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271.
This paper shows that the bootstrap does not consistently estimate the asymptotic distribution of the maximum score estimator. The theory developed also applies to other estimators within a cube‐root convergence class. For some single‐parameter estimators in this class, the results suggest a simple method for inference based upon the bootstrap. 相似文献
272.
Adaptive two-echelon capacitated vehicle routing problem (A2E-CVRP) proposed in this paper is a variant of the classical 2E-CVRP. Comparing to 2E-CVRP, A2E-CVRP has multiple depots and allows the vehicles to serve customers directly from the depots. Hence, it has more efficient solution and adapt to real-world environment. This paper gives a mathematical formulation for A2E-CVRP and derives a lower bound for it. The lower bound is used for deriving an upper bound subsequently, which is also an approximate solution of A2E-CVRP. Computational results on benchmark instances show that the A2E-CVRP outperforms the classical 2E-CVRP in the costs of routes. 相似文献
273.
In order to broadcast an alert message from the accident site to the control center as soon as possible, the roadside units (RSUs) act as the critical component in vehicular ad hoc networks (VANETs). It is not possible to make a pervasive RSU deployment due to the huge cost and market requirement. Hence, how to deploy a minimum number of RSUs in a given region becomes a challenge problem. In this paper, we present an analysis for the total delay of broadcasting alert messages in VANETs along highways. Based on the analysis, the relationship between optimal number of RSUs with the highway distance is given. Moreover, the experiment results verifies the delay analysis and the optimization of RSUs deployment. 相似文献
274.
We provide an exact myopic analysis for an N‐stage serial inventory system with batch ordering, linear ordering costs, and nonstationary demands under a finite planning horizon. We characterize the optimality conditions of the myopic nested batching newsvendor (NBN) policy and the myopic independent batching newsvendor (IBN) policy, which is a single‐stage approximation. We show that echelon reorder levels under the NBN policy are upper bounds of the counterparts under both the optimal policy and the IBN policy. In particular, we find that the IBN policy has bounded deviations from the optimal policy. We further extend our results to systems with martingale model of forecast evolution (MMFE) and advance demand information. Moreover, we provide a recursive computing procedure and optimality conditions for both heuristics which dramatically reduces computational complexity. We also find that the NBN problem under the MMFE faced by one stage has one more dimension for the forecast demand than the one faced by its downstream stage and that the NBN policy is optimal for systems with advance demand information and stationary problem data. Numerical studies demonstrate that the IBN policy outperforms on average the NBN policy over all tested instances when their optimality conditions are violated. 相似文献
275.
中国上市公司终极控制权及其与东亚、西欧上市公司的比较分析 总被引:19,自引:4,他引:19
本文运用终极产权论对上市公司的控股主体进行分类,通过追踪上市公司终极控制股东,发现在1260家样本公司中,终极控制股东拥有的控制权平均为43.67%,而其投入的现金流平均只有39.33%,就是说控制股东投入的现金流显著小于其获得的控制权,有4.34%的差异,两者的比值为0.890。在三种终极控制股东中,家族企业投入了相对较少的现金流量,却取得了相对较多的控制权,控制权和现金流量权的偏离达到了49.16%。同时,通过对中国上市公司和东亚、西欧国家的上市公司进行比较分析,得出了许多有意义的结论。 相似文献
276.
渠道冲突管理的"生命周期观"——机会主义及其治理机制 总被引:2,自引:1,他引:2
渠道冲突管理是营销研究的热门课题之一.遗憾的是,文献对于渠道冲突管理的分析都是以结果为导向,忽视了对渠道冲突的前因分析,也没有树立渠道冲突管理的全程意识.本文指出,机会主义是渠道冲突的直接前因,必须引入渠道冲突的全程管理.机会主义治理的渠道冲突观认为,渠道关系初期进行渠道成员选择,渠道关系持续期谋求长期导向、互动、协商、开放的渠道关系,可以确保渠道冲突管理树立全程的"生命周期观".本文结合中国市场渠道中机会主义的渠道冲突案例进行剖析,为如何进行机会主义治理、杜绝渠道冲突之源,保持渠道和谐提供了新的视角. 相似文献
277.
本文使用结构方程方法,基于问卷调查结果,对政策和经济环境变化对于企业投资决策方法选择的影响进行了研究。研究结果表明,政策环境对企业投资决策方法有影响,在政策因素变化条件下,上市公司回避使用净现值方法;经济环境对于企业投资决策方法影响不大,论文分析结果没有表现出经济因素是否变化对投资决策方法选择有明显影响。 相似文献
278.
Jianer Chen Xiuzhen Huang Iyad A. Kanj Ge Xia 《Journal of Combinatorial Optimization》2006,11(2):231-247
The notion of linear fpt-reductions has been recently introduced to derive strong computational lower bounds for well-known
NP-hard problems. In this paper, we formally investigate the notion of W[t]-hardness under the linear fpt-reduction, and study the structural properties of the corresponding complexity classes. Additional
complexity lower bounds on important computational problems are established. Some observations on structural properties of
the standard parameterized hierarchy, the W -hierarchy, are also presented.
In this paper, we always assume that complexity functions are “nice” with both domain and range being non-negative integers
and the values of the functions and their inverses can be easily computed. 相似文献
279.
280.
We consider firms that feature their products on the Internet but take orders offline. Click and order data are disjoint on such non‐transactional websites, and their matching is error‐prone. Yet, their time separation may allow the firm to react and improve its tactical planning. We introduce a dynamic decision support model that augments the classic inventory planning model with additional clickstream state variables. Using a novel data set of matched online clickstream and offline purchasing data, we identify statistically significant clickstream variables and empirically investigate the value of clickstream tracking on non‐transactional websites to improve inventory management. We show that the noisy clickstream data is statistically significant to predict the propensity, amount, and timing of offline orders. A counterfactual analysis shows that using the demand information extracted from the clickstream data can reduce the inventory holding and backordering cost by 3% to 5% in our data set. 相似文献