One modified method of characteristics used to analyze the multiconductor transmission lines

1.INTRODUCTIONThe analysis of electromagnetic compatibility becomesmorei mportant in the analysis of the multiconductortransmissionlines(MTLs).It provides the effectivemethod for designing the MTLs.Several methodsbased on frequency domain and ti me domain tech-niques have beenrecently proposed[1,2].Thefrequen-cy method should performthe inverse Fourier trans-formation,so it is not more accurate than ti memethod to some degree.The method of characteris-ticsis based ontheti me domain met…     

局域网中基于ASP的办公信息的采集

办公事务中经常要求采集各种信息，传统的做法是印发数据表、填写数据表、再把数据录入到微机数据库保存和处理；现利用Windows98的PWS和Access数据库，以Weh浏览器和Web服务器交互访问的方式，将局域网上收集的信息直接保存到数据库中．     

油库管理控制系统的集成化实现

介绍了计算机集成过程控制系统（ＣＩＩＰＳ）在没库储运生产中的应用，以及组成ＣＩＰＳ的局域网络，数据库和现场总线的结构，最后针对ＶｉｓｕａｌＢａｓｉｃ语言编制管理控制软件中的问题提出了解决方案。     

凹甲陆龟的泌尿生殖系统

凹甲陆龟的肾扁平，左右肾形状大小不一，呈荷兰豆荚形或块状方形．有特殊折叠，折起的形成可能与消化系统发达、遗传发育等因素有关．泄殖腔内有明显的环褶将肛道与尿、生殖道分开．附睾长而大，可能与精子的发育成熟和繁殖习性有关．     

我国城市绿地系统的规划与建设

城市绿地系统作为城市自然系统的主体,发挥着重要的生态功能.我国城市绿地建设普遍滞后,现在的城市绿地系统规划还存在不少问题,本文在分析绿地功能的基础上指出了在我国城市绿地系统规划与建设中所存在的几个主要问题,粗略地点明了解决这些问题的几点对策,尝试构建了使我国城市绿地系统规划顺利进行的内外条件.     

Recent Progress of Somatic Cell Nuclear Transfer in Pigs

Research in the field of somatic cell nuclear transfer (SCNT) and transgenic cloning in pigs has become a global hotspot，because porcine organs probably can be the first source of donor organs for human xenotransplantation. In recent years, though great progress has been made in porcine SCNT, the efficiency of nuclear transfer remains very low (<1%). Thus, it is necessary to improve the procedure of nuclear transfer and to investigate some basic problems further. Recent progress and the related problems of SCNT in pigs are reviewed and analyzed so as to offer some beneficial illumination to researchers.     

霍林河水库渗漏探测试验研究

高密度电法是常用的物探方法,在水库大坝探测方面也经常用到.文中介绍了高密度电法的原理和反演分析方法,采用高密度电法对霍林河水库大坝渗漏情况进行了探测试验,采用"单极-单极"阵列方式分别对大坝的4个断面进行了渗漏探测试验,并结合实测资料分析大坝渗漏原因.试验结果表明:高密度电法有效地探测了霍林河水库大坝渗漏情况,检验了防渗处理的效果,为大坝防渗加固提供了依据,也进一步验证了高密度电法在水库渗漏探测中具有较好的效果.     

Weighted symbol-flipping decoding algorithm for nonbinary LDPC codes with flipping patterns

A novel low-complexity weighted symbol-flipping algorithm with flipping patterns to decode nonbinary low-density parity-check codes is proposed.The proposed decoding procedure updates the hard-decision received symbol vector iteratively in search of a valid codeword in the symbol vector space.Only one symbol is flipped in each iteration,and symbol flipping function,which is employed as the symbol flipping metric,combines the number of failed checks and the reliabilities of the received bits and calculated symbols.A scheme to avoid infinite loops and select one symbol to flip in high order Galois field search is also proposed.The design of flipping pattern’s order and depth,which is dependent of the computational requirement and error performance,is also proposed and exemplified.Simulation results show that the algorithm achieves an appealing tradeoff between performance and computational requirement over relatively low Galois field for short to medium code length.     

基于EEMD-Renyi熵和PCA-PNN的滚动轴承故障诊断

针对滚动轴承故障特征提取与状态监测问题,提出一种基于集合经验模式分解(EEMD)、Renyi熵、主元分析(PCA)和概率神经网络(PNN)的新方法.首先,将轴承振动信号通过EEMD分解成一组本征模态函数(IMF),计算每个IMF分量的Renyi熵值作为表征故障特征的向量,采用主元分析(PCA)对特征降维,提取主元输入概...     

基于规则的神经网络在模式分类中的应用

针对模式分类任务,提出一种基于粗糙集规则的神经网络构造方法.首先,利用粗糙集理论和遗传算法约简输入特征,在尽量保持分类能力不变的情况下降低条件属性维数,并推导出简练的分类规则集合.然后,以规则集为基础构造BP神经网络结构、确定网络层数、输入输出节点数等,并计算规则的条件属性重要度和依赖度2个参数对连接权值进行初始化.最后,通过一个实例验证了方法的有效性,结果表明该方法能有效解决传统神经网络构造难、解释难、过拟合等问题,提高了分类精度,降低了训练时间.此外,初步探讨了网络训练时对知识提炼的影响.