SWARM INTELLIGENCE: APPLICATION OF THE ANT COLONY OPTIMIZATION ALGORITHM TO LOGISTICS‐ORIENTED VEHICLE ROUTING PROBLEMS

This research evaluates a set of logistics‐oriented vehicle routing problems (VRP) taken from the logistics and supply chain literature under the widely used Clark‐Wright Savings algorithm and the newer metaheuristic method employing a type of swarm intelligence called Ant Colony Optimization (ACO). ACO simulates the decision‐making processes of colonies of ants as they forage for food and is related to other artificial intelligence techniques such as Tabu Search, Simulated Annealing and Genetic Algorithms. Experimentation shows that ACO is successful in finding solutions near the best‐known solutions for problems with up to 20 demand locations. In addition, testing for the affect of spatial patterns suggested by the logistics literature for facility locations appears to make a difference in the quality of the solutions for the two algorithms. Finally, ACO is shown to be superior to the savings algorithm found in software packages and as a result should be tested on even larger, more complex logistics‐oriented vehicle routing problems, representative of those encountered in larger industrial and retail settings.     

Design of limited-stop bus service with capacity constraint and stochastic travel time

This paper develops a mathematical model for the optimal stopping design of limited-stop bus service, which allows each bus vehicle to skip some stops. To better reflect the reality, this paper considers the vehicle capacity and stochastic travel time. Also, vehicles are all allowed to skip stops whereas any stop is not allowed to be skipped by two consecutive vehicles. A hybrid artificial bee colony (ABC) and Monte Carlo method is developed to solve the optimal stopping strategy. Finally, the model and solution method are validated by a numerical example, and a sensitivity analysis is performed on the passenger demand.     

农资连锁经营应急机制下车辆调度研究

连锁经营,作为农资流通领域的新模式,逐步取代了原本散乱的农资零售格局。物流配送活动作为连锁经营理念的核心,是农资连锁经营能够成功运作的关键。但由于农业生产对农资产品的特殊要求,当消费者对农资产品有紧急需求,但就近的连锁店铺不能供货时,会给农业生产带来不利影响。本文引入应急概念,构建了应急车辆调度模型,来实现配送中心对企业配送系统内部各节点的库存的协调,使该连锁店能够快速响应消费者需求。     

A survey on pickup and delivery problems

This paper is the first part of a comprehensive survey on pickup and delivery problems. Basically, two problem classes can be distinguished. The first class, discussed in this paper, deals with the transportation of goods from the depot to linehaul customers and from backhaul customers to the depot. This class is denoted as Vehicle Routing Problems with Backhauls (VRPB). Four subtypes can be considered, namely the Vehicle Routing Problem with Clustered Backhauls (VRPCB – all linehauls before backhauls), the Vehicle Routing Problem with Mixed linehauls and Backhauls (VRPMB – any sequence of linehauls and backhauls permitted), the Vehicle Routing Problem with Divisible Delivery and Pickup (VRPDDP – customers demanding delivery and pickup service can be visited twice), and the Vehicle Routing Problem with Simultaneous Delivery and Pickup (VRPSDP – customers demanding both services have to be visited exactly once). The second class, dealt with in the second part of this survey, refers to all those problems where goods are transported between pickup and delivery locations. These are the Pickup and Delivery Vehicle Routing Problem (PDVRP – unpaired pickup and delivery points), the classical Pickup and Delivery Problem (PDP – paired pickup and delivery points), and the Dial-A-Ride Problem (DARP – passenger transportation between paired pickup and delivery points and user inconvenience taken into consideration). Single as well as multi vehicle versions of the mathematical problem formulations are given for all four VRPB types, the corresponding exact, heuristic, and metaheuristic solution methods are discussed.      

大话车坛奥斯卡

影坛最星光璀璨的一刻，就是一年一度的奥斯卡颁奖礼。仿照这一国际影坛盛事的奖项设置，我们制作了这期的“车坛奥斯卡”，用6个奖项为过去半年的车市做一个总结。此榜属一家之言，纯属娱乐。     

日本汽车“整零”关系模式及其对中国汽车产业的启示

日本汽车产业不但推动了日本国内相关产业的协同发展,而且在全球汽车产业中占据优势地位,之所以如此,与其先进的"整零"关系模式是分不开的。日本汽车产业"整零"关系是供应商承担"一揽子委托",组织体系呈金字塔式,整车企业通过多种形式对下游供应商进行渗透,资产专用性投资程度很高,其效果是:形成规模经济,减少内部成本;达成知识共享,促进产能提高;实现双向提升,增进关系稳固。我国汽车产业"整零"关系具有诸多局限性,应借鉴日本经验,处理好整车企业与零部件供应商之间的关系,形成"战略-利益"共同体,使汽车产业的"整零"关系进入一个良性循环,从而促进我国整个汽车产业的高速、高质发展。     

The Trucking Sector Optimization Model: A tool for predicting carrier and shipper responses to policies aiming to reduce GHG emissions

In response to the growing Climate Change problem, governments around the world are seeking to reduce the greenhouse gas (GHG) emissions of trucking. The Trucking Sector Optimization (TSO) model is introduced as a tool for studying the decisions that shippers and carriers make throughout time (focusing on investments in Fuel Saving Technologies), and for evaluating their impact on life-cycle GHG emissions. A case study of fuel taxation in California is used to highlight the importance of (1) modeling the trucking sector comprehensively, (2) modeling the dynamics of the stock of vehicles, and (3) modeling different sources of emissions.     

试论超限超载运输长效治理机制的建立

基于对当前治理超限超载运输工作中所存在问题和建立长效治理机制必要性的分析,文中提出治理超限超载运输工作要建立长效治理机制的观点和建议.为建立长效治理机制并提高长效治理的有效性,文章提出4项具体的治理措施,即建立健全治理超限超载运输法律的建设、加速进行动态轴重检测装置的应用和推广、营运车辆配备电子营运证、培育健康正常的市场经济环境.     

Object-based,multi-sensor habitat mapping of successional age classes for effective management of a 70-year secondary forest succession

Multi-temporal change detection over decades including the pre-satellite era is challenging due to the different image types available over time, and this explains the scarcity of long-term studies of vegetation succession which can play a pivotal role in the restoration of biodiversity in regenerating forests. This study describes a semi-automated, object-based habitat classification method for change detection of tropical forest succession since 1945. The study uses a set of black and white aerial photographs and high-resolution satellite images which differ in quality and resolution, to investigate forest successional patterns and their implications for informed ecosystem and land rehabilitation management. For optimized habitat boundary delineation from black and white aerial photographs and panchromatic satellite images, three levels of hierarchical image object primitives were created. The minimum object sizes of 50 m², 500 m², and 1000 m² maximized inter-object and minimized intra-object variability according to the scale of habitat patches and imagery used. Object-Based Image Analysis (OBIA) provided additional Grey-Level Co-occurrence Matrix (GLCM) textural features of segmented objects which helped to incorporate knowledge-based rule-sets into the final habitat classification which was done manually. Results show accuracies for grassland greater than 94%, monoculture plantations were distinguished from natural forest with 95% accuracy, and isolated mature stands of natural forest achieved 75% accuracy. Consideration of multi-date images increased the accuracy of distinguishing between mixed plantations and natural forest as well as between shrubland and young secondary forest. The resulting maps of vegetation structure at five time periods from 1945 to present gave new insights into the ecological processes of secondary forest succession. These include the surprising rapid rate of natural forest regeneration, at an annual rate of 7.7% from 1945 to 2014, and an even faster rate of 11% during a period when hill fires were controlled. The last areas to succeed to forest are those which are still, or at some time have been under exotic mono-cultural plantations. This suggests that long term protection from hill fire would be a better option for assisting natural succession in the landscape than plantations, which are both costly, and act as barriers to natural succession. Overall, with more than 92% mapping accuracy, the method can be adapted for other multi-temporal, multi-sensor studies as it enables inclusion of spatial theories by dividing the satellite image into time-consistent geographic entities according to the scale of target objects and image resolution. The accurate maps of forest cover patches at different successional stages can also help in site specific management of the recovering forest, such as introduction of shrub seedlings to bridge bottlenecks in seed dispersal according to shrub density and dispersal distances for forest birds. Late successional tree species can also be introduced in areas where only early successional species are present after 50 years of succession.     

特种车队培训工作的几点思考和建议

随着石油企业发展步伐的加快,将在更新管理手段、引入经营理念等领域进行改革。随着新设备、新技术的大量投入运用,在强化职工培训、提高员工素质等人力资源方面进行改革和探索变得尤为重要。