查询词典 gradient method

In this paper, we construct the differential equation to solve the unconstrained optimization problem. Such methods solving the ill-conditioned problems are very effective. It indicates that the asymptotically stable region of explicit the Euler method to solve the differential equation equals to the descent region of the gradient method to solve the original unconstrained optimization problem.

我们发现，在用Euler方法求解二次优化问题的等价动力系统的方程时，由方法的步长确定的稳定区域对应于这些方法所得到的迭代公式的步长满足单调下降算法的条件确定的单调下降区域，因此我们可以利用这个性质构造解无约束优化问题的数值方法而不采用标准的常微分方程的数值求解公式。

In the ***, all types and fundamental principles of Radon transform are summarized systematacially. This *** starts from the general linear Radon transform, and then researches how to use the damped least square method to find the solution of the forward transform. However, the least squares smoothing effect will lead to a certain degree of trails in the data of Radon domain, which led to the application\'s limitations. After that the implementation in Radon domain and relative merits of linear Radon transform, parabolic Radon transform and polynomial Radon transform which have time invariance are introduced, the conjugate gradient method that can solve numerical solution is also given. And then the high resolution Randon transform is discussed, it introduces the regularization theory and Bayes principle into inversion, which successfully remove the negative affect caused by discrete Radon transform. Finally, we introduce the optimal weighting similar coefficient Radon transform, which adapt to the time variant quality of hyperbolic Radon transform.

本文系统总结了Radon变换的各种类型及其基本原理，从τ- p变换(即一般线性Radon变换)出发，研究利用阻尼最小二乘平方法求解其正变换，但是最小平方法的平滑作用会导致Radon域数据存在一定程度的拖尾效应，给这种方法的应用带来了很大的局限性；然后先容了具有时不变性的线性、抛物和多项式Radon变换在频率域的实现及其优缺点，给出了求解其数值解的共轭梯度算法；接着讨论了高分辨率Radon变换，它把正则化思想和贝叶斯原理引进到了反演中，很好的克服了离散Radon变换产生的截断效应对结果的不利影响；最后先容了适应双曲Radon变换时变性质的高分辨率最优相似系数加权Radon变换。

First of all, on the base of the reduced gradient method of Wolfe, we added accurate one dimension searching method into it and gained a new algorithm (algorithm 1,2) for the nonlinear programming with linear equality constraints and quadratic programming problems, and proved convergence of algorithm, then, we use above algo...

首先本文在Wolfe既约梯度法的基础上，针对具有线性等式约束的非线性规划问题和二次规划问题，引入了精确的一维搜索，得到了带一维搜索的新算法(算法1、2)，并给出了算法的收敛性证明。

In this paper the characters of MA model and the trust region method are analyzed, a subproblem with MA model and trust region technique is presented, and a projected gradient method is use.

本文分析了MA模型和信赖域方法的特点，构造了MA模型信赖域子问题，并利用投影梯度法进行求解，在此基础上提出了一个新的求解非线性规划问题的MA模型信赖域方法。

The function is proved to be positive and its different sign can not be changed.By applying this method to the Y_series made in China,it can meet the needs of the industry driver system. different geometry ; two_order system ; variable gradient method ; alterate current induction motor stability function

在工程领域中，具有稳定特性的传动系统是非常需要的，当然，最好能够在系统运行前就能够判断出系统的稳定性区域，以便在设计系统的控制方法和选择系统控制量的时候能够避免系

A mixed algorithm is developed to id entify parameters used in air conditioning objects with great lag, nonlinearity and time-variation. The algorithm makes use of the gradient method and the leas t square method.

针对空调对象这一时变迟延环节，提出了一种基于最速下降法和最小二乘法的混合参数辨识算法。

Through adding new state variable and using supplement functions,the problem with restriction conditions was converted into nonrestriction problem.In addition,the dynamic searching method of optimal step coefficient was developed to modify the conventional gradient method,consequently the calculation problem of the multivariable optimal periodic control was able to be resolved better.

通过增加新的状态变量和用补偿函数法，将本课题的有约束条件问题化为无约束条件问题，并提出了最优步长参数的动态搜索法来修改传统的梯度法，从而较完善地解决了多变量最优周期控制的计算问题。

Using Huber function, the method can alleviate the oversmooth problem at the "motion edge". To get the displacement field, the conjugated gradient method is used to minimize the energy function.

该算法采用共轭梯度法优化能量方程，并利用小波分解进行分级计算，能快速可靠地得到稳定的位移场。

The preconditioned conjugated gradient method is a very efficient iterative method for solving large sparse linear equations.

预处理共轭梯度法是求解大型稀疏线性方程组的极为有效的迭代法。

Based on experiment data, equivalent gray absorption coefficient s at various gas temperature distributions are calculated using inverse analysis,which combines the zone method and the minimization of a performance function stylizing the conjugated gradient method.

以实验数据为基础，采用区域法与求目标函数最小值的共轭梯度法相结合的方法反演计算了不同烟气温度下的当量灰吸收系数。

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。