查询词典 method of difference

This thesis consists of two parts. The first one was that boundary value problem was discrete with five point difference method. Three kinds of memory formats were studied, which were full matrix, half band width and row compress sparse. Full matrix memory format and half band width memory format first was contrasted. The results show that half band width has efficiency in space. Then the algebraic system of finite element method was solved by Gauss-Seidel iteration method to popular row compress sparse memory format.

本论文由两部分组成，第1部分针对边值问题，用5点差分格式进行离散，并对离散矩阵这类大型稀疏矩阵，研究了系数矩阵的3种存储格式的优劣，即：满矩阵存储格式、半带宽存储格式和按行压缩稀疏存储格式，首先我们将满矩阵存储方式和半带宽存储格式进行了对比，迭代法的数值实验表明：利用半带宽存储的矩阵在空间运算方面具有高效性；然后针对目前数值实验中流行的按行压缩稀疏存储格式，实现了有限元离散代数系统的迭代法的求解。

New inspection method was deduced by using constant coefficient of variation in sequence inspection method, and the approximate relationship of inspection variables between mean method and sequence one was gained by analyzing difference of two methods.

将变差系数不变的条件引入到序贯检验方法中，推导出新的结构强度检验方法，分析检验变量与均值法的差异，得到两者的近似关系。

In this paper, we consider hyperbolic conservation laws, and the following work has been done to the finite volume method on unstructured meshes :In preface , we introduce the backupground of the oringe of the finite volume method, and point out the limitation of the finite difference methods and the finite element methods, and import the finite volume method.

本文主要考虑双曲型守恒律方程，对二维非结构三角形网格有限体积方法作了如下工作：介绍了有限体积方法的产生背景，指出了有限差分方法和有限元方法中的特点，对有限体积方法的产生和发展给出了比较详细的分析。

Appraised the clinical effect of the flavone of rhizome drynania on Senile Osteoporosis, according to the dynamic observation on integrative scores of lumbodorsal pain and lumbodynia,"VAS section grading method" on lumbodynia,"Barthel index rating method" on ADL, detected BMD on anterior-posterior position lumbar2~4 vertebra body and proximate of femur including neck/ward/troch, and determined the index of bone transition including BGP/PINP/ICTP through the radioimmunity method before and after treated half a year, then contrast intragroup and selfgroup. Depending on the standard of curative effect, contrast the difference of curative effect between two groups.

采用随机对照的方法，分为治疗组36例，对照组34例，依据对腰背痛及腰痛综合评分进行动态观察；依据"疼痛VAS线段分级法"对腰背痛（静止痛、翻身痛、久坐痛、起身痛、弯腰痛、步行痛、睡眠痛、叩击痛、压痛）进行量化动态观察；依据"Barthel指数评定法"对老年性骨质疏松症日常生活活动能力进行观察；采用双能X线骨密度仪对腰椎(L2-L4)、股骨近端各部位：股骨颈、股骨三角区、股骨粗隆进行骨密度定量检测；应用放射免疫法对骨转换指标进行测定，骨形成指标：骨钙素、Ⅰ型前胶原氨基端前肽；骨吸收指标：Ⅰ型胶原交联羧基末端肽等，评价骨碎补总黄酮治疗老年性骨质疏松症的临床效果。

In Chapter 4, a symmetric triangular partitioned secant method for solving large scale sparse unconstrained optimization problems is constructed, which is a combination of a secant method and a finite difference method, and depends on a consistent partition of the columns of the lower triangular part of the Hessian matrix; it reduces the number of gradient evaluations required by Powell and Toints algorithm (the indirect lower triangular substitution algorithm) by one at every iterative step.

此算法是基于稀疏Hesse阵的下三角部分的列的相容分划的基础上建立起来的，把割线法和有限差分法有机的结合在了一起，在每次迭代中，把由Powell和Toint的算法所需要的梯度赋值次数减少了一。

In this paper, we use this numerical method and adopt operator splitting method to simulate the conduction model of action potential in two-dimensional cardiac ventricle tissue,the conduction model of the action potential in two-dimensional cardiac ventricle tissue is denoted by one reaction-diffusion equation with a series of ODE describing ionic channels of cell, at the same time,we adopt the compact alternate direct implicit difference method to simulate that model,compar-ing these value results,get some conlusions.

本文中，我们利用摄动有限差分方法和算子分裂思想去模拟二维心室肌中动作电位的传导模型，该模型由一个描述细胞离子通道的常微分方程组和一个反应扩散方程组成。

Also the response amplitude will be changed with the initial conditions due to the nonlinear properties of the cables.Taking the bending stiffness, cable sag and cable inclination into consideration, the space vibration control of the cables using the visco-elastic dampers in cable-stayed bridges is investigated by joining the center difference method and the state space strategy. Both the maximum modal damping ration and the optimal damper size are obtained, then the practical suggestions are proposed for the design of the dampers. The space nonlinear vibration equations of the cable-damper system are derived, and anew hybrid method for solving the cable-damper system is presented by combing the Newmark method and Pseudo-force technology. According to the known properties of the cable-damper system, the nonlinear transient responses are analyzed under all kinds of excitations. Based on the transient response, the control effectiveness of the visco-elastic dampers is further demonstrated.

综合考虑了拉索抗弯刚度、垂度的影响，研究了粘弹性阻尼器对斜拉桥拉索的空间振动控制，联合中心差分方法及状态空间法，得出了拉索面内、外振动各阶模态可能达到的最大阻尼比及相应的最优阻尼器系数，并对斜拉桥拉索的阻尼器设计提出了参考建议：考虑拉索抗弯刚度、垂度及几何非线性，导出了索-阻尼器系统的空间振动非线性方程组，结合Newmark方法及伪力(Pseudo-Force)方法，创新地提出了求解非线性方程组的杂交方法，根据拉索-阻尼器系统的阻尼特性，在各种荷载作用下，对索-阻尼器系统的非线性瞬态振动响应进行了研究，从系统响应的角度更加直接地验证了阻尼器的控制效果。

In this dissertation, the numerical method solving the model equation influid motion in some sense has solved some tough problems which traditionalmethods cannot, as in the case of capturing shockwave, enhancing resolution, andspeeding computation. In terms of capturing shockwave and enhancing resolution,this method has proved to be superior to difference method; in terms of speedingcomputation, superior to TVD scheme. Particularly, it is highly effective to solveodd singular solution problems.

本文研究的求解描述流体运动的若干模型方程的数值方法，在一定程度上解决了传统方法在某些方面的难点问题，如在捕捉激波、提高分辨率方面优于差分法，在计算速度方面优于TVD格式，特别是对处理有奇异解的问题很有效。

There are many methods for computation of the slope and deflection of beams such as the integration method, the finite difference method, the Macaulay's method, the Mohr's 'area-moment' method and so on. They possess mostly the characteristics of complex computing or searching schematics.

有多种方法求梁的位移，如积分法、迭加法、初参数方程法、其轭梁法、有限差分法、奇异函数法和莫尔&面积一力矩&法等等，其大都具有或计算复杂或依赖各种不同的图表等特点。

The mathematical model of complex countercurrent multi-effect evaporation with condensed water flash is established, which aims at minimum annual cost (including cost of fresh vapor, vacuum pump power, evaporator, maintenance and depreciation).Based on such decisive variables as the pressure of fresh vapor, the pressure of condenser and heat-transfer mean temperature difference of vari-effect,the model is solved by the complex method,Lagrangian multiplier method, iteration method and matrix method.The practical example indicates that the influence of the pressure of fresh vapor, the pressure of condenser and flash of condensed water on the optimum design results is notable.

建立了带有冷凝水闪蒸的复杂逆流多效蒸发系统优化设计的数学模型，该模型以整个蒸发系统的年总费用(包括加热蒸汽年费用、真空泵年动力费用以及蒸发器和辅助设备的年折旧维修费用等)最小为优化目标，以生蒸汽压力、冷凝器真空度及各效有效传热温度差为决策变量，提出一种新算法———复合形法结合Lagrangian乘子法、迭代法和矩阵法求解模型。

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。