On the multi-dimensionality and sampling of air transport networks

Complex network theory is a framework increasingly used in the study of air transport networks, thanks to its ability to describe the structures created by networks of flights, and their influence in dynamical processes such as delay propagation. While many works consider only a fraction of the network, created by major airports or airlines, for example, it is not clear if and how such sampling process bias the observed structures and processes. In this contribution, we tackle this problem by studying how some observed topological metrics depend on the way the network is reconstructed, i.e. on the rules used to sample nodes and connections. Both structural and simple dynamical properties are considered, for eight major air networks and different source datasets. Results indicate that using a subset of airports strongly distorts our perception of the network, even when just small ones are discarded; at the same time, considering a subset of airlines yields a better and more stable representation. This allows us to provide some general guidelines on the way airports and connections should be sampled.     

Mediation Between Tourism Contribution and Economic Growth in the Greater Mekong Subregion

The objective of this paper is to determine the mediation between tourism contribution and economic growth in the Greater Mekong Sub-region (GMS) (i.e. Cambodia, Laos, Myanmar, Thailand and Vietnam). The sample period is semi-annual data from 1995 to 2013 and is also estimated by bootstrap panel cointegration, Panel Fully Modified Ordinary Least Squares method and the Sobel test. The results show that the variables are cointegrated as three models; economic growth is running to tourism's total contribution to GDP and international tourism expenditure for passenger transport whereas international tourism expenditure for passenger transport is running to tourism's total contribution to GDP. Therefore, this study finds that international tourism expenditure for passenger transport is a mediator and has partial mediation. The GMS needs to develop every economic sector and improve the potential of the transport sector as a regional integration project which supports the sustainable development of the region.     

A neuro-fuzzy combination model based on singular spectrum analysis for air transport demand forecasting

Air transport demand forecasting is receiving increasing attention, especially because of intrinsic difficulties and practical applications. Total passengers are used as a proxy for air transport demand. However, the air passenger time series usually has a complex behavior due to their irregularity, high volatility and seasonality. This paper proposes a new hybrid approach, combining singular spectrum analysis (SSA), adaptive-network-based fuzzy inference system (ANFIS) and improved particle swarm optimization (IPSO), for short-term air passenger traffic prediction. The SSA is used for identifying and extracting the trend and seasonality of air transport demand and the artificial intelligence technologies, including ANFIS and IPSO, are utilized to deal with the irregularity and volatility of the demand. The HK air passenger data are collected to establish and validate the forecasting model. Empirical results clearly points to the enormous potential that the proposed approach possesses in air transport demand forecasting and can be considered as a viable alternative.     

大秦铁路榆次站枢纽现状分析及扩能探讨

铁路枢纽运转效率的高低直接影响着铁路运输企业的竞争力。随着石太、侯月、丰沙大线三线增量及车流的调整，榆次站枢纽的地位显得尤为重要。调研榆次站枢纽现状，分析车流现状、各场能力及运用情况，针对既有运输组织方式下局部运转不畅的问题，提出优化作业组织、人员配备、编组计划等提升榆次站枢纽能力的扩能建议。     

高速公路路面裂缝的养护模式初探

本文结合某省高速公路实际状况,针对高速公路养护过程中出现的一系列新问题,着重阐述了高速公路早期裂缝养护的重要性,并对养护模式改革进行简要的探索。     

论路面贫混凝土基层施工控制环节

文章以广西全州至兴安高速公路路面第二合同段施工项目为例,介绍了在路面贫混凝土基层施工过程中应注意控制的施工环节。     

中国物流企业运输成本控制浅析

运输是物流体系的核心部分,运输的合理化对物流起着至关重要的作用。如何能够有效降低企业运输成本,增强企业的竞争力,这需要从当代物流发展的实际状况出发,分析影响运输成本的因素,从而采取有效措施来合理组织运输,进而实现降低运输成本,提高物流效益的目的。     

公路工程质量管理探讨

文章介绍了公路工程项目质量的内涵，分析了影响公路工程质量的主要因素，在此基础上就如何提高公路工程质量提出了具体的措施。     

浅谈公交优先对城市综合发展的作用

随着城市规模的扩大和城市人口的增加,城市交通的压力也正在不断加剧,公交优先的方向应当始终坚持。实行公交优惠票价政策,体现了社会资源共享的公平性和经济合理性,有助于缓解交通拥堵,减轻大气污染保护环境,也有助于建立和谐社会,促进城市繁荣和城市综合发展。     

一种基于Edline线特征的车道线识别算法

为了提升车道线检测的准确性和实时性,改良车道偏离预警系统的性能,提出了一种新的车道线识别算法。首先应用投影法对采集到的图像设立感兴趣区域,以此来减少图像中存在的干扰信息;其次应用一种改进后的自适应高斯滤波算法对采集所得图像进行平滑处理,减少图像中不必要的细节;最后采用边缘绘制算法进行边缘检测,在此基础上,提出一种线段检测算法——Edline算法提取边缘线,对检测到的直线段进行筛选和聚类。利用引用计数法对车道线进行跟踪和预测。结果表明,新算法的平均处理时间为17.1 ms,准确率为96.19%,将其应用在车道偏离预警系统中可以有效地提高预警效率,提升预警的准确性和响应速度。研究结果丰富了车道线识别理论,可为车道偏离预警系统的应用及基础研究提供参考。