Monitoring Median Queries over Moving Objects

The k-median problem has attracted a number of researchers. However, few of them have considered both the dynamic environment and the issue of accuracy. In this paper, a new type of query is studied, called continuous median monitoring (CMM) query. It considers the k-median problem under dynamic environment with an accuracy guarantee. A continuous group nearest neighbor based (CGB) algorithm and an average distance medoid (ADM) algorithm are proposed to solve the CMM problem. ADM is a hill climbing schemed algorithm and achieves a rapid converging speed by checking only qualified candidates. Experiments show that ADM is more efficient than CGB and outperforms the classical PAM (partitioning around medoids) and CLARANS (clustering large applications based on randomized search) algorithms with various parameter settings.     

对流扩散方程的特征线MWLS算法

针对对流扩散方程,采用无网格法中的移动最小二乘近似方案与加权最小二乘法离散方案,结合特征线法,构造了特征加权最小二乘无网格算法(MWLS),并进行了数值试验验证.新算法克服了传统数值方法求解动态问题网格限制的缺陷,摆脱了在空间域上离散受制网格的束缚,不需要网格的初始划分或重构.试验结果显示,本算法可以达到与有限元求解几乎相同的结果,体现了不失精确度但却方便实用的优点.     

悬索线无铰拱桥自重内力实用计算方法研究

鉴于影响线加载法计算效率低和有限元法建模工作量大,无铰拱桥自重内力无法进行简便计算。基于桥面系作用主拱圈荷载的等效膜张力假定,采用解析法对悬索线无铰拱桥自重内力进行求解,得出实用公式,并用实桥算例验证了该方法。     

个人信息权民事确权刍议

2009年《侵权责任法》第2条,明确列举了包括隐私权在内的各项民事权益。而随后的全国人大法工委、国务院法制办对《侵权责任法》中"隐私权"涵义的解读,引起了人们对隐私权背后的个人信息权益的关注。论文从隐私权解读的角度,比较分析确认了个人信息与隐私相互交融、彼此独立存在的民事法律关系,并从我国人格权法律发展的角度,详细论证了个人信息权民事确权的必要性与可能性,以其丰富完善人格权理论。     

内模控制策略在混合隔振系统中的应用研究

内模控制作为一种独特的控制结构,能够清楚地表明控制系统调节参数与闭环响应及系统鲁棒性的关系,从而兼顾系统性能和鲁棒性.为提高混合隔振系统的隔振性能,将内模控制理论应用于混合隔振系统.分析了混合隔振系统的动力学传递关系;设计了混合隔振系统的内模控制器.仿真结果表明,内模控制效果明显.     

基于车速推算的改进地图匹配算法研究

车载GPS/DR组合导航监控系统中,GPS/DR数据不可避免受到各种误差源的影响而产生较大的误差,为了降低各种误差源对车辆导航的影响,有机结合能改善GPS/DR数据误差对导航影响的地图匹配算法,从而构成了GPS/DR/MM智能导航系统.文中通过分析地图匹配算法的关键技术和影响地图匹配算法可靠性等因素,提出一种基于车速递推的地图匹配算法,该算法利用基本可信数据--车速,从而很大程度地提高了地图匹配算法的可靠性.通过跑车实际数据测试表明,该算法是行之有效的.     

Numerical analysis and experimental study of the effect of workpiece thickness on flow field in laser cutting

Based on Navier-Stokes equation and renormalization group (RNG) onflow model, the 3D symmetrical impinging jet model of laser cutting is established by adopting a taper nozzle and a convergence nozzle. Numerical simulation of gas flow in laser cutting is used to investigate the effect of workpiece thickness on flow field of assist gas in cutting slot. The isolines of static pressure as well as the distributions of static pressure and velocity are analyzed in details with different workpiece thickness, and the trend of dynamics characteristics of gas jet is shown in the study. For taper nozzles and convergence nozzles, the dynamic structure of assist gas being close to the lower surface of workpiece is exacerbated while the cutting quality and cutting efficiency become worse with the increasing of workpiece thickness. The parallel degree between assist gas and the axis of convergence nozzle is better than that of taper nozzle after the gas goes out of the nozzles. Two typical subsonic nozzles are designed for the cutting experiment at the end of the paper.     

一种离散GM(1,1)模型的研究

分析了离散GM(1,1)模型与原始GM(1,1)模型的关系,二者形式相同,建模机理相同,但建模过程不完全相同,所以二者的时间响应函数不同。解释了离散GM(1,1)模型比原始GM(1,1)模型优越的原因,并从理论上证明了该离散GM(1,1)模型不仅具有白化指数律、白化系数律重合性,而且具有线性变换一致性。     

新时期高职院校学生管理工作探索

学生管理工作是学校管理工作的重要组成部分,新时期面临着诸多新的情况。本文根据新时期大学生特点,研究当前学生管理工作的新思路、新方法,就如何在新时期做好高职学生的教育管理工作进行了阐述。     

无砟轨道道床翻浆修复技术

针对遂渝铁路蔡家车站4号道岔岔枕及区间部分双块式轨枕与道床混凝土脱离、出现无砟轨道道床翻浆的问题,分析了其原因,提出了修复原则,简述了修复的材料和工艺,以及修复工作注意事项,对无砟轨道的养护维修具有重要的指导作用。