一种公路隧道机电设施运营质量评价方法

为掌握运营隧道机电设施运行状况,准确判断安全隐患,首先,从公路隧道机电设施的运营现状出发,对运营管理制度、设备技术状况和设施设置进行了分析,利用层次分析法构建了公路隧道机电设施运营质量评价体系,并确定了体系中的指标权重。然后,运用灰色关联分析法,计算比较序列与标准序列的关联度,从而得到隧道机电设施运营质量等级。最后,以我国青海省某隧道为例进行验证。结果表明,该方法不仅为隧道机电设施运营质量综合评价提供了有效段,还可以找出隧道机电设施运营过程的薄弱环节,为其科学管理提供依据。     

境外BOT项目经营开发面临的机遇与挑战

本文以境外某"一带一路"铁路项目为例,旨在通过分析所在国经济和市场状况,结合项目当前具备的资源和外部条件,在当地法律和特许经营协议框架下,分析经营开发面临的机遇和挑战,按照市场原则,研究经营开发工作思路和配套的投融资模式,为促进境外BOT项目可持续发展进行有益探索。     

浅谈国内船舶制造企业的效率管理

近年来,中国船舶工业飞速发展,取得了巨大的成就,然而国内船企在生产效率方面与日韩的差距还很明显,本文对当前的水平与差距进行了阐述,并着重就如何提高生产效率的措施与方法做了一些探讨与思考。     

基于舱室三维重建模型的舱容计量技术研究

快速高效的舱容计量技术对国内外液货公平贸易、舰船的续航力与自给力以及国防建设具有十分重要的意义。针对传统的舱容计量方法存在的效率低、精度差等缺点,提出了一种基于舱室三维重建模型来实现舱室容量计量的新方法。探讨分析了该方法中所存在的关键技术问题,通过对比试验验证了该方法的可行性与可靠性。     

浅谈高速公路桥梁管理系统外业数据的采集

介绍了桥梁管理系统外业数据采集的过程、方法与步骤。     

浅谈高速公路收费员管理的误区及改进措施

文章分析了目前大多数高速公路公司在收费员管理上存在的误区,并结合收费员的工作特点,提出了针对性的改进措施,同时介绍了广西坛百高速公路有限公司收费员管理的经验做法。     

基于改进未确知测度模型的内河客船夜航风险评价

为确保内河客船在夜间的安全营运,对客船夜航安全因素进行辨识,并将影响客船通航安全的因素分为人-船因素、自然环境因素、港口因素和管理因素4类一级指标,建立内河客船夜航风险评价指标体系.通过使用层次分析法(AHP)和熵权理论相结合的方法,降低各评价指标在权重分配中主、客观因素造成的影响.运用未确知度理论,处理客船夜航风险评价中评价因子的随机性和不确定性.以天津海河为例,运用改进的未确知度模型对客船夜航进行综合安全评价.实例验证结果表明,船员适任、船舶适航、背景光强和船公司安全管理以及船舶安全管理等5个评价指标权重比值较大,海河客船夜航风险等级属于"一般"风险且置信度不低于70%.     

集成模糊评价和层次分析法的大城市公交系统综合评价研究

本文在分析我国大城市公共交通特性的基础上,建立了大城市公交系统综合评价体系,并对选取的评价指标给出了相应的评价标准。然后采用模糊综合评价与层次分析方法集成的理论,建立结合层次分析法（AHP）的模糊综合评价模型,该模型是基于政府、公交企业和出行者三方主体的综合评价体系,对大城市公交系统进行综合评价,为政府和公交决策部门提供依据。最后以郑州市为例,依据调查的公交线路的基础资料,运用已建立的模型进行实例验证,分析模型的正确性及评价方法的可行性,效果良好。     

Modeling the cost of bird strikes to US civil aircraft

The objective of our analysis is to develop a model of damage costs that arise from collisions between aircraft and birds, based on data drawn from the Federal Aviation Administration National Wildlife Strike Database (NWSD). We develop a two-part model, composed of two separate statistical models, that accounts for the effects of aircraft mass category, engine type, component of the aircraft struck, and the size and number of birds struck. Our results indicate the size of bird, number of birds, and engine ingestions are the largest determinants of strike-related costs. More generally, our result is a model that provides a better understanding of the determinants of damage costs and that can be used to interpolate the substantial amount of missing data on damage costs that currently exists within the NWSD. A more complete accounting of damage costs will allow a better understanding of how damage costs vary geographically and temporally and, thus, enable more efficient allocation of management resources across airports and seasons.     

Three-dimensional conflict count models for unstructured and layered airspace designs

This paper presents analytical models that describe the safety of unstructured and layered en route airspace designs. Here, ‘unstructured airspace’ refers to airspace designs that offer operators complete freedom in path planning, whereas ‘layered airspace’ refers to airspace concepts that utilize heading-altitude rules to vertically separate cruising aircraft based on their travel directions. With a focus on the intrinsic safety provided by an airspace design, the models compute instantaneous conflict counts as a function of traffic demand and airspace design parameters, such as traffic separation requirements and the permitted heading range per flight level. While previous studies have focused primarily on conflicts between cruising aircraft, the models presented here also take into account conflicts involving climbing and descending traffic. Fast-time simulation experiments used to validate the modeling approach indicate that the models estimate instantaneous conflict counts with high accuracy for both airspace designs. The simulation results also show that climbing and descending traffic caused the majority of conflicts for layered airspaces with a narrow heading range per flight level, highlighting the importance of including all aircraft flight phases for a comprehensive safety analysis. Because such trends could be accurately predicted by the three-dimensional models derived here, these analytical models can be used as tools for airspace design applications as they provide a detailed understanding of the relationships between the parameters that influence the safety of unstructured and layered airspace designs.