考虑道路通行能力的应急避难点选址模型及算法

在k-中心点问题的基础上,考虑道路的通行能力限制,提出了k-避难点问题。在一般树图结构下,重点分析了1-避难点选址问题,并设计了有效的求解算法;在直线图结构下,首先改进了一般图1-避难点的求解算法,其次分析了2-避难点问题的特点,并给出了一个基于"二分思想"的求解算法,在此基础上,为一般的直线图k-避难点问题设计了求解算法,一般算法的时间复杂性为O(nlog^kn)。所提出的模型在理论上扩展了经典的k-中心点选址问题,所设计的求解算法能够为现实的应急管理规划提供良好的理论支持。     

科学理论的使命与本质特征及其对管理理论发展的启示

理论在科学研究与学科发展中具有基础性作用.在科学发展中,理论作为一种人造物,其使命在于帮助人们正确地解释、预测认识对象,并指导相关的社会实践.管理学科在过去30年中理论进步相当缓慢,出现的诸多问题在一定程度上起源于对理论的认识偏差.基于亨普尔对理论的界定,从理论的本质特征出发,进行分析发现,当前主流管理学研究对于理论本身存在着比较普遍的误读,导致管理研究的“理论贡献”不能很好地促进学科发展.鉴于此,为了推动管理理论的发展,管理学界需要正确认识科学理论的使命和本质特征.最后,讨论了所提出的观点对发展管理理论的启示.     

IT能力与市场响应性的关系研究

基于动态能力理论和能力层级观,提出IT能力(IT整合和IT重置)通过促进吸收能力来提高企业市场响应性.同时,市场动荡性也可能调节IT能力与吸收能力的关系.通过对203个样本的问卷调查,分析结果表明:吸收能力在两种IT能力和市场响应性之间都起到中介作用;市场动荡性正向调节IT整合与吸收能力之间的关系,而对IT重置与吸收能力间关系的调节效应不显著.     

总承包工程建设供应链利润分配模型研究

利润分配是工程建设供应链的重要问题.本文以总承包工程市场为背景,基于收益共享理论和Stackel-berg博弈求解方法,建立了总承包商和分包商利润分配模型,得出为获得额外激励奖金二者所愿意付出的最大努力水平,及该奖金在总承包商和分包商之间的最优分配比例.考虑到总承包商和分包商之间的能力差异会对利润分配产生影响,在此基础之上,分析供应链、总承包商及分包商利润函数随奖金分配比例的变化趋势及产生的原因,最后对模型的应用进行算例分析,并画出函数图像,定量而直观地证实了文中提出的结论.     

Setups and effective capacity: the impact of lot sizing techniques in an MRP environment

This study investigates how lot sizing techniques influence the profit performance, inventory level, and order lardiness of an assembly job shop controlled by MRP. Four single-level lot sizing techniques are compared by simulation analysis under two levels of master schedule instability and two levels of end item demand. A second analysis investigates the influence of a multilevel lot sizing technique, the generalized constrained-K (GCK) cost modification, on the four single-level techniques at low demand and low nervousness. The analyses reveal a previously unreported phenomenon. Given the same inventory costs, the single-level lot sizing techniques generate substantially different average batch sizes. The lot sizing techniques maintain the following order of increasing average batch size (and decreasing total setup time):

economic order quantity (EOQ)

period order quantity (POQ)

least total cost (LTC)

Silver-Meal heuristic (SML)

The causes for different average batch sizes among the lot sizing techniques are analysed and explained. Demand lumpiness, inherent in multilevel manufacturing systems controlled by MRP, is found to be a major factor. The number of setups each lot sizing technique generates is the primary determinant of profit performance, inventory level, and order tardiness. EOQ, a fixed order quantity technique, is less sensitive to nervousness than the discrete lot sizing techniques. EOQ_, however, generates the smallest average batch size, and, therefore, the most setups. Since setups consume capacity, EOQ, is more sensitive to higher demand. SML generates the largest average batch sizes, and is, therefore, less sensitive to increased demand. At low demand, the other lot sizing techniques perform better on all criteria. They generate smaller batches and, therefore, shorter actual lead times. The GCK cost modification increases the average batch size generated by each lot sizing technique. GCK improves the profit and customer service level of EOQ the lot sizing technique with the smallest batches. GCK causes the other lot sizing techniques to generate excessively large batches and, therefore, excessively long actual lead times.     

零部件循环取货越库物流系统关键因子研究——仿真实验设计与分析方法

汽车和物流产业是国家重点扶持的两大振兴产业． 在众多汽车制造企业产能扩大的背景下,以零部件平均物流时间(cycle time,CT) 为绩效评价指标,深入研究了基于第三方物流的零部件循环取货越库物流模式( 简称 3PL－MRCD) 的优化设计问题． 建立了符合企业实际运作的离散系统随机仿真模型,即零部件循环取货与越库内部运作的集成模型． 与现有供应链仿真模型相比,由于存在较多的仿真因子,提出首先运用序贯分支法( sequential bifurcation, SB) 筛选 3PL－MRCD 系统关键因子,再应用响应面法(response surface methodology,RSM) 找到关键因子最优运作水平的方法步骤( SB－RSM) ,解决了大型仿真系统的优化设计问题． 基于调研的数据进行仿真实验,结果表明 SB－RSM 可准确找出影响CT的关键因子最优取值, 该值使CT达到较为理想的水平． 对大型仿真系统的优化而言,SB － RSM 比传统 RSM 更具实 验效率与效力,SB－RSM 为产能扩大3PL 物流决策的制定提供了可靠的解决方案,具有良好的应用价值．     

Risk management: a competitive advantage in the purchasing function

This paper aims to explore the purchasing function on behalf of the provider, when the purchasing takes the form of a request for proposals (RfP) from the client. A methodology for handling the bidding process is presented, illustrated by a case study from the IT sector. The proposed methodology places risk as a factor for the selection of the best and final offer of the provider in addition to the traditional decision factors: delivery time, product cost and performance. The method is supported by a structured corporate memory and a decision support system based on the analytical hierarchy process.     

Performance of TOC based finite capacity material requirement planning system for a multi-stage assembly factory

This paper aims to develop a finite capacity material requirement planning (FCMRP) system based on TOC philosophy (TOC-MRP) for multi-stage assembly factory that has some bottleneck stations. The proposed TOC-MRP system tries to load and schedule operations on bottleneck stations in a manner that they are free of idle time and overtime. The schedules on non-bottleneck stations will be arranged until they are not conflicting with those on the bottleneck stations. The non-bottleneck stations are allowed to have idle time and overtime if necessary. To analyse whether TOC-MRP is effective, it is compared with a FCMRP method that does not adopt TOC philosophy. The experimental results reveal that the TOC-MRP outperforms the FCMRP without TOC philosophy.     

Managing Downstream Competition via Capacity Allocation

Consider a supply chain with one supplier and multiple retailers. The supplier produces a single product and sells it to the retailers, who in turn sell the product to consumers. The supplier has limited production capacity, and the retailers are engaged in a Cournot competition at the consumer/market level. When the sum of the retailer orders exceeds the capacity, the supplier allocates her capacity according to a pre‐announced allocation mechanism. Two mechanisms are considered: proportional allocation and lexicographic allocation. An extensive study of the two allocation mechanisms shows that the lexicographic mechanism has the ability to dampen the competition at the retail level, increasing the profits for both the supplier and the supply chain.     

依托渝怀铁路实施以路兴区发展战略

结合渝怀线的现有资源和经济状况，采用定性和定量相结合的方法分析了渝怀经济带在西部大开发中的地位、作用及近远期发展战略和思路。