参数变量

To avoid or reduce re-analysis, we derived the augmentative matrix variation only in summation of the previous matrices time the outside-perturbed parameters by decomposing the element stiffness and mass matrix. The implicit function of amplitude about design variables such as cross-areas and lengths is changed into simplistic function about the perturbed parameters of design variables. Several methods for determining the value of perturbed parameters are detailed.

为避免或减少重分析，将有限元单元阵进行了分解变换组装，使振幅与设计变量如截面面积、长度的复杂隐函数关系转化为对设计变量摄动参数的显式关系，进而将设计变量摄动参数提取在分解后的几个常数刚度阵、质量阵之外，避免了在迭代求解过程中重组刚度阵与质量阵，较快地获得问题的解。

For fitting ROC curves and getting the area under the ROC curve, we applied the parametric methods of binormal models and ordinal regression models, the semiparametric method of Cox proportional hazards model, the nonparametric methods of Hanley, Delong This paper also include estimation of required sample size, evaluation of confounding effects, and estimation of standard error and confidence interval by resampling method for ROC analysis.

目前该模型用于ROC分析的统计学方法比较完善，属于"经典"的ROC分析参数法。本文探讨了单变量、双变量双正态ROC模型的构建及其参数的最大似然估计方法；采用双变量卡方检验、真阳性率z检验、面积z检验三种方法比较了ROC曲线间是否具有显著性差异。

In presented method, the correlated variables are transformed into uncorrelated variables equivalently, and the performance functions in the correlated variables space are transformed into those in the equivalent uncorrelated variables space, in which the reliability sensitivity of the system failure probability with respect to the distribution parameters of the uncorrelated variables can be solved by the moment method for the uncorrelated variables. Finally the equivalent relationship between the correlated variables and the uncorrelated variables, the chain rule for derivative are employed to obtain the reliability sensitivity of the system failure probability with respect to the means of the correlated variables.

在所提的方法中，首先将相关变量空间等效转化为不相关变量空间，并将系统多个失效模式的功能函数转化为不相关变量空间的功能函数，进而利用矩方法得到多模式系统失效概率对不相关变量空间基本分布参数的灵敏度，最后利用相关变量空间与不相关变量空间的等价关系及复合函数求导法则，求得多模式系统失效概率对相关变量空间中变量均值的灵敏度。

Secondly, in our methods, the essential geometry of the image single axis geometry may be specified by six parameters and this may be estimated from one conic and one fundamental matrix (a total of 12 parameters) or may be minimally estimated from two conics (a total of 10 parameters).

本文证明了单轴旋转运动的不变量可以通过一个基本矩阵和一条二次曲线来确定，在这种情况下，由于基本矩阵的自由度为7，二次曲线的自由度为5，所需确定的参量个数仅为12，大大减少了不变量的计算量；本文同时证明单轴旋转运动的不变量可以通过最少两条二次曲线来确定，在这种情况下所需确定的参量个数仅为10，该方法是目前同类算法中参数最少的；本文提出了用多条二次曲线求解单轴旋转运动的不变量的最大似然估计算法，其所需确定的参量个数为6+2n，其中n为二次曲线的个数，该公式更深刻地反映了二次曲线与不变量的参数关系。

Based on description method of damping motion in mechanical vibration, variables movement of generator are divided into two basic motion models: damping oscillation and critical damping motion. Detail methods of extracting damping parameters from simulation data is introduced to establish variable motion models. An approximate method is put forward to simulate low-frequency signal and generator response characteristic, from which motion models and damping parameters of main variables are obtained. The influences of oscillation amplitude, frequency and initial operating point of power system to the motion damping parameters are analyzed.

借鉴机械振动中阻尼运动的描述方法，将低频振荡下发电机主要变量的运动归纳为阻尼振荡和临界阻尼两种基本运动形态；介绍了从仿真数据提取阻尼参数建立参数运动模型的方法，实现对发电机振荡特性的量化分析；提出一种系统侧低频振荡信号的近似模拟方法，并应用于发电机响应仿真，获得了主要变量的运动模型和阻尼参数；分析了系统侧振荡幅度、频率以及初始工况对发电机功角振荡的影响。

Optimization design is often used in the design of MRI superconducting main magnet, where all variables are treated as continuous ones. According to the fact that not all variables are continuous, here the design problem is seen as a global optimization problem with discrete variables.

软件简介：在进行MRI超导主磁体的设计时常采用优化设计的方法，将各设计参数看作连续变量处理，但实际上很多参数是离散变量，为了更符合工程实际，将超导MRI 主磁体的设计作为一个含有离散变量的全局优化问题。

The mechanical parameters in the model are treated as random variables and it is then resolved with Taylor extension stochastic finite element method, The distribution characteristics of the pore pressure, the effective stress and the displacement are researched by treating the mechanical parameters of the rock as random variables. The sensitivities of the pore pressure, the effective stress and the displacement to the random mechanical parameters are also analyzed.

视模型中的参数为随机变量，采用Taylor展开随机有限元法对该模型进行数值模拟，研究参数具有随机性情况下耦合场中孔隙压力、有效应力，位移等场变量的随机分布特征及孔隙压力、位移等场变量对参数的灵敏度。

They are as following: to establish the selection method of the slaving designed quality functions according to the interrelationship among designed quality functions; to construct the measurement functions of the optimality robustness with the hypersurface characteristics around the current iterative point of designed quality functions.

具体地，根据设计性能函数之间相互关系给出了处于支配地位设计性能函数的选择方法；利用设计性能目标函数在当前迭代点附近的超曲面特征，构造设计性能目标函数的最优性健壮度量函数；按照系统有序化设计模型的最优解应同时具有可行性健壮与最优性健壮的要求，通过计算设计性能目标函数与约束函数对设计变量的波动与非设计参数的波动的一阶敏度来确定系统有序化设计模型中的健壮参数；并以此为基础建立了进一步考虑非设计参数波动对设计变量波动有影响的后健壮分析方法。

The problem of PI controller design for the multi-input and multi-output system is transformed to that of static output feedback controller design via the new state variable. As to the problem of the static output feedback, a new LMI-based sufficient condition of the controller is presented in this thesis. We can gain the multivariable PI controllers just solving one LMI inequality. The numerical example is provided to illustrate the proposed design approach. 3.The H_∞ robust control is able to solve the multivariable problem, also the control problem characteristic of the modeling error, parameters uncertainties and unknown perturbation, Its application research in the power electronics is beginning now. Considering the characteristics of the PWM DC-DC converters, a multivariable PI controllers which is based on H_∞ Performance Index is designed.

通过构造新的状态变量，可以将多输入多输出系统的PI控制器设计问题转化为静态输出反馈控制问题，利用后者的成熟理论来设计控制器；本文在问题转化后采用更为简便的算法，只需通过求解一个LMI不等式，就能求取基于H_∞性能指标的多变量PI控制器参数，实例验证了算法的有效性。3.H_∞鲁棒控制具有处理多变量问题的能力，可解决具有建模误差、参数不确定和干扰未知系统的控制问题；它在电力电子学中的应用研究刚刚开始。

In the formulas of stochastic input and output, when the coefficient of direct consumption and final demand are exponentially distributed, the interrelationship between parameters of stochastic variables can be divided into three types: all the parameters are the same; parameters are inequivalent to each other; some of the parameters are the same, but the rest are inequivalent to each other.

在随机投入产出方程中，当直接消耗系数和最终需求为指数型随机变量时，方程中随机变量分布中参数间的关系有3种基本情况：所有参数都相等、所有参数两两不相等、有部分相等而其余则两两不相等。实际上，前2种情况是第3种情况的特殊形式。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。