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71.
中国港口信息化30年辉煌建设及其展望 总被引:3,自引:0,他引:3
回顾了中国港口信息化建设30年的主要历程,阐述了中国港口信息化领先水平的表现和用高新技术改造传统产业的成绩。介绍了中国港口信息化的典型成果——电子政务和港航企业信息化对港口生产管理的促进作用,证实了我国港口建设坚持用“高新技术改造传统产业,提高管理水平”这一发展原则的正确性。 相似文献
72.
目前公路货运站场管理模式低下,科技含量甚少,企业再发展前景渺茫,必须依靠新的高科技手段,采用信息化管理方案,以新的经营理念,打造出可持续发展的交通站场企业模式来。 相似文献
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In recent years, increasing attention has been drawn to the development of various applications of intelligent transportation systems (ITS), which are credited with the amelioration of traffic conditions in urban and regional environments. Advanced traveler information systems (ATIS) constitute an important element of ITS by providing potential travelers with information on the network's current performance both en-route and pre-trip. In order to tackle the complexity of such systems, derived from the difficulty of providing real-time estimations of current as well as forecasts of future traffic conditions, a series of models and algorithms have been initiated. This paper proposes the development of an integrated framework for real-time ATIS and presents its application on a large-scale network, that of Thessaloniki, Greece, concluding with a discussion on development and implementation challenges as well as on the advantages and limitations of such an effort. 相似文献
75.
Katharina ParryMartin L. Hazelton 《Transportation Research Part B: Methodological》2012,46(1):175-188
Estimation of origin-destination (OD) matrices from link count data is a challenging problem because of the highly indeterminate relationship between the observations and the latent route flows. Conversely, estimation is straightforward if we observe the path taken by each vehicle. We consider an intermediate problem of increasing practical importance, in which link count data is supplemented by routing information for a fraction of vehicles on the network. We develop a statistical model for these combined data sources and derive some tractable normal approximations thereof. We examine likelihood-based inference for these normal models under the assumption that the probability of vehicle tracking is known. We show that the likelihood theory can be non-standard because of boundary effects, and provide conditions under which such irregular behaviour will be observed in practice. For regular cases we outline connections with existing generalised least squares methods. We then consider estimation of OD matrices under estimated and/or misspecified models for the probability of vehicle tracking. Theoretical developments are complemented by simulation experiments and an illustrative example using a section of road network from the English city of Leicester. 相似文献
76.
Dongjoo Park Laurence R. Rilett Byron J. Gajewski Clifford H. Spiegelman Changho Choi 《Transportation》2009,36(1):77-95
With the recent increase in the deployment of ITS technologies in urban areas throughout the world, traffic management centers
have the ability to obtain and archive large amounts of data on the traffic system. These data can be used to estimate current
conditions and predict future conditions on the roadway network. A general solution methodology for identifying the optimal
aggregation interval sizes for four scenarios is proposed in this article: (1) link travel time estimation, (2) corridor/route
travel time estimation, (3) link travel time forecasting, and (4) corridor/route travel time forecasting. The methodology
explicitly considers traffic dynamics and frequency of observations. A formulation based on mean square error (MSE) is developed
for each of the scenarios and interpreted from a traffic flow perspective. The methodology for estimating the optimal aggregation
size is based on (1) the tradeoff between the estimated mean square error of prediction and the variance of the predictor,
(2) the differences between estimation and forecasting, and (3) the direct consideration of the correlation between link travel
time for corridor/route estimation and forecasting. The proposed methods are demonstrated using travel time data from Houston,
Texas, that were collected as part of the automatic vehicle identification (AVI) system of the Houston Transtar system. It
was found that the optimal aggregation size is a function of the application and traffic condition.
相似文献
Changho ChoiEmail: |
77.
城市客车内饰风道设计的好坏对车辆的运行性能似乎没有什么影响,往往容易被忽视。风道不仅影响到内饰的美观而且对空调客车内室的保温、减少空调系统的损失,提高运行经济性起到至关重要的作用。这里对城市客车风道的结构设计、材料应用及其隔热措施保温提出了自己的见解,并着重叙述了风道的保温。 相似文献
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79.
针对国内某型客车的实车侧翻试验,通过采集、处理试验数据,探讨客车侧翻试验及评价的方法和内容,为其他客车侧翻试验提供经验。 相似文献
80.
针对当前通用BIM建模软件无法反映填海工程的大沉降量问题,基于商用BIM软件进行二次开发,创建了填海工程BIM应用管理平台。平台支持监测数据的实时导入,实现了BIM模型与施工期沉降监测数据的动态关联。该平台可通过读取钻孔数据实现BIM模型生成,支持4种填海工程常用的监测数据分析与管理功能;并可以调用Navisworks软件实现施工进度与工程量的管理。此外,开发的专用数据库网站,利用配置权限、异地备份、数据加密等手段,提供数据存储、安全策略、数据归档的一整套解决方案。平台成功应用于实际工程中,效果良好。 相似文献