近似法

RCS of facets of targets coated RAM was resolved by combining Impedance Boundary Condition and Geometric Optics and RCS of those edges were approximated by computing the RCS of edges of impedance wedge through Method of Equivalent Currents.

其中，涂覆目标面元的散射场是通过结合阻抗边界条件和几何光学法而得到；而涂覆目标棱边的散射场则是通过等效电磁流法求解阻抗劈的边缘绕射场近似得到的。

First, the two convex hulls from the training set of approximate linear classification are similarly squeezed into the linearly separable ones, and based on the two similarly squeezed linearly separable convex hulls, an optimal separating hyperplane is figured out by using the method of halving the nearest points and the maximal margin method.

首先对近似线性分类中的训练集所形成的两类凸壳进行了相似压缩，使压缩后的凸壳线性可分；基于压缩后线性可分的凸壳，再用平分最近点和最大间隔法求出最优的分划超平面。

Sensitive range from 49.1% to 100%, specificity range from 18.2% to 90%,accurate range from 45.5% to 88.3%, PPV range from 34.1% to 95.2,NPV range from 22.2% to 100%,the combine sensitive was 82.7%,specificity was 63.3%;there were not obvious publish bias in the 9 articles, and there was heterology of the 9 articles, the forest figure show RR was 2.34[1.43,3.05],and its 95% confidence interval did not include 1,the chance of malignancy nodules'SUV above 2.5 were more than benign nodules.

文献报道的敏感性49.1-100%，特异性18.2-90.0%，准确性45.5-88.3%，阳性预测值34.1-95.2%，阴性预测值22.2-100%，Meta分析合并后的敏感性82.7%，特异性为63.3%，准确性为71.8%，阳性预测值80.8%，阴性预测值57.0%；漏斗图成近似倒三角形，认为文献无明显发表偏移；对文献异质性检验，P小于0.05，认为文献来源存在异质性；选用随机效应模式得到森林图，RR为2.34[1.43，3.05]，其95%的可信区间不包括1，认为肿瘤病人最大SUV 2.5法呈阳性的可能性大于非肿瘤病人，二者之间具有统计学差异；两篇来源于日本的文献显示日本国的18F-FDG PET肺占位显像假阴性率高于我国。

In order to reasonably depict four basic problems with friction, one Coulomb friction new form in first Kirchhoff stress is proposed to deal with finite deformation problems, other Coulomb friction form in incremental mode to elastoplastic flow theory; Hilbert function spaces concerning elastoplastical problems with friction are established, so it makes all operations and calculations in the treatise standardized within the scope of reasonably topologic structure; In view of functional extremum, the equivalence between generalized variational inequalities principles in elastoplasticity with friction and corresponding basic problems are testified by inducing Lagrangian multipliers, so it provides a rationally theoretical basis for numerical methods in elastoplasticity with friction; From the viewpoint of variational inequality, the theory of generalized variational inequalities in elasticity and elastoplasticity with frictional constraint is studied, and the uniqueness and existence of the solution of FEM is proofed under the proposed conditions of stress compatibility, and them FEM approximation and a discrete solution are discussed; Based on the principles of generalized variational inequalities in elastoplasticity with friction, direct generalized variational inequalities methods is pretended, which is a natural generalization and development of direct variational methods; Using generalized variational inequalities methods, some examples in metal forming including plane deformation, upset and extrusion are analyzed and the results prove that all the theories and methods in the paper are right, feasible, accurate and advanced.

主要内容有：为了合理地描述金属塑性成形中摩擦约束弹性、弹塑性基本问题，提出和研究了有限变形下以Kirchhoff第一应力表示的Coulomb摩擦定律形式和弹塑性流动理论下以增量形式表示的Coulomb摩擦定律表示形式；系统建立了摩擦约束弹塑性问题的Hilbert函数空间，使本文规范在一个具有合理的代数拓扑结构内进行一切操作和运算；利用Lagrange乘子，从泛函极值的角度系统地阐述和论证了一系列摩擦约束弹性、弹塑性广义变分不等原理与相应的实际问题之间的等价性，它为处理摩擦约束的弹塑性力学数值方法提供了合理的理论基础；从变分不等式的角度出发，阐述了对应于摩擦约束弹性、弹塑性问题的广义变分不等式理论，首次提出了在应力相容性条件下，它的有限元解具有存在唯一性，进而讨论了其有限元近似及离散解法；基于摩擦约束弹塑性广义变分不等式原理，首次提出了直接广义变分不等式方法，这一方法是直接变分法的合理推广和发展；利用直接广义变分不等式方法对金属压力加工中的平面变形问题、镦粗、挤压等塑性成形问题进行了分析计算，验证了该理论和数值算法的正确性、实用性、精确性和优越性。

Based on the modem FEM with the dynamic substructure method, itd dynamic equation is established with almost no limits to DOFs of the system, in which the left side is the first approach of the nonlinear system and the right side is the excitation and coupling nonlinear pseudo forces. The modal analysis method is used to get the eigen solution to the reduced linear homogeneous dynamic differential equation. When the system is excited by the harmonic excitation at the right side of the equation, the nonlinear dynamic response can be calculated by the numerical method to give quantitative analysis.

基于近代有限元和子结构模态综合法的动力学建模方法，获得非线性系统动力学微分方程，其自由度几乎没有限制，对左端首次近似齐次方程进行模态分析，选取对响应有贡献的部分本征对，同样对右端激励和非线性伪力作模态变换，得到减缩后非线性系统耦合动力学微分方程。

In this method,without depending upon small parameter,a trial function with possible unknowns is used as initial approximation,then a correction functional is constructed by means of a general Lagrange multiplier ,which can be identified via variational theory.

本文提出了一种求解非线性方程的迭代算法，它不依赖于小参数，是先给方程一个带待定函数的试函数作为初始近似解，然后用拉氏乘子法构造一个迭代公式。

Based on MLS and direct collocation,themeshless methods for function interpolation and solving elastic-static problem areestablished.Combining the advantages of direct collocation method and Galerkinmethod,the method based on least-square collocation is also proposed.

基于MLS近似和直接配点格式，本文建立了函数插值、弹性静力问题求解的无网格方法；结合Galerkin方法和直接配点法的优点，提出了最小二乘配点型的无网格方法。

The experiment results of Al-Mg-Sc-Zr alloy plate show that the precision of H-M inverse pole figure calculated by LG method has the obvious superiority over other current approximated methods.

Al-Mg-Sc-Zr合金板材反极图测算实验结果表明，由LG法所测算的H-M反极图精度显著地高于各种现行的近似方法。

Iterative method is used for equations or equations approximate root of a common algorithm design methods.

迭代法是用于求方程或方程组近似根的一种常用的算法设计方法。

The averaging method is used to analyze this model,the phase diagrams and the time history curve of this system are achieved,the results show that its movement converges to a limit circle oscillation.

利用平均法对系统进行了近似求解，得到了系统的运动相图及时间历程曲线，结果表明系统运动收敛于稳定的极限环，所得结果与实验吻合得较好。

I urge any American living outside the country to get an early start checking his/her registration and receiving an absentee ballot, because it can take a while.

我奉劝身在国外的所有美国人早点着手核对登记表，并接收缺席选举人票，因为这得花点时间。

He is too young to join the army.

他太年轻了，还不能参军。