基于复杂网络理论的城市路网脆弱性研究

首先,介绍了复杂网络的静态统计特性,并以新乡市区路网为例计算了映射后包括度、介数、聚类系数等在内的复杂网络统计特征值。然后,针对城市路网的拓扑特性,以复杂网络理论统计特性为基础,建立了路网脆弱性研究模型。以新乡市路网为例,研究了新乡市路网在随机性攻击和最大度攻击两种攻击策略下路网显示出的脆弱性。最后,通过逐个攻击网络节点的方法定量计算出路网中各个节点对于攻击表现出的脆弱性,通过该方法找到了路网中的关键路段,这对于后交通时代以维护为主体的路网保护具有重要的现实意义。     

Torque-based optimal vehicle speed control

This paper describes an optimal vehicle speed controller that uses torque-based control concepts. The controller design was divided into two steps: first, for a given vehicle speed trajectory, the engine torque demand was determined; in the second stage, a torque controller was implemented to track this torque demand. The torque demand was determined by a primary component and a correction component. The primary component was determined by solving an off-line optimization problem, and the correction component was added to compensate for the error caused by the off-line optimization. A modelbased proportional-integral (PI) feedback torque controller was employed to realize the engine torque tracking. Simulation results generated by a benchmark simulator were given to demonstrate performance of the optimal vehicle speed controller and a conventional PI speed controller that was included for comparison.     

双容水箱液位控制系统的设计

船舶上用到的多输入/输出的液位控制系统是一个非线性系统,常存在容积延迟时间长、抗干扰能力差的现象。运用滑模控制算法,并用组态王(Kingview)编制了上位机控制界面和算法程序,组建接近于实际的控制系统。通过在线运行,获得滑模变结构控制自适应能力强,动态、静态品质优良,鲁棒性好等优点,有效地解决了类似系统难于控制的问题。     

路面抗滑性能与交通安全的相关性研究

根据汽车动力学原理计算车辆安全制动距离,利用泊松分布函数研究武汉市长江隧道路面的车辆间距分布及路面摩擦系数与交通事故率的相关性。研究结果表明,摩擦系数的提高首先缩短了车辆的安全制动距离,从而减小了事故高发区域和意外状态下交通事故发生率。     

安徽省ETC收费车道改造工程实践

随着安徽省高速公路网络化步伐加快和高速公路电子不停车收费工作的快速发展,用户对高速公路服务水平的要求逐渐提高。结合ETC工程改造的实践,阐述了系统功能、设备选型及车道布局等方面的关键技术。     

一种基于贝叶斯特征的视频图像人脸检测

提出了一种基于仿射运动模型和贝叶斯理论的视频图像人脸检测方法.建立仿射运动模型进行运动估计,提取运动对象区域;对训练图像提取人脸与非人脸的统计特征,利用贝叶斯准则建立概率模型;根据贝叶斯分类器和支持向量机分类器将图像特征分为人脸类与非人脸类,从而检测出视频运动图像中的人脸区域.     

Multi-element ultrasound phased array applicator for the ablation of deep-seated tissue

High-intensity focused ultrasound (HIFU) has attracted increasing interests as a promising noninvasive modality for the treatment of deep tumors in the thoracic and abdominal cavity. A 90-element HIFU spherical phased array applicator operated at 1MHz has been developed for deep tissue ablation. The spherical array with a 5 cm wide central hole has a 21 cm diameter and an 18 cm radius of curvature. Annular element distribution with unequal element spacing is used to reduce the number of elements. The array is constructed with piezoelectric lead zirconate titanate (PZT-8) circular elements that are 1.4 cm in diameter and have a wall with thickness of 0.2 cm. The array offers an effective ablating depth of at least 8 cm in the tissue for both simulations and ex vivo experiments. The simulations demonstrate that the developed array can steer the focus with good quality of intensity distributions up to 6mm off center over ranges from 17 to 21 cm when the water depth is set at 11 cm. We also present the beam focusing capability in deep tissue through a series of ex vivo experiments by measuring discoloration areas after sonications. These results indicate that the developed array is ideal for the ablation of deep-seated tissue.     

混合动力轿车非平原地区工况燃油消耗试验研究

针对中国西南非平原地区典型城市道路坡度起伏较大的特点,制定了包括拥堵城市主干道、拥堵城市快车道、山区高速公路和狭窄山区道路的试验工况,进行了混合动力轿车在该地区实际路况下的油耗测量试验,并对测试的油耗数据进行了统计分析.在此基础上,研究了该地区实际路况下导致混合动力轿车燃油消耗存在差异的原因.     

采用NSGA-Ⅱ算法的管件液压成形加载路径优化

提出了一种将精英保留非劣排序遗传算法(NSGA-Ⅱ)与动态显式有限元软件LS-DYNA集成起来对管件液压成形加载路径进行优化的新方法.并应用该方法对某汽车仪表板梁液压成形中的加载路径进行了优化.结果表明,采用该方法获得了良好的效果.另外,该方法一次运算可同时获取多个Pareto最优解,为加载路径的确定提供了更多的选择.     

柴油机进气道流通特性的分析与设计

选取UG和Matlab软件作为进气道开发平台;通过引入表征气道面积利用率的函数分析了气门喉口处的流通特性;并应用正向设计方法直接得到了进气道CAD实体模型.由于正向设计方法增加了缸盖设计方案选择的多样性,为缸盖冷却水套流场优化和机械强度校核提供了更富余的调整空间.