基于广义GM（1,1）预测模型的装备管理费用预测

针对目前对武器装备寿命周期费用估算建模难以实施的情况,以准确预测武器装备寿命周期费用的主要组成部分——装备管理费用为出发点,依据装备管理费用的特点建立了装备管理费用的广义GM（1,1）预测模型,通过对某舰船系统装备管理费用的实例应用预测效果较好.     

Examination of factors affecting freeway incident clearance times: a comparison of the generalized F model and several alternative nested models

Traffic incidents are a principal cause of congestion on urban freeways, reducing capacity and creating risks for both involved motorists and incident response personnel. As incident durations increase, the risk of secondary incidents or crashes also becomes problematic. In response to these issues, many road agencies in metropolitan areas have initiated incident management programs aimed at detecting, responding to, and clearing incidents to restore freeways to full capacity as quickly and safely as possible. This study examined those factors that impact the time required by the Michigan Department of Transportation Freeway Courtesy Patrol to clear incidents that occurred on the southeastern Michigan freeway network. These models were developed using traffic flow data, roadway geometry information, and an extensive incident inventory database. A series of parametric hazard duration models were developed, each assuming a different underlying probability distribution for the hazard function. Although each modeling framework provided results that were similar in terms of the direction of factor effects, there was significant variability in terms of the estimated magnitude of these impacts. The generalized F distribution was shown to provide the best fit to the incident clearance time data, and the use of poorer fitting distributions was shown to result in severe over‐estimation or under‐estimation of factor effects. Those factors that were found to impact incident clearance times included the time of day and month when the incident occurred, the geometric and traffic characteristics of the freeway segment, and the characteristics of each incident. Copyright © 2012 John Wiley & Sons, Ltd.     

广义预测算法在综合减摇系统控制器设计中的应用

在综合减摇系统中,由于变量间耦合因素的存在,往往会导致系统达不到最佳控制状态。基于广义预测算法具有自适应、鲁棒性强等优点,将其应用到综合减摇系统控制器设计中,不仅可降低系统内在耦合作用,还能消除因外界随机干扰产生的不利影响。为验证该算法的有效性,对嵌入广义预测算法的控制模型进行跟踪特性分析,并对系统横摇角进行仿真,结果表明基于广义预测算法的控制器具有良好的控制效果。     

异型拱桥的几何非线性分析

异型拱桥由于造型独特其非线性行为规律较为复杂且难以掌握.利用自编程序分析了5座各具特点的异型拱桥的非线性行为规律,通过对比总结出以下结论:整体上,拱梁组合式蝶形拱桥中梁柱效应的影响最大,飞燕式系杆拱桥中大位移效应的影响最大,拱塔斜拉桥中索的垂度效应最为明显,而对于有推力的新月形拱桥,各非线性因素的影响均较小,可忽略不计;相对竖直索,斜索的垂度效应较为明显,且其索力受各非线性因素的影响均较大,计算时宜计入斜索的垂度效应并应对斜索索力进行非线性分析;对于仅承受荷载而不参与整体受力的桥面板和横梁,内力受非线性因素的影响很小,采用线性方法具有足够的精度,但计算位移时需计入大位移效应的影响.     

蝶形拱桥主梁的非线性行为及影响因素分析

由于蝶形拱桥造型独特其主梁部分的非线性行为规律相对其他拱桥较为难以掌握,传统的未充分考虑非线性影响的设计方法已不再适用.在自编程序的基础上,全面分析了各种非线性因素下蝶形拱桥主梁部分的非线性行为并研究了外倾角、矢跨比、含钢率等设计参数的影响及规律.结果表明:拱肋单元的梁柱效应对主梁弯矩的影响是不利的,而主梁单元的梁柱效应能够有效地抵消这种不利影响;主梁弯矩的非线性行为规律相对挠度更加复杂;未加载侧边梁的影响系数受偏载距离的影响较大;各梁跨中挠度和弯矩的影响系数均随着主拱肋外倾角的增大而增大;主拱肋含钢率和索拱平面间夹角对主梁非线性行为的影响可以忽略.     

拟闭算子

本文提出闭算子与广义零空间的概念，从一个新的角度讨论算子性质，得到一些有意义的结果。     

High accuracy NURBS interpolation for five-axis machine of table-rotating/spindle-tilting type

In this paper, the definition of NURBS curve and a speed-controlled interpolation in which the feed rate is automatically adjusted in order to meet the specified chord error limit were discussed. Besides those, a definition of linear interpolation error of post-processed data was proposed, which should be paid more attention to because it will not only reduce quality of the surface but also may cause interference and other unexpected trouble. In order to control the error, a robust algorithm was proposed, which successfully met a desired error limit through interpolating some essential CL data. The excellence of the proposed algorithm, in terms of its reliability and self-adaptiveness, has been proved by simulation results.     

液力变矩器叶轮内流场计算的无粘—有粘迭代法

本文提出了液力变矩器叶片表面准三维边界层计算的一种数值方法，并将边界层的计算与叶轮主流区三维流动计算相互迭代，完成了叶轮内无粘－有粘相互作用的三维流场计算。利用激光多普勒测速仪对ＹＢ－３５５变矩器内部流场进行了实测，测定结果与理论计算对比表明，本文所提出的计算变矩器内部流场的方法是合理的。     

基于广义矩方法的多目标网络优化模型实证检验

多目标稳定性网络优化模型是多目标优化模型的改进,文中以南昌市2000~2006年机动车辆管理处累计的历史数据为例,采用广义矩估计方法对所提出的多目标稳定性网络优化模型进行了实证检验.结果表明,改进后的优化模型比传统网络优化模型对网络优化的结果有相当程度的改善,采用多目标稳定性网络优化模型优化现实交通网络具有相当的适应性和稳定性.     

Can the Polynomial Based Key Predistribution Scheme Be Used Many Times in One Wireless Sensor Network Key Establishment Protocol？

Key establishment is the basic step for the wireless sensor network (WSN) security. The polynomial based key predistribution scheme of Blom and Blundo et al. has been the basic ingredient for the key establishment for WSNs. It is tempting to use many random and different instances of polynomial based key predistribution scheme for various parts of the WSN to enhance the efficiency of WSN key establishment protocols. This paper indicates that it is not secured in general to use many instances of Blom-Blundo et al. polynomial based key predistribution scheme in a WSN key establishment protocol. Thus the previously constructed group-based type WSN key predistribution schemes using polynomial based key predistribution scheme are insecure. We propose new generalized Blom-Blundo et al. key predistribution schemes. These new generalized Blom-Blundo et al. key predistribution schemes can be used many times in one WSN key establishment protocol with only a small increase of cost. The application to group-based WSN key predistribution schemes is given.