Multiple L(j,1)-labeling of the triangular lattice

Let n,j,k be nonnegative integers. An n-fold L(j,k)-labeling of a graph G is an assignment f of sets of nonnegative integers of order n to the vertices of G such that, for any two vertices u,v and any two integers a∈f(u), b∈f(v), |a?b|≥j if uv∈E(G), and |a?b|≥k if u and v are distance two apart. The span of f is the absolute difference between the maximum and minimum integers used by f. The n-fold L(j,k)-labeling number of G is the minimum span over all n-fold L(j,k)-labelings of G. Let n,j,k and m be nonnegative integers. An n-fold circular m-L(j,k)-labeling of a graph G is an assignment f of subsets of {0,1,…,m?1} of order n to the vertices of G such that, for any two vertices u,v and any two integers a∈f(u), b∈f(v), min{|a?b|,m?|a?b|}≥j if uv∈E(G), and min{|a?b|,m?|a?b|}≥k if u and v are distance two apart. The minimum m such that G has an n-fold circular m-L(j,k)-labeling is called the n-fold circular L(j,k)-labeling number of G. This paper provides upper and lower bounds for the n-fold L(j,1)-labeling number and the n-fold circular L(j,1)-labeling number of the triangular lattice and determines the n-fold L(2,1)-labeling number and n-fold circular L(2,1)-labeling number of the triangular lattice for n≥3.     

An improved algorithm for tree edit distance with applications for RNA secondary structure comparison

An ordered labeled tree is a tree in which the nodes are labeled and the left-to-right order among siblings is relevant. The edit distance between two ordered labeled trees is the minimum cost of transforming one tree into the other through a sequence of edit operations. We present techniques for speeding up the tree edit distance computation which are applicable to a family of algorithms based on closely related recursion strategies. These techniques aim to reduce repetitious steps in the original algorithms by exploring certain structural features in the tree. When these features exist in a large portion of the tree, the speedup due to our techniques would be significant. Viable examples for application include RNA secondary structure comparison and structured text comparison.     

Strategic Information Sharing in Competing Channels

We investigate strategic information sharing in two competing channels. The retailer in a channel can ex post decide whether to share private demand information with his upstream manufacturer after the content of information becomes known. We find that a retailer discloses low demand and withholds high demand to induce lower wholesale prices from his manufacturer. We show that a retailer should share less information when the retail market becomes more competitive, but should disclose more information when his capability to acquire information improves. When a decentralized supply chain competes with an integrated channel, we show that firms in the supply chain benefit from the rival channel's effort to improve information capability, that the incentive for the retailer in the supply chain to improve his information capability increases with the intensity of competition and with the rival channel's information capability, and that the retailer may not want to pursue perfect information acquisition even when doing so is costless. Extensive numerical studies demonstrate that similar results also hold for two decentralized supply chains competing with each other.     

董事会特征与总经理变更

本文以在上海证券交易所1999年前上市的公司为样本,研究董事会特征等治理变量对总经理变更的影响。研究结果表明,对相对业绩下降公司的总经理变更能起到显著解释作用的变量只有董事会会议的次数和公司的领导结构。而其它治理变量,诸如董事会规模、管理董事比例、独立董事比例、股权集中度、董事会成员持股比例等,未能对总经理变更起到显著的解释作用。     

Demand and Production Management with Uniform Guaranteed Lead Time

Recently, innovation‐oriented firms have been competing along dimensions other than price, lead time being one such dimension. Increasingly, customers are favoring lead time guarantees as a means to hedge supply chain risks. For a make‐to‐order environment, we explicitly model the impact of a lead time guarantee on customer demands and production planning. We study how a firm can integrate demand and production decisions to optimize expected profits by quoting a uniform guaranteed maximum lead time to all customers. Our analysis highlights the increasing importance of lead time for customers, as well as the tradeoffs in achieving a proper balance between revenue and cost drivers associated with lead‐time guarantees. We show that the optimal lead time has a closed‐form solution with a newsvendor‐like structure. We prove comparative statics results for the change in optimal lead time with changes in capacity and cost parameters and illustrate the insights using numerical experimentation.     

Evolution of Quality: First Fifty Issues of Production and Operations Management

Many contributions have been made to the field of quality since the inaugural issue of Production and Operations Management in 1992. The first issue called for more research and teaching on TQM, which resulted in two special issues dedicated to TQM. Many other articles related to quality have also been published in the first fifty issues of the journal on topics ranging from technical methods to the Baldrige Award and ISO 9000. As we review these articles, we assess their contribution and the progression of the field of quality. Although past research has advanced our understanding of quality, there still exists many research opportunities in developing more theory, using additional research methodologies, and studying emerging topics in this field.     

电子商务环境下管理理论与方法研究回顾

回顾了国家自然科学基金重点资助项目"电子商务环境下管理理论与方法研究"(70031020)的立项及实施过程,介绍了项目已取得的科研成果及经济社会效益,系统总结了项目组织实施的若干成功经验.提出的"官、产、学"一体化的研发管理模式,对于组织实施管理类大规模的重点基金项目具有借鉴价值.     

图书馆服务质量评价模型研究

图书馆服务质量是不同属性的综合体,它包括许多很难被测量的不可感知属性,这种特性给被测者在接受问卷调查时带来了一些困难.为了避免上述情况出现,在分析了图书馆服务质量综合评价中现存主要问题和影响因素的基础上,建立了基于灰色局势决策的模糊多属性决策模型,将灰色系统和模糊集理论引入定性指标值的测度中,得到了满意的结果.     

基于C/S和B/S模式的高校基建项目管理信息系统的设计与实现

通过结合华中科技大学基建与后勤管理处MIS系统的开发实例,提出了建立高校基建后勤管理信息系统建设的必要性和可能性,并给出了系统的整体结构和主要功能,最后分析了系统实现过程中的一些问题.