查询词典 discrete

Since we adopt Newton interpolation of difference quotient from the discrete data pool of unequal distance node among the scaled temperature (20℃, 1000℃), aluminum purity and aluminum density, it can greatly be approached.

我们从刻画的温度( 2 0℃、1 0 0 0℃)、铝纯度与铝密度间不等距结点的离散数据集中、采用了Newton差商插值、能极好地加以逼近、从而建立了高精度的四阶非线性数学表达式、由此从该模型中给出了 2 0℃时的高纯度铝( 99 999%～ 99.99999%)的密度值，其结果令人满意。

College: Differential and Integral Calculus, Differential Equations, Linear Algebra, Probability and Statistics, Discrete Math

大学：微积分，微分公式，线性代数，概率和统计，离散数学

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。

The surface representation in discrete form and its differential computation are important issues in computer graphics and geometric design.

0引言一般来说，曲面的一阶微分量是指曲面的切平面方向和法向量，二阶微分量是指曲面的曲率等有关量·它们作为重要的曲面信息度量指标，在计算机图形学，机器人视觉和计算机辅助设计等领域发挥了重要的作用·传统的曲面是连续形式的参数曲面和隐式曲面，其微分量的计算已经有了较完备的方法·随着激光测距扫描等三维数据采样技术和硬件设备的长足进步，以及图形工业对任意拓扑结构光滑曲面造型的需求日益迫切，离散形式的曲面———细分曲面、网格曲面和点云曲面正在逐渐成为计算机图形学和几何设计领域的新宠·于是，对这种离散形式的曲面如何估

And then, we review the history, development and actuality of the discrete differential geometry and subdivision method.

第一章介绍了古典微分几何的思想、历史与发展等情况；回顾了离散微分几何的思想起源与发展情况；介绍了细分的思想、历史与发展情况。

Application of FLAC and numerical differential to surface deformation observation;2. The formulas solving numerical differential and integral of discrete function arc deduced in this paper.

推导了三次样条插值在求解列表函数的数值微分与积分的公式，给出了余项估计，编写了用于求解数值微分与积分的通用程序，通过数值算例表明，三次样条在插值逼近中具有非常好的性质。

Numerical differentiation is that derivative value of a function at a certain point is approximately solved in discrete method.

中文摘要：数值微分就是用离散方法近似地求出函数在某点的导数值，关于数值微分已有许多求解方法，但这些方法都有各自的局限性，并且关于高阶导数近似逼近的方法研究相对较少。

Digital control of electrical machines is the digitalization control techniques based on discrete time system and technology.

电机的数字控制是基于离散时间的数字化电机控制技术。

Subdivision is one of the discrete modeling methods that can achieve data from the devices such as digitizer.

网格细分是一种离散造型方法，可以从数字化仪等设备直接获得数据。

Aiming for discrete transfer function, on the basis of solving Diophantine equation, constrained Generalized Predictive Control is studied by using Quadratic Programming and Goal Programming.

针对离散传递函数模型，在求解Diophantine方程的基础上，分别用二次规划和目标规划对有约束广义预测控制进行了研究。

Through comparing with the results by simulation to study the effects of theprojectile"s final velocity, the angle of rotation and the ballistic trajectory"s migration withdifferent projectile"s rotating speeds, different target"s moving speeds and differentpenetration angles.

通过比较数值模拟的结果来研究不同弹头转速、目标速度、侵彻角对侵彻过程中弹头最终速度、翻转角度和弹道偏移的影响。

I love stationery and all the accoutrement of writing.

我爱文具以及所有的书写的工具装备。