函数的周期

A methodology of noise-like key generation is presented. Chaotic process of tentmap function is used as a deterministic generation of noise-like key, image storage and retrieval are completed in a algebraic form. A mathematics model of noise-like chaotic coding memory is constructed, meanwhile the basic mechanism of circulant convolution and circulant correlation in image information storage and retrieval are demonstrated.

在详细阐明数字序列和字母序列的1-D映射函数设计方法的基础上，利用构造出的1-D映射的稳定周期环和不稳定极限环完成了存储和联想记忆功能，为了识别有关的输入信息，提出了映射函数直接控制的方法；在此基础上，提出了一种1-D映射型混沌神经网络模型，该网络本身不当作一个"黑箱"处理，网络的参数值由网络中实现的映射函数来确定，该网络模型具有联想记忆、容错性、模式识别和奇异滤波等一系列智能信息处理的基本功能。

This paper consists of three parts: Firstly, we discuss a nonautonomous -species two-patches cooperative Lotka-Volterra diffusion system. Using Brouwer fixed-point theory and Liapunov function, under some conditions, we obtain that the system has a unique globally asymptotically stable positive periodic solution. Secondly, we consider a kind of nonautonomous predator-prey model, in which preys are with stage structure and the predator are with two patches.

中文摘要：本文分三部分讨论三类生态模型周期解或概周期解的存在性及全局渐近稳定性等内容：第一部分讨论了两斑块种群的互惠Lotka-Volterra扩散系统，运用不动点理论和构造Liapunov函数，得到了系统存在唯一一个全局渐近稳定的正周期解的充分条件。

In §3, the sufficient conditions under which the homogeneous linear differential equation with periodic confficients possess nontrivial periodic solutions a...

最后还讨论了当系数为周期函数时方程存在周期解的条件。

Consider symmetry of periodic area we get the symmetry transform group, act the eigenvector of self-cognation operator on the node bases element function, a series of orthogonal function is constructed.

找出一般周期空间的对称变换群，并将已知的有限元的单元基函数转化为节点基函数，将变换群的特征子空间作用有限元的节点基函数得出一系列的正交有限元函数。

An investigation shows the relationship between the impairment and PN codes partial correlation,and its influence on BER performance.

而在实际的系统中，一般仅把一部分PN码用作扰码，而PN码的部分自相关函数和部分互相关函数要比其周期相关函数复杂的多。

Studied periodic function and its least positive period.

研究了周期函数及其最小正周期的若干问题。

The separability of asymptotically strongly periodic function space and asymptotically periodic sequence space are also discussed.

研究了渐近强周期函数空间、渐近周期序列空间的可分性质。

In this research,we first examine 117 students who have not learnt Periodic Function middle school to analyse studentsunderstanding level towards period.

本研究通过对117位初三学生问卷测试作为前测，分析学生在还没有学习周期函数之前，对周期的了解水平。

With this method, we had several important differences compared to the YDmodel. First, the ratio of daily increment of PDT and the deficit of both water and nitrogen was used to estimate the effect of environment. Second, a nonlinear function was adopted to describe vernalization and thermal effectiveness (instead of three-stage linear function). Third, sinusoidal function was used to describe photoperiod curve cluster for different cultivars.

本模型在YDmodel基础上的改进主要有3点：（1）将每日生理发育时间的增量乘以水肥丰缺因子，改为除以水肥丰缺因子表现水肥对大麦发育的影响，客观体现了大麦在水肥丰缺条件下的发育延迟或提早现象；（2）将三段线性函数改为非线性函数表达春化效应和相对热效应，确立了不同品种相对春化效应和相对热效应的曲线族；（3）将线性函数改为正弦函数表达不同品种光周期效应。

For general periodic functional differential equations,the suffcient conditions for the existence of periodic solution are obtained,therefore,the existence of positive periodic solution to the chemostat model is verified.

对一般的周期泛函数微分方程，导出了周期解存在的充分条件，并由此获得了微生物培养模型正周期的存在性。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了