查询词典 gradient method

Furthermore, the first-order optimality condition and its equivalent reformulations for generalized semi-infinite max-min programming with a non-compact set are presented using the lower-Hadamard directional derivative and subdifferential.2. Chapter 3 studies the gradient-type methods for unconstrained optimization problems. Section 1 proposes a new class of three-term memory gradient methods. The global convergence property of the method is established. Furthermore, in order to improve the convergence property of the method, a new class of memory gradient projection methods is presented with the property that the whole sequence of iterates converges to a solution to the problem under the conditions such as pseudo-convexity and continuous differentiability of objective function. In section 2, two new classes of methods, called gradient-type method with perturbations and hybrid projection method with perturbations, are proposed. In these methods, non-monotone line search technique is employed, which makes them easily executed in computer.

第3章研究了无约束优化问题的梯度型算法，第1节提出了一类新的三项记忆梯度算法，讨论了算法的全局收敛性，进一步提出了一类新的具有更好收敛性质的记忆梯度投影算法，并证明了该算法在函数伪凸的情况下具有整体收敛性，第2节在非单调步长搜索下提出了带扰动项的梯度型算法及其混合投影算法，这两类算法的一个重要特征就是步长采用线搜索确定而不象许多文献中那样要求步长趋于零，这样更容易在计算机上实现，在较弱的条件下证明了这些算法的全局收敛性，数值算例表明了算法的有效性。

Due to its good effect in the reservation of information of signal abrupt change, mathematical morphology is often applied in the detection and location of short-term power quality disturbance, however, there is still a defect of invalid detection existing in partial detection methods based on mathematical morphology while some zero-crossing disturbances are detected. In this paper three mathematical morphology based disturbance detection and location methods, i.e., the method based on first-order derivation and morphological gradient, the method based on morphological gradient and soft threshold processing and the method based on dq decomposition and top-hat transform, are analyzed, that is, by means of simulation the adaptability of these methods in the analysis on the signals of voltage sag, voltage swell and electromagnetic transient oscillation is compared.

数学形态学因其在保留信号突变点信息方面有很好的效果，因此常用于短时电能质量扰动的检测和定位，但基于数学形态学的部分方法仍存在对某些过零点扰动检测失效的缺点，文章分析了3种基于数学形态学的扰动检测和定位方法，即基于1阶求导和形态梯度的方法、基于形态梯度和软阈值处理的方法、基于dq分解和高帽变换的方法，通过仿真比较了3种方法在分析电压暂降、电压暂升、电磁暂态振荡等信号方面的适应性，结果发现基于dq分解和高帽变换的方法在检测过零点扰动时具有很好的效果，因此选取这种方法对实测扰动数据进行了检测和定位分析。

Then depended on the Gradient Projection Method, the gradient projection direction is deduced. The gradient direction is the basement for sensitivity analysis.

接着，根据投影梯度法，推导出了投影梯度方向，该方向是灵敏度分析的基础。

But the projection used in gradient projection method is an orthogonal projection which does not contain the second derivative information of objective and constrained functions,thus the convergence rate of gradient projection method is not contented.

但是，梯度投影法所采用的投影是正交投影，不包含目标函数和约束函数的二阶导数信息·因而；收敛速度不太令人满意。

By using generalized projection matrix, conditions are given on the scalars in the three term-memory gradient direction to ensure that the three term-memory gradient projection direction is a descent direction. A new three term-memory gradient projection method for nonlinear programming with nonlinear equality and in-equality constraints is presented.

利用广义投影矩阵，对求解无约束规划的三项记忆梯度算法中的参数给一条件，确定它们的取值范围，以保证得到目标函数的三项记忆梯度广义投影下降方向，建立了求解非线性等式和不等式约束优化问题的三项记忆梯度广义投影算法，并证明了算法的收敛性。

In the optimal control of kinematics for redundant robots, two new concepts, the matrix weightability measure and the self-motion declinability measure are proposed. Further, a modified weighted gradient projection method which combines gradient projection method with weighted least-norm solution is presented, it can attain ideal optimal effects at low velocities.

本文对冗余自由度机器人的运动学、动力学和容错等方面的优化控制进行了深入的分析和探讨：在冗余度机器人运动学优化控制方面，提出矩阵可加权度和自运动可衰度的概念，将梯度投影法和加权最小范数解法有机的相结合，形成可优化能力强、关节速度较低的改进的加权梯度法。

An application of conjugate gradient method to fit concrete creep coefficient is in good agreement with experimental results. 4. There are 8 CFST members bearing capacity tests with different initial stress factor and eccentric distances having been launched. 5. A generalized analysis program which could be considered steel tube initial stress influence of CFST arch bridge is developed. The correct and accuracy of the program were verified by the experimental results of the axis, eccentric compression initial stress CFST member and a model of CFST arch bridge.

应用共轭斜量法拟合混凝土徐变系数，拟合结果与试验值吻合良好； 4、开展了8根不同初应力系数和偏心距的钢管混凝土初应力构件承载力试验； 5、编制了钢管混凝土拱桥考虑钢管初应力影响的综合分析程序，程序得到轴心受压、偏心受压初应力试验构件和模型拱桥的验证。

Therefore, it is very important to study on high nitrogen content diamond synthesis in HPHT condition.In this study, we use a cubic anvil HPHT apparatus. Using catalysts, graphite and addition of NaN3, large green single crystal diamond with high nitrogen concentration is firstly synthesized by temperature gradient method.

本文使用国产六面项压机，首次用不同触媒(FeNiMnCo、FeNiCo)+C+不同比例的添加剂NaN3合成出具有完整晶型的优质深绿色高氮含量宝石级金刚石单晶，研究了NaN3对宝石级金刚石中氮含量及生长行为的影响。

Conjugate gradient method, the use of Newtons law or the use of parabolic interpolation.

共轭梯度法，使用牛顿法或者使用抛物线插值法。

This new method mainly comprises three steps: firstly, normalize the point-gradient vectors and calculate the block-gradient vectors and the corresponding block-coherence; then detect the noisy areas to eliminate the side effect of noise diffusing; finally, re-estimate all block- gradient vectors based on iteration and transform the gradient field to orientation field.

提出了一种基于梯度的健壮的指纹方向场估计算法，新算法首先归一化点梯度向量并计算块梯度向量及相应的块一致性；然后估计噪声区域；最后采用基于迭代的方法，重新估计所有块梯度向量并将梯度向量场转化为方向场。

The concept of equivalent rotationally rigidity is offered and the formula of rotationally rigidity is obtained.

主要做了如下几个方面的工作：对伸臂位于顶部的单层框架—筒体模型进行分析，提出了等效转动约束的概念和转动约束刚度的表达式。

Male cats normally do not need aftercare with the exception of the night after the anesthetic.

男猫通常不需要善后除了晚上的麻醉。