查询词典 falling gradient

The system parameters are determined by optimizing an output-error cost function. To deal with the non-uniqueness of the fully parameterized state-space system, a projected gradient search algorithm is presented by restricting the update of the parameters to the tangent space to the manifold of observationally equivalent state-space systems. The sufficient condition to employ L-M algorithm for optimizing parameters is also introduced. The proposed hierarchical optimization identificationmethod includes two steps: First, the parameter search direction is determined by the proposed adaptive L-M projected gradient approach; Second, the optimum step size is computed according to a line search method.

通过极小化输出误差目标函数获得了系统参数估计；提出了正交梯度搜索方法用于解决系统参数的非唯一性问题，正交梯度搜索的本质是在输入-输出等价类相切平面的正交垂空间更新系统参数；给出了用 L-M 算法进行参数优化的充分条件；提出的系统参数递阶优化辨识方法包括两步：首先用给出的自适应 L-M 算子正交梯度方法确定参数优化方向；其次由一维搜索方法计算最佳步长。

While these gradients could all be detected reasonably well,we found a slight shift in discriminability in favour of positive gradients and found that surfaces with no gradient at all were more likely to be judged to have a positive gradient.

让被试辨别表面质地密度变化的方向，结果发现被试能够很好地判别表面质地密度变化的方向，但在判别正向变化的表面时显得更准确；当表面密度没有变化时，被试倾向于判别为正向变化。

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。

Based on a Hopfield neural network mode for combinational circuit test generation, a test generation algorithm with global searching ability is proposed. This algorithm is the combination of chaotic searching with gradient algorithm. By means of the inherent stochastic and ergodic property of chaotic searching, the problem of being trapped in local minimum of gradient algorithm can be solved.

基于组合电路测试生成的离散Hopfield神经网络模型，将混沌搜索与Hopfield网络的梯度算法相结合，利用混沌搜索的内随机性及遍历性来克服梯度算法易于陷于局部极小的缺点，形成一种具有全局搜索能力的测试生成有效算法。

Relative positive temperature-gradient applicable for China is discussed, it proves that positive temperature-gradient can be expressed as exponential curve.

研究了我国公路桥梁混凝土箱梁的正温度梯度，证明其可以用指数函数来表达，并提出了本桥混凝土箱梁的正温度梯度指数函数表达式。

The expression of exponential curve is brought out to describe positive temperature-gradient of this bridge in this dissertation. Moreover, the relation of different factors to positive temperature-gradient is determined quantitatively.

根据计算研究结果，定量地确定了各影响因素与正温度梯度曲线的关系，证明了太阳辐射强度和日气温变化的幅值是影响混凝土箱梁正温度梯度的重要因素。

METHODS: HPMSCs were isolated from placenta of fetation human by density gradient centrifuge. Following bone marrow heparin anticoagulation, human BMSCs were isolated, purified and passaged by density gradient centrifuge.

采用密度梯度离心法从胎盘中分离、纯化和传代培养人胎盘源性间充质干细胞；骨髓肝素抗凝后，采用密度梯度离心法分离、纯化和传代培养人骨髓基质干细胞。

Bone marrow was obtained from healthy adult donors. METHODS: HPMSCs were isolated from placenta of fetation human by density gradient centrifuge. Following bone marrow heparin anticoagulation, human BMSCs were isolated, purified and passaged by density gradient centrifuge.

采用密度梯度离心法从胎盘中分离、纯化和传代培养人胎盘源性间充质干细胞；骨髓肝素抗凝后，采用密度梯度离心法分离、纯化和传代培养人骨髓基质干细胞。

The whole inverse problem may be viewed as a two-stage optimal procedure, and the optimal algorithm based on gradient, such as BFGS algorithm, is adopted as the gradient of the objective functions which may be derived by using Frechet differential.

由于两次优化的目标函数的导数都是可求得的，因此采用基于梯度的优化算法，如Broyden-Fletcher-Goldfard-Shanno变尺度算法。

Produced the gradient wind equation and showed examples of gradient wind (and its difference from the geostrophic wind) in 500mb height maps.

推导出梯度风方程并在500毫八高度地图中举出梯度风的例子（以及它与地转风的不同之处）。

Who? I never heard of him, Paul said, before asking teammate James Posey if he had heard of him.

赛后，科比说，他一直都是一名非常出色的射手，今天他打得很棒。

When I joined the company, I rotated around the different sections.

我加入这个公司时，轮换过几个不同的部门。