石家庄地铁地下停车场通风空调系统方案设计

结合石家庄地铁地下停车场通风空调系统设计,通过对停车库通风、空调、采暖、排烟4个方面的难点问题进行分析,并通过利用工程经验、借鉴规范等方法,提出全面的系统设计解决方案。研究结论:停车库内通风量、排烟量分别按照3 m层高、实际层高,6次/h换气考虑;检修平台考虑局部空调,提高作业人员舒适度;土壤有蓄热效应,按局部考虑采暖即可,不必对停车库内进行大面积采暖。     

基于AVR单片机的消毒机控制系统设计

介绍了基于AVR单片机ATMEGA8的空气消毒机系统的功能及设计原理,并给出了具体的设计方案,包括系统的硬件电路设计和软件设计流程图。该消毒机不仅具有臭氧、紫外线和高效滤器组成的三重杀菌消毒功能,还能实时检测并显示室内空气质量情况。此仪器经投入使用后,具有运行稳定可靠,适应性好等优点。     

A census of the US near-roadway population: Public health and environmental justice considerations

This study estimates the size and distribution of the population living near high volume roads in the US, investigates race and income disparities in these near roadway populations, and considers the coverage of the national ambient air quality monitoring network. Every US census block is classified by traffic density and proximity to roads falling within several traffic volume ranges using year 2008 traffic data and the 2010 and 2000 US Census. The results indicate that 19% of the population lives near high volume roads. Nationally, greater traffic volume and density are associated with larger shares of non-white residents and lower median household incomes. Analysis at the county level finds wide variation in the size of near roadway populations and the severity of environmental justice concerns. Every state, however, has some population living near a high volume road and 84% of counties show some level of disparity. The results also suggest that most counties with residents living near high volume roads do not have a co-located regulatory air quality monitor.     

潜艇大气污染与大气质量内部控制措施

根据国内外潜艇舱室大气污染的状况,论述了舱室主要污染物的来源、造成的危害和大气质量内部控制措施及其发展技术,为我国开展潜艇大气控制研究提供了依据。     

晕车影响因素及对策探讨

对晕车的传统研究认为晕车是视觉与平衡感官失衡造成矛盾引发的自我过度保护的后果。这个结论以及基于此结论开展的防治晕车措施已经持续了40余年。防治晕车的文献及市场上主流产品均以各种类型的晕车药物为主。本研究对现有晕车相关文献、专利、杂文等进行调查研究,总结分析出影响晕车主要因素为车内空气、车辆运动状态、视觉失衡、噪声、成员。使用对车辆乘员问卷调研的方法获取信息,对数据进行分析来研究晕车影响因素。数据表明晕车是一种发生频率高、普遍存在的乘车舒适性问题,具有明显的性别差异概率,是汽车行业发必须要面对和解决的重要问题之一。调查研究结果表明车内空气、车辆运动状态、视觉失衡三类诱发晕车的因素与文献研究结果一致。改善和防治晕车需要从车内空气、车辆运动状态、视觉失衡、噪声、成员这五类因素入手。使用车内空气的措施可以有效防治晕车现象的发生。清爽舒适的气味、降低温度、提高空气质量是三项有效的具体措施。     

地下铁道车辆空调技术参数探讨

比较了地下铁道车辆空调和地面铁路车辆空调在运用条件，舒适性要求等方面的差异，并对地下铁道车辆空调技术参数的选择和确定进行了探讨。     

Characterization and prediction of air traffic delays

This paper presents a new class of models for predicting air traffic delays. The proposed models consider both temporal and spatial (that is, network) delay states as explanatory variables, and use Random Forest algorithms to predict departure delays 2–24 h in the future. In addition to local delay variables that describe the arrival or departure delay states of the most influential airports and links (origin–destination pairs) in the network, new network delay variables that characterize the global delay state of the entire National Airspace System at the time of prediction are proposed. The paper analyzes the performance of the proposed prediction models in both classifying delays as above or below a certain threshold, as well as predicting delay values. The models are trained and validated on operational data from 2007 and 2008, and are evaluated using the 100 most-delayed links in the system. The results show that for a 2-h forecast horizon, the average test error over these 100 links is 19% when classifying delays as above or below 60 min. Similarly, the average over these 100 links of the median test error is found to be 21 min when predicting departure delays for a 2-h forecast horizon. The effects of changes in the classification threshold and forecast horizon on prediction performance are studied.     

Spoke airports,intentional and unintentional ground travel,and the air travel decision-making process

For air travelers originating from the spokes of the US hub-and-spoke air network, price, flight frequency, and aircraft type are all known factors in their travel decision-making process. Less well known, however, is the extent to which different elements of ground travel enter into these travelers’ air journeys. Based on 51 interviews at four universities at spokes surrounding O’Hare International Airport, this article describes how considerations such as vehicle availability, individual driving ability, localized weather, and unanticipated ground travel are fundamentally part of the air travel decision-making process for spoke travelers.     

Technical efficiency of automobiles – A nonparametric approach incorporating carbon dioxide emissions

We conduct an empirical analysis of the technical efficiency of cars sold 2010 in Germany. The analysis is performed using traditional data envelopment analysis (DEA) as well as directional distance functions (DDF). The approach of DDF allows incorporating the reduction of carbon dioxide emissions as an environmental goal in the efficiency analysis. A frontier separation approach is used to gain deeper insight for diesel and gasoline cars. Natural gas driven cars and sport utility vehicles are also treated as different groups. The results show that the efficiency measurement is statistically yet not economically significantly influenced by the incorporation of carbon dioxide emissions. Moreover, we find that natural gas driven cars are highly inefficient even if the reduction of emissions is accounted for in the analysis.