Optimizing station location and fleet composition for a high-speed rail line

This paper proposes a new strategic planning model for high-speed rail ventures. It is a mixed-integer optimization model that applies to a given line and focuses on two key strategic decisions: station location and fleet composition. Our purpose is to improve on previous station location models by including fleet composition decisions. In the new model, we additionally take into account in an approximate fashion the interrelationships between strategic and subsequent tactical decisions, regarding line planning, train scheduling and fleet assignment issues. The usefulness of the model is demonstrated for a case study involving a planned Lisbon-Oporto high-speed rail line.     

Sequential estimation of a location parameter and powers of a scale parameter from delayed observations

The problem of sequentially estimating a location parameter and powers of a scale parameter is considered in the case when the observations become available at random times. Certain classes of sequential estimation procedures are derived under an invariant balanced loss function and with the observation cost determined by a convex function of the stopping time and the number of observations up to that time.     

我国吸引跨国公司设立地区总部的区位优势分析

跨国公司地区总部承担着制定区域性经营战略和协调区域内众多子公司生产、销售、物流、研究与开发、资金统筹、人力资源培养等经营活动的职能。它的区位发展提升了东道国及所在区域的竞争力。近年来跨国公司在华设立地区总部数量一直不断上升,我国在吸引方面有哪些区位优势呢,这是本文研究的重点。     

农业旅游空间布局研究

农业旅游是农业与旅游业的交叉行业,也是一种新兴的专项旅游活动,由于具有贴近自然、参与性强等诸多优点,深受城市旅游者的青睐。通过对农业旅游空间布局的理论基础进行探寻,分析影响农业旅游空间布局的因素,提出农业旅游空间布局模式及其演化规律,并对农业旅游空间布局的优化提出了建议。     

高压输电线路故障测距算法综述

高压输电线路故障定位的准确性对电网的稳定运行有着非常重要的意义。文章对高压输电线路现有的各种测距方法进行了归纳总结和研究分析,并评述了各自的优点和不足。     

广西北部湾经济区城市群物流经济联系的中心性城市分析

广西北部湾经济区城市群作为一个新兴城市群,物流经济联系日益紧密,但中心性城市效应尚不明显,拟通过区位商法,对南宁、北海、钦州、防城港以及玉林、崇左等市的城市中心性指标值进行测定,以期对广西北部湾经济区城市群物流经济发展提供借鉴。     

基于模糊综合评价法的市郊铁路客运站选址研究

本文针对其特点,应用层次分析法建立市郊铁路客运站站址比选的指标体系,确定各指标的权重,结合模糊综合评价原理建立相应的站址方案评价模型,并给出算例分析,为市郊铁路客运站站址方案的比选提供了一种更科学、更符合实际的方法。     

喷雾器喷头工艺优化模拟

本文利用moldflow软件优化喷雾器喷头,得到合理、可靠的注射工艺参素,优化模具结构。     

企业选址中的区位粘性问题

绝大多数企业并没有遵循区位理论的指引,将企业选址在具有明显区位优势的地区,这个基本事实表明区位理论对企业选址的解释存在缺陷。文章试图从区位粘性的角度弥补理论缺陷,增加区位理论对企业选址的解释力度。文章在综述区位理论的基础上,从空间经济学的角度定义了区位粘性,采用路径依赖理论和网络嵌入性理论对区位粘性的内涵进行了深入剖析,结合出生于小城市的中国企业区位选址的实践分析了区位粘性的构成因素。研究结果发现非理性决策因素、商业模式的地域关联性、社会资源优势、集聚效应、洼地效应以及政治资源优势等六种因素构成了区位粘性的基本内涵,并形成了企业原址对企业的强大粘着力,对企业选址决策具有强烈的影响和作用,只有在外在的冲击力强到足以打破区位粘性时,企业才会做出再选址决策。     

Hub location problems in transportation networks

In this paper we propose a 4-index formulation for the uncapacitated multiple allocation hub location problem tailored for urban transport and liner shipping network design. This formulation is very tight and most of the tractable instances for MIP solvers are optimally solvable at the root node. While the existing state-of-the-art MIP solvers fail to solve even small size instances of problem, our accelerated and efficient primal (Benders) decomposition solves larger ones. In addition, a very efficient greedy heuristic, proven to be capable of obtaining high quality solutions, is proposed. We also introduce fixed cost values for Australian Post (AP) dataset.