基于地空信息融合的无人机交通状态感知方法研究

现有的无人机（UAV）交通状态感知方法，主要针对宏观交通状态参数的获取，同时尚未克服UAV自运动对交通参数检测精度的影响，难以满足智能交通系统对于高精度微观交通参数的应用需求。为此，提出一种基于地空信息融合的UAV交通状态感知方法，该方法包括：地空信息融合模型、道路关键点（IKP）检测及跟踪、车辆目标检测及追踪算法和交通状态参数提取及估计。其中，地空信息融合模型利用地基信息（IKP世界坐标）与空基信息（IKP像素坐标）进行最优化融合，并通过自适应IKP追踪算法与自适应UAV位置偏移判断算法实时更新模型参数，以此克服UAV自运动对车辆轨迹精度的影响，进而获取可靠的车辆级（瞬时速度、车头间距和车头时距）与车道级（车道动态密度、车道流量和空间平均车速）交通状态参数。利用提出的感知方法获取实地拍摄视频的车辆级交通参数并进行了分布检验，同时比较了基于不同交通流模型的车道级参数估算方法。结果表明：该方法在车辆检测的mAP@0.5指数超过90%，同时提取的车辆轨迹相对完整，获取的车辆级和车道级交通状态参数也符合实际交通流状况。最后，将该模型应用于实地道路的交通拥堵检测及交通事件检测，该研究结果为UAV在现代交通感知和管理中的应用提供了一种理论和技术参考。     

武汉市城市轨道交通建设规划

结合武汉市城市快速轨道交通建设规划,分析总结了其规划研究过程的一些方法和特点,简要介绍其规划方案,以期探讨适合我国国情的轨道交通建设规划的科学思路和做法.     

轿车板MOBILITY特性对阻尼垫位置影响分析

利用分析板MOBILITY特性的方法,优选阻尼垫位置.首先通过建立轿车板MOBILITY模型,然后在前后塔形支座加载类随机载荷,对比分析添加阻尼垫前后车身主要板件MOBILITY特性变化,优化阻尼垫位置,并通过实验验证了方法的可行性,为合理布置阻尼垫位置提供参考.     

THE EFFECT OF HBsAg ANTIGENEMIA IN PREGNANT WOMEN ON FETUSES AND INFANTS

ＴＨＥＥＦＦＥＣＴＯＦＨＢｓＡｇＡＮＴＩＧＥＮＥＭＩＡＩＮＰＲＥＧＮＡＮＴＷＯＭＥＮＯＮＦＥＴＵＳＥＳＡＮＤＩＮＦＡＮＴＳＹｕｅＹａｆｅｉ（岳亚飞）；ＺｈａｎｇＳｈｕｌｉｎ（张树林）；ＷｕＬｉｎｇ（吴玲）；ＬｉＧｕｉｌｉｎ（李桂林）；ＤｉＰｅｎｇｃｈ...     

Transit fare differentials: A theoretical analysis

This paper compares the ridership. operator revenue, passenger-km, and consumer surplus in uniform pricing policy versus the differential fare pricing system. The comparisons are assumed that the flat fare is set equal to average differential fares. With mathematical derivation, the paper investigates some of the properties of fare differentiation and discusses characteristics of a general nature. The theoretical results have spelled out the conditions under which pricing policy may yield higher performances. A simple numerical example is used to demonstrate the sensitivity of the model. Some recommendations for setting transit pricing policy are drawn from the results.     

THE EFFECT OF STATUS OF ZINC, CALCIUM ON GROWTH OF CHILDREN AGED 3～6 YEARS IN XI'AN AND ANALYSIS OF EFFECTIVENESS OF ZINC SUPPLEMEINT

Traceelementsareimportantnutri-tioussubstancesforgr0wthofchildren.Ithasbeenrep0rtedthatzincdeficiencyisthecause0fgrowthretardation,dwarfisminchildren.Thec0rrelation'0flevel0fzinc,calciumwiththegr0wthofhealtllychildren,howeverFasn0tbeenclearlyin-vestigated.Inthispaper,thecorrelationofheightandweight0fchildrenwithzinc(Zn),calcium(Ca)statusisanalysedandtheeffect0fzincsupplementongrowthofchildrenisinvestigated,accordingt0anobservati0n0n456healthychildrenaged3～6yearsinXi'an.MATERIALSANDMET…     

基于特征的几何造型中数据结构的研究

提出了一种在几何特征建模中用于定义特征的交互技术,以相应的数据结构定义基本的几何特征,几何模型的建立就可通过添加特征与另一特征而实现使用得图形在一组几何尺寸发生改变时能方便地重新生成几何图形。     

基于PLC的船艏侧推筒体封盖系统的控制设计

介绍船艏侧推筒体封盖系统的工作原理，分析侧推封盖系统工作时所需要的控制内容和控制电路原理，设计PLC简体封盖的主控程序、分时使用封盖开关状态指示灯程序和专用报警程序。     

Assessing Service Quality,Switching Costs and Customer Loyalty in Home‐Delivery Services in Taiwan

Abstract

This study empirically investigated service quality, switching costs and customer loyalty from home‐delivery services' customers' perceptive. With regard to service quality attributes, findings indicated that customers were most satisfied with ‘range of delivery’, followed by ‘seldom loses parcels’, ‘invoice accuracy’, ‘prompt and reliable collection’ and ‘delivery by due time’. They were least satisfied with competitiveness of price. A structural equation modelling (SEM) approach was employed to analyse the impact of service quality and switching costs on customer loyalty from customers' perspective. Results revealed that service quality positively influenced switching costs and customer loyalty, and switching costs had a positive effect on customer loyalty. Investigation of the moderating effect of switching costs on the relationship between service quality and customer loyalty indicated that it was significantly important. Theoretical and practical implications of the findings for firms providing home‐delivery services are discussed.     

从加强思想政治教育工作入手提升当代大学生的责任意识

大学生的责任意识是其自身素质的重要内容,培养大学生的责任意识是高等教育的重大使命。本文从当代大学生责任意识的客观现状入手,深刻分析了当代大学生责任意识淡化的原因,重点阐述了提升大学生责任感的措施。