首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   49篇
  免费   4篇
公路运输   11篇
综合类   1篇
水路运输   7篇
综合运输   34篇
  2020年   1篇
  2019年   2篇
  2018年   3篇
  2017年   2篇
  2016年   4篇
  2015年   3篇
  2014年   2篇
  2013年   17篇
  2012年   1篇
  2010年   2篇
  2009年   1篇
  2008年   4篇
  2004年   1篇
  2003年   1篇
  1991年   2篇
  1988年   1篇
  1986年   1篇
  1985年   1篇
  1984年   3篇
  1982年   1篇
排序方式: 共有53条查询结果,搜索用时 46 毫秒
21.
Abstract

This paper develops a heuristic algorithm for the allocation of airport runway capacity to minimise the cost of arrival and departure aircraft/flight delays. The algorithm is developed as a potential alternative to optimisation models based on linear and integer programming. The algorithm is based on heuristic (‘greedy’) criteria that closely reflect the ‘rules of thumb’ used by air traffic controllers. Using inputs such as arrival and departure demand, airport runway system capacity envelopes and cost of aircraft/flight delays, the main output minimises the cost of arrival and departure delays as well as the corresponding interdependent airport runway system arrival and departure capacity allocation. The algorithm is applied to traffic scenarios at three busy US airports. The results are used to validate the performance of the proposed heuristic algorithm against results from selected benchmarking optimisation models.  相似文献   
22.
Check lists represent a very important tool within the International Safety Management Code, aimed at the regular and thorough assessment of the safety on board ships along with the operation of their parent companies. There seems to be only a few academic articles studying the communicative and rhetorical aspects of these maritime forms explaining why they are written in the way they are, especially in the light of their users who constitute a specific discourse community. The structure of a sample of representative lists is presented, as these check lists do not differ from the forms used by other European shipping companies. After interviews with the seafarers (deck and engine officers) to whom the check lists were administered, the conclusion was reached that they prefer short and unambiguous forms. In addition, a correlation about the language competence of the crew members on board ship was found: the simpler the discourse of the check list, the lower the responsibility of the crew member on board. Further, investigation into these complex language patterns focuses on the practical benefits.  相似文献   
23.
The paper models the operational, economic and environmental performance of an air transport network consisting of airports and air routes connecting them. The operational capacity represents the operational performance. Thresholds on the network’s environmental burdens reflect the environmental performance. The economic performance comprises the network’s profits. Modelling the network performance includes using integer programming techniques to maximise total network profits for given operational capacity and environmental constraints under conditions where environmental externalities are internalised.  相似文献   
24.
Dispatchers in many public transit companies face the daily problem of assigning available buses to bus routes under conditions of bus shortages. In addition to this, weather conditions, crew absenteeism, traffic accidents, traffic congestion and other factors lead to disturbances of the planned schedule. We propose the Bee Colony Optimization (BCO) algorithm for mitigation of bus schedule disturbances. The developed model takes care of interests of the transit operator and passengers. The model reassigns available buses to bus routes and, if it is allowed, the model simultaneously changes the transportation network topology (it shortens some of the planned bus routes) and reassigns available buses to a new set of bus routes. The model is tested on the network of Rivera (Uruguay). Results obtained show that the proposed algorithm can significantly mitigate disruptions.  相似文献   
25.
This paper presents a multidimensional examination of the infrastructural, technical/technological, operational, economic, environmental, social, and policy performance of the future advanced Evacuated Tube Transport (ETT) system operated by TransRapid Maglev (TRM) (the ETT-TRM system). The examination implies analyzing, modeling, and estimating selected performance criteria using the case of the Trans-Atlantic passenger transport market currently served exclusively by the Air Passenger Transport (APT) system. The purpose is to assess the ETT-TRM system’s competitive capabilities compared to those of the current and future APT system and consequently its potential contribution to mitigating impacts of both systems on society and the environment – the sustainability of the transport sector - under given conditions.  相似文献   
26.
Electro-hydraulic braking system for autonomous vehicles   总被引:4,自引:0,他引:4  
Reducing the number of traffic accidents is a declared target of most governments. Since dependence on driver reaction is the main cause of road accidents, it would be advisable to replace the human factor in some driving-related tasks with automated solutions. To automate a vehicle, it is necessary to control the actuators of a car, i.e., the steering wheel, accelerator, and brake. This paper presents the design and implementation of an electro-hydraulic braking system consisting of a pump and various valves, allowing the control computer to stop the car. It is assembled in conjunction with the original circuit for the sake of robustness and to permit the two systems to halt the car independently. This system was developed for installation in a commercial Citroën C3 Pluriel of the AUTOPIA program. Various tests were carried out to verify its correct operation, and an experiment showing the integration of the system into the longitudinal control of the car is described.  相似文献   
27.
Disruptions in carrying out planned bus schedules occur daily in many public transit companies. Disturbances are often so large that it is necessary to perform re-planning of planned bus and crew activities. Dispatchers in charge of traffic operations must frequently find an answer to the following question in a very short period of time: How should available buses be distributed among bus routes in order to minimize total passengers' waiting time on the network? We propose a model for assigning buses to scheduled routes when there is a shortage of buses. The proposed model is based on the bee colony optimization (BCO) technique. It is a biologically inspired method that explores collective intelligence applied by honey bees during the nectar collecting process. It has been shown that this developed BCO approach can generate high-quality solutions within negligible processing times.  相似文献   
28.
This paper applies multi-criteria decision-making (MCDM) methods to the evaluation of solutions and alternatives for matching airport system airside (runway) capacity to demand. For such a purpose, ‘building a new runway’ is considered as the solution and candidate airports of the system as alternatives for implementing the solution. The alternative airports are characterized by their physical/spatial, operational, economic, environmental, and social performance represented by corresponding indicator systems which, after being defined and estimated under given operating scenarios, are used as evaluation attributes/criteria by the selected MCDM methods. Two MCDM methods – Simple Additive Weighting and Technique for Order of Preference by Similarity to Ideal Solution – are applied to the case of the London airport system to rank and select the preferred alternative from three candidate airports – Heathrow, Gatwick, and Stansted – for where a new runway could be built.  相似文献   
29.
30.
The environmental hazard potential of a total of 15 chemicals that are transported through the Finnish coastal areas was assessed in this paper using a scoring method developed for accidents. The study indicates that the chemicals most commonly transported/handled in Finnish ports are methanol, sodium hydroxide solution, acids, pentanes, phenol, xylenes, methyl tert-butyl ether, ethanol and ethanol solutions. For the evaluation of the environmental hazardousness of various chemicals, a priority list of chemicals that are the most commonly transported regionally in marine environments was compiled for this study. The method used has many similarities to other commonly used scoring systems, but this study gave more weight to specific characteristics of an accidental release, water biota and impact on the environment. Nonylphenol, ammonia and sulphuric acid ranked as the most hazardous substances on the list. The results of the study can be used by rescue and environmental authorities and enterprises to improve preparedness for accidents and to mitigate the effects of accidental spills.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号