查询词典 projection gradient method

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。

The nonlinearity and discrete gradient inherited in CAViaR model is a conundrum for parameter estimation. We take the asymmetric Laplace distribution with scale parameter as the error process; indicate the variance has a minimum positive value when the scale parameter is a constant, conflicting with the distribution of real financial data. Further we estimate the parameters of indirect TARCH-CAViaR model base on Bayesian framework and Markov chain Monte Carlo method. The optimal scale parameter can also be obtained by Markov chain Monte Carlo method.

CAViaR一般模型中递归分位回归方程的非线性和非连续可微性是参数估计的一个难题，基于含有尺度参数的不对称拉普拉斯分布作为误差过程，指出将尺度参数固定为常数会导致不对称拉普拉斯分布随机变量的方差存在最小正值的限制，与实际金融数据分布不符；进而提出采用贝叶斯分析和马尔科夫链蒙特卡罗模拟方法，估计间接TARCH-CAViaR模型的参数，并可获得尺度参数的合理估计。

An applied method was put forward to select regularization parameters in the iterative process of gradient regularization method.

并给出了该方法在计算过程中求正则解时一种实用正则参数选取方法。

Compared with JBN method, the advantage of this method is that the influence of starting pressure gradient is considered.

新方法与原有的JBN 方法类似，主要区别是：在注入能力公式中加入启动压力梯度的影响，可以看作为JBN 方法的推广。

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。

First, based on the analysis of the grid Reynold number, the necessity for adopting high order scheme is emphasized when there is the complex flows with strong separation and high parameters gradient regions. Then, according to the entropy increased condition, the third order ENN scheme is constructed. Meanwhile, a fast, effective, and simple implicit numerical method called hybrid flux splitting method is developed. After that, the one dimensional model problem with many extrema and Burgers equation are simulated. Through the comparisons with exact solutions, the accuracy and effectiveness of the ENN scheme are confirmed.

首先通过对网格雷诺数的分析，论证了在求解含分离及较大参数梯度的流动时，采用高阶格式的必要性，然后从熵增原理出发，提出了建立三阶ENN格式的准则，同时发展并建立了一种快速、有效的简单隐式算法"混合通量分裂法"，通过对一维模型问题及Burgers方程的数值试验，检验了三阶格式的计算精度。

At the same time,it designed the project of construction supervision and measure aimed at the strengthening bridge by external presttessing,through the contrast between the result in theory and fact,we can see that it is feasible to use predigestion's computing based on elasticity to analyse continuous rigid frame briges reinforced by external presttessing ,and it can ignore the effect of the second stress. So, it can be capable of the analyses in the strengthening bridge by external presttessing using the method of controlling by flexibility and stress to set up the model of scathe,and,the method of external presttessing can ensure stress reserve of the main beam, to reduce effectively PrinciPal tensile stress, to renew line state of bridge structure and gradient. The effect of strengthenment was obvious and the reinforcement scheme was successful.

同时，进行了该桥体外预应力加固监测方案设计，并通过理论计算结果与实际监测成果的比较，验证了在施工阶段及正常使用阶段，大跨连续刚构体系的体外预应力加固计算中忽略二次应力增量的影响，采用弹性分析方法进行简化计算的可行性，进而说明采用双控拟合方法建立的结构损伤模型能够满足体外预应力加固计算的要求，并且体外预应力加固法能够显著增大主梁的应力储备、有效地减少了主拉应力、恢复了桥面线形和坡度，加固效果明显，加固方式成功。

With the idea of smoothing Newton method, we propose a new class of smoothing Newton methods for the nonlinear complementarity problem based on a class of special functions. In this paper, complementarity problem is converted into a series of smoothing nonlinear equations and a modified smoothing Newton algorithm is used to solve the equations. We use Newton direction and Gradient direction together in the algorithm which guarantees that our method is globally convergent. Also using another smoothing function, we reformulate the generalized nonlinear complementarity problems defined on a polyhedral cone as a system of smoothing equations and a smooth unconstrained optimization problem. Theoretical results that relate the stationary points of the merit function to the solution of the generalized nonlinear complementarity problems are presented, we use the modified smoothing Newton algorithm in generalized nonlinear complementarity problems, under mild hypothesis, a global convergence is proved.

本文一方面基于现有的各种光滑Newton法的思想和半光滑理论，利用著名的F-B互补函数的光滑形式，首先将互补问题的求解转化为求解一系列光滑的非线性方程组，然后给出了一种修正的光滑Newton法，该方法不仅放宽对函数F的要求，在Newton方程不可解时引入初始效益函数的最速下降方向，而且光滑因子的选择也比较简单可行，同时在适当的条件下，证明了其算法具有全局收敛性；另一方面，借助另一种F-B光滑函数，将多面体锥上的广义互补问题转化为一种光滑形式，讨论了优化问题的稳定点与广义非线性互补问题的解之间的理论关系，并将这种修正的光滑Newton法用于求解广义非线性互补问题中，在适当的条件下，该算法同样具有全局收敛性。

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

We have something to do in the new stage.

在这段崭新的时期中，我们有一些要做的。

The difference between tourism decision-making under uncertainty and risky tourism decision-making is indistinctive.

其中不确定性旅游决策和风险旅游决策的界线比较模糊，两者的区分是相对的。