow path, firstly, uses the single-phase numerical simulation of the computational fluid dynamics technique to analyse the influence of different geometrical parameter on discharge coefficient and flow state exponent of drip emitter. Secondly, uses the two-phases numerical simulation of CFD (1% sand content ) to analyse the influence of the above mentioned geometrical parameter on the contribution regulation of sand and anti-clogging performance. Thirdly, uses the PIV （ particle Tracking Velocimetry ） technique which can see the small-scale flow path to observe and test the trajectories and velocities of solid particles in labyrinth flow path, and analyses the basic factors which can influence the movement characteristic of solid particles and the flow state in flow path.

本文以齿形流道、梯形流道为主要研究对象，以流道转角、流道高，流道宽、偏差量及梯形流道上底宽为主要结构参数，首先应用 CFD 单相流数值模拟技术对不同结构参数灌水器流道水力性能进行模拟，分析了不同结构参数对流态指数和流量系数的影响，其次，应用 CFD 两相流（含沙量为1%）数值模拟技术分析了结构参数对含沙量分布规律和抗堵塞性能的影响，然后，应用 PIV 可视化测试方法测试了固体颗粒在流道内运行轨迹及速度，分析了影响固体颗粒运动特性及流道内流体流态的基本因素，最后，对上述流道结构形式通过模具加工及滴灌带试制，进行了标准化测试（ GB/T 17187-1997 农业灌溉设备滴头技术规范和试验方法与 ISO 标准 ISO /TC23 /SC18 /WG5N4短周期堵塞测试程序），测试结果验证了 CFD 模拟结果，并提出了迷宫结构流道灌水器的抗堵塞设计方法。

The conventional numerical simulation of a reverberant field as a launch acoustic environment was introduced. Following the reciprocity theorem used in the coupled FE-BE model, the structural response due to reverberant acoustic excitation was substituted by the sound pressure caused by force excitation on the structure, then the output response power spectrum density of the coupled model subjected to reverberant environment was evaluated based on the stochastic analysis principle.

首先介绍了传统的构建混响声场的数值模拟方法；其后利用声振耦合中的互易定理，将混响声场的激励问题转化为结构模型上力激励引起的场点声压响应问题，并采用随机分析原理，用谱分析方法推导了结构在混响声场激励下的响应计算公式；最后建立了航天器典型结构的声振耦合模型，并分别用传统方法和利用互易定理的方法进行了数值模拟。

After the brief retrospect of spectral methods applied to get the numerical solutions of partial differential equations, the Walsh spectral methods are extensively studied. A new method of designing the "derivate operator" and a new Walsh spectral method based on quasi-Walsh order are proposed, which primarily prove the special uses of it.

回顾了数值求解偏微分方程的谱方法，比较深入地考察了数值求解偏微分方程的Walsh谱方法，提出了一种新的设计"求导算子"的方法，基于这样设计出来的"求导算子"，提出了一种新的基于类Walsh序的Walsh函数的Walsh谱方法，初步验证了这种序的特殊价值。

In this paper,a three dimensional elastic plastic hydrodynamical numerical method and the code MEPH3D using this method which can be used on high speed impact problems are introduced.

介绍一种可用于高速碰撞问题数值模拟的三维弹塑性流体动力学数值计算方法，以及应用该方法研制的应用软件MEPH3D，并给出了一些高速碰撞问题的数值计算结果，计算结果表明该程序具有计算三维高速碰撞问题的能力。

This method makes the general average loss of the losses for fail report and misdeclaration to be minimum, and make up for the lower degree of accuracy of debris flow forecast in a certain extent.

利用泥石流运动数值模拟和GIS技术相结合的方法对泥石流在出山口后的运动和堆积过程进行数值模拟和危险性分区，创建了泥石流运动数值模拟和危险性分区的新方法。

There are two modeling methods used in this research area, that is analytical method and numerical method. Analytical method can be used to analyze the sound pressure within enclosures, and to analyze the control mechanisms theoretically, however it can be used for regular cuboids only. Numerical modeling method can manage enclosures with arbitrary boundaries, nevertheless, the results obtained using this method are dispersed sound pressure. It is hard to conduct real time control with this method. The two modeling methods have their own inherent defects.

对于封闭空间的结构声辐射，目前有解析建模和数值建模两种建模方法，解析建模方法可以从理论上对系统进行分析，探讨消声机理，但它只适用于长方体等规则封闭空间；数值建模方法不受空间边界形状的限制，得到的是空间声压的离散结果，难以用于实时控制，两种方法都存在着局限性。

A detailed model of non-linear parametric excitation vibration coupling the stay cable and the girder, in which the static sag as well as the geometric non-linearity are considered, is proposed in this paper. Based on several numeric examples investigated by the Galerkin method composed with the integration strategy, several kinds of factors effecting stay cable parameter vibration are studied. Another parameter vibration model by the axial excitation is presented and the corresponding nonlinear equations are derived. The smallest excitation amplitude,the transient state and steady state resonance amplitudes, and the changing characteristics of the axial force are obtained by using harmonic balance method. According to numerical examples calculated by numerical integration method, the effects of the inner damping of the stay cables are investigated.

本文创新地提出了斜拉桥拉索-桥面耦合参数振动模型，推导了索-桥耦合非线性参数振动方程组，联合Galerkin法及数值积分方法，对各种特性的拉索进行了数值求解，得出了影响拉索参数振动的各种因素；提出了斜拉索受轴向端激励参数振动模型，导出了模型的非线性振动方程，使用谐波平衡法得出了产生参数振动需要的最小激励幅值、共振时瞬态及稳态的振动幅值及索拉力的变化特性，并用数值积分方法对实际斜拉桥拉索进行了计算，分析了拉索阻尼对参数振动的影响。

The debris flow movement on the alluvial fan is simulated with the technology of numerical simulation and GIS. A new method of debris flow risk zoning is made out.

利用泥石流运动数值模拟和GIS技术相结合的方法对泥石流在出山口后的运动和堆积过程进行数值模拟和危险性分区，创建了泥石流运动数值模拟和危险性分区的新方法。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。