查询词典 gradient method

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。

A practical simulation example, which 155HP-1 robot performs pick and place bullet task, is given, and the gradient projection method with balanced scale factor proposed above is verified to be a general feasible method.

利用所构造的均衡比例因子梯度投影算法对155HP-1装填机器人的搬运装填弹丸作业进行了数值仿真计算，验证了均衡比例因子方法是一种通用可行的算法。

After solving the problem, the variational inequality sensitivity analysis method, generalized inverse approach, and gradient projection method are adopted to provide the solution algorithms for the bi-level programming model.

综上所述，本研究旨在建一套灾后网信赖评估方法，以解网是否满足灾后疏散的运输需求，并针对段容退化的关键段进修，进而提供灾害应变单位有效的决策支援。

For the optimization of the continuous variables, the author combines the weaken idea, the DFP and the gradient projection method to form a modified Goldfarb method by which the optimal problems of the trusses can be solved.

对于连续变量优化，作者将松弛思想、变尺度公式和梯度投影法相结合，建立了一种专门解决杆系优化问题的修正Goldfarb法，算例计算表明本法是针对性强、效率高的优化算法。

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。

It was just a normal day of school

那只是上学的普通一天

Which is a very good reference in this issue.

这是一个在这个问题上很好的参考。