最小化

Objective To determine the action spectrum of ultraviolet in chronic actinic dermatitis and further analyze the influence of course of disease and period in the sunlight everyday on the decrease of minimal erythema dose respectively.

目的 测定慢性光化性皮炎的紫外线作用光谱并进一步分析患者病程及日均户外曝光时间对作用光谱最小红斑量降低的影响。

In the implementation of the adjoint model, there is always a contradiction between storage expense and recomputation.

依据模式对象所固有的结构化和问题本身的特点，本文提出了基于最小程序行为分解的模式伴随方法。

In this paper,we propose a concept called interval implicitization of rational bézier surfaces,that is ,finding an interval algebraic surface with lower degree which bounds a given parametric rational bézier surface such that some objective function involving the width and the tention term of the interval algebraic surface is minimized.

本文提出有理Bézier曲面的区间隐式化的概念，即找到一条较低次的区间代数曲面使得给出的有理Bézier曲面落在该区间代数曲面内，并使得一包含区间代数曲面的宽度和张量项的目标函数达到最小。

To improve the precision of tree biomass parameter calculation, this paper explicates the principle, method and process to estimate the parameters of tree biomass by the nonlinear least square according to the formula of allometry method. It gives the formula to calculate the variance and covariance estimated parameters, and reveals the essence of logarithmic linearization regression of power function.

为了提高林木生物量参数的计算精度，根据林木相对生长公式，阐述用非线性最小二乘法求解生物量参数估值的原理、方法和过程；给出计算参数估值之方差与协方差的公式；揭示幂函数对数线性化回归的本质。

First, in the composite hypothesis testing, circular dispersion error which is more practicable than horizontal and vertical error is used to discuss some problems of the dispersion of impact points; and the critical area of decision in the dispersion problem is analyzed; the specific expression of Bayesian risk is worked out, which ameliorates the method that only can get the approximate solution by calculating numerical integration.

由此，本文主要应用Bayes方法对以下几方面进行了探讨：首先，在复杂假设下，本文利用圆散布误差这一精度指标对落点散布鉴定问题进行研究，它比以往所用的纵、横向偏差精度指标更具现实意义；分析了此鉴定问题的决策临界区域；给出其Bayes风险的具体表达式，对用数值积分进行近似求解的方法进行了改进；在此基础上，通过极小化试验的风险确定最优试验数n，并讨论了决策中犯两类错误的概率，给出了验前信息的表示。

Using partial least squares in conjunction with the chebyshev polynomial representation, the expression for the simplifying model is built, and is provided to determine the optimal MR damper marker.

采用偏最小二乘法误差估计、Chebyshev多项式拟合建立了MR阻尼器简化模型的参数化表达式，为合理选择MR阻尼器提供了便捷的可靠的手段。

In order to eliminate the influence caused by the nonminimum phase characteristic of a common Boost DC／DC converter, Viswanathan K has proposed a novel tristate Boost DC／DC converter. For enhancing performance, the statespace averaging model of this converter was first presented in this paper. Due to the nonlinear nature in this model, an inputoutput feedback linearization technique was adopted, and a complete controllable linear system was obtained. Then a statefeedback control strategy was designed based on this linear system. Simulation results show that the proposed control strategy can assure constant output voltage in a wide range, so as to realize the stability of the system during large fluctuation of power supply and load disturbance. Good dynamic performance can also be achieved.

针对 Viswanathan K为消除普通BOOST DC／DC变换器的非最小相位特性而提出的三态Boost DC／DC变换器，为进一步提高这种电路拓扑的性能，在建立了变换器状态空间平均模型的基础上，针对其多变量、非线性特点，采用输入输出线性化将其转化为一个完全可控的线性系统，在此基础上应用现有成熟的线性控制策略进行了控制系统的设计，并且采用MATLAB进行仿真验证，结果表明：这种非线性控制策略可以确保输出电压在大范围内恒定可调，且即使存在大范围扰动(输入电压和负载变化均较大)的情况下，系统也可以确保稳定性和良好的动态性能。

A new computational formula to nonlinear adjustment by parameters, in consideration of the second-order terms, is derived in this paper from the precise orthogonality condition equations to nonlinear least squares by analyzing the direct solving process and iterative computing method of the linearized model.

在分析线性化的非线性参数平差的近似直接解法与迭代解法基础上，利用非线性最小二乘的精确正交性条件方程，推导出顾及到二次项的非线性参数平差的一种新的计算公式。

Based on the modal superposition method and the exact solution of beam nature vibration, the motion equations of the simply supported and continuo...

基于模态叠加法和梁固有振动的精确解，建立了移动荷载作用下简支梁和连续梁的运动方程；利用样条最小二乘法逼近桥梁应变响应，由样条数值微分求得响应导数；再通过Tikhonov正则化方法结合奇异值分解技术得到了荷载识别的正则解。

First,an optimal filtering operator on the continuous fractional Fourier domain is provided according to the orthogonality principle about the linear minimum mean square error estimation,and then,a discrete algorithm of the filtering operator is further proposed.

首先由线性最小均方误差估计的正交条件出发，得到了连续分数阶傅立叶域上的等效Wiener滤波算子的求解方法；在此基础上，进一步给出了滤波算子的离散化算法。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。