查询词典 descent method

FR conjugate gradient methods with perturbations are proposed. The global convergence property of the first method is proved under the condition of main directions' sufficient descent. Whereas, in the proof of the convergence for the other two methods, we only need main directions' descent. Importantly and quite interesting, boundedness conditions such as objective function being bounded below, boundedness of level set are not needed. Chapter 5 presents a version of Dai-Yuan conjugate gradient method with perturbations.

在主方向充分下降的条件下证明了第一个方法的全局收敛性，而后两个方法的收敛性是在主方向下降的条件下证明的，这些收敛性证明的一个共同特征就是不需要目标函数有下界或水平集有界等有界性条件，第5章采用Wolfe或Armijo步长规则提出了带扰动项的Dai-Yuanabbr。

Combined CD method and a new conjugate gradient method given by Liu.Y, Storey. C, the second class of nonlinear conjugate gradient method is proposed, which not only has descent property, but also is proved global convergence with the general Wolfe line search. Finally, the numerical results show this class of conjugate gradient methods is very efficient.

第二类算法是结合CD法和Liu.Y， Storey.C提出的新共轭梯度法，提出一类新的非线性共轭梯度法，新方法不但具有下降性质，而且在推广的Wolfe线搜索下是全局收敛的，最后进行了数值验证。

This paper illustrates various methods which are being used and being researched both home and overseas at the present time, such as the method of steepest descent, dynamic programming method, expert system method and genetic algorithm etc.

分析了低空突防路径规划应满足的条件和特点，阐述了目前国内外正在应用和研究的几种路径规划方法：最速下降法、动态规划法、专家系统法和遗传算法等的研究现状和发展方向。

By combining this method with descent methodand NCP function, we establish a globally convergent method for the GNCP.

其次，在局部积极集牛顿算法的基础上，结合互补函数以及最速下降算法，我们又建立了一类新的求解广义互补问题的全局收敛算法。

In chapter 2 we propose a linear equality constraint optimization question , the new algorithm is combined with the new conjugate gradient method(HS-DY conjugate gradient method)and Rosen"s gradient projection method , and has proven it"s convergence under the Wolfe line search.In chapter 3 we have combined a descent algorithm of constraint question with Rosen"s gradient projection, and proposed a linear equality constraint optimization question"s new algorithm, and proposed a combining algorithm about this algorithm, then we have proven their convergence under the Wolfe line search, and has performed the numerical experimentation.

在第三章中我们将无约束问题的一类下降算法与Rosen投影梯度法相结合，将其推广到线性等式约束最优化问题，提出了线性等式约束最优化问题的一类投影下降算法，并提出了基于这类算法的混合算法，在Wolfe线搜索下证明了这两类算法的收敛性，并通过数值试验验证了算法的有效性。

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。

The choice of step-length strongly affects the convergence rate of the Gradient Method, the classical Gradient Method—the method of steepest descent converges rather slowly in most cases, the poor behavior of the method is due to the optimal choice of step-length.

步长的选取对梯度法的收敛速度影响非常大，经典的梯度法-最速下降法在大多数情况下收敛得相当慢的原因在于最优步长的选取。

This principle eradicates local minima or invalid solutions caused by consistent reduction of the energy function via the usual gradient descent method.

利用这一理论，可以克服由于梯度下降法所导致的网络能量函数总是下降，从而使网络陷入局部极小值或不可行解的现象。

According to contraction theory, this algorithm is based on gradient descent method, which adopts linear average as performance evaluation of value function. So the iterative process of value function becomes a convergent process to a fixed value.

该算法基于梯度下降法，根据压缩映射原理，通过采用线性平均法作为值函数估计的性能衡量标准，把值函数估计的迭代过程转化为一个收敛于不动点的过程。

A mapping population of 81 F11 lines, derived from a cross between a japonica variety Kinmaze and an indica variety DV85 by single-seed descent method, was used to detect quantitative trait loci for traits associated with photosynthetic functions.

利用粳稻Kinmaze/籼稻DV85杂交后代单粒传衍生的81个F11家系所组成的重组自交系(Recombinant Inbred Lines，RILs)群体，研究水稻光合功能相关性状的数量性状基因座。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。