电子商务环境下基于B2C的物流配送路径优化

电子商务环境下的物流配送具有客户位置分散、订单多、批量小和重复线路多的特点,传统的线路优化方法都在不同程度上遇到各种问题。文中针对电子商务环境下的配送特殊性,采用改进两阶段算法混合进行求解。第一阶段用K-means聚类法将客户群分成若干区域,在每个区域又用扫描算法分解成若干符合约束条件的小规模子集;第二个阶段对各个分组内的客户点,就是一个个单独的TSP模型的线路优化问题,采用改进遗传算法进行优化求解。最后,结合具体实例,实验证明了该改进算法的有效性。     

有时间窗的车辆路径问题改进蚁群算法研究

针对目前蚁群算法在求解有时间窗的车辆路径问题上较少对蚁群算法本身进行优化的问题,提出了一种改进蚁群算法,通过改进状态转移概率和信息素更新规则,以及使用改进的精英蚂蚁策略,改善蚁群算法搜索能力。通过对Solomon标准数据集的实验,结果表明改进的蚁群算法在求解有时间窗车辆路径问题上是有效的。     

突发事件下的车辆路径问题研究综述

车辆路径问题是物流管理研究中的一项重要内容。概述突发事件下车辆路径问题研究的背景和意义,介绍车辆路径问题的衍化分类,针对突发事件下车辆路径问题的特点,综述国内外研究现状。重点探讨突发事件下车辆路径问题的研究范围和前景。     

中继终端设备的天地网关功能设计与性能测试

近年来,空间网络协议大力发展,CCSDS空间网络协议体系已成为事实上的标准。基于跟踪与数据中继卫星系统（TDRSS）地面站中低速中继终端设备进行相应改造,增加网关路由板卡,加载CCSDS空间传输协议软件,将原来的中低速中继终端设备改造成带有路由网关功能的中低速中继终端设备。在此基础上,采用两台增加路由网关功能的中低速中继终端设备以及信道模拟器搭建天地网络演示验证系统,并分别对采用TCP协议和PEP增强协议作为传输层协议的HTTP应用进行了性能分析比对,证明PEP增强协议更能适应天地网络传输。     

Circulation of autonomous agents in production and service networks

The inherent complexity characterizing production and/or service networks strongly favors decentralized and self-organizing mechanisms to regulate the flows of matter and information in circulation. This basic observation motivates us to study the flow dynamics in queueing networks roamed by autonomous agents which, at a given time and at a given vertex location, select their routing according to (individual) historical data (such as waiting times) collected during their past progression in the network. For several simple network configurations and despite the intrinsically non-Markovian character of the dynamics, we are able to discuss analytically the emerging collective dynamics that such a circulation of autonomous agents generates. Feedback loops in the network topology coupled with the presence of delays in the routing selection mechanisms produce a wealth of dynamical phenomena like self-sustained generically stable oscillations, spatio-temporal patterns, stabilization by noise phenomena and oscillator synchronization that are explicitly discussed in this paper.     

基于节约里程法的阳原县果蔬市场配送路线优化

高效率的物流配送是企业顺利运营和提高效益的重要条件,正确合理的设计公司的运输线路,可以有效节约人力、物力、财力、提高经济效益。文章在对蔬菜市场物流配送进行调查的基础上,建立配送优化路径模型并且进行了有效求解,提出了具体的物流配送线路优化方案,并结合运输中的实际情况,计算每次配送中的柴油的消耗费用和使用司机的成本,进行了总成本的节约优化。     

Inductive research in last-mile delivery routing: Introducing the Re-Gifting heuristic

The last-mile problem presents a daunting challenge for many logistics service providers, especially some 7000 small, localized operations for whom the cost of complex software solutions is often prohibitive. As a result, last-mile dispatchers rely on simple heuristics to ensure adequate customer service at an acceptable cost. This research effort extends prior qualitative work by developing and testing a simple vehicle routing heuristic, based on behaviors observed in practice, that prioritizes customer service over cost against other simple vehicle routing heuristics across a variety of environments using simulation. The results support the inclusion of a customer service focus in vehicle routing and the addition of such heuristics to existing algorithm portfolios, specifically in urban areas with well-developed highway systems.     

Managing returnable transport items in a vendor managed inventory system

This paper addresses a closed-loop inventory routing problem with demand uncertainty, which manages the delivery operations to customers and pick-up operations of empty returnable transport items (RTIs) from customers. The problem involves decisions regarding forward and backward vehicle routes, the delivery and collection quantities, the amount of production in terms of the number of filled RTIs, and the number of RTIs produced/ bought by the vendor during the defined planning horizon. The problem considers the holding costs, fixed cost of operating vehicles, fuel consumption cost, producing/buying costs, cleaning costs of RTIs, and loading and unloading costs. We formulate the problem as a mixed integer linear programming model and propose a Relax and Fix based solution approach to solve large instances. We conduct extensive analyses on a case study derived from a fruit and vegetable distribution network and several hypothetical instances. Our analyses investigate the effects of several problem parameter changes (i.e., average collection rate, customer service level, cost of buying crate and handling cost) on the total logistics cost. Additional numerical analyses are performed to demonstrate the usage of the model for evaluating the cost of being more green and environmental-friendly. Moreover, experiments on relatively large-scaled problems allow us to demonstrate the potential benefits of the proposed heuristic     

一种最小误码率约束的动态地理协作路由算法

为了提高无线多跳通信的可靠性，提出一种联合物理层和网络层设计的动态地理协作路由(DGCR)算法，推导计算了单个协作单元协作中继节点的选择区域，在该区域内选择的协作中继节点可以满足误码率要求。最佳中继节点的位置会根据实际协作中继节点的位置和目的节点的位置动态选取。仿真计算表明，该算法相比非协作路由算法和传统地理协作路由算法具有更好的误码率性能，更适用于多径条件下的应用。     

无线传感器网络UDHR协议的设计与实现

针对无线传感器网络(WSN)数据流的特点,提出一种WSN上下行路由异构的协议(UDHR),上下行路由可采用不同的算法,适合于时间驱动、事件驱动以及查询的数据收集模式.利用OMNeT++平台对UDHR协议进行建模仿真,结果表明该协议开销小、扩展性好、健壮稳定.并且在自主开发的Testbed平台上实现了该路由协议,利用该平台可实时观察整个WSN网络拓扑变化、网络开销、监测每个节点能量消耗以及数据收集等情况.