离散连续系统

Finite Element Method is an important means of engineering subject and has been proved to be a common method in many subjects. However, disadvantages still remained. During the structural analysis, large amount of high-order units were used in order to ensure the precision of arithmetic solution when using Finite Element Method to do discrete processing. This will cause high order of coefficient matrix of corresponding equation group.

有限元方法是工程学科的重要工具，被证明为在许多科学和工程领域中连续物理系统模拟的一种普遍方法，但缺点是随着工程结构分析问题越来越复杂，在结构分析中，为保证数值解的精度，在使用有限元方法离散处理时，往往要用大量的高阶单元将结构剖分得很密，这时相应的代数方程组的系数矩阵的阶数很高，即使用目前速度最快的串行机来进行求解，费时仍然太多且问题的规模受到内存容量的限制。

The number of being serviced Buffer selected as discrete index, the work number of Buffer as continuous state, an algebra-differential equation of the switched arrival system was naturally developed.

采用被服务Buffer编号为离散标识，Buffer中待处理任务数为连续状态，建立了系统的代数微分方程模型。

Performing the continued fraction expansion of the generating function corresponding to Al-Alaoui rule to obtain discrete approximation is better than the others.

研究表明，对分数阶控制系统进行离散化时，采用Al-Alaoui法和连续分数展开法相结合的方法可以得到较好的结果。

About one third of the book focuses on the existence and properties of the flow on the global attractor for a discrete or continuous dynamical system.

关于一本书的第三个重点是存在和关于离散或连续动力系统全局吸引流动性。

The faults of pipelines were separately treated in discrete random variable and continuous random variable using the probability analysis method and choosing the reasonably different probability models based on the fault statistics data of pressure pipelines extracted from random inspection, and the fracture failure probability of pressure pipelines was calculated using the fracture failure risk analysis system for pressure piping system containing defects.

以抽检得到的压力管线缺陷统计数据为依据，采用概率分析方法，通过合理选取不同概率模型，将缺陷分别按离散型及连续型随机变量进行处理，应用在役压力管道失效风险分析系统计算出管线的断裂失效概率。

The model is set up in view of the optimum design of midship section of container ships with crankle strength and frequency constraints according to CCS rules and thin-walled beam theory .

结合CCS规范和薄壁杆件理论，建立了考虑弯扭强度和频率约束的集装箱船中剖面优化设计的模型，考虑到中剖面优化设计中的设计变量为连续和离散的混合变量，利用isight中集成的自适应模拟退火算法，建立了巴拿马型集装箱船中剖面优化设计系统，并对3100TEU集装箱船中剖面进行了优化设计，取得了合理的结果。

The stability of a continuous or discrete-time system is determined by its response to input or disturbance.

连续或离散系统的稳定性由其对输入或者干扰的响应决定。

The results of simulations on a tank model, a discrete and a continuous two-order system, and a high order system demonstrate the feasibility and effectiveness of ITS and TS_SQP.

通过对液位储罐模型、离散、连续以及高阶系统的仿真实验表明了算法的可行性及有效性。

3D-CTM (Coupled Thermo-Mechanical Forming Simulation) software for precision forging process of aero-engine blade was developed. The key technologies of 3D coupled rigid-viscoplastic thermo-mechanical FEM simulation of blade forging process were studied systematically. By using the remeshing method of contracting from the boundary to the inner, new mesh system from old distorted mesh system can be obtained. A method of modifying the position of nodes touching on the die according to its original normal was proposed to avoid "dead lock" problem due to uncontinuity of normal of scatted die meshes. The pseudo-static iterative algorithm was used to simplify the coupled thermo-mechanical computation. In particular, formulations to determine relaxation factor β was established for rigid viscoplastic FEM adopting penalty function method, and an improved cubic factor rapid algorithm derived from these formulations was proposed by combining with the advantage of advance and retreat search method.

采用基于边界构形的内缩法，实现了三维畸变网格的重新划分；提出了初矢修正法对触模节点的位置进行修正，解决了由于离散的模具网格的法矢不连续造成的&死锁&问题；采用准静态迭代法简化了速度场和温度场耦合计算过程；特别是针对减速因子β的选取，建立了适用于三维复杂成形过程刚粘塑性罚函数法有限元三次因子法的计算公式，并结合进退搜索法提出了改进的三次因子快速算法，提高了模拟计算效率和稳定性，在此基础之上，开发了面向叶片精锻过程的三维刚粘塑性热力耦合有限元模拟分析系统(3D-CTM)，系统的可靠性得到了圆柱体镦粗的验证。

Simulations of the full system demonstrate that the development of the MI in the former regime leads to the establishment of a regular or chaotic array of pulses if the MI saturates, or a chain of well-separated peaks with continuously growing amplitudes if the instability does not saturate.

系统仿真结果表明：如果充分考虑调制不稳定性，则该系统将产生规则或者不规则的脉冲序列。反之，如果不考虑调制不稳定性它将产生一连串具有连续增长振幅的离散峰。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。