A scenario on the evolving road service informatics in Europe

Road Transport Informatics is being developed to improve road transport. Telecommunication links will connect microcomputers in vehicles with roadside beacons and traffic control centers. Drivers can get better information and guidance en route. If these functions are charged as services rather than sold as products, a better traffic can be obtained. This can improve traffic safety, efficiency and the environment.     

Aggregate expenditure elasticity for transport and communication in Australia

For the purpose of estimating Engel elasticity, one needs to find the best functional form among various alternatives. In this paper, a new function, which is called the double semi-log Engel function turns out to be the best functional form for the transport and communication items in Australia on the basis of the distance function (D²) criterion, and the non-nested hypothesis testing procedure. This function is then used to estimate total expenditure elasticity, and the percentage change in consumer demand due to changes in total expenditure and total expenditure inequalities; using the 1975–76 Household Expenditure Survey data. The results of the analyses demonstrate that transport and communication is a necessary item in Australia on the basis of two criteria, viz., its elasticity is not significantly greater than unity, and the percentage change in demand increases with a decrease of the total expenditure inequality [emphasised by Iyengar (I960)]. Policy implication of the analyses has also been discussed.     

原油运输市场分析

分别概述了世界与中国的石油资源储量分布、可持续开采年数、不同地区的生产量与消耗量、以及产销平衡状况,由此派生的全球不同地区原油、成品油的进出口量、海运量与主要的海运航线,我国石油进口的主要来源和途径;分析了油轮的船型和船龄的分布,进而预测了世界上几种主要原油轮运力的供应、需求、船价与运价的发展趋势。这些分析和预测可以作为制定油轮发展的技术政策、战略、规划等宏观决策时的参考。     

Meta-analysis of public transport demand

The present study uses meta-regression in order to explain the wide variation in elasticity estimates obtained in previous demand studies, and provide summaries of several bus demand elasticities.One important finding as to the price elasticity is that the often cited rule of thumb of −0.3 holds good if quality of service represented by vehicle-kilometres is treated as an exogenous variable, but not when it is treated as endogenous.Based on the results it is recommended that demand models should include car ownership, price of petrol, own price, income and some measure of service among the explanatory variables and that the service variable should be treated as endogenous.In previous meta-studies in this field focus has been on own price elasticity only while this study also includes elasticities with respect to, level of service, income, price of petrol and car ownership. The short run for the US are found to be −0.59, 1.05, −0.62, 0.4 and −1.48 respectively.     

论我国公路客运与客车的发展

本文分析了我国公路客运在国民经济与整个交通系统中的地位与前景,探讨了我国客车生产发展中的问题并提出了相应的建议。可供政府有关部门决策时参考。     

基于ADSP-BF533的网络音视频监视系统

主要介绍ADSP-BF533的基本特征，并提出了一种基于ADSP-BF533的具有体积小、成本低等特点的网络视频监视系统的软件和硬件设计方案。     

一种改进的基于密度和网格的高维聚类算法

提出了一种改进的基于密度和网格的高维聚类算法,并对算法有效性进行了验证.该算法通过减少样本点数量的方法达到减少稠密子空间数量.在发现高维稠密子空间时,对样本库进行精简.这些样本点的求得能有效减少求解最小聚类的时间复杂度.     

铁路货物运输的随机过程分析和及时送达概率估计

应用随机过程理论，分析铁路运输系统中货物及时送达的概率分布，得到货物运输延续时间的平均值，为实现用户要求的运到期限提供了合理保证，并可通过评估与货主商定的运到期限与实际货物送达时间误差的概率，来找到货物及时送达过程中的关键环节，改进货物送达流程。最后举例说明它的应用。     

城市轨道交通APP发展现状及展望

"互联网+城市轨道交通"是轨道交通运营管理企业未来的发展趋势,移动客户端APP则是运营管理企业与乘客之间进行信息服务沟通的有效媒介。在介绍分析目前已发布的城市轨道交通官方APP和非官方APP基础上,提出基于实时数据的城市轨道交通APP信息服务系统,有效结合传统静态交通信息服务模块和动态交通信息服务模块,克服传统APP交互性弱、数据库不全面、信息发布实时性差等缺点,是未来城市轨道交通APP的发展方向。