查询词典 discrete problem

Optimization solution algorithm is the most important in topology optimization.Algorithms fit for discrete structure and continuum structure are all investigated. Thecharacteristic and different using limit of both optimization criteria method andmathematics programming method are all analyzed in this paper. OC algorithm and theseries MMA algorithm based on SIMP approach are deducedand used for the topology optimization problem of continuum structure.

优化求解算法是拓扑优化问题求解的核心和关键，本文系统分析了适用于离散结构和连续体结构优化的优化求解算法，重点讨论了 OC 算法和 MP 算法，分析比较了不同算法的特点和适用范围，推导了基于 SIMP 理论的优化准则法和 MMA 系列算法，并将MMA 系列算法应用于连续体结构拓扑优化问题的求解。

The discrete element method and the finite element method have their own advantages and weaknesses. Basically, the DEM was developed for predicting the failure problems accompanying with the transition from continuum to non-continuum media. However, it is not accurate to calculate the problem of continuum media. The FEM may forecast the failure area of the material reasonably, while it is hard to calculate the failure process in brittle media. Therefore it becomes a good choice to combine the two methods to construct a hybrid model.

离散元法和有限元法等数值计算方法各有其优势，同时也都存在不足之处：离散元法适于处理由连续介质向非连续介质转化的破坏问题，但对于连续体计算结果精度不高；有限元法适于预测材料破坏的区域，但难以直接用于计算脆性材料破坏过程，因此将两种方法结合可以形成一种较好的混合模型。

The problem of the design of variable structure control for discrete-time systems is considered.

针对离散时间系统变结构控制的设计问题进行了研究。

The problem of robust stability analysis for convex polytopic uncertain discrete-time systems with multiple-state delays is investigated.

研究了具有多重状态时滞的凸多面体不确定离散系统的鲁棒稳定性分析问题。

For a class of discrete systems, the problem of MPC with terminal constraint convex set is investigated.

针对一类离散系统，研究了带有终端约束凸集的MPC控制问题。

ECC system makes use of the finite group of elliptic curve on the finite field instead of finite cyclic group used in the discrete logarithm problem. The theory of ECC is being studied a lot and it is the focus of the cryptography and the industrial estate, especially the technique of the implementation of ECC.In this thesis, the meaning of the information technology is discussed firstly, then we analyze the classical cryptography algoritham. After that, the mathematics base of elliptic curve cryptosytems are introduced, especially the theory of the finite field. As for some algorithms, we also give out the program of reliazation.

随后，介绍了研究椭圆曲线密码系统所需要的数学理论基础，特别是有限域中的椭圆曲线理论，并对相关的方法给出相应的实例及其程序实现；论文第三章讨论给出了椭圆曲线密码体制的研究现状，综述了椭圆曲线与现有一些密码算法的结合，介绍了椭圆曲线的离散对数问题以及椭圆曲线面临的攻击，详细描述了椭圆曲线密码系统的实现细节及各个部分的实验数据。

Based on the discrete logarithm problem on cyclic group Z and the intractability of reversing a one-way Hash function, an improved scheme is proposed which can satisfy alt the desired security requirements, by using a provably secure shortened signature scheme.

基于循环群Z上离散时数困难问题以及单向Hash函数的不可逆性，利用可证安全的短签名方案，设计了一个新的能弥补H-C方案安全隐患的认证加密方案。

The concept of synchronization and several kinds of classical synchronization method are given, then the parameter identification process of chaotic system based on adaptive synchronization is given. Parameter identification problem can be converted into optimization with a given index function. Finally the paper explains the whole process with discrete Henon system and continuous Lorenz system.

首先，介绍了同步的定义和几种经典的同步的方法，说明了基于自适应控制方法的混沌系统参数辨识过程，并把参数辨识问题转化为对性能指标的优化问题。

The method solves the low efficiency problem of contact detection algorithm in wide size distribution particle discrete element numerical calculation in some extent.

改进方法在很大程度上解决了大尺寸分布颗粒离散元中接触检测算法效率低下的问题。

Fast Fourier transform and discrete cosine transform a simple, and it is only a small problem, not repaired, huh.

快速傅立叶变换和离散余弦变换的简单实现，有一些小问题，就不修复了，呵呵。

Although translator has turned from being a crystal ball by which the original culture can unrestrainedly penetrate to another crystal ball by which the target culture can freely traverse, the translator's personal embodiment, in the process of cognitive act, are still absent in translation studies. Translators are still subjects without body or simply disembodied subjects.

译者虽然由原语文化可以自由穿透的玻璃球变成了译语文化可以自由穿越的玻璃球，但译者认知过程中的个体体验在翻译研究中依然缺席，译者依然仅仅是一个没有躯体体验的主体。

Chillingly, he claimed our technology is 'not nearly as sophisticated' as theirs and "had they been hostile", he warned 'we would be been gone by now'.

令人毛骨悚然的，他声称我们的技术是'并不那么复杂，像他们一样，和"如果他们敌意"，他警告说，'我们将现在已经过去了。