The establishment of edge-based loop algebra theory of kinematic chains and its applications

Based on the edge-based array representation of loops in the topological graphs of kinematic chains, this paper first proposes three arithmetic operations of loops. Then the concept of the independent loop set as well as its determination rules is introduced, and a new structure decomposition algorithm of kinematic chains is presented. Based on the algorithm, an automatic and efficient method for rigid sub-chain detection and driving pair selection of kinematic chains is proposed. Finally, an index is proposed to assess computation complexity of kinematic analysis with respect to different driving pair selections.     

A passive tree-based backbone construction scheme for MANETs

Backbone-based broadcast schemes are effective in alleviating the broadcast storm problem in mobile ad hoc networks (MANETs). However, periodically hello packets used to maintain a backbone usually lead to extra control overhead. In this paper, passive tree-based backbone construction scheme (PTBCS) is proposed as a backbone construction scheme for MANETs. Different from other schemes, each node in PTBCS determines its role by intercepting packet transmissions in the air during a special waiting period. Hence, its most remarkable advantage is that there are no periodical packet transmissions specially for backbone construction. The property that the nodes selected by PTBCS make up a connected dominating set (CDS) of the network is proven with several ideal assumptions. Simulation results show that PTBCS is effective when compared with some other typical backbone construction schemes.     

The research on mechanism of color management system based on iCAM color appearance model

Since color recording and color representing abilities of various media are very different, color information is often lost or misrepresented in the process of image transmission and reproduction. A Color Management System (CMS) based on iCAM color appearance model is presented in this paper. It can be used either in computer operation system software or application software for obtaining color consistency across different software applications, imaging devices, imaging media and viewing conditions.     

基于网络状态参数估计的主动队列管理PI改进算法

作为一种重要的主动队列管理手段,PI控制器算法通过积分嚣的引入有效地消除了队列长度控制的稳态误差,在提高网络吞吐的同时缩短了排队时延.但是PI控制器不能根据网络状态变化而自动调整控制参数,故当网络流量变化时PI控制器的收敛速度很慢.基于TCP-AQM系统模型,对经过中间节点的活动连接数、平均往返时间和前向链路容量等3个参数进行估计.通过计算击中概率的倒数,估计出活动流数;通过计算单位时间的数据包数,估计出网络容量;通过往返时延、活动流数、网络容量以及丢包概率在稳态时的关系式,估算出平均往返时延.在此基础上,提出了对网络状态变化自适应调整控制参数改进的快速收敛PI算法——FCPI算法.仿真结果表明,该算法有效提高了算法的收敛速度,并且鲁棒性好,易于实现,适用于未来高速网络的路由器.     

基于蚁群优化的DBN转移网络结构学习算法

针对动态贝叶斯转移网络的特点,以I-ACO-B为基础,提出基于蚁群优化的分步构建转移网络的结构学习算法ACO-DBN-2S。算法将转移网络的结构学习分为时间片之间和时间片内2个步骤进行,通过改进隔代优化策略,减少无效优化次数。标准数据集下的大量实验结果证明,该算法能更有效地处理大规模数据,学习精度和速度有较大改进。     

基于VQ和LBG的移动AdHoc网络中分簇算法

应用信息论与数据压缩中的矢量量化理论和LBG算法,在簇和Voronoi胞腔、簇首和码矢、节点和矢量之间建立起——对应的关系,把分簇的过程转换成二维矢量量化中胞腔的分裂过程。设计一个以簇结构稳定性高和负载均衡度好为目标的移动自组网分簇算法,仿真结果显示,分簇算法能够迅速地进行分簇,并且簇的结构具有较高的稳定性。     

基于HTTP请求的ORM性能优化研究

针对对象关系映射工具,提出一种性能优化方法,该方法使得对象关系映射工具通过统计在HTTP请求处理过程中加载的和实际使用的对象字段,在后续请求处理中仅加载必需的对象字段,从而提升应用程序持久层性能。将改进过的对象关系映射工具应用到开源电子商务示例应用程序XPETSTORE后,HTTP请求响应时间平均降低8%。     

基于遗传算法的直线光流刚体运动重建

建立一种新的基于直线光流场从单目图像序列恢复刚体运动和结构的模型,推导出直线光流场与刚体的运动参数之间的关系,用2个二阶线性微分方程表达这种关系,并提出一种求解刚体运动参数的遗传算法,只需要获得图像平面的2条直线光流即可求解刚体的旋转参数,并用合成图像测试了该算法的有效性。     

通用的个性化自动谈判服务框架及其实现

针对目前缺少从用户的个性化服务需求到主体服务实现角度设计的通用框架的问题,给出一个通用的个性化自动谈判框架。提出用户个性化服务需求转换为主体服务实现的方法和主体谈判服务的实现步骤,通过一个典型案例的实现与分析结果表明,该框架具有较好的实用性。