钢丝绳激光在线测长方法研究

针对目前传统接触测长固有的打滑、磨损等问题,提出一种钢丝绳激光在线测长方法,利用激光成像技术、视觉检测技术以及数字图像处理技术对线结构激光器投射到钢绳表面所形成的图像纹理进行分析和处理,间接获得运动钢绳在线实时长度.实验证实,此方法能有效解决打滑、磨损等问题,同时还具备精度高的特点.     

基于不等长序列相似度挖掘的数据关联算法

针对不等长序列数据的关联问题,提出基于滑动窗口的最优匹配增权法不等长序列相似度度量算法。以较短序列作为滑动窗口遍历较长序列得到一组滑动相似度,利用这组相似度形成最优权重,加权得到不等长序列的相似度,并根据相似度大小对序列数据进行关联判决,以解决截断法相似度度量仅能反映截断序列局部相似度的问题。仿真实验验证了所提出算法对不等长序列数据关联的有效性,并对序列长度和量测误差等因素对相似度度量和关联效果的影响进行了讨论。     

Improved phase performance for rotman lens

Rotman lenses are used to obtain multiple beams from a single array. Although the beams produced by the feed antennas at focal points have no path length errors, the beams produced by feed antennas at off focal points may have large path length errors. These path length errors cause deterioration in the multiple beams. In this article, two novel methods are introduced to obtain feed curves which reduce the path length errors of off focal feed points significantly, compared with the commonly used circular and elliptical feed curves. The first method obtains feed curve points based on having zero path length error at three chosen points of the radiating array for each beam direction. The second method uses the particle swarm optimization method for obtaining optimum feed points for each beam direction. The results show that there is a very significant drop in the level of the maximum path length errors (in the order of about 1:4). © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE 23: 634–638, 2013.     

黄土地区隧道锁脚锚管作用机理分析研究

锁脚锚管在隧道施工中被广泛应用,而目前施工中锁脚锚管的长度、下插锚角度等几乎全部依靠工程经验来确定。通过有限元软件模拟了黄土隧道锁脚锚管在不同长度和角度下承担的最大内力和最大变形量,对比分析了锁脚锚管的长度、锚管下插角度与位移的关系。研究结果表明,锚管长度越长,变形越小,但最为经济的锚管长度为3 m左右;当所加锚管下插角在±30°时有利于支护内力的发挥。在研究结论基础上提出了隧道施工中应该采用的锁脚锚管合理长度及下插角度。     

基于复杂网络理论的无线传感器网络特征度量分析

通过研究复杂网络的理论,介绍了复杂网络的几种主要特征度量,并以此分析了无线传感器网络的特性。列举了无线传感器网络的节点度分布、集聚系数、平均路径长度、网络联通性等特性。研究了节点数、通讯半径、连通率间的关系,由仿真的数据得出,增加节点不能完全保证网络的联通,只能增加联通的概率,而增加通讯半径则可以迅速地使网络联通。因此,在条件允许的情况下,选择通讯半径大的传感器比增加撒布节点更能保证网络的联通。最后给出了适合于无线传感器网络的介数的评价方法。     

Semi-parametric nonlinear regression and transformation using functional networks

Functional networks are used to solve some nonlinear regression problems. One particular problem is how to find the optimal transformations of the response and/or the explanatory variables and obtain the best possible functional relation between the response and predictor variables. After a brief introduction to functional networks, two specific transformation models based on functional networks are proposed. Unlike in neural networks, where the selection of the network topology is arbitrary, the selection of the initial topology of a functional network is problem driven. This important feature of functional networks is illustrated for each of the two proposed models. An equivalent, but simpler network may be obtained from the initial topology using functional equations. The resultant model is then checked for uniqueness of representation. When the functions specified by the transformations are unknown in form, families of linear independent functions are used as approximations. Two different parametric criteria are used for learning these functions: the constrained least squares and the maximum canonical correlation. Model selection criteria are used to avoid the problem of overfitting. Finally, performance of the proposed method are assessed and compared to other methods using a simulation study as well as several real-life data.     

基于可变染色体长度的遗传K均值聚类算法

针对传统K-均值聚类算法需要事先确定聚类数,以及对初始质心的选择具有敏感性,从而容易陷入局部极值点的缺点,使用了一种基于可变染色体编码长度的遗传算法对传统K-均值聚类进行改进.该算法可以在事先不确定K值的情况下,通过多次的选择、交叉.变异的遗传操作,最终得到最优的聚类数,以及最优的初始质心集.通过Reuters数据集的实验结果表明,基于该算法的聚类划分结果明显优于传统K-均值聚类算法,并且好过基于固定染色体编码长度遗传算法的K-均值聚类算法.     

索引折半查找算法的研究与设计

当前对有序数列查找常用二分查找,但是二分查找具有一定的约束性和特殊情况下的低效性,为此研究并设计了索引折半查找算法,理论上其平均查找效率优于二分查找的平均查找效率。对比实验验证了索引折半查找算法的良好性能。     

基于复杂网络的非正式团体知识交互网络分析

针对知识在非正式团体中的传播特征,结合复杂网络理论,为了企业知识不断创新,提出了一种非正式团体知识交互网络模型.通过仿真得出,在小世界网络模型下知识的传播速度和平均知识水平比其他网络模型有明显优势,进而在非正式团体知识交互网络的描述与分析中提出利用"小世界"的平均路径长度和聚类系数来表征IFG知识交互网络中的交互频繁度和交互聚集度的思想,为进一步研究IFG组织及管理与其内部知识创新的内在联系提供了数量分析基础.