维数

Characteristics of the Internet traffic data flow are studied based on the chaos theory. A phase space that is isometric with the network dynamic system is reconstructed by using the single variable time series of a network flow. Some parameters, such as the correlative dimension and the Lyapunov exponent are calculated,and the chaos characteristic is proved to exist in Internet traffic data flows. A neural network model is constructed based on radial basis function to forecast actual Internet traffic data flow.

摘 要：应用混沌理论，分析了网络流量，用单变量的网络流量时间序列重构与网络动力系统等距同构的相空间，进而计算了实际网络的关维数和Lyapunov指数，并证实了网络流量存在混沌特性；据此建立了基于径向基函数神经网络的模型，并对实际网络数据流进行了预测。

However, It is difficult to specify the probabilistic model with a joint distribution function because of the large dimensions of the problem.

可是由于问题本身的维数，如何用联合分布来表示概率模型是件棘手的事情。

The character values of the wood disfigurement styles distinguishability based on connecting the wavelet multi- distinguishability with autocorrelation fractal dimention, uses four kinds disfigurements of knag 、 bark pocket 、 wormhole and molder as output of distinguishability typtles,uses L-M Calculation methods to train BP neural network.

本文以小波多分辨率下自相关分形维数作为木材缺陷类型识别的特征量，以夹皮、腐朽、节子、虫眼四种缺陷作为识别类型输出，选用L-M算法对BP神经网络进行训练。

Characteristic data have been worked out, including the maximum Lyapunov index λ, fractional dimension D, lacunarity Λ and eight energies of various frequency bands. After being normalized, they can function as the characteristic vectors. Then, they are transmitted into an artificial neural network to perform pattern recognition.Starting from the mechanism of ultrasonic generating, initial ultrasonic pulses are calibrated. A stylish discharge source is directly coupled with the ultrasonic sensors, and work out actual discharge magnitude.

利用非线性和非平稳的方法对超声波信号进行了分析处理，对于局部放电模型得到的信号，计算了超声波信号的Lyapunov指数、分维数D、空缺率、小波包分解的8个频带能量，得到了11个特征数据，归一化处理后形成特征向量，由人工神经网络进行识别，实现了对局部放电典型模型的模式识别，显著提高了模式识别的正确率，并分析了传播途径对识别的影响。

The results of experiment show that,the novel algorithm losses the recognition rates of 2.7 percent,but the length of feature vector is one fifth of traditional ones,and simplifies the complexity of classifier.

实验数据的特征选择实验表明，提出的算法仅以损失2.7%识别率的代价，得到的特征维数却是传统遗传算法的1/5，极大地简化了分类器设计的复杂度。

Each data line must consist of the coordinates of a single point in the set whose fractal dimension is to be estimated Successive coordinates must be separated by one or more spaces.

每个数据行必须包括单个点的所有坐标，这个点是被测分形维数集合中的点。连续的坐标必须由一个或更多的空格分开。

This is a judgment of the saddle point algorithms, user input when a two-dimensional array, When one element per line for the smallest, which is the largest per, it is saddle point!

这是一个判断马鞍点的算法，当用户输入一个二维数组，当一个元素为每行的最小，而又是每列的最大时，它就是马鞍点！

The situation of linear PDAEs is extended to the nonlinear PDAEs. Furthermore the dimension formula of linear differential idea is given.

推广了在线性情况下获得的结果，并进一步给出了线性微分理想的维数公式。

Large rotating machinery ; chaos ; correlation dimension ; non linear fault ; fault diagnosis

大型旋转机械；混沌；关联维数；非线性故障；故障诊断

A good linear relationship meet between fractal dimension and specific surface area of slag powder,and positive correlation with the cementitious properties of steel slag-based cement material.

分形维数与钢渣微粉的比表面积间满足良好的线性关系，并与钢渣基水泥材料的胶凝性能良性相关。

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。