查询词典 discrete process

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。

Study on design of the discrete state PI regulator and observers We extend the results of continuous system to discrete system in order to realize the state PI regulator by using computers.

离散状态PI调节器及估计器的设计研究将连续系统的有关结果推广到离散系统中，便于利用计算机进行计算和控制。

In response to signals and system simulation studies, MATLAB also demonstrated its strong role, with MATLAB simulation for the time signal convolution, discrete, continuous LIT system of time-domain analysis, synthesis and periodic signal of decomposition, the bi-frequency system Domain analysis, signal modulation and demodulation, discrete systems, the Z-domain analysis.

在信号与系统仿真响应的研究中，MATLAB也体现其强大的作用，用MATLAB仿真连续时间信号的卷积计算，离散、连续LIT系统的时域分析、周期信号的合成与分解、系统的复频域分析、信号的调制与解调，还有离散系统的Z域分析。

For the dynamic system of discrete coupled and nonlinear three phase voltage source PWM rectifier, the cycle switch average operator is introduced to transform the discrete system into continuous and the small signal perturbation method is used to transform the nonlinear system into linear, the small signal dynamic mathematical models are set up.

中文摘要：针对三相电压型PWM整流器这个离散的、耦合的、非线性的动态系统，引入开关周期平均算子将离散的系统变换为连续的系统，应用小信号扰动法将非线性的系统化解为线性的系统，进而分析系统的小信号动态数学模型。

Further more, we get the necessary and sufficient conditions for the two-dimensional discrete system, where the permanence and extinction of the system are decided and only decided by the relationship of the non-delay coefficients in the system. Further, we for the first time find the equivalent permanence and extinction between the two-dimensional discrete Lotka-Volterra and its corresponding continuous system.

进一步，本得到了此类离散系统二维自治情形下，其持续生存和灭绝分别等价于系统非时滞系数构成的相应不等式；通过比较本文中二维自治Lotka-Volterra竞争系统的连续和离散两种情形的有关结论，首次发现这两类系统具有等价的持续生存和灭绝性质，建立了这两类系统之间的联系。

The course is divided into two parts: Part 1: Signal representations - discrete and continuous; System representations; Linear time invariant systems (Superposition, Causality, Impulse response, Stability, Transfer functions); Discrete and continuous convolution.

通过 本课程的学习，学生应能掌握信号分析与线性系统的基本理论及分析方法，应能建立简单电路与系统的数学模型，并对数学模型求解，为后续课程的学习打好基础。

For the dynamic system of discrete coupled and nonlinear three phase voltage source PWM rectifier, the cycle switch average operator is introduced to transform the discrete system into continuous andthe small signal perturbation method is used to transform the nonlinear system into linear, the small signal dynamic mathematical models are set up.

中文摘要：针对三相电压型PWM整流器这个离散的、耦合的、非线性的动态系统，引入开关周期平均算子将离散的系统变换为连续的系统，应用小信号扰动法将非线性的系统化解为线性的系统，进而分析系统的小信号动态数学模型。

The effective prediction space concept is established, On the base of these, this paper deduces two representations' evaluating equation, one evaluates the prediction error and the other evaluates the prediction error in limited space. First, the error transfer characteristic among subsystems at different space locations is analyzed, and the direct transfer characteristic from discrete standard measure space to the workpiece measure space under measured in measure system is proven. Second, the error reconstruction condition and method of mapping from discrete standard measurement system to continuous standard measurespace are analyzed.

分析了不同空间位置子系统间的误差传递特性，证明了在测量系统中离散标准量值空间向被测量工件量值空间的直接传递性；分析了离散标准量系统向连续量值空间映射的误差重构条件和方法；基于测量样本的有限距离的平稳性，证明了预报模型对动态测量误差的有限收敛性和预报误差的可测度性，进而证明了以离散标准量值系统对被测工件预报修正的可行性和合理性。

Liapunov—Schmidt method is one of the most important method in the bifurcation theory.

Liapunov—Schmidt方法是分叉理论的最重要方法之一。

Be courteous -- even when people are most discourteous to you .

要有礼貌──即使当別人对你最不礼貌的时候。