Automation of paratransit reservation,routing, and scheduling

Santa Clara County, California experienced a sharp growth in demand‐responsive paratransit ridership for individuals with disabilities, as a result of the passage of the 1990 Americans With Disabilities Act (ADA). This paper describes an automated paratransit system for the ADA‐type paratransit operation implemented in Santa Clara County. It automated paratransit reservation, scheduling, and routing functions. The key components of this system were a digital geographic database (DGD) and an automated trip scheduling system (ATSS). Empirical evidence after one year of operation indicates numerous benefits of this automation. There were significant reductions in the paratransit operating costs and an increase in the percent shared rides. The savings in operating costs far exceeded the annualized capital cost of automation. A user survey indicates that these improvements were achieved without degradation to service quality such as vehicle on‐time performance, invehicle travel times, vehicle response to open return, and ride comfort.     

The planning of aircraft routes and flight frequencies in an airline network operations

This research is aimed at developing a model that maximizes system profit when determining the aircraft routes and flight frequencies in a network. The model employs network flow techniques to effectively collect or deliver passenger flows from all origins to all destinations using non‐stop and multi‐stop flights in multi‐fleet operations. The model was formulated as a multi‐commodity network flow problem. A Lagrangian‐based algorithm was developed to solve the problem. To test the model in practice, a case study is presented.     

Special issue: Importance of public transport

The transport demand in most major cities around the world can only be met with a high‐quality public transport system. The requirements on bus, rail, underground and tram systems are manifold with reliability and efficiency as the key factors. The service operating hours and the size of the network are often extended in order to serve the needs better. Further, most metropolitan areas are trying to provide more incentives for citizens to leave the car at home and use the local transit systems instead. The reasons are well known. Not only does a public transport system only make economical sense if it is well used, but most urban areas with a high car‐dependency face at least three major problems; safety, congestion, and pollution (noise and air pollution, land separation, etc.). It is generally recognised that to decrease car usage and to increase public transport usage a stick & carrot approach is needed. The London congestion‐charging scheme is an example since all revenues collected by the scheme are put into the improvement of bus and underground services.     

我国轨道交通企业应加强自主知识产权的技术创新

通过分析跨国公司及发达国家在技术创新和知识产权的管理、运用等方面所具有的优势,以及我国轨道交通企业在知识产权国际竞争环境中所面临的现状,指出我国轨道交通企业应加强具有自主知识产权的技术创新,并迅速提高我国轨道交通企业的技术创新和自主知识产权保护能力,不断积累知识产权和制定标准的优势,才能为实现又好又快发展创造条件.     

On the dilution of liquid waste in ships' wakes

A study of the mixing behavior of liquid waste after ocean dumping is essential for the identification of dump sites, as well as for impact assessment on the surrounding oceanic waters. The dilution of liquid waste in the wakes of ships at sea is explored in this study, and the effects of the circumstances of the discharge operation such as the discharge rate, and the size and speed of the vessel, and the oceanic parameters such as currents and turbulence level in the water column, are examined. the mixing process is categorized into three stages: near-wake, far-wake, and long-term diffusion. Dilution rates in the three stages are derived, based on the theories of diffusion and momentumless wakes. In the far-wake stage, the speed of the ship is the most effective parameter in enhancing the dilution rate. The formulae for dilution rates in the farwake stage and for long-term diffusion agree well with field measurements, while the well-known IMCO formula underestimates the dilution rate. Presented at the International Conference on Technology for Marine Environment Preservation (MARIENV '95), Tokyo, Japan, September 24–29, 1995.     

数据库技术在舰船重量重心计算中的应用

本文根据舰船重量重心计算过程，绘出计算及管理的数据流图。应用数据地分项计算和汇总统计进行编程，从而使此项工作规范化，简单易行。     

冷藏运输香蕉急需解决的几个问题

香蕉是我国南方主要水果之一.香蕉具有皮薄、肉质柔滑、香甜等特点,深受人们的喜爱.特别是近年来海南省在利用其阳光足、雨水多等优势,生产出果大饱满、色泽鲜丽、糖分高、品质好的香蕉,在我国西部市场很受欢迎.香蕉在西部市场上的销售量日益增大,柳州铁路局在香蕉运量也在不断增加.据柳州机保段近年的运量统计:冷藏运输香蕉1998年为22列,1999年为33列,今年1-6月份为42列,运量急剧上升.冷藏运输香蕉的运价高、运距远,给铁路局货物发送万吨公里数和运输营业收入都有较好的效益.但是,在机保车冷藏运输香蕉的过程中,由于香蕉摘采后保存处理、车站的装载方式、车辆贮运温度控制等因素的影响,使香蕉运输终到站后,常发生一些香蕉受冷变黑或变黄腐烂,给铁路装车站、机保段和货主都造成一定的损失.如何搞好香蕉铁路冷藏运输?是当前急需解决的一项重要工作.……     

Modeling traffic operation at signalized intersections without explicit left‐turn yielding rules with an enhanced cell transmission model

This paper presents an enhanced cell transmission model (CTM) to capture traffic operation at signalized intersections without explicit permissive left‐turn yielding rules (i.e. aggressive permissive left‐turn maneuvers may not necessarily yield to opposing through traffic), which can be widely observed in many developing countries. Different from previous studies that focus on traffic dynamics on approaching links, this study contributes to modeling traffic operations within the intersection. A novel cell transmission framework with various types of virtual cells is proposed to model the dynamics of traffic movements from approach to exit. The unique phenomenon of competitive occupying of the conflict point between the left turn and opposing through movements is modeled. The cell state indicating its blockage is proposed to capture the dynamic queue formulation and dissipation and to evaluate the operational traffic performance at the intersection. Field validation results show that the proposed model can capture the operation of traffic at signalized intersections without explicit permissive left‐turn yielding rules with significantly higher level of accuracy than traditional traffic flow models. Copyright © 2016 John Wiley & Sons, Ltd.     

Hybrid model for prediction of bus arrival times at next station

Effective prediction of bus arrival times is important to advanced traveler information systems (ATIS). Here a hybrid model, based on support vector machine (SVM) and Kalman filtering technique, is presented to predict bus arrival times. In the model, the SVM model predicts the baseline travel times on the basic of historical trips occurring data at given time‐of‐day, weather conditions, route segment, the travel times on the current segment, and the latest travel times on the predicted segment; the Kalman filtering‐based dynamic algorithm uses the latest bus arrival information, together with estimated baseline travel times, to predict arrival times at the next point. The predicted bus arrival times are examined by data of bus no. 7 in a satellite town of Dalian in China. Results show that the hybrid model proposed in this paper is feasible and applicable in bus arrival time forecasting area, and generally provides better performance than artificial neural network (ANN)–based methods. Copyright © 2010 John Wiley & Sons, Ltd.