查询词典 method of artificial variables

As a result, it shows thatthe static or dynamic subsystem optimum alone is not equal to the system optimum. Three initial value problems met in the optimal design of flying vehicle are studied andconclusions are derived that: orthogonal test method can be adopted to decide the initial valueof static optimization problem, some mathematical techniques can be used to deal with thecostate variables of Maximum Principle and decide the initial value of the costate variable,the indirect method can be used to get the analytical solution under ideal case to guide thechoice of the initial control curve in the direct method. With some numerical examples oftrajectory optimization, it shows that all these methods are useful not only in accelerating theconvergence but also in converging to the global optimum.

针对飞行器优化设计中的三种初始值问题进行了研究，以远程弹道导弹弹道的工程优化为例说明，对于静态优化问题，采用正交试验法选取初始值，不仅可以大大加快收敛的速度，而且更有可能收敛到全局最优解；以气动力辅助变轨问题为例说明，用共态变量的一阶泰勒级数展开可以解决极大值原理中共态变量初值难于确定的问题；以二级弹道导弹的主动段弹道优化为例说明，利用间接法在理想情况下得到的解析解来指导直接法初始控制曲线的选择，将大大有利于提高直接法的收敛速度。

Traditional multivariable analysis method, for example, principal component analysis method and factor analysis method, are common in calculating the mean vector, the covariance matrix of sample and other variables.

摘要传统的多元统计分析方法，如主成分分析方法和因子分析方法等的共同点是计算样本的均值向量和协方差矩阵，并在这两者的基础上计算其他统计量。

This article founds synthetic indicator systems for sustainable development, which cover the economic system, the social system and the system of resources environments and include 33 variables. In this article two kinds of objective weight method: principal components analytic method and entropy value method have carried on assessment of indicator systems for sustainable development.

本文建立了涵盖经济、社会、资源环境三大系统包括33个变量指标的可持续发展综合评价指标体系，用主成分分析法和熵值法两种客观赋权法进行了各系统可持续发展能力变动趋势的测度。

The advantages and limitations of every kind of methods for calculating the failure probability is reviewed. The frist order reliability method, the second order reliability method and many kinds of boundary method have achieved remarkable success and formed nature fields of reliability. However, the precision of these methods decrease as the increase of complexity of problem. The numrical methods are versatile, except numerical intergration is only adaptable to special problems which have small number variables and regular intergral domain. Particularly, the advanced variance reduction techniques own the following character: high precision and a small amount computation. But some questions remain to study in the future because only an initial work about these techniqes is developed.

全面评述了计算失效概率各种方法的优点和局限性，其中经典的解析法包括一次可靠性方法、二次可靠性方法、一阶边界法、Vanmarcke上边界、PENT上边界和Ditlevsen二阶窄边界法，这些方法对于多设计点、变量较多且相关、密度函数不是正态以及极限状态方程较复杂的情况，其计算精度较差；而已有的数值方法却是具有较好的通用性，其中除数值积分法只对变量较少、积分域较规则的特殊问题适用外，各种数值模拟方法均具有较广的适应性，特别是各种改进的方差减小技术，精度高、计算量小，但由于其处在研究的初级阶段，还有许多问题有待于解决。

A character-codes model based pattern recognition method by using amplitude data of targets frequency response is proposed after the establishment of high frequency response equation of radar targets. The method uses the same unvariant character-codes to express the same target of different angles and uses sequential separating of regions of target's reference variables to obtain multiple coding vectors of all regions for every target. The category and pose of target can be determined after a two-staged classification processing such as coding processing of target range profile data and errors correcting processing of coded data. The two-stage classification results are used to target identification as posterior hypothesis to be tested by sufficient convincing and necessary convincing. The character-codes model based pattern recognition method is also adaptive to variation of target angles and controllable in error probability. Time-consuming and complicated iterative computation is not necessary in the train process of pattern recognition.

首先建立了雷达目标的高频频率响应方程，这种方程将目标多散射中心理论与目标局部谐振理论有机地结合起来；进而提出了目标多频响应结构成像方法，这种方法将瑞利区频率响应或谐振区频率响应曲线的不同部位用各种不同的近似方法去逼近，通过特征谱估计方法将目标的局部频响特征与宽带距离响应特征结合起来；然后提出了一种基于姿态角变化区域的序贯划分与多模匹配的特征编码识别方法，这种方法具有能适应目标姿态角的变化以及能控制识别的差错概率α等优点，在目标识别时只需要目标在少数有限个频率激励下的幅频响应数据。

The type of the limit state function is set up according to the Mohr-Coulomb yield criterion which can consider the direction of the slip surface; and the derivatives of the stress to the basic stochastic variables of the slope are computed by using partial differential method based on the incremental tangent stiffness method and the accelerating convergence method of Aitken.

其中功能函数的形式是以考虑滑面方向的Mohr-Coulomb屈服准则来建立的；导数的求解采用的是基于增量切线刚度法及Aitken加速算法的偏微分法；边坡整体可靠指标取的是所有可能滑面的可靠指标的最小值。

Main purification role is played by artificial medium and aquatic macrophyte in pollutants removal, but the Corbicula fluminea introduced to food chain of combined floating bed enhances the purification effect through the ways as follows: improving the resolvability, ammonification and biodegradability of particulate organic matters, meliorating the substrate supply condition for absorption of plant and degradation of microorganism attached on artificial medium, hastening the growth and activity of microorganism.

污染物的直接净化主体为人工介质和水生植物单元，但在生态浮床中引入河蚬增加水生动物单元，通过食物链的"加环"作用，提高了颗粒性有机物的可溶化和无机化以及可生化性，改善了植物吸收以及人工介质单元生物膜中微生物的基质条件，促进微生物的生长和活性，提高了浮床的净化效果。

Objective To study the effect and safety of propofol and fentanyl used in artificial abortions.Methods 2000 women who desired to terminate pregnancy and operate artificial abortions without pain, were selected to anesthetize with propofol and fentanyl or propofol.

目的 研究丙泊酚复合芬太尼用于人工流产术的效果和安全性。

Intelligent artificial leg consists of knuckle, an executive mechanism, an anklebone, a foot and an intelligent controller. The executive mechanism controls the bent and stretchs movement of knuckle and the pendular movement of calf. The key components of the intelligent artificial leg are the executive mechanism and the intelligent controller.

智能人工腿主要由膝关节、控制膝关节屈伸运动及小腿摆动的执行机构、踝关节、脚以及智能控制器等组成，其最关键部件是控制膝关节屈伸运动及小腿摆动的执行机构和智能控制器。

RESULTS:In vertebral pulp extirpation group, the stress was proved to be the highest at superior edge, posterior middle part, lower edge and anterior middle part of small joints under anteflexion, backward extension, compression, lateroflexion and revolving states, moreover, small joint stress in artificial lumbar intervertebral disk was higher than that in normal intervertebral disk, but obviously lower than that in vertebral pulp extirpation group;however, the small joint of the middle part of artificial lumbar intervertebral disk bore the highest stress under revolving states.

结果：髓核摘除组小关节的上边缘部、后中部、下边缘部和前中部在前屈、后伸、压缩、侧屈、旋转状态应力最大，人工腰椎间盘组的小关节的应力比正常椎间盘高，但明显小于髓核摘除组，但正中部在旋转状态下，人工腰椎间盘小关节的中心部位承受的应力最大。

If you were not , and OS X just booted normally, have no fear.

如果你没有，和OS X刚刚启动通常，没有恐惧。

I only want to preserve our all .

我只想保存好我们的一切