基于机场子区划分的机场网络交通拥挤传播预测

为了预测机场进离场交通的拥挤态势,本文从机场网络的角度进行研究.首先针对交通拥挤形成的动态过程,建立了基于出入流率的交通拥挤的定义及其度量;接着,引入多维标度法对机场之间的交通相关性进行定量分析,划分机场子区,以降低网络分析的复杂度及解空间维数;然后,构建了基于Elman神经网络实现机场子区内多个相关机场的交通拥挤传播预测方法;最后,基于美国机场的实际航班数据对机场网络拥挤传播预测方法进行验证.验证结果表明,预测结果的平均绝对百分比误差和平均绝对偏差较小,明显优于对比算法.     

Categorisation for air quality assessment in car cabin

The objective of this work was to propose a way of preparing information about in-cabin air quality for the car driver or passenger. It was assumed that information should be objective, relevant, current, complete and useful. The major elements of our concept were: (1) monitoring of selected air parameters inside the cabin, (2) determination of indicators that characterise indoor air, based on measurements, and (3) the method of information extraction. We proposed to realise the first task with a sensor system. The second and third goals were reached by categorisation. The basis for defining categories were ranges of values of measured parameters or their combinations. In a way, the categories were used to quantify indicators of air quality. Shannon entropy and mutual information were applied to find the best categorisation. The concept was investigated using experimental data from car cabin air monitoring in various driving conditions. We conclude that information about air quality in car cabins may be successfully conveyed using the following indicators: thermal conditions – determined based on temperature and relative humidity measurements; air exchange – determined based on CO₂ concentration; and air freshness – determined based on volatile organic compounds (VOCs) content in car cabin air. Each indicator has three categories: bad, intermediate and good.     

A methodological approach for environmental characterization of ports

This paper introduces a methodology for the characterization of ports, employing specifically defined eco-efficiency indicators and combining typically available data (handled cargo, containers and passengers) with ship exhaust pollutants values (mainly NO_x, SO_x and PM) and anticipated external costs (ECs) due to emitted air pollutants to provide a collective overview of all port-related economic and environmental activities. The results from an applied case study allow a comparative evaluation of 16 selected ports based on 17 different evaluation criteria and denote that the employment of such an overall approach can allow port authorities to improve managerial aspects, potentially lower operational costs and promote reduced environmental effects.     

A system based approach to develop hybrid model predicting extreme urban NOx and PM2.5 concentrations

One of the major drawbacks of conventional air quality models is their inability in accurately predicting extreme air pollutant concentrations. Hybrid modelling is one of the techniques that estimates/predicts the ‘entire range’ of the distribution of pollutant concentrations by combining the deterministic based models (capable in predicting average range) with suitable statistical (probability) distribution models (capable in predicting extreme range). This research paper describes system based approach in developing hybrid model to predict hourly averages as well as extreme percentile ranges of NO_x and PM_2.5 concentrations at two urban locations having complex traffic heterogeneity, highly variable tropical meteorology and different geographical characteristics. At one of the selected locations i.e. Delhi megacity, during winters, hybridization of AERMOD and Lognormal predicts NO_x and PM_2.5 concentrations satisfactorily with index of agreement ‘d’ values of 0.98–0.99, respectively; however, during summers, AERMOD-Log-logistic and AERMOD-Lognormal are best predicting NO_x and PM_2.5 concentrations with d values of 0.98–0.96, respectively. In another, i.e., Chennai, a coastal megacity, AERMOD-Lognormal predicts PM_2.5 concentrations satisfactorily with d values of 0.98 and 0.99 during winter and summer seasons, respectively. Further, hybrid model has also been used to evaluate regulatory compliance.     

Explaining shipping company participation in voluntary vessel emission reduction programs

Ports are under increasing pressures to increase sustainability and reduce the local and global emissions impacts associated with their operations. Due to limits on their jurisdictional authority, ports may design effective voluntary programs and appropriately motivate participation from global shipping companies that visit their ports. This paper investigates the success of the Vessel Speed Reduction Program at the Ports of Los Angeles and Long Beach and uses qualitative methods to analyze the factors that contributed to the success of the program at reducing local air quality pollutants. In particular, why did individual private firms participate in a non-required, voluntary effort? This research found that external pressures such as community concerns about emissions and regulatory threats are important to motivating voluntary behavior and may even be more important than financial incentives. Furthermore, simplicity of program design, clear goals and presence of a monitoring mechanism are important in influencing participation. These findings broaden our understanding of the business strategy behind slow steaming and its applicability as an operational practice as much work to date is focused on how fuel prices and financial incentives influence the choice for shipping companies to slow their speeds. While the VSR program led to significant emission reductions, an additional lesson for voluntary programs is the need for them to evolve and strive for continuous improvement.     

航空摄影新技术推动数字摄影测量的发展

本文介绍了国内航空摄影新技术的发展及应用情况,并对航空摄影技术进行了具体的应用前景分析。     

R407C环保制冷剂在列车空调上的应用研究

通过对R407C制冷剂进行理论分析和性能试验,研究其在列车空调机组上替代R22制冷剂的可行性及应注意的问题。     

空气污染对室内空气品质的影响

通过将各空气污染因子区分为物理性、化学性和生物性等因子,分别分析了它们对人体的医学危害性,揭示了目前影响室内空气品质的一些主要因素,并讨论了在空调工况下空气污染对室内空气品质的影响问题.     

97新款“现代”（HYUNDAI）轿车自动温控式空调系统

９７新款“现代”轿车上，安装了一套自动温控式空调系统，它设计新颖，操作简单，由ＥＣＵ控制所需的温度。详细地介绍了该系统的系统的组成，以及各主要部件的功用；同时分析了该系统常见故障原因，并提出了相应的检修措施。     

文丘里型末端变风量阀弹簧设计探讨

文章提出了当量直径概念,根据量纲分析理论对绕圆球充动的绕流阻力公式进行了修改,从而得出文丘里型末端变风量瘩中阀芯绕流阻力与其所处位置的关系,在理论上提出了设计主等节距弹簧的方案,这对建立数学模型进行数值计算有着启发性的意义。