查询词典 approximate method

Aiming at the shortage of traditional numerical methods, the Adomian Decomposition Method is introduced to solve the nonlinear model equations in reaction engineering. ADM can give the approximate analytical solutions in a form of algebraic expressions for nonlinear equations.

针对传统数值求解方法存在的不足，将Adomian分解法(Adomian Decomposition Method，ADM)引入到反应工程非线性数模求解中，可给出非线性数模逼近解析解的代数表达式。

The WKB approximate method is one of effective approximate methods in the quantum mechanics .

WKB近似方法是量子力学中有效的近似方法之一。

There is no good method to solve such problems. T method is proposed to solve problems, the method is a simple but quite efficient approximate method.

提出的t方法是一个简单同时又效率很高的近似方法，能够很好地解决这类问题。

Finishing calculation of mean value, standard deviation, skewness, kurtosis of Beta distribution.(2) Fitting parameters of many kinds of typical distribution and using residual deviation to evaluate fitting precision.(3) Using Beta distribution as an agreed indication distribution applied to many kinds of practical photoelectric measurement distributions.(4) Deriving theory formula of Bayes point estimation about Beta distribution parameters and mean value and standard deviation on the condition of mean square error loss function and supposed the prior distribution is uniform distribution.(5) Generating MCMC sample from post distribution by the method of Gibbs sample algorithm. Calculating bayes point estimation from sample on the condition of mean square error loss function. Calculating confidence interval by an approximate method to complete interval estimation.

本文的主要工作有：(1)解决了Beta分布参数a和b的精确计算以及均值、标准差、偏度、峰度的计算问题；(2)拟合出10余种典型分布的Beta分布的两个参数，并且采用剩余标准差评价该Beta分布的拟合精度；(3)对多种典型的光学与光电测量系统的测量分布进行了Beta分布统示表示；(4)在假设先验分布为均匀分布前提下，得到参数a和b以及均值μ和标准差σ在均方误差损失函数下的贝叶斯点估计理论计算公式；(5)利用直接抽样的Gibbs抽样算法，从后验分布中产生MCMC样本，从样本直接计算均方误差损失函数下的贝叶斯点估计，并使用一种近似方法计算其置信区间，完成区间估计。

In chapter 3, the linear approximate method of Bessel function for measuring nanometer vibration is studied. The error of linear approximate is analyzed and the theoretical measurement range of this method is given.

在此基础上，首次提出了一种双光路DSPI振动测量系统，利用退敏感光路使贝塞尔函数线性近似法的测量范围扩大了24倍，由近50nm增至1150nm。

First of all,we have given some of the basic concepts of differential equations, described the constant coefficient linear ordinary differential equation solution, for a class of second-order variable coefficient linear ordinary differential equation initial value problem, an approximate solution, the method is first unknown function of a definition for N sub-interval, and then in between each district within a constant coefficient ordinary differential equations similar to the replacement, the solution has been the problem as similar to the original analytical solution, and then gives a detailed second-order change order coefficient of linear homogeneous ordinary differential equation solution examples, the examples of the approximate method proposed in this paper is valid.

首先给出了微分方程的一些基本概念，讲述了常系数线性常微分方程的解法，针对一类二阶变系数线性常微分方程初值问题，提出了一个近似解法，本方法是先对未知函数的一个定义区间作N等分，然后在每一个小区间内用一个常系数常微分方程近似替换，所得到的解作为原问题的近似解析解，随后详细给出了一个求二阶变系数齐次线性常微分方程的解的实例，该实例说明本文提出的近似方法是有效的。

The results are the following: When calculating the motion mass, it is better to use idler's equivalent mass instead of the rotating part mass and serial idler's rotating inertias and equivalent mass are calculated. The accurate analysis result for the deflection curve length of the belt shows: The error calculated by the approximate parabola length is lower than 10〓. Thus the approximate method is accurate enough for calculation. The relations between the running resistances coefficient and the belt velocity are studied by experiment, which are the bases for calculating the linear coefficient values between them.

得出：在计算参与运动质量时对托辊应采用托辊的等效质量而不是目前采用的托辊旋转部分质量，并计算出了系列的托辊转动惯量和等效质量；对输送带的挠曲线长度进行了精确的分析，结果表明：采用近似的抛物线长度计算方法其误差在10〓以下，因而得到在计算输送带挠曲线长度时采用近似的抛物线具有足够的精度；对输送机运行阻力系数与带速间的关系进行的实验研究，得出阻力系数与带速线性关糸的系数值。

Sampling points were obtained by using optimal Latin hypercube design of experimental method,meantime,in order to improve computing efficiency,application of stepwise regression response surface approximate method in the MDO system of the vehicle crashworthiness and free mode of Body-In-White,the approximate model was optimized by using sequential quadratic programming method.

采用最优拉丁方试验设计方法进行样本数据设计，同时，为了提高计算效率，采用了一种新型的响应面构建方法——逐步回归响应面方法构建了整车耐撞性与白车身自由模态多学科系统的近似模型，利用序列二次规划优化方法对此近似模型进行优化，避免了整车碰撞传统优化设计方法计算量大，在碰撞非线性系统优化中常常易导致收敛缓慢甚至不收敛的缺点，在满足了CMVDR294安全法规的同时，使得白车身的扭转模态值得到提高，汽车重量得到较大程度的减轻。

As an approximate method,with the trigonometric function,the simple pendulum dynamical equation is simplified,and the approximate formula for the period of simple pendulum movement is presented.Comparison is made between approximate formula and exac...

对近似公式和精确公式进行了对比，最后进行了数值计算，结果表明，所得到的单摆运动周期的近似公式在大多数情况下都与精确公式符合的很好。

At the same time, pattern recognition has been used for abstracting characteristics、predicting the life and evaluating the properties of engine. This research contributes toward global diagnosis for the diesel engine in eight ways.(1) Put forward"the Arithmetic of distinguish the period automatically using auto-correlation method";(2) Separate the waves of continuous knocks using WV distribution;(3) Propose"the logarithmic spectrum approximate method"to analysis the response of the knock between the steel and steel;(4) Discuss the relationship between the time-frequency distribution and timescale distribution in detail, and give the principle of classification;(5) Use the wavelet method to analysis the pressure signal of exhaust、suction;(6) Use the shape of vibration signal to analyse the working situation of cylinder;(7) Use the pattern recognition to select the good samples and abstract the effective characteristics;(8) Develop the model of total properties evaluation and life prediction.

本文在广泛的、深入研究的基础上，应用多种信号处理手段来分析处理数据，同时利用模式识别方法对故障的特征提取、寿命预测以及性能评价作了探讨，本文进行了以下几项工作：（1）提出了基于自相关自动周期识别算法的柴油机振动信号预处理策略；（2）提出了基于WVD分布的连续撞击响应信号的分离策略；（3）提出了基于对数谱拟合方法的钢—钢撞击响应求解模型；（4）提出了基于波形分析的非正常燃烧振动信号的诊断模型；（5）提出了基于小波细节信息的进气压力信号和曲轴箱压力信号的诊断模型；（6）提出了基于小波近似的喷油正时信号中燃烧位置的自动定位；（7）提出了基于统计模式识别方法的故障诊断知识的自学习与自组织策略；（8）提出了基于特征压缩思想的柴油机总体性能评价及寿命预测模型。

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。