【作者】 黄建华；

【导师】 党延忠；

【作者基本信息】 大连理工大学 ， 管理科学与工程， 2012， 博士

【摘要】 网络优化问题一直都是物流、交通、计算机、通信、数学和运筹学等领域研究的热点,以往研究的焦点大多集中在如何设计有效的算法,以解决优化过程中多目标、多约束条件以及高计算复杂度等问题。本论文所研究的快递网络系统,是一个具有多维、多层和多目标等特征的超网络系统。在这个系统中配送网点和配送线路所构成的物理层网络仅仅是超网络系统的组成部分之一,在其上部还存在着管理层网络。管理层网络由以分公司为管理单元的组织管理维度子网和以转运中心为区域货物集散中心的业务管理维度子网构成,物理层网络中货物的配送过程受管理层网络的调度和制约。因此,研究物理层网络的优化问题时,需要考虑管理层网络的影响。另外,由于快递网络系统内部各层次之间要素的相互关联性,针对物理层网络和管理层网络的破坏行为均可能对快递公司造成重大损失。因此,从不同层次研究其抗毁性能,有助于更好的保护快递网络系统。本论文分析了快递企业配送系统所具有的超网络结构,探讨了在矩阵式的管理结构和快递行业“限时派送”经营模式的制约下,物理层网络的综合优化问题；论文还从超网络的视角,分别研究了快递网络系统中的物理层网络和管理层网络遭受破坏时,其抗毁性能特征：(1)构造了一种适合描述快递网络系统特征的超网络模型为了能兼顾配送成本和效率,快递企业通常采用矩阵式的管理结构,一方面以省级分公司为管理单元,实现对物理层网络的分区管理和成本控制；另一方面,以转运中心作为区域货物的集散中心,对货物进行统一调度和配送。这种矩阵式的管理模式,使得快递企业在管理层形成两个不同维度的子网络,物理网络中货物的配送是在管理层网络中两个不同维度子网络的管理和调度下完成的,本论文构建了适合描述快递网络系统内部复杂结构和关系的超网络模型。(2)提出了一种新的快递网络优化方法分析了组织管理维度基于成本的优化方法和业务管理维度基于效率的优化方法,以此为基础,结合快递企业“限时派送”的经营模式,提出了基于时间阈值的优化方法。该优化方法能保证快递企业在承诺的时间内完成快件送达任务的前提下,最大限度的降低配送成本。论文还以某快递企业的网络系统为例,对模型和优化方法进行了验证,结果表明,阈值取值的差异,不仅会影响总配送时间和总配送成本,也会改变快件的最优配送路径。(3)设计了适合物理层网络结构特点的优化算法论文针对快递网络系统中物理层网络具有社区结构和子核的特征,设计了具有并行运算特征的基于局域搜索的分段优化方法,并以某快递企业的网络为例,对该优化算法进行了验证,结果表明,该算法能够在保证计算精度的前提下,降低运算的复杂度。(4)评估了快递网络系统的抗毁性能首先,设计了评价快递网络抗毁性能的效率指标,该效率指标不仅能反映快递网络静态结构的破坏状况,同时还能反映动态流所受的影响,因此能科学评价快递企业因网络破坏而遭受的损失；其次,采用节点删除法模拟物理层网络遭受的破坏,在考虑相继故障和拥挤度影响的前提下,分析了物理层网络的抗毁性能；最后,定义了管理层网络中分公司的管理效率值指标,模拟了管理层网络遭受破坏后,由于管理效率值下降,从而导致物理层网络中的配送效率下降的过程。研究结果显示,管理效率的少量下降,将会导致物理层网络中总配送成本大幅度的增加,说明了相比于物理层网络的局部破坏,管理层网络的局部破坏对企业影响更大。更多还原

【Abstract】 Network optimization problem is a popular issue in many research fields, such as logistics, transportation, computer science, communication,mathematic and operation research. Previous studies mainly deal with it focusing on how to design an more effective algorithm to solve optimization problems with properties of multi-objective, multi-constrained and high computation complexity. The express network system is a super-network system with characteristics of multi-dimention, multi-layer and multi-objective, as one part of super-network system, the physical layer network is composed of delivery centers and routes, goods delivery in physical layer network is scheduled and restricted by the management layer network, which consisted of organization management dimension subnetwork and business management dimension subnetwork, the former take the branch company as its management unit and the latter regard the transshipment center as the collecting and distributing center. As a result, the management dimension subnetwork has an effect on the optimal outcome of physical layer network. In addition, for the interdependence of internal factors in express network system, acts of sabotage committed both against physical layer network and against management dimension subnetwork, may bring about heavy loss to the express company, so, to analyze its survivability at a different layer will help to protect express network system better.It analysizes the super-network structure of express distribution system, discusses the optimization problem of physical layer network which restricted by "time-limited delivery" and matrix management mode which is adopted widely in express industry, it also investigates the vulnerability of express network system when the physical layer network and the management dimension subnetwork is damaged respectively.(1)It designs a super-network model which suitable for describing the characteristics of express distribution network systemIn order to consider cost and efficiency simultaneously, a matrix management mode is adopted by express companies, on one hand, they consider province-level branch company as management unit to supervise the physical-layer network and control its operation cost divisionally, on the other hand, they regard the transshipment center as the collecting and distributing center for goods unified dispatching, as a result, two different dimension subnetworks who schedule goods distribution in physichal layer network jointly, are formed in management layer network. A supernetwork model is designed to describe the complex construction and complicated relation of express network system.(2) It proposes a new optimization method of express networkOn the basis of the cost optimization-based method raised in organization management dimension and the time optimization-based method of physical layer network raised in business management dimension, combines with the "time-limited delivery" in express industry, an optimization method of multicriteria express super-network based on time threshold is proposed, the optimization method can reduces the distribution costs to the utmost on the premise of that the express consignments are delivered in the commitment time, the method is also illustrated by an application case, results show that the delivery routes, delivery time and delivery cost is related to time threshold.(3) It designs an optimization algorithm according to structure characteristics of physical layer networkIt proposes a segmental optimization method with features of parallel operation based on local searching, according to the community structure and sub-cores of physical layer network, the method is also illustrated by an application case, results show that our optimization method can effectively reduce computation complexity while keeping the calculation precision.(4) It studies the vulnerability of express network systemIn the first place, it designs an efficiency index to evaluate the vulnerability of express network system, the index can not only accesses the damage of express network structure reasonably, but also can measures the influence degree of flow on network, as a result, it can evaluates the losses of express company scientifically when the express network damaged. Secondly, node-removal method is used to simulates the damage to physical layer network, its vulnerability is also analysized in consideration of the effect of cascading failures and crowding. It defines the management efficiency index of branch company in the end, the drop course of delivery efficiency in physical layer network results from the reduction of management efficiency is also simulated. Results show that a little decrease of management effeciency may results in a sharp increase of total delivery cost of physical layer network, so, we can conclude that compares with local failure in physical layer network, partial failure in management layer network brings express company a worse influence.更多还原