Innovative systems for the transportation disadvantaged: Toward more efficient and operationally usable planning tools

When considering innovative forms of public transport for specific groups, such as demand responsive services, the challenge is to find a good balance between operational efficiency and 'user friendliness' of the scheduling algorithm even when specialized skills are not available. Regret insertion-based processes have shown their effectiveness in addressing this specific concern. We introduce a new class of hybrid regret measures to understand better why the behaviour of this kind of heuristic is superior to that of other insertion rules. Our analyses show the importance of keeping a good balance between short- and long-term strategies during the solution process. We also use this methodology to investigate the relationship between the number of vehicles needed and total distance covered - the key point of any cost analysis striving for greater efficiency. Against expectations, in most cases decreasing fleet size leads to savings in vehicle mileage, since the heuristic solution is still far from optimality.     

基于路段交换的多基地动车组运用计划的编制算法

多个基地的动车组共同完成某一运行图规定的任务 ,是动车组运用的一种较为普遍的方式 ,开发该种运用方式的编制算法 ,是研究动车组编制算法的重要组成部分。基于路段交换的思想开发了编制算法 :首先利用已有算法构造出较好的初始解 ,然后利用路段交换不断改进解的质量。利用实际线路数据进行实验 ,证明算法有效。     

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以车辆调度问题为实例引出一种新的组合优化算法，并与原有的方法进行比较，说明新方法可以有效地抑制组合爆炸，极大地提高算法寻优效率.然后，本文用数学方法来证明该新方法再寻优上的正确性，最后根据两种不同算法编写各自对应的程序，用实际运行的结果来验证新算法带来的效率的提高.     

货物合理配装的实用启发式算法

提出了货物配装中的一种实用启发式算法，详细地描述了该算法的相关术语、定义和步骤，进行了实例验算，并时算法提出了改进。结论表明实用启发式算法具有较为满意的效用性，改进的实用启发式算法具有很好的效用性。该算法有助于提高装载单元的载重能力和货物配装水平。     

非标准HFS-B问题的设备协同调度研究

在同贝位边装边卸工艺的集装箱作业环境中,提出了一类非标准的HFS-B问题,即同时存在2种方向互逆的工件流、与紧前紧后机器相关的准备和处理时间.这类来自港口背景的非标准HFS-B问题,主要涉及空间位置决策、任务分配和设备调度等子问题的决策,目标是makespan最小.鉴于HFS-B的NP-hard特性,在分析设备顺序约束和协同关系基础上,基于Fill ratio启发式、表调度理论和设备的状态空间变换,设计了3阶段决策的启发式算法.基于阶段的下界理论和makespan的下界理论,对多个实际的大规模案例进行仿真分析,结果表明:算法的makespan与理论下界的最大偏差不大于7%,具有良好的实用性.     

Choosing Public Transport—Incorporating Richer Behavioural Elements in Modal Choice Models

The development of behaviourally richer representations of the role of well-established and increasingly important influences on modal choice, such as trip time reliability and accounting for risk attitude and process rules, has moved forward at a fast pace in the context of automobile travel. In the public transport setting, such contributions have, with rare exception, not been considered. In this paper, we discuss and empirically illustrate the merits of advanced modelling developments aimed at improving our understanding of public transport choice, namely the inclusion of reliability in extended expected utility theoretic forms, to recognize risk attitude and perceptual conditioning, the consideration of passenger crowding and its inclusion in linear additive models, and the role of multiple heuristics in representing attribute processing as a way of conditioning modal choice. We illustrate the mechanics of introducing these behaviourally appealing extensions using a modal choice data set collected in Sydney.     

A hybrid heuristic strategy for liquefied natural gas inventory routing

As liquefied natural gas (LNG) steadily grows to be a common mode for commercializing natural gas, LNG supply chain optimization is becoming a key technology for gas companies to maintain competitiveness. This paper develops methods for improving the solutions for a previously stated form of an LNG inventory routing problem (LNG-IRP). Motivated by the poor performance of a Dantzig-Wolfe-based decomposition approach for exact solutions, we develop a suite of advanced heuristic techniques and propose a hybrid heuristic strategy aiming to achieve improved solutions in shorter computational time. The heuristics include two phases: the advanced construction phase is based on a rolling time algorithm and a greedy randomized adaptive search procedure (GRASP); and the solution improvement phase is a series of novel MIP-based neighborhood search techniques. The proposed algorithms are evaluated based on a set of realistic large-scale instances seen in recent literature. Extensive computational results indicate that the hybrid heuristic strategy is able to obtain optimal or near optimal feasible solutions substantially faster than commercial optimization software and also the previously proposed heuristic methods.     

几种启发式集装箱优化配装方法的比较

集装箱配装是个多约束的复杂组合优化问题 ,属于NP -Hard问题 ,其求解是很困难的 ,所以实际应用中一般多用启发式方法来解。分析和比较了几种启发式集装箱配装的特点 ,并对未来的研究发展趋势做出了预测。     

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行人动力学建模的关键是对行人运动方向和速度的选择进行描述.本文构建了基于多层有限状态自动机的行人Agent适应性决策模型;在此基础上,针对行人运动过程中快速决策的特征,通过构建基于认知启发式规则的行人运动行为规则集合,建立了描述行人微观运动行为的动力学模型.通过设计仿真实验并收集数据,对模型的有效性进行了验证.研究结果表明：模拟得到的行人交通流密度-速度关系与实测数据具有较好的一致性,流率-密度关系符合理论计算结果,基本图较好地符合实际观测的行人宏观交通流关系,认为本文提出的行人动力学模型具有交通上的合理性.     

A Hybrid Heuristics for Irregular Flight Recovery

Adverse weather conditions, congestion at airports, and mechanical failures often disrupt regular flight schedules. The irregular flight recovery problem aims to recover these schedules through reassignments of flights and cancellations. In this article, we develop the classic resource assignment model for the irregular flight recovery problem, and a new hybrid heuristic procedure based on greedy random adaptive search procedure (GRASP) and simulated annealing algorithm is presented to solve this problem. As compared with the original GRASP method, the proposed algorithm demonstrates quite a high global optimization capability. Computational experiments on large-scale problems show that the proposed procedure is able to generate feasible revised flight schedules of good quality in less than five seconds.