基于逆向FD超图环的全部候选关键字求法

本文通过对逆向ＦＤ超图的环的分类的深入研究，找到了组成候选关键字的属性对应的结点的特征，进而给出了求解全部候关键字的多项式时间的新算法。     

不规则地形散射场的MEI方法分析

本文将非均匀、不规则的地形处理成阻抗表面，沿地形表面作共形网格剖分，并利用不变性测试方程法（ＭＥＩ方法），使截断边界进一步靠近地表，从而减少计算机内存的占用量，使对实际工程中遇到的电大尺寸地形的分析及研究成为可能，文中计算的电大尺寸达１８０个波长。本文对比了不同电尺寸和地形结构的散射和传播特性计算，并给出几个实用模型的计算结果。     

A new approach to estimate fractal dimensions of corrosion images

A new approach is proposed based on box-counting method to estimate the fractal dimensions, D_2d and D_3d of corrosion images. They denote two-dimensional (2D) and three-dimensional (3D) characteristics of corroded surface morphology. The results have been tested through dealing with classical fractal figures, pit morphology of moon surface and practical corroded samples etc. to show that this new method is computationally simple, convenient and accurate. More specially, D_2d and D_3d have definite corrosion expressions, which respectively denote the fractal dimensions for pit diameter distribution and pit depth distribution on real corroded surface.     

基于FrFT-FD和KPCA模拟电路故障特征提取方法

为获得有效的故障特征信息,提出一种基于分数阶傅里叶变换分形维的模拟电路故障特征提取方法。首先,把原始数据空间中的特征数据映射到不同的分数阶空间,分别计算不同分数阶次下故障响应信号的分形维数;然后,采用核主元分析进一步对候选特征实施降维;最后,将优化后的特征向量作为故障特征,利用神经网络进行分类诊断。仿真结果表明,本方法能很好地获取不同故障响应信号的细微差异,增强不同故障模式的可分性,提高故障诊断准确率。     

基于FD法和模型组合的柔性直流输电可靠性评估

建立柔性直流输电系统的可靠性模型,为柔性直流输电系统的可靠性评估提供理论基础和方法。根据Markov过程的基本原理和累积状态间转移频率性质,在对基于电压源型换流器的柔性直流输电系统的构成以及故障方式研究的基础上,通过对系统进行划分,建立各子系统的数学模型。然后使用模型组合的方法,在子系统模型的基础上,组合建立整个柔性直流输电系统的数学模型。该方法有效地降低了采用状态穷举法时计算的复杂度,减小了求解维数并且加快了求解速度。通过一个算例和ABB公司的统计数据比较,说明该方法可以有效地应用于柔性直流输电的可靠性评估中,对柔性直流输电工程有一定的指导意义。     

基于分形理论和Kohonen神经网络的纹理图像分割方法

分形理论作为描述自然现象的一种模型,受到人们越来越多的重视。该文提出采用分形维数和多重分形广义维数谱q－D（q）作为纹理特征,采用自组织神经网络Kohonen网络作为分类器的图象分割方法。通过对纹理图象的分割实验,结果令人满意,证实该方法的有效性。     

基于聚类的软件失效数据预处理

应用失效数据进行软件可靠性参数的评估与预测是软件可靠性工程的主要内容之一。利用分层聚类算法对失效数据中的扰动和异常数据点进行隔离,并将以故障密度为相似性度量进行聚类处理后的失效数据集进行SRGM建模与软件可靠性参数估计,以较好的曲线拟合度提高SRGM参数估计与可靠性预测的精确性和抗干扰性,从而得到良好的软件可靠性分析与预测结果。     

Full Duplex Media Access Control Protocol for Multihop Network Computing

Intelligent communication technologies beyond the network are proposed by using a new full-duplex protocol. The Media Access Control (MAC) is a data interaction network protocol, which outperforms the IEEE 802.15.4e. This research discusses the planning and execution of full-duplex (FD) pipeline MAC protocol for multihop wireless networks (MWN). The design uses a combination of Radio frequency and baseband methods to realize full-duplexing with smallest impact on cross layer functions. The execution and trial results specify that Pipeline Media Access Control (PiMAC) protocol considerably develops network implementation in terms of transmission protocol (TP) and transmission delay. The advantage of using FD-MAC will increase the range of nodes. Also takes benefit of the FD mode of the antenna, which outperforms additionally 80% for all assessed cases. In this analysis, it was considered of that Psz = 8184 bits and Rc = 1Mbps; that’s, T_DATA represents an excellent portion of total UTC. Tests on real nodes displays that the FD theme achieves a median gain of 90% in mixture throughput as equated to half-duplex (HD) theme for MWN. The energy consumption of proposed system method is 29.8% reduced when compared with existing system method.