基于灰色新陈代谢马尔科夫模型对跑道侵入事件的分析及预测

本文综合运用灰色预测和马尔科夫两种方法,建立了我国机场跑道侵入的灰色新陈代谢马尔科夫预测模型。新陈代谢用来克服旧数据失去时效性的不足,马克科夫可以解决现有数据波动较大的问题,揭示了我国民航跑道侵入事件的动态变化规律并对我国民航跑道侵入事件的发生次数进行了较为准确的预测。为我国民航部门制定相关事件防范计划、降低跑道侵入的危害以及改善民航安全提供了依据,此方法也可以用于其他典型不安全事件类型的预测。     

基于K-means的印尼民航事件触发机制风险规律分析

航空安全信息的统计分析可以为航班的风险控制与安全预警提供有效支持。本文在收集整理印尼2007—2017年民航事件信息，基于事件触发机制的思想对其产生原因进行研究分析，运用统计分析法总结印尼民航不安全事件发生的主要原因及类型，同时采用K-means聚类分析法对飞行事故的风险等级进行评估，以发生次数和受伤人数作为观测集，得出跑道外接地的事故风险等级为高，冲出跑道的事故风险等级为中。在此分析基础上，提出相关的改进建议，并对我国处在特殊地理位置和气候条件的机场提供改进的角度和思路，对于同类型不安全事件频发的航空公司起到警示和预防作用。     

跑道助航灯光照明效果研究

夜间，飞机航行需要灯光照明指引，以确保夜航着陆安全。目前，在民航内普遍认为，飞机配备的着陆灯会为夜间跑道提供照明，而民航机场配备的助航灯光系统则用作指示信号灯。但在实际运行中，跑道助航灯的发光特性会对机场的跑道照明有一定的贡献。本文以此为出发点，考虑影响跑道灯光照明的四个决定性因素，构型、颜色、光强和有效范围，利用DIAlux Evo仿真，对跑道助航灯的照明效果进行分析。仿真结果表明：机场跑道是低照度环境，所提供的平均照度可以达到飞机滑行时着陆灯的照度要求。但由于跑道的照度均匀性低，跑道的纵向照度值变化明显，会加重飞行员的视觉疲劳。该结论对民用飞机的照明设计具有一定的参考意义。     

基于性能分析的ARJ21-700飞机签派放行研究——以“包头/东河—北京/首都”航线为例

随着ARJ21-700飞机在国内多家航司的投产运营，如何提升该机型的签派放行质量成为各运行控制部门确保安全飞行的重要工作之一。依据民航局颁布的《燃油和飞行计划手册》、《航空承运人燃油政策优化与实施指南》和《大型飞机公共航空运输承运人运行合格审定规则》等规章相关条款的规定和要求，课题研究采用10%不可预期燃油政策，在System Operations Center系统的DM模块的工作平台上模拟ARJ21-700飞机签派放行工作流程，完成ARJ21-700飞机在包头机场起飞的签派放行评估工作，最后结合该飞机起飞性能的计算分析，评估出机场跑道道面状况、跑道方向、大气温度、风方向等因素对飞机性能的影响程度，最后从道面情况、航空气象和备降场优选三个方面梳理运行控制的风险点，总结了ARJ21-700飞机签派放行流程的关键点，以期达到ARJ21-700飞机安全运行的目的。     

左转过饱和考虑相位均衡的信号配时优化研究

提出在保障交叉口总体效益最优和考虑驾驶员对红灯时长容忍度的前提下，设置逆向可变车道达到降低交叉口延误和提升通行能力。以各相位有效绿灯时长为优化变量，建立交叉口信号配时优化模型，并采取MOEA/D算法进行求解，结合设计案例，利用VISSIM7.0仿真软件在单位时长下对比优化前后各相位车均延误、车均排队长度和通行能力。求解的有效绿灯时长为19s、16s、15s、16s，有效验证了均衡相位绿灯时长的假设；仿真结果表明，车均延误平均下降26.15%；车均排队长度平均下降76.84%；通行能力平均提升约11.39%。提出的方法在降低交叉口延误，提升通行能力同时，能够均衡分配各相位有效绿灯时长，进而降低驾驶员等待红灯的焦虑感。     

中国国内民航飞机污染排放的 时空分布特征研究

近年来,飞机污染物排放问题日益凸显。本文分析了中国国内航班(除港澳台外)飞机污染排放的时空分布特征。结果显示,2016年中国国内民航飞机活动产生的CO_2、NO_x、CO、SO_x、HC和PM排放量分别为9468万t、46.4万t、8.3万t、2.6万t、1.02万t和0.46万t。各飞行阶段污染排放分析表明,CO_2、NO_x、SO_x和PM等排放主要集中在巡航阶段,而CO和HC在巡航阶段和起降循环阶段(LTO)的排放量相当。空间分析表明,飞机在起降循环阶段的排放主要集中在大型机场,飞机在航路上的排放主要集中在京沪、沪深等主要繁忙航路上。研究结果可为今后有效控制飞机大气污染排放提供研究基础。     

隧道施工事故统计分析

为了解我国隧道施工事故的发生规律,文章对2005—2019年间国内发生的109起隧道施工事故进行统计分析,获得了事故类型与单次施工事故造成的人员伤亡情况、各年度的施工事故次数以及造成的人员伤亡情况、各月份的施工事故情况、各省份的地区分布等统计特征。数据研究表明:事故次数和死亡人数均呈下降趋势,自2009年起各年份的施工事故次数和死亡人数基本达到稳定;坍塌、爆炸、透水突水和冒顶为隧道主事故类型,其中坍塌是第一要害;根据各月份的施工事故发生死亡人数情况,8月、11月和12月是死亡人数最多的三个月;事故主要集中在湖北、广西、云南、贵州、广东、陕西等西部和南部省份城市,东部地区则很少。     

基于数字地球的QAR数据飞行航径复现研究

为了更好的实现飞行品质监控和飞行事后分析，本文设计了可将QAR飞行数据关联到响应的地理空间和时间序列的显示平台。针对数据精度有限，提出了基于地理特征点的积分航迹分段修正模型，同时复现飞机实际垂直剖面时对气压高度进行了温度修正。以某航班实际QAR数据为例，通过数据筛选和仿真计算，并对数字地球进行二次开发，复现的飞行航径与时间空间相互关联，从而为飞行品质监控、安全评估以及事故/事故征候调查提供了技术支持。     

公路纵面视距行车安全性分析

驾驶员应有足够的视距来判断运行车辆前方环境发生的变化,如交通状况、道路线形组合形式及沿线景观设计等,以便采取相应措施确保汽车安全行驶。文章从道路纵面竖曲线设计原理出发,讨论了汽车安全行驶的条件,推导出停车视距与竖曲线设计长度、变坡角的关系,同时结合某高速公路安全性评价,对事故多发路段提出了合理化建议。     

逃逸事故伤害严重程度影响因素分析

为明确逃逸事故各因素特征与事故伤亡严重程度的关系,以便有针对性的制定防治逃逸事故发生的措施方案,结合逃逸行为的特点及统计模型的适用性,采用有序Logit模型来鉴别逃逸事故各特征变量对其事故严重程度的影响规律。结果表明:男性驾驶人在被肇事逃逸和路面条件良好情况下的逃逸事故会显著增加事故严重程度的可能性;商业公用车辆肇事逃逸和白天时间段的逃逸事故则会降低事故伤害程度增大的可能性;逃逸事故与非逃逸事故的伤害严重程度影响因素存在差别。据此提出应加强对驾驶人道路交通安全法规的宣讲和教育,以促使其懂法、守法,并加强对夜间交通的监控。     

The cost of general aviation accidents in the United States

Very few studies examine the costs associated with general aviation accidents. Given the large number of general aviation operations as well as the large number of fatalities and injuries attributed to general aviation accidents in the United States, understanding the costs to society is of great importance. This study estimates the costs associated with general aviation accidents in the United States. The direct costs are estimated and the indirect costs are estimated via the human capital approach in addition to the willingness-to-pay approach. The average annual accident costs attributed to general aviation are found to be $1.64 billion and $4.64 billion (2011 US$) utilizing the human capital approach and willingness-to-pay approach, respectively. These values appear to be fairly robust when subjected to a sensitivity analysis.     

Competing risks analysis on traffic accident duration time

Different clearance methods in traffic accident management lead to varied duration distributions. Apart from investigating the influence of various factors associated with accidents on the duration of such accidents using different clearance methods, this study also examines the cumulative incidence probability. We used traffic accident data obtained for 12 months from the Fourth Ring Expressway main line in Beijing to develop a subdistribution hazard regression model, which can assess the risk factors of two clearance methods. The regression results show that the different factors have statistically significant effects on the duration of two accident groups with different clearance methods; furthermore, opposite effects occur even for some factors that have a strong effect on both accident groups. For example, an accident involving a taxi extends the duration time with clearance method 1; in comparison, the accident is shorter with clearance method 2. The predicted cumulative incidence curves of the two types of clearance methods are shown as examples, with stratification based on the influence factors (taxi involved, season). Finally, the Gray test of the cumulative incidence functions and the log‐rank test of the Kaplan–Meier estimates of the survival functions are compared, in order to demonstrate the importance of using proper methods for analyses. Copyright © 2014 John Wiley & Sons, Ltd.     

Organizational effects of experience from accidents. Learning in the aftermath of the Tretten and Åsta train accidents

This article explores possible signs on learning in organizations following two major railway accidents in Norway, the Tretten accident in 1975 and the Åsta accident in 2000. These are the most serious railway accidents to have occurred in the past decades and both involved collisions on a single track system. The two events have been analyzed and compared in order to investigate possible learning effects and possible differences in learning given the 25-year span between them. The study is based on the analysis of selected documents related to the accidents in general and the narrative components in the documentation related to learning in particular.Our findings indicate that learning from these events was not expressed as an explicit goal in the aftermath. Learning in these cases seems to be linked for a large part to a change in measures, technical, operational and organizational, but we have not observed any managed confirmation or comprehension processes. The Tretten accident report suggests that the possibility of human error should be mitigated through the implementation of technological barriers, while it omits all other elaborations and risk reducing measures. The Åsta accident report recommended that the work to introduce modern safety management principles that had already been initiated before the accident should be continued. Neither of the accidents yielded any new insights and the knowledge brought forward was merely perceived as confirmation of already-agreed changes.     

Accident severity analysis using ordered probit model

To reduce injuries in road crashes, better understanding is needed between the relationship of injury severity and risk factors. This study seeks to identify the contributing factors affecting crash severity with broad considerations of driver characteristics, roadway features, vehicle types, pedestrian characteristics and crash characteristics using an ordered probit model. It also explores how the interaction of these factors will affect accident severity risk. Three types of accidents were investigated: two-vehicle crashes, single vehicle crashes and pedestrian accidents. The reported crash data in Singapore from 1992 to 2001 were used to illustrate the process of parameter estimation. Several factors such as vehicle type, road type, collision type, location type, pedestrian age, time of day of accident occurrence were found to be significantly associated with injury severity. It was also found that injury severity decreases over time for the three types of accident investigated.     

Accident cost saving and highway attributes

Two semi-logarithmic regression models are developed to estimate accident rates and accident costs, respectively, for rural non-interstate highways in the state of Iowa. Data on 21,224 accidents occurring between 1989 and 1991 on 17,767 road segments are used in the analysis. Seven road attributes of these road segments are included as predictor variables. Applying the resulting regression models to a rather typical highway upgrade situation, the present value of the accident cost saving is computed. The sensitivity of the estimated cost saving to values for fatal, personal injury, and property damage only accidents is tested.Because factors other than road characteristics greatly influence accident costs, the models developed in this research explain a limited amount of the variance in these costs among road segments. Results of the analysis indicate that the most important attribute associated with accident costs is average daily traffic per lane, followed by conditions requiring passing restrictions and the sharpness of curves. Varying the values for the three categories of accidents shows that results are far more sensitive to the value of personal injuries than fatalities. The feasibility of using predictive models of accident costs in benefit-cost analyses of highway investments is demonstrated.     

基于关联规则的重大道路交通事故影响因素分析

相比于一般交通事故,重大道路交通事故的特征及其影响机理会有所差异,本文旨在研究重大道路交通事故的分布特征及其主要影响因素。收集2014至2018年的重大道路交通事故数据,从驾驶员行为、车辆状况、道路线形和时空分布方面对重大道路交通事故的基本特征进行分析,采用关联规则技术深入挖掘重大道路交通事故多因素的影响机理。从人、车、道路和环境四个方面,重点讨论了重大道路交通事故中的两因素和三因素交互作用的影响机理,并据此提出了针对性的事故预防措施。     

广西高速公路木冲隧道交通安全性分析

长大隧道是高速公路的控制路段,其运营安全对高速公路畅通和安全有重要影响。文章通过研究木冲隧道交通事故分布特征,分析了长大隧道发生交通事故的原因,提出了改善木冲隧道交通安全状况的工程措施和管理建议,其对提高木冲隧道运营安全性具有指导意义。     

道路交通事故发生机理与实例分析

交通事故发生机理是认识道路交通事故发生过程、交通事故预防和改善交通安全的基础。文章以道路交通系统为研究对象,分析道路交通事故的形成过程,将交通事故发生机理分为驾驶行为差错类事故发生机理、外部因素突变类事故发生机理、综合性事故发生机理三类,并在此基础上绘制了道路交通事故发生机理图,同时结合国道109线兰州八盘村路段进行了实例分析。     

Climate change modeling and the weather-related road accidents in Canada

The objective of this research is to study the impact of climate change on the hazardous weather-related road accidents in the New Brunswick, Canada. We develop an Exposure to Weather-Accident Severity (EWAS) index multiplying accident and weather severity. The Negative Binomial Regression and Poisson regression models are applied to estimate the spatial–temporal relationship between the EWAS index and weather-related explanatory variables of road accidents. The regression results show that the surface-weather condition, weather, driver’s gender, weather-driver’s age, weather-driver’s experience, and weather-vehicle’s age have strong positive correlation with the EWAS index, while the surface-road alignment and surface-road characteristics have negative relationship with the EWAS index. The climate change model also indicates that the number of accidents declines during snowy and freezing days—most people stay at home and those who travel extra cautious—accidents do occur. The study suggests that the Road Safety Strategy 2015 of the Transport Canada should take a holistic approach to help minimize the incidences of severe road accident during the normal as well as hazardous weather conditions.