查询词典 propagation loss

So we put forward fracture criterion of the deviator strain energy density factor and fracture criterion of the deviator strain energy for the mixed-mode crack propagation, simplifies as criterion and criterion respectively.

作为应用举例，它们成功地预测了复合型裂纹的启裂角和临界荷载，将其与现有的理论结果和实验数据进行比较，其结果是在预测裂纹启裂角方面优于Sih的S准则，而预测的临界荷载偏保守。

Among used machine learning methods, the gradient descent method is widely used to train various classifiers, such as Back-propagation neural network and linear text classifier. However, the gradient descent method is easily trapped into a local minimum and slowly converges. Thus, this study presents a gradient forecasting search method based on prediction methods to enhance the performance of the gradient descent method in order to develop a more efficient and precise machine learning method for Web mining.However, a prediction method with few sample data items and precise forecasting ability is a key issue to the gradient forecasting search method. Applying statistic-based prediction methods to implement GFSM is unsuitable because they require a large number of data items to model a prediction model. In the contrast with statistic-based prediction methods, GM(1,1) grey prediction model does not need a large number of data items to build a prediction model, and it has low computational load. However, the original GM(1,1) grey prediction model uses a mathematical hypothesis and approximation to transform a continuous differential equation into a discrete difference equation in order to model a forecasting model.

其中梯度法是一个最常被使用来实现机器学习的方法之一，然而梯度法具有学习速度慢以及容易陷入局部最佳解的缺点，因此，本研究提出一个梯度预测搜寻法则(gradient forecasting search method， GFSM)来改善传统梯度法的缺点，用来提升一些以梯度学习法则为基础的分类器在资讯探勘上的效率与正确性；而一个所需资料量少、计算复杂度低且精确的预测模型是梯度预测搜寻法能否有效进行最佳解搜寻之关键因素，传统统计为基础之预测方法的缺点是需要较大量的数据进行预测，因此计算复杂度高，灰色预测模型具有建模资料少且计算复杂度低等优点，然而灰色预测理论以连续之微分方程式为基础，并且透过一些数学上的假设与近似，将连续之微分方程式转换成离散之差分方程式来对离散型资料进行建模及预测，这样的作法不尽合理，且缺乏数学理论上的完备性，因为在转换过程中已经造成建模上的误差，且建模过程仅考虑相邻的两个资料点关系，无法正确反应数列未来的变化趋势。

Based on the theory of light propagation and diffraction characteristics of grating, the optical energy transfer of bi-grating imaging system is studied and the expression for the intensity of combined beams is given.

从光传播基本理论和光栅衍射性质出发，研究了双光栅成像效应中的光能量传递，得到了确定汇合级光强的表达式。

Numerical simulation of propagation of diffuse reflection light of extended object.

扩展物体漫反射光传输及成像的数值模拟研究。

This article adopts error back propagation of neural network which can quickly and exactly synthesize and analyze data from actual environment to make so accurate conclusion that helps to control the compressor, wind engine and electronic dilatometer with frequency conversion to control intelligently.

采用了神经网络的误差反传算法，可以快速、准确的对从实际环境中获得的数据进行综合、分析，得出正确的结论，从而通过控制单元调节压缩机、风机和电子膨胀阀，使其根据现状迅速地做出反应，达到智能控制的效果，具有先进性、经济性、和实用性。

Objective: To establish a protocol of rapid clonal propagation of Dioscorea zingiberensis using mature leaves as explants.

中文摘要：目的：以成熟叶片为外植体，建立一套盾叶薯蓣 Dioscoreazingiberensis 的快速繁殖技术。

The minute pressure exerted on a surface normal to the direction of propagation of a wave.

波在传播时施加在一表面上的微小压力，方向与波传播的方向相同。

The study aimed to provide the scientific direction of rapid propagation technique.

［目的］为二色补血草的决速繁殖技术提供科学指导。

In Chapter 2, we firstly examine the propagation direction of travelling target waves induced by the localized inhomogeneity.

在第2章中，我们首先研究振荡系统中缺陷对靶波传播方向的选择。

The direction of propagation is in a direction perpendicular to the wavefront.

传播方向(除了各向异性的媒介物以外)是与波阵面垂直的方向。

Diabetes is a social disease that affects several million people worldwide.

糖尿病是一个社会性疾病，全世界有数百万人罹患此病。

I'll call you on Friday to see if we can reschedule our luncheon meeting at your convenience.

我星期五会给您打电话在您方便的时候我们重新安排我们的午餐约会。