Exact approaches for the pickup and delivery problem with loading cost

In this paper, we propose a branch-and-cut algorithm and a branch-and-price algorithm to solve the pickup and delivery problem with loading cost (PDPLC), which is a new problem derived from the classic pickup and delivery problem (PDP) by considering the loading cost in the objective function. Applications of the PDPLC arise in healthcare transportation where the objective function is customer-centric or service-based. In the branch-and-price algorithm, we devise an ad hoc label-setting algorithm to solve the pricing problem and employ the bounded bidirectional search strategy to accelerate the label-setting algorithm. The proposed algorithms were tested on a set of instances generated by a common data generator in the literature. The computational results showed that the branch-and-price algorithm outperformed the branch-and-cut algorithm by a large margin, and can solve instances with 40 requests to optimality in a reasonable time frame.     

Residents,recreationists, ridge regression,and revenues:the five r's of florida's motor- tax

Ridge regression is applied to the question of how to revise Florida's motor-fuel tax to remedy the shortfall of its transportation revenues. Along the way a model of gasoline consumption by residents and tourists is presented, and the differences in consumption patterns between the two types of purchasers are reported.     

国外城市交通发展经验对重庆的启示

目前重庆处于城市迅速扩展的时期，交通问题日益突出，急需通过比较来获得国内外大城市扩展时期交通发展的经验。分析、归纳、总结一些国际大都市的交通结构、轨道网络以及交通政策，结合重庆交通发展现状，为重庆的交通发展建设提供借鉴。     

铁路运输经济的若干问题

近年，中国铁路铁路的快速发展，取得了很多成就，引起国内外的广泛关注。但同时我们也应看到，铁路企业经营效益不容乐观。资产负债率逐年攀升，货运量大幅递减，市场份额不断下降。在铁路建设加快发展的同时，铁路运输经济出现了哪些亟待解决的问题，需要进行深入的探讨和研究。主要问题包括铁路投资经营问题、铁路运输市场问题、铁路运价管理问题、铁路收入清算问题、铁路人才队伍问题。     

A Lean transportation approach for improving emergency medical operations

Abstract

This paper extends the approach of Lean transportation to improve the performance of emergency medical processes (EMP) by adapting its main concepts into the main characteristics of the EMP environment. The paper is based on an inductive theory-building process initiated from a case study in the field of emergency medical services. The development of the suggested performance improvement approach triggered from an exhaustive analysis of a process involved and an exploratory review of the existing improvement approaches available. The process of concern can be described as a specialized transportation process, where human lives are at risk. Its characteristics led to a natural application of Lean transportation. The results include, a novel approach for improving the agility and efficient EMS processes. This is validated with an application for improving ambulance response times and turnaround times of the Red Cross operations located in Monterrey, Mexico. The approach proved to be an integrated scheme for identifying waste opportunities at a systems level. This characteristic is important to let operations management prioritize improvement efforts in a limited budget situation. This work suggests the application of the emerging Lean transportation approach for increasing the agility performance of EMS processes.     

铁路客运分段能力配置策略研究

铁路客运分段能力配置策略能够针对季节客流特征,在春节等节假日客运需求非常巨大、平时客流明显减少的情况下,最大程度地满足旅客出行需求。基于线性回归方程的铁路客运需求预测模型,能够科学合理、有效地配置客运能力。运用MATLAB软件,结合南京站旅客运输数据,通过实证分析研究,验证优化模型在阶段性运能配置方面的期望效应。     

重庆市EBD核心区交通渠化研究

EBD即生态商务区，指兼顾人本与环境，以现代产业、商务为主导的生态新城区。高效率的交通网络是EBD的命脉，而交通渠化以其拆迁少、投资少、占地少、见效快等特点，在提高交通网络运行水平，加快EBD进程的实践中具有重要意义。结合渠化的原则与理论，分析重庆市EBD核心区内的交通现状，提出优化改善的对策。     

从交通方式的变迁看近代山东经济格局

濒临海洋的山东半岛自古以来就是对外经济文化交流的重要地区。明清以来,京杭大运河逐渐衰微,山东交通方式由河运转移到海运,其中港口发挥了重要作用,加之胶济铁路“诞生”,铁路沿线的城镇迅速兴起,使得港口、铁路联动起来,形成了以港口为基础的海运和胶济铁路构成的新式交通体系,揭开了近代山东交通方式的“变迁图景”,带动了山东经济格局的变化。     

基于 Borda 计数法的机场航班时刻分配研究

为提高机场航班时刻分配的科学性,把社会选择理论中的Borda计数法运用到机场航班时刻分配决策中。以首都机场航班时刻分配为例,针对枢纽机场从市场规模、运营效率、市场潜力和政策因素4个方面建立了航班时刻分配评价指标体系,选取层次分析方法对指标权重进行确定,建立航班时刻分配的Borda计数模型,并运用算例验证模型的可行性。研究结果表明,所确定的航班时刻分配指标体系科学合理,Borda计数法运用到航班时刻分配过程中,能够有效提高决策过程与结果的科学性。     

我国交通发展水平与经济增长关系的协整分析

利用我国1985-2008年29个省区的面板数据,运用面板协整和因果检验理论,分析了全国及东、中、西部的交通发展水平和经济增长相互作用的机制.检验结果表明,交通发展水平和经济增长均为一阶单整变量,它们存在稳定的协整关系.就全国以及东部地区而言,经济增长与交通发展水平在长期和短期中相互促进;而对于中西部地区,经济增长能够促进交通业的发展,但交通业的发展无法促使本地区经济增长.这一现象的形成与我国各地区产业分布不均衡、交通运输业的空间溢出效应和一些其他因素的影响有关.据此提出的政策建议包括:统筹规划,科学论证交通投资方案,将发展交通运输业和地区产业优惠政策相结合,降低物流成本.