离散问题

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。

The paper discusses a generalized non-autonomous discrete relaxed system in time optimal control with generalizing the target constraint from the point curve to convex set hyper curve.

本文讨论了一类广义非自治离散松驰系统的时间最优控制问题，将R中点曲线的目标约束推广为凸集值函数的超曲线约束。

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。

In the second we give the necessary and sufficient conditions for strict convexity of power function of exponential family in the discrete case.

在第二个问题中，我们给出了在离散的情形下，指数族势函数严凸的充分必要条件。

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。

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。

Firstly, chaotic kinetic characteristic of Kent mapping is analyzed, using it to encrypt watermark image; Secondly, an algorithm of only modifying the decimal part of DC components is given, bringing the least error, effectively solving the problem which embedding watermark in DC components is easy to the image's block effect; Watermark is extracted without original image utilizing two-bits algorithm.

深入分析了帐篷映射的混沌动力学特性，并将其应用于水印图像的预处理；在分析了 DCT域嵌入对策的基础上提出了一种只修改 DC 分量小数部分的嵌入算法，引入的误差小，有效的解决了以往人们在 DC 分量嵌入水印容易引起图像块效应的问题；检测过程中利用二值离散算法使得水印提取时无需原始图像。

A theoretical model is presented which adopts maglev system to decompound complex problems in micro assembly and makes the system simple.

针对现有微装配系统存在的问题，给出了一种新的理论模型；将微产品装配离散化，便于建立标准化、模块化的实用微装配系统。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。