极小值

There are some disadvantages in BP algorithm, such as low rate of convergence, easily falling into local minimum point and weak global search capability. In order to settle these problems, a genetic algorithm was used to train BP neural network to replace classical learning algorithms. An evolutionary neural network learning algorithm was founded.

针对BP算法存在收敛速度慢、容易陷入局部极小值及全局搜索能力弱等缺陷，采用遗传算法训练BP神经网络，取代了一些传统的学习算法，设计了基于进化神经网络的学习算法。

BP neural network based on adaptive UKF is introduced in this paper for the standard BP neural network has slow converges, local minimum value and weak generalization ability.

针对BP神经网络收敛速度慢、容易陷入局部极小值点和泛化能力差等问题，基于自适应Kalman滤波理论，提出一种自适应非线性滤波训练BP神经网络的方法。

The optimization method is an effective tool in back-analysis of displacements of roadway, choosing the bad iteration method will lead to many problems, such as slow constringent speed, bad stability of solutions, local minimization.

最优化方法是进行巷道位移反分析的有力工具，如果优化迭代方法选择不当，将导致迭代过程收敛缓慢、解的稳定性差、陷入局部极小值等问题，不能保证搜索到全局最优解。

The optimization method is an effective tool in back-analysis of displacements of roadway, choosing the bad iteration method will lead to many problems, such as slow constringent speed, bad stability of solutions, local minimization. The globally optimal solution cant be found out.

最优化方法是进行巷道位移反分析的有力工具，如果优化迭代方法选择不当，将导致迭代过程收敛缓慢、解的稳定性差、陷入局部极小值等问题，不能保证搜索到全局最优解。

But the back propagation algorithm often gets into the minimum value and its constringent speed is slow. Aim at the gases, we design a optimum back propagation algorithm.

传统的前馈神经网络多采用误差反传学习算法对网络进行训练，但是误差反传学习算法具有容易陷入局部极小值，收敛速度慢以及容易导致震荡等缺点。

To cope with highly nonlinear, nondifferentiable and multi-peak objective function, evolutionary algorithms which have the advantage of global solution searching can overcome the drawbacks of conventional algorithms such as slow speed, relatively poor precision and convergence to local solutions.

针对微波领域中优化问题的目标函数的高度非线性、不可导、多极值等特点，利用演化算法的全局搜索特性，可以避免确定性优化方法收敛速度慢、精度低、易于收敛到局部极小值的缺点。

In order to obtain the global best result, the starting point is chosen at random and rotatively in the feasible region, and the optimization toolbox of MATLAB is employed. Then the minimum is searched again and by means of some rotations the global heat result is achieved.

为获得全局最优解，提出了在可行域内随机循环给定初始点，采用MATLAB工具箱优化计算，在优化结果中二次搜索极小值的方法，经过少量循环即可求得全局最优解。

For undoped sample 〓, a minimum of resistivity and semiconductor-like behavior present on the low-temperature side.

对未掺杂样品〓，低温下出现电阻率极小值和半导体型输运行为。

There is much noise in the state of eyes opening unforcedly, so the noise processing is necessary, the upper and lower eyelids are removed by parabola fitting, the facular is removed by neighboring gray average, the eyelashes are removed by finding all the candidate eyelashes by local gray minimum firstly, then the false eyelashes are removed by the beginning location, directional and length information of the eyelashes.

在人眼自然睁开状态下存在噪声，因此需要进行去噪操作：通过抛物线拟合的方法去除上、下眼睑；利用邻域灰度均值法去除光斑；去除眼睫毛时先用局部灰度极小值的方法找到所有候选眼睫毛点，然后利用眼睫毛的起始信息、方向信息和长度信息去除伪眼睫毛点。

The active contour model is a powerful image segmentation method for representing image contour, but it has three severe difficulties. First, active contour model highly depends on its initial position. Second, active contour model lacks the ability to handle boundary concavities.

动态轮廓模型(active contour model； ACM)是一种功效强大的影像分割描绘方法，但却具有三个严重的缺点：第一、此模型非常依赖待描绘图形的起始位置，第二、此模型缺乏进入图形凹陷处的能力，第三、此模型有停滞在局部能量极小值的倾向。

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。