随机的

Random Sequence is very important in cryptograph ic technology, just as the famous cryptograph ! st Bruce Schneier said: within the six elements of Cryptograph ic Technology, the generation of Random Sequence is seldom discussed, but it is also important as others.

随机序列在密码技术中是很重要的，正如著名的密码学家Bruce Schneier所说：在密码技术的六个要素中，随机序列的生成是谈论最少的加密要素，不过它也和其它要素一样重要。

Methods: 154 inpatients with PCI in AMI therapy were divided into two groups randomly.78 patients in experiment group were given directed intervention of whole nursing according to their risk factors of AMI.76 patients in control group were given functional nursing.

随机将入住我院心血管内科的154例确诊为急性心肌梗死的患者随机分为对照组和实验组，针对78例实验组患者引起急性心肌梗死的主要危险因素，在进行经皮冠状动脉介入术治疗的同时，给予有针对性的整体护理干预措施；对76例对照组患者采用以往常规的功能制护理。

And we show that random walk model converges to the stable law of Lévy-Feller advection-dispersion equation by use of a properly scaled transition to vanish-ing space and time steps,We propose an explicit finite difference approximation for Lévy-Feller advection-dispersion equation.

第三章讨论描述服从某种稳定分布反常扩散的非对称空间分数阶对流-扩散方程——Lévy-Feller对流-扩散方程，首先利用Fourier变换和Laplace变换给出方程的基本解，然后利用Grünwald-Letnikov分数阶导数移位离散算子离散方程中的Riesz-Feller分数阶导数得到离散格式，证明此格式可以解释为离散随机游走模型，并且证明了当时间和空间步长以一定的比率同时趋于0时，所提出的离散随机游走模型收敛到Lévy-Feller对流-扩散过程的稳定分布。

The calculation of reliability was based on the three dimensional perturbation stochastic finite element program which was developed by ourselves.

在结构可靠性计算中，采用自行编制的基于摄动理论的三维随机有限元程序，就焊接残余应力对结构可靠性的影响进行了计算，并讨论了断裂韧度、外载荷、裂纹尺寸三个随机变量的变异对结构可靠性的影响。

Chapter 4 puts up the basic theory of non-linear finite element calculation methods and deduces calculation iterative formula and relevant accelerating iterative format. In the calculation of non-linear finite element, yielding element calculation is a difficult problem,"fictitious elastic stress" methods propounded in this paper puts the axe in the helve.

第四章提出了非线性随机有限元法的基本理论，并推导了计算迭代公式，为加快计算速度，提出了相应的加速迭代格式，对于基于非线性随机有限元的可靠度计算中，屈服单元的计算方法是一个难题，本文提出了"虚拟弹性应力"法，较好的解决这个难点。

According to the theory of extreme value of independent and identically distributed random variables, the reliability of external unbonded presertressed concrete structures is discussed.

论文讨论了体外筋面积的变化对体外预应力梁可靠度的影响，将其离散化为多个正态分布的随机变量，并根据独立同分布随机变量的极值理论，讨论了体外无粘结配筋对结构可靠度的影响问题。

By performing an inverse Laplace transformation of the stretch exponential function a distribution curve of the diffusivity is obtained which is enables the molecular weight distribution to be extracted.The results show that the width of the molecular weight distribution increasing as the average molecular weight decreases during the degradation process.

结果发现，在降解过程中随着聚合物平均分子量的降低，体系中的分子量分布不断变宽，这一结果与GPC实验结果完全吻合，而且从PFG实验中得到的平均分子量变化趋势和随机断裂方式下的Monte Carlo模拟实验结果十分吻合，据此可以认为聚合物的降解是一个随机断裂的过程。

In our thesis, contents are organized as following In Chapter 1 we present our topic's internal and overseas research situations, theoretical and practical significance, and introduce the research object and contents, and the main contributions of this dissertation. Chapter 2 reviews the development of the stability results for nonlinear systems and some relevant recent results, which include Lyapunov and LaSalle-Yoshizawa theorems for nonlinear systems, and stochastic edition for stochastic nonlinear systems. Sontag's formula for systems affine in control is presented in the frame of CLF. The concepts of disturbance attenuation and the inverse optimality are also explained in this Chapter. In chapter 3 we present the solvable theorem of inverse optimal gain assignment problem, design the inverse optimal controller and the inverse optimal tracking controller for strict-feedback nonlinear continuous systems with unknown time-varing bounded disturbances and constant unknown parameters using an adaptive backstepping algorithm, which are nonlinear, continuous and are easier to realize. These designs are fully systematic and the algorithm can be directly coded in symbolic software. The results of simulation show the effectiveness of the control algorithms.

论文的结构如下：在第1章中，给出了本文研究课题的研究现状、理论意义和实际应用，并介绍了本文的研究对象、研究内容以及主要贡献；在第2章中，针对确定性非线性系统和随机非线性系统，分别介绍了Lyapunov定理、LaSalle-Yoshizawa定理及其随机版本；对仿射系统，在控制Lyapunov函数框架下，给出了Sontag公式；同时给出了非线性系统扰动抑制和逆最优控制问题的基本概念；在第3章中，针对具有未知时变有界扰动和未知定常参数的一类不确定非线性系统，给出并证明了逆最优增益配置可解定理，使用自适应Backstepping算法和均值定理，系统地设计了自适应逆最优控制器和逆最优跟踪器，这种设计方法可同时获得逆最优控制策略和自适应律，简单明了，仿真结果表明该控制算法的有效性，并给出了性能估计。

Numerical solution of the model is maed by using Monte-Carlo sampling method.Its solution is astochastic field. It is showed by a real case that the model can describe the main trend and changing range ofpollutant'sconcentration at any calculating point,and the probability is added to the isopleth of the pollutant'sconcentration.

该随机模型的解是一个随机场，实例计算表明，它的解能够反映任一计算点的浓度变化趋势及范围，并能够给程度等值线附加上概率的意义，表现了在不确定因素的影响下，污染带随机变化的情况。

Finally,by applying a ran-dom version of Kifer's large deviation theorem and the volume lemma,we prove thelevel-1 LDT for randomly perturbed Axiom A attractors of diffeomorphisms withrespect to the Lebesgue measure.

最后，利用Kifer的大偏差定理的随机版本和体积引理，我们证明了微分同胚的公理A吸引子的随机扰动系统相对Lebesgue测度的level-1 LDT。

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。