定量分析雷达回波——雾天中的船舶驾驶

文章利用数学、物理中行程问题等理论,通过特定的雷达指标,把目标回波相对观察船的移动速动和方向进行描述,测定来船速度和方向,经简化,确定来船动态,实现船舶在能见度不良在航时安全选择航路及其避让的目的。     

沥青路面就地热再生二次养护对策分析研究

针对目前高速公路就地热再生路段二次养护需求,通过对江苏省高速公路典型就地热再生路段路用性能、材料性能发展规律的统计及试验分析研究,提出针对不同路况、路面材料性能衰减条件下的就地热再生路段二次养护对策,为就地热再生路段二次养护方案的选择提供参考。     

自然通风公路隧道有害气体浓度分布

研究目的:分析计算隧道各个分段的有害气体浓度,以把握公路隧道在自然通风状态下,其有害气体浓度在隧道内部的分布情况。研究方法:对于设有开孔的自然通风隧道,根据其隧道气流运动规律的研究成果,以工程实例计算正常工况下隧道各个分段的有害气体浓度;根据热压作用原理,探析交通阻塞工况下有害气体浓度的计算方法。研究结果:在正常工况和阻塞工况下,自然通风隧道的内部空气质量皆有明显的改善。研究结论:在顶部设有开孔的单向公路交通隧道中,自然通风可以控制隧道有害气体浓度在卫生标准的之内。     

基于嵌入式服务器的多模航行信息接收系统设计

文章设计了一种基于嵌入式服务器的多模航行信息接收系统,具有自动接收船舶识别信息、航行告警信息和气象传真信息的功能,同时具备了通过多功能显示器和热敏打印装置进行集中显示和图像打印的功能。文中给出了系统硬件组态及相应软件设计流程,测试和试用结果显示系统具有极高可靠性和实用性,具有很大的市场推广价值。     

Winter problems on mountain passes – Implications for cost-benefit analysis

Cost-benefit analysis is a tool in government decision-making for determining the consequences of alternative uses of society’s scarce resources. Such a systematic process of comparing benefits and costs was adopted in early years for transportation projects and it has been the subject of much refining over the years. There are still some flaws, however, in the application of the method. In this article we have studied the impact of weather conditions on traffic speed on low traffic roads often exposed to adverse weather. This is an issue not currently considered in the cost-benefit analysis of road projects. By using two analytical approaches—structural equation modelling and classification and regression tree analysis—the impact of the weather indicators temperature, wind speed, and precipitation on traffic speed has been quantified. The data relates to three winter months on the European Route 6 road over the mountain pass Saltfjellet in Norway. Increase in wind speed, increase in precipitation and temperatures around freezing point all caused significant decrease in traffic speed in the case studied. If actions were taken to reduce the impact of adverse weather on traffic (e.g. by building a tunnel through the mountain) this study indicates that the road users would gain a total benefit of approximately 2,348,000 NOK (282,000 EUR) each winter at Saltfjellet if all the weather related benefits were included. We argue that this is a significant number that is highly relevant to include in CBAs. This applies both to the CBAs of new transportation projects as well as when resources are allocated for operation, maintenance, and monitoring of the existing transport systems. Including the weather related benefits would improve the application of CBA as a decision-making tool for policy makers.     

汉画像石与封建“孝”

秦汉时期是中国封建社会的上升时期,这一时1期统治者的统治策略不断发生变化,至汉武帝时,“忠孝”思想成为中央及地方各种社会活动的准绳,而后“孝”的发展进而滋生了一种陋俗—一薄养犀葬,在“孝”的思想的主宰和薄养厚葬之风气的双重影响下,墓葬艺术得到空前发展,为后世留下了辉煌的艺术财富…汉画像石。它虽然以尽孝为目的,然而却在无意中涵括了秦汉时期的艺术气象,通过画像石的形成和发展轨迹来探寻它与封建“孝”的关系。     

雨天环境下高速公路可变限速控制方法研究

降雨对高速公路交通安全和通行效率具有一定的负面影响.运用可变限速控制技术,根据高速公路实时交通流状态和降雨强度,对各路段限速值进行动态优化和调整,减小降雨带来的不利影响.阐述了雨天可变限速控制系统的总体方案,分析了降雨对能见度和路面摩擦系数的影响,建立了雨天环境下高速公路安全车速计算模型;在宏观动态交通流模型METANET基础上,提出了适用于雨天可变限速控制条件的改进模型,并以控制周期内所有车辆总行驶里程最大为目标,建立了雨天可变限速控制优化模型.利用Matlab软件仿真实验,结果表明,与固定限速方式相比,本文建立的可变限速控制方法可提高雨天环境下高速公路车辆运行速度,并降低各路段车速差,保障雨天环境下高速公路安全高效运行.     

综合舰桥系统综述

简要介绍了综合船桥系统的发展过程,阐述了舰桥系统的特点,提出了舰桥系统研究内容.这对舰船控制实现自动化,指挥决策科学化,提高舰船安全性具有重要意义.     

期租合约下的航速计算和索赔

期租下的履约航速计算结果涉及到航速索赔和燃油索赔,关系到船舶的营运成效,因而航速计算显得很重要。航速计算和索赔涉及期租合约及相关条款的订立和良好天气的定义、根据租约相关条款采用的计算方法、良好天气下的航速计算、气象导航公司的评估报告。     

沥青结合料裂化装置试验

低温热裂化是沥青路面损坏的一个主要原因。每年交通主管部门都要下拨数量可观的经费用于修复或更换开裂部分的路面,但是根据气候环境合理地评估沥青结合料并加以处理可以最大限度地降低热开裂导致的路面过早损坏。