Vulnerability analysis of the Chinese coupled aviation and high-speed railway network

The integrated aviation and High-Speed Railway (HSR) transportation system plays a vital role for today’s inter-city transportation services. However, an increasing number of unexpected disruptions (such as operation failures, natural disasters, or intentional attacks) pose a considerable threat to the normal operation of the system, especially on ground transfer, leading to the extensive research on its vulnerability. Previous approaches mainly focus on interruptions within a single transportation mode, neglecting the role of ground transfer which serves as a coupled connection between aviation and High-Speed Railway. This paper proposes a network-based framework for evaluating the vulnerability of the Chinese Coupled Aviation and High-Speed Railway (CAHSR) network from the viewpoint of ground transfer interruption. Taking the end-to-end travel time and passenger flow information into consideration as an evaluation measure and analyzing from the perspective of urban agglomerations, an adaptive method is developed to identify the critical cities and further investigate their failure impacts on the geographic distribution of vulnerability. In addition, the proposed model explores variations of vulnerability under different failure time intervals. Based on the empirical study, some major conclusions are highlighted as follows: (A) Only a few cities show significant impacts on the network’s vulnerability when ground transfer interruptions occurred. (B) The distribution of vulnerability is not proportional to the distance between failure city and influenced city. (C) The vulnerability is more serious in the morning and evening when the ground transfer is disconnected. Our findings may provide new insights for maintenance and optimization of the CAHSR network and other real-world transportation networks.     

EU ETS对中国航空公司中欧市场运量的影响分析

为了研究EU ETS对中国航空公司在中欧航空旅客市场上的影响,运用系统理论和系统动力学的方法建立了仿真模型。欧盟EU ETS（温室气体排放交易体系）的颁布实施,将严重制约中国航空公司在中欧航空旅客运输市场上的发展。通过模型分析,发现EU ETS实施的前2年内,中国航空公司在中欧市场上的旅客运输量累计下降66%,并且2014年—2020年的年旅客运输量基本将保持在2011年旅客运输量的30%左右。     

The capital, energy, and time economics of an automated, on-demandtransportation system

Many transit and rail planners believe that the only way to decrease the capital and operating cost of rail and transit systems is to decrease the size and weight of the vehicles. The authors discuss the requirements of such a downsized transportation system and the benefits to be gained by decreasing the size of the operational vehicles. Not only can the capital and operating cost of the system be dramatically decreased, but the operational requirements of a system involving the use of smaller vehicles permits its use as an on-demand system, further increasing system utility to the passenger and system operator. The capital cost, energy economics, and the economics of the CyberTran transportation system are reviewed     

On the optimum cruise speed of a hypersonic aircraft

Some preliminary results that have been obtained in the frame of the SANGER system studies are presented. SANGER is a West German study project and technology reference system for a future advanced space transportation system. The first stage of this vehicle is a hypersonic aircraft from which a passenger version could be derived. The analyses indicate that a speed of Mach 4.4 will lead to maximum seat mileage per day as well as to minimum propellant consumption. The speed-related cruise altitude of 24500 m or 80000 ft is above the most sensitive ozone layer and high enough to produce only one-third of the noise ground pressure which is considered as the acceptable limit (1 lb/ft²) over populated areas. The aircraft surface temperatures at these conditions can still be managed by a conventional titanium alloy structure with special provisions only at the leading edge and the engine inlets. The potential route structure and economics of such an aircraft are discussed     

大型客机国内民航旅客市场特征分析

民航旅客是航空运输市场的消费者,旅客市场则是航空运输市场的核心部分和民机市场的基础。通过对旅客市场细分理论方法的研究和旅客市场特征的调查验证,形成适合大型客机项目的旅客市场细分方法和中国旅客市场特征分析,最终确定大型客机的市场定位和市场需求。本研究成果作为大型客机市场可行性研究支持报告之一,参与完成了大型客机项目市场可行性论证。     

河南省城镇体系空间布局优化的思路

在区域经济一体化、“中原经济区规划”和“郑州航空港经济综合实验区发展规划”实施的大背景下，针对河南城镇体系空间布局的基本特征和面临的问题，提出以郑州航空港经济综合实验区建设为契机，构建郑汴大都市圈；充分发挥交通网络优势，推进城镇轴带扩展；着力培育城镇新“网结”，不断完善城镇网络；推进新型城镇化进程，不断完善城镇体系规模结构等优化河南城镇体系空间布局的建议，以促进河南省城镇地域空间的协调发展。     

中国区域多机场系统旅客吞吐量预测方法研究

随着航空运输业的发展,区域单一枢纽格局被打破,区域性枢纽和次枢纽逐渐形成,进而产生区域多机场系统。对影响旅客在区域多机场系统中选择机场时的主要因素进行了分析,并以上海、杭州为中心的区域多机场系统为例,根据旅客选择机场的偏好,确定了三方面主要影响因素——机场的航班状况、航空运输票价水平和机场服务质量,运用多项式logit（MNL）模型对区域多机场系统中各机场分担率,以及相应旅客吞吐量的预测方法进行了研究,为未来机场预测体系的建立提供了定量分析的方法和思路。     

A geographical and operational deep graph convolutional approach for flight delay prediction

Flight delay prediction has attracted great interest in civil aviation community due to its significant role in airline planning, flight scheduling, airport operation, and passenger service. Flight delay is affected by numerous factors and irregularly propagates in air transportation networks owing to flight connectivity, which brings critical challenges to accurate flight delay prediction. In recent years, Graph Convolutional Networks (GCNs) have become popular in flight delay prediction due to the advantage in extracting complicated relationships. However, most of the existing GCN-based methods have failed to effectively capture the spatial–temporal information in flight delay prediction. In this paper, a Geographical and Operational Graph Convolutional Network (GOGCN) is proposed for multi-airport flight delay prediction. The GOGCN is a GCN-based spatial–temporal model that improves node feature representation ability with geographical and operational spatial–temporal interactions in a graph. Specifically, an operational aggregator is designed to extract global operational information based on the graph structure, while a geographical aggregator is developed to capture the similar nature among spatially close airports. Extensive experiments on a real-world dataset demonstrate that the proposed approach outperforms the state-of-the-art methods with a satisfying accuracy improvement.     

空港与城市创新能力相关性研究——基于动态面板数据

作为全球化运输网络的重要节点,空港具有汇聚资本和人才等研发资源的强大能力,同时航空运输也有助于知识精英远距离旅行和跨区域交流,从而能促进知识和技术的空间扩散,因此空港通常成为城市创新的推动者.选取我国29个主要空港2006～ 2010年客流量的相关数据,用一步系统广义矩估计法,实证检验了空港对城市创新能力提升的重要作用.研究结果表明,航空客流每增加1个百分点,该城市研发产出将增加0.22个百分点.     

斜网格修正的低速计算方法及应用

采用无坐标变换的一种有限体积法对RANS方程进行离散求解,离散方法考虑了对网格非正交情况的二阶修正,通过构造一个动量插值实现了同位网格下的压力修正算法,并发展了相应的分区算法.利用以上方法对轿车绕流和三峡坝区主流摆动问题进行了数值计算,计算结果与实验吻合较好.     

中国民航国内客运需求价格弹性研究

首先根据旅行目的、航程距离、居民可支配收入和需求季节性构建了旅客分类概念模型,在此基础上运用经济学理论和计量经济学方法,建立了民航国内旅客需求函数,并使用2006年行业运行数据,测算分析了不同类型旅客、不同季节和不同航程距离下的价格弹性系数及其特征,获得了城镇居民可支配收入是国内民航旅客价格弹性主要影响因素的结论,最后对政府提高价格政策的科学性和有效性、航空公司提高收益管理水平提出了建议和应对策略。将经济学和计量经济学的经典理论与中国民航实际相结合,定量分析中国民航旅客的需求行为特征是本研究的创新之处。     

发动机技术进步对飞机先进性的重要作用

推进技术的创新曾经是空中运输进步的基本推动力.研制大型客机,必须认识发动机技术进步对飞机性能先进性的重要作用.以用于波音公司B787梦幻飞机的美国通用电气公司(GE)的GEnx发动机为例,分析发动机技术先进性对飞机高效、低污染、智能化、低成本和舒适性的作用.最后从国外的技术发展途径,提出发展我国发动机技术的一些想法.      

运输决策模型对中枢航线网效益的影响

介绍了旅客／货主运输决策模型，并根据有关方法做出旅客／货主运输决策模型。然后通过将运输决策模型应用于中枢航线网络的USAPHMP模型，得到旅客／货主运输决策对中枢航线网络效益的影响因素。列举了中国民航某航空公司的实例。     

基于天地一体化信息网络的智能航空客运系统

计算机小型化、物联网、无线宽带通信、人工智能技术近年来发展迅速,对社会产生了巨大影响,作为使能技术,其在航空上的应用将对飞机设计、飞机飞行和维修保障等领域产生革命性的变革。未来的飞机将具有强大的信息智能感知和处理能力,依托天地一体化信息网络实现多维度物联,并结合智能地面系统,共同完成智能飞行、智能维护和智能运营等业务流程。本文总结了上述新技术的发展现状及其航空应用前景,提出了基于天地一体化信息网络的智能航空客运系统的概念,设计了系统架构,描绘了典型应用场景,识别了关键技术并指出了面临的挑战。研究成果有助于飞机制造商更好地设计面向未来的智能飞机,也有助于航空公司对智能飞机进行高效的运营和管理。     

创新生态学视角下的知识城市构建

知识城市是21世纪城市可持续发展的一种全新理念，是西方后城市化时代对城市空间结构的一种新认识，也是知识经济崛起的必然产物，其目的就是要通过创新和城市空间的再造促使原型城市转型到以知识为基础的发展之上来。实践证明，城市这种转型和城市空间再造的有效性需要营造一种良好的创新生态环境。文章以创新生态学的视角，分析了这门新兴学科对构建知识城市的意义，为我国在城镇化进程中实施知识城市战略提供了一种新路径。     

人工智能赋能空域系统,提升空域分层治理能力

为应对未来平台无人化、用户多元化、服务个性化的航空发展趋势,空域运行将呈现分层治理的发展趋势。而随着算力、算法与数据的持续提升与积累,数据驱动的人工智能方法将持续为层次化的空域系统赋能。本文从超低空、城市、区域、枢纽、亚轨道等5个层次化场景梳理我国空域系统的发展趋势;提炼得出空域运行面临的核心难点与关键科学问题;提出基于数据驱动的人工智能方法求解空域运行科学问题的研究框架、研究内容和应关注的关键技术;结合层次化典型应用场景,简要分析智能空域运行的具体应用案例;最后对人在空域运行中的作用提出了新的思考。     

一种融合个体属性与社交关系的民航旅客价值度量方法

针对目前民航旅客关系网络中旅客关系类别单一、旅客价值计算滞后、旅客潜在价值计算没有考虑旅客之间的相互影响,使得一些具有极大消费潜力的旅客因为目前乘机次数较少而被航空公司忽略的现状,提出了一种融合个体属性与社交关系的民航旅客价值度量方法,采用RFM_c模型计算旅客个体价值,并采用多关系评价（MRE）模型分析旅客关系,然后通过改进的PageRank算法设计实现融合旅客个体价值和社交关系的民航旅客价值排序（CAPV-Rank）算法,实现旅客价值度量、旅客价值预测和潜在高价值旅客挖掘。实验结果表明：设计实现的CAPV-Rank算法可通过调整权重因子实现多种模式下的旅客价值计算,满足各种业务需求,并能实现旅客价值预测、潜在高价值旅客挖掘,旨在为民航旅客价值度量和预测提供灵活、高效的解决方案。     

基于BP神经网络的机场安检旅客流量预测模型

机场安检服务资源智能分配及调度是提高机场旅客服务水平及运营效率的有效途径之一,而准确的机场安检旅客流量预测则是实现机场安检服务资源动态分配及调度的前提。以天津机场安检旅客流量的历史数据为研究对象,利用BP神经网络算法建立机场安检旅客流量预测模型,并将该预测模型通过天津机场实际旅客流量进行验证。结果表明:该基于BP神经网络的机场安检旅客流量预测模型的预测精度可达90%以上,证明其具有较高的预测精度,能很好地应用到机场安检流量预测中,为机场运营者动态调度安检服务资源提供高效的解决方案。     

Robustness analysis metrics for worldwide airport network: A comprehensive study

Robustness of transportation networks is one of the major challenges of the 21st century. This paper investigates the resilience of global air transportation from a complex network point of view, with focus on attacking strategies in the airport network, i.e., to remove airports from the sys-tem and see what could affect the air traffic system from a passenger's perspective. Specifically, we identify commonalities and differences between several robustness measures and attacking strate-gies, proposing a novel notion of functional robustness: unaffected passengers with rerouting. We apply twelve attacking strategies to the worldwide airport network with three weights, and eval-uate three robustness measures. We find that degree and Bonacich based attacks harm passenger weighted network most. Our evaluation is geared toward a unified view on air transportation net-work attack and serves as a foundation on how to develop effective mitigation strategies.     

Energy efficiencies: Rickshaw to 757

Transportation efficiencies in terms of passenger miles per gallon are examined for a wind range of transportation methods: muscle-powered (running, swimming, flying), human-powered machines (bicycles), and fuel-consuming machines (trains, ships, sailplanes). The practicality of vehicles that can deliver 1000 passenger miles per gallon is evaluated