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991.
董事会特征与总经理变更 总被引:17,自引:1,他引:17
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。 相似文献
992.
Uday S. Rao Jayashankar M. Swaminathan Jun Zhang 《Production and Operations Management》2005,14(4):400-412
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. 相似文献
993.
Roger G. Schroeder Kevin Linderman Dongli Zhang 《Production and Operations Management》2005,14(4):468-481
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. 相似文献
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Binwu?Zhang Jianzhong?ZhangEmail author Yong?He 《Journal of Combinatorial Optimization》2005,9(2):187-198
In this paper, we consider the center location improvement problems under the sum-type and bottleneck-type Hamming distance. For the sum-type problem, we show that achieving an algorithm with a worst-case ratio of O(log |V|) is NP-hard, and for the bottleneck-type problem, we present a strongly polynomial algorithm. 相似文献
999.
Jueliang Hu Yiwei Jiang Ping Zhou An Zhang Qinghui Zhang 《Journal of Combinatorial Optimization》2017,33(3):866-881
This paper investigates an online hierarchical scheduling problem on m parallel identical machines. Our goal is to minimize the total completion time of all jobs. Each job has a unit processing time and a hierarchy. The job with a lower hierarchy can only be processed on the first machine and the job with a higher hierarchy can be processed on any one of m machines. We first show that the lower bound of this problem is at least \(1+\min \{\frac{1}{m}, \max \{\frac{2}{\lceil x\rceil +\frac{x}{\lceil x\rceil }+3}, \frac{2}{\lfloor x\rfloor +\frac{x}{\lfloor x\rfloor }+3}\}\), where \(x=\sqrt{2m+4}\). We then present a greedy algorithm with tight competitive ratio of \(1+\frac{2(m-1)}{m(\sqrt{4m-3}+1)}\). The competitive ratio is obtained in a way of analyzing the structure of the instance in the worst case, which is different from the most common method of competitive analysis. In particular, when \(m=2\), we propose an optimal online algorithm with competitive ratio of \(16\) \(/\) \(13\), which complements the previous result which provided an asymptotically optimal algorithm with competitive ratio of 1.1573 for the case where the number of jobs n is infinite, i.e., \(n\rightarrow \infty \). 相似文献
1000.
The cutwidth problem for a graph G is to embed G into a path such that the maximum number of overlap edges (i.e., the congestion) is minimized. The investigations of critical graphs and their structures are meaningful in the study of a graph-theoretic parameters. We study the structures of k-cutwidth \((k>1)\) critical trees, and use them to characterize the set of all 4-cutwidth critical trees. 相似文献