闭环物流系统的成本因素分析

根据定位-配给。运输车辆安排，定位运输，定位-路径-库存等问题概念给出了此类问题的国内外研究现状，并结合闭环物流系统特征，给出闭环物流系统中关于选址-路径-库存问题的研究思路及成本因素分析。     

A local bicycle helmet ‘law’ in a Swedish municipality – the structure and process of initiation and implementation

On May 1, 1996, the Municipality of Motala in Sweden introduced a local bicycle helmet ‘law.’ It is, however, not an official law in a legal sense, but a municipally endorsed recommendation supported by promotional activities. This ‘law’ applies to children (ages 6–12), although the objective is to increase helmet use among cyclists of all ages. The study is a qualitative evaluation of the structure and process during initiation and implementation of the Motala bicycle helmet law. The aim was to describe the activities that were carried out, which actors took part and the opinions of the most closely involved actors. The results are based on analysis of written material and on interviews with eight of the actors. The mass media focused much attention on the bicycle helmet law, especially during the first six months after its introduction. The name helmet law was presumably of significance in this context. It is essential that relevant target groups provide sufficient support and that committed individuals initiate and promote the work, which, however, must not become dependent on a single individual. All issues concerning bicycle helmets should be coordinated with the law. Also, continuous engagement of the municipal government and a strategy for the control and follow-up of the law are needed. Local bicycle helmet laws of this type have a potential to produce a long-lasting effect on helmet use, provided some of the problems encountered can be avoided and some of the promotional activities are intensified.     

交路在地铁乘务运作中的作用

目前国内城市轨道交通的发展迅速,在确保顺利完成硬件建设,安全运作的基础下,合理挖潜增效,充分利用现有人力资源,提高地铁的运作效率是一个很重要的议题,同时也是响应国家节能减排的重要措施之一。乘务无疑是地铁运作的核心之一。     

Modeling mobile health service delivery to Syrian migrant farm workers using call record data

A significant number of Syrian refugees under temporary protection in Turkey work in agriculture seasonally in various rural areas during several months a year. These migrant farm workers and their families are deprived of access to the regular health care system and preventive services due to their remote locations. The government supports the delivery of different types of mobile health care services, such as vaccination for children, reproductive health and screening services. While planning the mobile health care service delivery, it is critical to know where the refugees will work during what time frame; hence the demand for the services. By analyzing the call record data of a major mobile network operator in Turkey, we quantify the increase in the volume of calls made by Syrian refugees in various agricultural areas during the harvesting season of local crops. This information helps us to forecast spatial and temporal distribution of demand for mobile health care services at a fine granularity. Taking demand over multiple periods as input into a mathematical programming model, we optimize the routing of mobile clinics that visit locations close to where refugees are concentrated over the given planning horizon. We consider three hierarchical objectives. Given the availability of a number of mobile clinics at community health centers in the districts, the first objective aims to maximize the percentage of refugees that can benefit from each service type within pre-defined close distances. The second objective minimizes the number of clinics needed while covering the maximum percentage of refugees. The third objective minimizes the total travel distance of the clinics, while keeping the maximum coverage level using a minimum number of clinics to achieve this level. We quantify the benefits of centralized planning (by the province directorate) over decentralized planning (by each district separately). We also show the trade-off between the required number of clinics and coverage of potential patients.     

漂浮的公交绿岛:扬州古运河线性文化遗产的景观复兴策略

线性文化遗产指“在拥有特殊文化资源集合的线形区域内的物质和非物质的文化遗产族群,往往是出于人类特定目的而形成的重要纽带”.中国大运河在时间上延续数千年、空间上贯穿南北地区,具有明显的线性文化遗产特征.然而,城市化进程的加速给大运河沿线的文化遗产保护和两岸居民的思想观念、生活方式等带来了极大冲击.当下,对大运河线性文化遗...     

无人机视频情报的压缩传输技术

视频图像信号是无人机主要的侦察信息.文中介绍了视频图像信号的数字压缩传输技术,重点讨论了几种压缩编码方法,给出了模拟视频数字化压缩传输方案,并进行了性能分析.     

Vehicle routing optimization with soft time windows in a fuzzy random environment

This paper is concerned with a vehicle routing problem with soft time windows (VRPSTW) in a fuzzy random environment. Two objectives are considered: (1) minimize the total travel cost and (2) maximize the average satisfaction level of all customers. After setting up the model for the VRPSTW in a fuzzy random environment, the fuzzy random expected value concept is used to deal with the constraints and its equivalent crisp model is derived. The global–local–neighbor particle swarm optimization with exchangeable particles (GLNPSO-ep) is employed to solve the equivalent crisp model. A case study is also presented to illustrate the effectiveness of the proposed approach.     

A logistics model for emergency supply of critical items in the aftermath of a disaster

This paper proposes a logistics model for delivery of prioritized items in disaster relief operations. It considers multi-items, multi-vehicles, multi-periods, soft time windows, and a split delivery strategy scenario, and is formulated as a multi-objective integer programming model. To effectively solve this model we limit the number of available tours. Two heuristic approaches are introduced for this purpose. The first approach is based on a genetic algorithm, while the second approach is developed by decomposing the original problem. We compare these two approaches via a computational study. The multi-objective problem is converted to a single-objective problem by the weighted sum method. A case study is presented to illustrate the potential applicability of our model. Also, presented is a comparison of our model with that proposed in a recent paper by Balcik et al. [6]. The results show that our proposed model outperforms theirs in terms of delivering prioritized items over several time periods.     

河南省县域金融支持县域经济发展的路径选择

结合河南省县域经济发展的现状,基于其县域金融服务县域经济的现状,分析了其制约因素,提出了推进县域金融创新,推进县域金融生态环境建设,引进现代科学技术支持农村金融机构提高服务水平,进一步推进利率市场化进程等一系列县域金融支持县域经济发展的路径。     

Combining service frequency and vehicle routing for managing supplier shipments

This paper proposes a new approach to designing inbound material collection routes that considers pick-up frequency and spatial design as joint decisions to minimize total logistics (transportation plus inventory) cost. The clustering-based optimization uses an approximation to the actual cost of a routing solution without actual route construction. We show that the problem is analogous to a single-source fixed-charge facility location problem, and near-optimal solutions can be found using an efficient heuristic algorithm. Tests show the effectiveness of how this model is formulated and a case study demonstrates that substantial total cost savings can be achieved in realistic applications.