不连续函数

Methods The relationship of dynamic model′s input and output was analyzed and a basic structure of system identification model based on the principle of optimization in model reduction and the property of a function approximator to be composed of feed-forward networks was presented.

分析了控制系统动态模型的输入、输出关系，依据模型等效的最优化原理和神经网络任意逼近有限不连续函数的性质，提出神经网络辨识模型的基本结构。

In this dissertation, the best simultaneous approximation with weight to infinite sequence from simultaneous-suns in complex normed linear space is considered, and in the case when the weight satisfies a certain condition, the characterizations of approximation from a simultaneous-sun and uniqueness of approximation from a RS-set are obtained; moreover, in the case when the weight is free, the characterizations of approximation to a totally bounded sequence from a convex set are established.

本文在复赋范空间中研究了同时太阳集对无限序列的加权同时逼近问题，在权满足一定条件时，通过把所研究问题转化为连续向量值函数空间中相应集对一个上半连续函数的最佳逼近问题，得到了逼近的特征和RS集逼近的唯一性定理，有例表明它们是已有结果的本质推广；在权不受限制时，得到了凸集对全有界序列逼近的特征。

In most meshless methods based on weights with compact support, difficulties arise in nonconvex bodies such as bodies containing crack.

大多数的无单元方法都使用具有紧支集特性的权函数。当求解域是非凸区域的时候，无单元的近似函数不能准确的描述裂缝带来的场函数不连续。

Based on the summation of numerical solutions of the free water surface seepage flow, a new concept called Regional Identification Function is put forward. It is pointed out that the reason why the initial flow method is unstable is that the RIF is discontinuous. Linearization continuity method for the RIF is suggested and then a revised initial flow method is presented.

在总结现有自由面渗流求解方法的基础上，提出了区域识别函数的新概念，指出区域识别函数不连续是导致初流量法解不稳定的主要原因，并对此函数进行了线性微调，提出了改进初流量法。

Based on the viewpoint of set and denseness,this paper discusses some characteristics of the of continuity set and differentiable function set,and the structure of differentiable function sets,and demonstrates that there does not exist a continuous functional sequence {fn} which is convergent to Dirichlet function.

从集合观点和稠密性出发，讨论了连续函数和可导点集的一些特性及可导函数点集的构造，并证明了R上不存在收敛于Dirichlet函数的连续函数列{fn

In a'variable structure system', the control law is a discontinuous function of the state variables when the trajectory crosses a prescribed hypersurface in the state space.

在一个变结构系统中，控制律是当状态轨迹经过规定的超平面时状态变量的不连续函数。

Simple step function, discontinuous function characterized by continuous segments between points of discontinuity and continuous function, and multi--type of components in a redundancy subsystem considered, a mixed integer nonlinear planning model for redundancy and reliability optimization was presented.

考虑子系统中冗余组件的多样性以及可靠性-成本之间可能的三种函数关系，即简单的阶跃函数、连续函数以及分段连续而在分段点不连续的非连续函数，建立了可靠性冗余优化的混合整数非线性规划数学模型，并以实例进行了说明。

On the basis of the idea of partition of unity, a discontinuous function and the two-dimensional asymptotic crack-tip displacement fields are added to the displacement interpolation formula to account for discontinuity of the contact surface and stress singularity near the contact surface tip respectively. Governing equations are deduced by virtual work principle and the integral of the discontinuous functions are calculated by Gauss integral through sub-elements cut by discontinuous surface.

该方法基于单位分解思想，在位移插值形式中引入不连续函数和裂尖渐近位移场函数分别反映接触面的不连续性和接触面端点的奇异性；根据虚功原理建立有限元支配方程，接触面不连续函数积分采用分区高斯积分的方法。

However, the solutions of the Cauchy problem of the nonlinear hyperbolic system generally develop singularities in finite time even if the initial data are small and smooth.For this reason, solutions must be found in the space of discontinuous functions. Therefore, one can not directly use the classical analytic techniques that predominate in the theory of partial differential equations of other types. Instead, we construct approximate solutions via the singular perturbation methods. By using the compactness of the approximate solutions, we can obtain the existence of the solutions of original system.

然而一般而言，即使是在初值很小且光滑的情况下，非线性双曲型守恒律的Cauchy问题的解在有限时间内也会出现奇异性，为此，我们必须在不连续函数空间中寻找上述问题的解，因此对这类问题的研究，我们也不可能直接利用在其它类型的偏微分方程中占主导地位的解析方法来解决问题，而是通过奇异扰动法构造近似解，由近似解的紧性得到原问题解的存在性。

Optimal algorithm of combined nonlinear Hopfield network appears powerful validity in solving nonlinear planning, which includes nonlinear objective function, linear constrains and high-demension of decision-making variants, for its ability of nonlinear parallel computation. It is prominent among optimal algorithms because of its function of simply implement with electrocircuit hardware. Genetic algorithm is expressly suitable for optimal calculation regarding the planning of massive, highly nonlinear, inconsecutively differentiable and multiobjective function as well as objective function without analytical expression. However, it inclines to prematurity, as well as its limitation in ability of partial optimal search. Introducing the optimal algorithm of niche genetic simulated annealing to standard Genetic algorithm, can therefore improve the full-scale or partial search ability of Genetic algorithm effectively. It has a far-flung perspective in the field of systemic planning of water pollution control.

组合式非线性Hopfield网络优化算法所具有的非线性大规模并行计算能力在求解具有非线性目标函数、线性约束条件及高维决策变量的非线性规划问题方面显示出了强大的生命力，它易于电路硬件实现的功能更是在优化算法中独树一帜；遗传算法采用概率搜索技术，不受目标函数与约束条件的限制，特别适合大规模、高度非线性的不连续可微的多峰目标函数及无解析表达式的目标函数的规划问题的优化计算，但其存在容易早熟、局部寻优能力较差等缺点，本文在标准遗传算法中引入小生境技术及模拟退火算法有效地改善遗传算法的全局和局部搜索性能，提高了全局最优解的寻优质量，小生境遗传退火模拟优化算法在水污染控制系统规划中的应用前景极为广阔。

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。