A multi-objective sustainable load planning model for intermodal transportation networks with a real-life application

Growing importance of intermodal transportation necessitates modeling and solving load planning problems by taking into account various complex decisions simultaneously like transportation mode/service type selection, load allocation, and outsourcing. This paper presents a mixed-integer mathematical programming model for a multi-objective, multi-mode and multi-period sustainable load planning problem by considering import/export load flows to satisfy transport demands of customers and many other related issues. Several multiple objective optimization procedures are utilized in order to handle conflicting objectives simultaneously under crisp and fuzzy decision making environments. A real-life case study is also performed to present application and usefulness of the proposed model.     

A profit-maximization location-capacity model for designing a service system with risk of service interruptions

This paper considers the design of an immobile service system in which each facility’s service process is subject to the risk of interruptions. The location-capacity decisions and allocations are simultaneously made to maximize the difference between the service provider’s profit and the sum of customers’ transportation and waiting costs. An efficient Lagrangian-based solution algorithm is developed, which solves large-sized instances with up to 50 service facilities and 500 customers in a few seconds. Several sensitivity analyses and managerial insights are presented. The model is also applied to a case study on a logistics network design problem in the zinc mining industry.     

如何进一步优化“哑铃式”生产工艺

煤炭科研院所转制后的企业大多采用"哑铃式"生产模式,即设计、组装(生产的两头)由自身控制,中间加工环节放在各外委厂家加工,以避免科研院所自身加工生产条件不足的缺陷,在转制起始阶段能迅速组织生产,形成较为快速的经济增长。但随着产品品种逐渐增多、产品生产数量日益增加,采用本模式的生产工艺逐步暴露出一定的缺陷,如:产品质量的不稳定、产品库存的积压、产品成本的增加等等一系列问题。因此本文将通过对多种新产生问题的分析,提出进一步优化"哑铃式"生产工艺的方法。     

A neuro-fuzzy combination model based on singular spectrum analysis for air transport demand forecasting

Air transport demand forecasting is receiving increasing attention, especially because of intrinsic difficulties and practical applications. Total passengers are used as a proxy for air transport demand. However, the air passenger time series usually has a complex behavior due to their irregularity, high volatility and seasonality. This paper proposes a new hybrid approach, combining singular spectrum analysis (SSA), adaptive-network-based fuzzy inference system (ANFIS) and improved particle swarm optimization (IPSO), for short-term air passenger traffic prediction. The SSA is used for identifying and extracting the trend and seasonality of air transport demand and the artificial intelligence technologies, including ANFIS and IPSO, are utilized to deal with the irregularity and volatility of the demand. The HK air passenger data are collected to establish and validate the forecasting model. Empirical results clearly points to the enormous potential that the proposed approach possesses in air transport demand forecasting and can be considered as a viable alternative.     

基于加权Voronoi多边形的山区农村居民点优化布局———以重庆市崇龛镇与石龙镇为例

中国的城市化进程伴随着农村人口向城市大量转移,使得乡村普遍面临人口流失、耕地撂荒及居民点闲置等问题,严重限制农村地区的经济发展,影响基础设施与公共服务设施的配置效率。优化农村居民点布局,实现资源的集约节约利用是国家新型城镇化规划的重要内容。文章以重庆市潼南县崇龛镇与巴南区石龙镇为例,探讨西南地区农村居民点空间布局优化的科学方法。首先,结合西南地区特有的自然人文条件,运用GIS空间分析技术与景观格局指数分析居民点分布特征;然后,构建包括限制性评价与适宜性评价两个阶段的西南地区居民点综合评价体系;基于对未来乡村发展趋势的判断,依据公平与效率原则,将现有居民点划分为发展型、保留型及迁并型等3类;在此基础上,运用加权Voronoi图确定重点发展型居民点的增长极引力范围,明确迁并型居民点与保留型居民点的发展方向,最终确定农村居民点布局的优化方案。经过优化,崇龛镇基于效率原则确定出222个重点发展型居民点,节约农村居民点用地0.813km2;石龙镇基于公平原则整理出416个重点发展型居民点,节约农村居民点用地0.301km2。研究能为2个示范镇农村居民点的规划优化提供科学依据,也为西南地区开展新型城镇化规划提供参考。     

工程优化设计

加强工程设计方案优化已成为现代工程建设开展的重要工作,是控制工程成本、提高工程造价管理的关键。基于此,论述工程优化设计的影响因素与不足,提出搞好优化设计的几点建议。     

Electrification of a city bus network—An optimization model for cost-effective placing of charging infrastructure and battery sizing of fast-charging electric bus systems

The deployment of battery-powered electric bus systems within the public transportation sector plays an important role in increasing energy efficiency and abating emissions. Rising attention is given to bus systems using fast charging technology. This concept requires a comprehensive infrastructure to equip bus routes with charging stations. The combination of charging infrastructure and bus batteries needs a reliable energy supply to maintain a stable bus operation even under demanding conditions. An efficient layout of the charging infrastructure and an appropriate dimensioning of battery capacity are crucial to minimize the total cost of ownership and to enable an energetically feasible bus operation. In this work, the central issue of jointly optimizing the charging infrastructure and battery capacity is described by a capacitated set covering problem. A mixed-integer linear optimization model is developed to determine the minimum number and location of required charging stations for a bus network as well as the adequate battery capacity for each bus line. The bus energy consumption for each route segment is determined based on individual route, bus type, traffic, and other information. Different scenarios are examined in order to assess the influence of charging power, climate, and changing operating conditions. The findings reveal significant differences in terms of required infrastructure. Moreover, the results highlight a trade-off between battery capacity and charging infrastructure under different operational and infrastructure conditions. This paper addresses upcoming challenges for transport authorities during the electrification process of the bus fleets and sharpens the focus on infrastructural issues related to the fast charging concept.     

集装箱船初稳性高度优化模型的建立

为解决目前集装箱配积载中尚需结合人工经验来进行箱位选配的问题,通过研究集装箱船配积载前重心距基线高,运用集装箱船初稳性高度计算原理,结合集装箱船的结构特点,建立集装箱船初稳性高度优化模型。运用交互式的线性和通用优化求解器编写程序,其研究成果将为实现集装箱船自动化配积载目标提供理论基础。     

基于多Agent的网络组织智能管理系统

网络组织是在信息技术和全球经济一体化趋势推动下,而出现的一种新型组织形式,是管理科学的一个重要研究内容。为了提高网络组织管理的智能化水平,应用智能协作技术方法,建立了一种网络组织智能管理系统,以及网络组织的智能协作机制模型。     

城市商业空间结构问题与优化探讨

城市空间结构研究一直都是城市地理学的主要研究领域 ,但其中的城市商业空间结构研究则发展缓慢。本文试探着阐述了城市商业空间优化的相关理论 ,包括商业空间优化的必要性与意义 ,接着描述了目前商业空间结构存在的普遍问题 ,并指出优化的四个主要目标 ,即视觉优先、经济优先、生态优先和社会优先 ,最后指出商业空间结构优化的主要方面和具体手段。