Reducing the climate change impacts of aviation by restricting cruise altitudes

Two of the ways in which air travel affects climate are the emission of carbon dioxide and the creation of high-altitude contrails. One possible impact reduction strategy is to significantly reduce the formation of contrails. This could be achieved by limiting the cruise altitude of aircraft. If implemented, this could severely constrain air space capacity, especially in parts of Europe. In addition, carbon emissions would likely be higher due to less efficient aircraft operation at lower cruise altitudes. This paper describes an analysis of these trade-offs using an air space simulation model as applied to European airspace. The model simulates the flight paths and altitudes of each aircraft and is here used to calculate emissions of carbon dioxide and changes in the journey time. For a one-day Western European traffic sample, calculations suggest annual mean CO₂ emissions would increase by only 4% if cruise altitudes were restricted to prevent contrail formation. The change in journey time depended on aircraft type and route, but average changes were less than 1 min. Our analysis demonstrates that altitude restrictions on commercial aircraft could be an effective means of reducing climate change impacts, though it will be necessary to mitigate the increased controller workload conflicts that this will generate.     

Methods for probabilistic safety assessments of ships

 At the 62nd MSC conference (MSC62) in 1993, the UK proposed a new methodology for the consideration of safety regulations. This method is called formal safety assessment (FSA). FSA is an application of probabilistic safety assessment (PSA). Risk is used as an index of safety. One of the most important parts of FSA is to evaluate the risk to a ship when it is equipped with the safety measures recommended by the proposed safety regulations. The National Maritime Research Institute (NMRI, formerly the Ship Research Institute) has been developing a method which allows the risk to be obtained holistically by utilizing a scientific method. To obtain the risk, the probability and consequences of every accident must be evaluated. This paper examines the following points: (a) a holistic methodology for risk evaluation; (b) a method used in the process of estimating the probability of collision; (c) a method to reduce the numbers of fire escalation scenarios; (d) a trial risk evaluation of cabin fire. Received: January 10, 2002 / Accepted: April 18, 2002     

船舶操纵中各种制动效果的比较

船舶操纵中的制动效果是评价一艘船整体性能的一项重要指标。对于不同船型、不同吨位的船舶采用不同的制动方法,直接涉及到船舶的安全。通过船舶操纵模拟器,设定测试条件,对船舶操纵中倒车制动、Z型操纵制动、满舵旋回制动、拖锚制动、拖轮协助制动效果进行试验,得出各种制动效果的差异,比较说明各种制动效果的适用场合,以利船长、驾驶员选择适合当时环境自身条件状况的制动方法,安全的操纵船舶。     

计算机联锁设备故障诊断专家系统的研究

计算机联锁故障诊断专家系统是针对近几年来计算机联锁系统的大面积推广,而现场维修力量相对薄弱等问题开发的。本文对该系统的总体结构进行了研究,并对其软件中的几个主要模块进行了分析。     

全自动封透气孔机PLC控制系统的设计与实现

全自动封透气孔机用于实现继电器等电子元件的自动点UV光胶、点胶完成后输送到烘干机,用紫外线烘干,确保产品的密封特性要求,适用于自动化装配流水线,与前后设备配套,实现自动上下给料。文章在介绍用户需求的基础上,详细介绍了43F全自动封透气孔机控制系统的设计与实现过程,承担电气设计和PLC编程设计的43F全自动封透气孔机产品已投产使用,系统运行正常,具有很好的应用前景。     

三角形内切圆的计算机求解

数学上求三角形内切圆传统的方法是求出三角形两个角的角平分线交点作内切圆的圆心,然后再求出内切圆的半径。但这种方法用计算机程序实现时要考虑的情况很多,实现复杂。文章就此提出改进办法,简化计算机程序实现。算法采用Visual C 描述。     

浅谈CTCS-2级列控中心系统功能人工仿真测试

以下辛店站列控系统试验为例,简要论述了CTCS-2级列控中心系统功能人工仿真测试的内容和方法.     

EPS电动机模型的建立及实现

EPS（电动助力转向系统）应用于众多车型，代表未来动力转向的发展方向。文章通过对EPS的分析，初步设定了用于该EPS的激他式直流电动机方案。通过建立电动机的数学模型，在MATLAB中实现了该模型，并通过仿真分析，进一步验证了该选择方案的正确性。指出所选择建立的电动机模型，对电动助力转向系统仿真分析中电动机模型的建立选择具有一定的借鉴作用。     

Computer Simulation of Mould Filling and Solidification of Castings

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实时远程诊断系统信息传输网络的研究

远程诊断是计算机联锁系统维护、维修及故障诊断的一个重要手段。为了能够及时、准确地诊断、处理现场故障，电务维修人员对其实时性提出了更高的要求。介绍了计算机联锁实时远程诊断系统信息传输网络的具体要求及其软、硬件系统构成，详细阐述了系统的具体实施方案及其安全保证措施。