查询词典 discrete continuous system

In this paper a method based on discrete wavelet transform and discrete cosine transform is presented to compress color image.

中文摘要：本文给出了一种基于离散小波变换和离散余弦变换的彩色图像压缩方法。

Methods of Discrete Cosine Transformation and Discrete Wavelet Transformation are two ways, and also make a comparison of these two ways.

采用的方法是离散余弦变换和离散小波变换两种方法，并且还对这两种方法进行了比较。

Mesh fairness problem We propose the conception of discrete curvature vector for meshes, and suggest a new fairness criterion that a mesh is fair if changes in discrete curvature vectors of this mesh are gradual and uniform Based on this fairness criterion, two algorithms are presented.

网格的光顺问题本文提出了离散曲率向量的概念，并以其变化平稳均匀作为网格光顺的准则，这一准则兼顾了曲率大小及法向的变化。

The discrete curvature vector based method to fair mesh by modifying vertex positions We first low-pass filter the discrete curvature vector function to make it change more gradually and uniformly, and then modify the vertex positions according the resulted function to improve the fairness of mesh.

以此为基础，给出了两个算法：网格改点光顺的离散曲率向量法基本思想是先用低通滤波算子修匀曲率向量，并由此修改顶点的位置以改善网格的光顺性。具体算法吸取了优化问题中Zoutendijk可行方向法的基本思想。

The motion of a discrete curve in Minkowski space is first introduced. Then by identifying the spin vector of HF models with the unit vectors of discrete curve, respectively, we obtain the corresponding DNLS.

我们将主要考虑闵可夫斯基空间中离散曲线的运动情况，并利用离散曲线的单位矢量分别替代离散的MHF方程中的自旋矢量，给出相应的离散非线性薛定谔方程，从而建立了两者之间的几何等价性。

In discrete operator difference method, the displacements of the elements can be reproduced exactly in the discrete forms whether the displacements are conforming or not.

在离散算子差分方法中，无论单元位移函数是否协调，其位移函数均能在离散格式中得到十分好再现，说明了离散算子差分方法的离散格式是一种性能很优良的离散格式。

The concept of topology optimization of truss structures with discrete variables including two kinds of variables and the relative difference quotient algorithm for discrete optimization are extended to the topology optimization of plate and shell structures composed by plate and shell elements.

将包含两类变量的桁架结构拓扑优化设计的概念及求解离散优化的相对差商法进一步推广到由板壳单元组成的板壳结构的拓扑优化，建立了包含两类变量的板壳结构拓扑优化设计模型，并采用相对差商算法进行求解。

The derivation course and the discrete scheme of the first model-Perona-Malik model have been expatiated on emphasis. One item of the P-M model is omitted in the P-M's discrete scheme, and the gradient magnitude is replaced by the absolute value of difference quotient.

Perona-Malik给出的离散格式是一种显式离散格式，这一格式的连续形式省略了原模型中的一项，且用差商的绝对值代替了梯度模。

The main objective of this dissertation was to develop methodologies with capability of engineering application for simulating flow in fractured rock using discontinuum models. The study work includes three parts. In the first part, numerical methodology of three-dimensional discrete fracture network model casing on hybrid BEM-channel was presented, and the technique for improve the model's computing efficiency was also studied. Firstly in this part, computer simulation methodology based on the Baechermodel for generating network of discrete fractures was presented, which includes the follow details: probability distributions of fracture density,orientation, trace length, size, and aperture and estimation of their statistical parameters; stochastic models of fracture network; Monte-Carlo's simulation method; numerical simulation procedure and technicality.

给出了离散裂隙网络模型所依据的基本假定；发展了基于Baecher模型的离散裂隙网络计算机随机生成技术：详细地推导了单裂隙渗流和多裂隙相交网络渗流的边界单元法公式，发展了离散裂隙网络中稳态渗流的边界元数值技术，并且讨论了相关的具体数值技术细节，如角点的处理方法，单元的自动剖分等：描述了混合边界元—管流模拟方法及其数值实现；研究了裂隙网络的简化方法，并针对裂隙网络边界元法的特点提出了一种改进的分块三角分解法。

For instance, the first prize winner-Investigation Study on Urban Traffic Flow Discrete pattern in China submitted by Beijing City Planning Institute analyzes the pattern of urban traffic and proposes a discrete pattern suitable for China.

如，获得一等奖的北京城市设计规划设计院的《我国城市道路车流离散规律初探》研究了我国城市道路交通流的离散规律及其影响因素，提出了适合我国的交通特点的离散系数

It was just a normal day of school

那只是上学的普通一天

Which is a very good reference in this issue.

这是一个在这个问题上很好的参考。