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951.
952.
A cluster methodology, motivated by a robust similarity matrix is proposed for identifying likely multivariate outlier structure and to estimate weighted least-square (WLS) regression parameters in linear models. The proposed method is an agglomeration of procedures that begins from clustering the n-observations through a test of ‘no-outlier hypothesis’ (TONH) to a weighted least-square regression estimation. The cluster phase partition the n-observations into h-set called main cluster and a minor cluster of size n?h. A robust distance emerge from the main cluster upon which a test of no outlier hypothesis’ is conducted. An initial WLS regression estimation is computed from the robust distance obtained from the main cluster. Until convergence, a re-weighted least-squares (RLS) regression estimate is updated with weights based on the normalized residuals. The proposed procedure blends an agglomerative hierarchical cluster analysis of a complete linkage through the TONH to the Re-weighted regression estimation phase. Hence, we propose to call it cluster-based re-weighted regression (CBRR). The CBRR is compared with three existing procedures using two data sets known to exhibit masking and swamping. The performance of CBRR is further examined through simulation experiment. The results obtained from the data set illustration and the Monte Carlo study shows that the CBRR is effective in detecting multivariate outliers where other methods are susceptible to it. The CBRR does not require enormous computation and is substantially not susceptible to masking and swamping. 相似文献
953.
This paper considers the maximin approach for designing clinical studies. A maximin efficient design maximizes the smallest efficiency when compared with a standard design, as the parameters vary in a specified subset of the parameter space. To specify this subset of parameters in a real situation, a four‐step procedure using elicitation based on expert opinions is proposed. Further, we describe why and how we extend the initially chosen subset of parameters to a much larger set in our procedure. By this procedure, the maximin approach becomes feasible for dose‐finding studies. Maximin efficient designs have shown to be numerically difficult to construct. However, a new algorithm, the H‐algorithm, considerably simplifies the construction of these designs. We exemplify the maximin efficient approach by considering a sigmoid Emax model describing a dose–response relationship and compare inferential precision with that obtained when using a uniform design. The design obtained is shown to be at least 15% more efficient than the uniform design. © 2014 The Authors. Pharmaceutical Statistics Published by John Wiley & Sons Ltd. 相似文献
954.
In this paper we study the robustness of the likelihood ratio, circular mean and circular trimmed mean test functionals in the context of tests of hypotheses regarding the mean direction of circular normal and wrapped normal distributions. We compute the level and power breakdown properties of the three test functionals and compare them. We find that the circular trimmed mean test functional has the best robustness properties for both the above-mentioned distributions. The level and power properties of the test statistics corresponding to these functionals are also studied. Two examples with real data are given for illustration. We also consider the problem of testing the mean direction of the von-Mises–Fisher distribution on the unit sphere and explore the robustness properties of the spherical mean direction and likelihood ratio test functionals. 相似文献
955.
In recent years many small, young firms have started internationalizing early and have become ‘born globals’ (BGs). This study traces the phenomenon to five individual‐level and company‐level antecedents, including propensity to act, risk tolerance, company‐level organization of knowledge, ability to forge company‐level consensus, and company‐level responsiveness to new environments. Individual‐level antecedents are entrepreneurs' psychological qualities and company‐level antecedents are organizational behaviors. While these antecedents may or may not individually contribute to the rapid internationalization of small BGs, their interaction significantly speeds up the process. Evidence collected in this study demonstrates that the interaction among these antecedents is a complex mechanism. The interaction can be moderation, mediation, and even mediated moderation. The complex interaction of these antecedents explains the fast internationalization of BGs. The evidence sheds light on the relationships between entrepreneurs' psychological qualities and organizational behaviors. 相似文献
956.
在上游供应商的战略性转移定价承诺策略与下游制造商投资创新决策之间存在着交互作用,笔者将静态环境下的这种交互作用与不同柔性层次下的动态供应网络架构相结合,以供应链路径柔性为切入点,基于承诺的交货提前期、投资创新、产量与供应链收益等供应链绩效维度来探讨战略性转移定价承诺策略下的供应链合作模式相关话题。考虑到AMj在不同CS#em/em#之间进行选择的柔性化特征,笔者至少得到如下三个方面的结论:首先,供应网络架构柔性是供应链整体及其各节点企业获取绩效改善的重要途径,与没有柔性相比,完全柔性和部分柔性情形下的供应链绩效均能得到明显改善,而其中又以完全柔性优势最为突出;其次,虽然部分柔性是供应网络架构中较为可行的柔性层次选择,但是,其与完全柔性一样,容易产生供应网络资源的供给与需求失衡现象;第三,不确定性情境下的一体化决策与确定性情境下的转移定价承诺决策对供应链利润绩效所产生的影响取决于供应网络柔性层次以及供应网络节点企业各自的能力特点,进而对供应链整体及其各节点的合作模式和行为取向起着主导作用。 相似文献
957.
As part of its preparation to review a potential license application from the U.S. Department of Energy (DOE), the U.S. Nuclear Regulatory Commission (NRC) is examining the performance of the proposed Yucca Mountain nuclear waste repository. In this regard, we evaluated postclosure repository performance using Monte Carlo analyses with an NRC-developed system model that has 950 input parameters, of which 330 are sampled to represent system uncertainties. The quantitative compliance criterion for dose was established by NRC to protect inhabitants who might be exposed to any releases from the repository. The NRC criterion limits the peak-of-the-mean dose, which in our analysis is estimated by averaging the potential exposure at any instant in time for all Monte Carlo realizations, and then determining the maximum value of the mean curve within 10000 years, the compliance period. This procedure contrasts in important ways with a more common measure of risk based on the mean of the ensemble of peaks from each Monte Carlo realization. The NRC chose the former (peak-of-the-mean) because it more correctly represents the risk to an exposed individual. Procedures for calculating risk in the expected case of slow repository degradation differ from those for low-probability cases of disruption by external forces such as volcanism. We also explored the possibility of risk dilution (i.e., lower calculated risk) that could result from arbitrarily defining wide probability distributions for certain parameters. Finally, our sensitivity analyses to identify influential parameters used two approaches: (1). the ensemble of doses from each Monte Carlo realization at the time of the peak risk (i.e., peak-of-the-mean) and (2). the ensemble of peak doses calculated from each realization within 10000 years. The latter measure appears to have more discriminatory power than the former for many parameters (based on the greater magnitude of the sensitivity coefficient), but can yield different rankings, especially for parameters that influence the timing of releases. 相似文献
958.
Marco Bassetto 《Econometrica : journal of the Econometric Society》2002,70(6):2167-2195
The goal of this paper is to probe the validity of the fiscal theory of the price level by modelling explicitly the market structure in which households and the government make their decisions. I describe the economy as a game, and I am thus able to state precisely the consequences of actions that are out of the equilibrium path. I show that there exist government strategies that lead to a version of the fiscal theory, in which the price level is determined by fiscal variables alone. These strategies are however more complex than the simple budgetary rules usually associated with the fiscal theory, and the government budget constraint cannot be merely viewed as an equilibrium condition. 相似文献
959.
以2008—2016年沪深两市A股上市公司为研究对象,根据税收规避和现金持有相关理论,探讨了税收规避对现金持有水平以及现金持有价值的影响。研究发现,税收规避程度较高的公司,其现金持有水平和超额现金水平较低;现金冗余和现金不足的公司,其税收规避程度存在显著差异;进一步检验发现,现金冗余的公司存在因税收规避程度提高带来的信息不透明和监管薄弱,从而诱发管理层机会主义问题,这也为企业利用税收规避寻租提供了证据;此外,由于代理问题的存在和我国税收制度的特殊背景,税收规避不会显著增加现金持有价值,同时股权结构在税收规避影响现金持有价值的过程中发挥了一定的调节作用,从侧面证明了公司治理机制的重要性。 相似文献
960.
管理者可信行为对员工激励作用的实验研究 总被引：2，自引：0，他引：2
管理者可信行为作为管理者的一种意志行为,能够建立和增强员工对管理者的信任,激励员工提高其努力水平,进而提高个人绩效和组织绩效.运用实验经济学方法,通过设计事前激励契约和惩罚契约两种薪酬契约分别反映管理者实施可信行为和实施不可信行为的实验环境,研究检验管理者可信行为对具有不同互惠倾向的员工的激励作用和效率.实验结果表明,管理者实施可信行为能得到比不实施可信行为更高的员工努力水平和收益.在管理者实施可信行为的情况下,具有较高正互惠倾向的员工将付出比具有较低正互惠倾向的员工更高的努力水平;在管理者实施不可信行为的情况下,具有较高负互惠倾向的员工将付出比具有较低负互惠倾向的员工更低的努力水平. 相似文献