变化光照条件下的交通标志快速鲁棒检测

变化光照条件下交通标志检测算法的准确率往往会显著降低。针对此问题,提出了1种新颖的概率图建立方法,并结合最大稳定极值区域特征进行交通标志检测。该方法包括3个处理步骤:①根据不同光照条件对真实场景交通标志样本图像进行明确分类以构建多类颜色直方图,将交通标志输入图像由原始色彩表达转变为概率图(直方图反投影);②通过在概率图上进行 MSER特征提取,获取候选的交通标志区域;③根据候选区域的面积、宽高比等特征快速有效去除非交通标志区域。实验结果表明在弱光照和强光照条件下基于归一化RGB的交通标志检测算法检测准确率分别下降到84.4%和83.0%,基于红蓝图的交通标志检测算法检测准确率分别下降到87.4%和86.3%,提出的算法在变化光照条件下依然可以保持90%以上的检测准确率,对光照变化有较好的鲁棒性。      

澜沧江急滩消滩水力指标确定方法

依据澜沧江多个急滩的实测和研究成果,采用成滩流量法获取了代表船型的初步消滩水力指标,指出初步消滩水力指标存在数据离散、指标不系统、难应用等不足,需要将其推算为常规的便于应用的系列指标;通过船舶有效推力与航行阻力受力平衡分析,导出急滩消滩水力指标的合理表达式,将流速、比降合并为一个称为消滩判数的综合消滩指标;用消滩判数表达式对初步消滩水力指标进行曲线拟合,可简单地确定出应用方便的合理的系列消滩水力指标。     

新型温拌阻燃沥青混合料的阻燃性能分析

针对我国隧道的特点,自主研发了温拌剂和复合阻燃剂,制备了新型温拌阻燃沥青混合料。为了探究其阻燃性能,通过验证两种添加剂的相容性,并结合重庆至长沙高等级公路黔江至彭水段试验路对新型混合料进行了室内燃烧试验、室外试验路现场铺筑、钻芯取样。结果表明,其各项性能指标均满足设计要求,验证了该新型混合料优良的阻燃性能,具有良好的市场前景和发展空间。     

轻型车海拔环境下滑行阻力试验研究

为了研究海拔高度和温度等试验条件变化时汽车滑行阻力的变化规律,并对一种汽车滑行阻力修正方法进行验证,本文对三辆试验车进行了四个海拔高度和四个温度条件下的滑行试验,得出了实测阻力和修正阻力,试验结果表明：文中提到的滑行阻力修正方法能够精确地将0米20℃条件下车辆的滑行阻力修正到不同海拔高度和温度条件下,误差在±5%以内,最大绝对误差可保持在10%以内,且对不同类型车辆都适用,通过该方法的使用,可节省试验成本和时间。     

Changes in travel mode use after residential relocation: a contribution to mobility biographies

In recent years, a growing body of research has been emerging that focuses on changes in travel behaviour over an individual’s life course. It has been labelled the ‘mobility biographies approach’ and highlights changes in travelling induced by key events and experiences in an individual’s life course. In this context residential relocation plays an important role. This paper examines changes in travel mode use after residential relocations using structural equation modelling. It draws on retrospectively recorded empirical data collected in the region of Cologne. The findings show that relocations and associated changes in the built environment induce significant changes in car ownership and travel mode use and thus may be regarded as key events in an individual’s mobility biography. Changes in levels of satisfaction with attributes of the built environment have a significant impact in this context as well. The causal direction of the changes fulfils expectations: suburbanisation is followed by increases in car use and decreases in public transport use, bicycle use and walking. The opposite is true for relocations into the city. In addition, changes in household structure that tend to go along with relocation have significant effects. The findings provide further evidence for the built environment having a causal impact on mode use: modal changes temporally follow changes in the built environment and thus appear to be adjustments to the new spatial setting.     

城市连绵地区轨道交通服务层级构建

面向城市连绵地区构建与之适应的轨道交通系统,关键在于提供具有针对性的服务层级,满足区域范围内不同的出行需求,应对出行链的复杂性和多样性。从城镇群、都市区、中心城市三个层面分析城市连绵地区的典型空间形态,并探讨与之对应的城际出行、城郊出行、城市内部出行活动特征。提出构建差异化的轨道交通层级,即区域轨道交通、市域轨道交通、市区轨道交通,重点探讨各个层级轨道交通的构成、作用、线路技术特征等,以及不同层级的衔接关系。     

非等时距灰色预测模型在连拱隧道监测中的应用

针对对门坡连拱隧道采用中导洞上下台阶法施工过程中隧道洞内变形的现场监测信息,采用非等距灰色预测模型对连拱隧道施工过程中隧道围岩的变形趋势进行了预测,并将预测结果与由指数模型和双曲线模型得到的结果进行了对比分析.分析结果和工程实践表明,其预测结果精度高,更接近于实测值,能很好地反映连拱隧道围岩的变形规律.     

Eye Robotic System for Vitreoretinal Surgery

Micro incision vitrectomy system (MIVS) is considered to be one of the most difficult tasks of eye surgery,due to its requirements of high accuracy and delicate operation under blurred vision environment.There-fore,robot-assisted ophthalmic surgery is a potential and efficient solution.Based on that consideration,a novel master-slave system for vitreoretinal surgery is realized.A 4-DOF remote center of motion (RCM) mechanism with a novel linear stage and end-effector is designed and the master-slave control system is implemented.The forward and inverse kinematics are analyzed for the controller implementation.Then,algorithms with motion scaling are also integrated into the control architecture for the purpose to enhance the surgeon's operation accu-racy.Finally,experiments on an eye model are conducted.The results show that the eye robotic system can fulfill surgeon's motion following and simulate operation of vitrectomy,demonstrating the feasibility of this system.     

大断面浅埋土质隧道施工工法优化分析

为探明大断面浅埋土质隧道在不同施工工法开挖下的变形及支护力学响应特征,寻求适用的工法,以宁安铁路钟鸣1号隧道工程为依托,采取现场试验与数值模拟相结合的方法,研究该类隧道在3种不同工法下的洞周及地表变形、围岩塑性区分布范围、初期支护及二次衬砌内力变化规律。研究结果表明：大断面浅埋土质隧道围岩变形有明显的空间效应,开挖面处预收敛变形所占比例约40%-50%;CRD法与六步CD法施工在控制洞周及地表变形方面明显优于三台阶临时仰拱法,且开挖产生的围岩塑性区分布范围小,两者均能满足围岩及支护稳定性的要求,而CRD法较六步CD法施工工期稍长、造价稍高,因此六步CD法为该类地层隧道施工的优选工法。     

异步电机磁链观测技术的研究

本文针对异步电机矢量控制的磁链观测技术进行了分析,给出了几种磁链观测的方法,并进行比较.实验结果证明其有效性.