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1.
This paper deals with a single server Poisson arrival queue with two phases of heterogeneous service along with a Bernoulli schedule vacation model, where after two successive phases service the server either goes for a vacation with probability p (0≤p≤1) or may continue to serve the next unit, if any, with probability q(=1−p). Further the concept of multiple vacation policy is also introduced here. We obtained the queue size distributions at a departure epoch and at a random epoch, Laplace Stieltjes Transform of the waiting time distribution and busy period distribution along with some mean performance measures. Finally we discuss some statistical inference related issues.  相似文献   
2.
从中介语语用学与听力策略对听力教学的指导作用得到启发,尝试以中介语语用学为理论指导,以TEM大纲为实践指导,在前人学习策略教学实证实践的基础上,提出按照二语习得理论中Krashen的"监察模式"(包括五个假说),以加强英语专业听力教学的中介语语用意识和语用能力训练。  相似文献   
3.
Utilisant des données sur le droit du travail dans six pays (Allemagne, Etats‐Unis, France, Japon, Royaume‐Uni et Suède) entre 1970 et 2010, les auteurs évaluent les effets de la réglementation du travail sur le chômage et la part du travail dans le revenu national. Leur méthode montre la différence entre les effets à court et à long terme des changements de réglementation: la législation protectrice des travailleurs n'est pas associée de façon systématique avec le chômage, mais est corrélée positivement avec la part du travail dans le revenu national. Les dispositions relatives au temps de travail et la représentation des salariés ont des effets bénéfiques tant sur l'efficacité que sur la répartition.  相似文献   
4.
Les auteurs examinent la différence entre fuites et alertes, ou dénonciations, notamment quant à la protection de leurs initiateurs. A ce propos, ils étudient les dispositions des conventions internationales sur les droits de l'homme et la corruption, ainsi que les textes en vigueur en Allemagne, aux Etats‐Unis, en France et au Royaume‐Uni. Leurs résultats mettent en évidence la complexité et les contradictions des questions en jeu: intérêt général et intérêts individuels, commerciaux et financiers; abus de pouvoir; sécurité et confidentialité face à la communication électronique; place de l'individu dans l'application de la loi; relations d'emploi.  相似文献   
5.
王革英 《云梦学刊》2012,33(2):140-147
新TEM4(Test for English Majors)在题量、时长、内容及能力四个方面进行了改革,倾向于测量学生的英语综合运用能力。新TEM4在检查学生是否达到了大纲所规定的各项英语专业基础阶段的技能要求和教学质量评估方面有高度的信度和效度。研究显示:在所有的基础阶段专业技能课程中,基础英语课和TEM4互动最大;选择优秀教材并将基础英语课的教学手段———听写、背诵、课堂陈述和语篇分析和TEM4测试内容进行和谐地融合,不仅能大力提高4级过关率,还能促进基础英语课教学质量的提高。  相似文献   
6.
In this paper, we empirically assess the role of individual social capital on personal bankruptcy and default outcomes in the consumer credit market. After controlling for a borrower’s risk score, debt, income, wealth, and legal and economic environments, we find that default/bankruptcy risk rises and then falls over the lifecycle, while a borrower who owns a home or is married has a lower risk of default/bankruptcy. Moreover, a borrower who migrates 190 miles from his “state of birth” is 17% more likely to default and 15% more likely to file for bankruptcy, while a borrower who continues to live in his state of birth is 14% and 10% less likely to default and file for bankruptcy, respectively. A borrower who moves to a rural area is 9% and 7% less likely to default and declare bankruptcy, respectively. We also find that measures of social networks, norms, and cooperation and trust (i.e., aggregate social capital) are inversely related to consumer bankruptcy.  相似文献   
7.
In this article, we introduce three new distribution-free Shewhart-type control charts that exploit run and Wilcoxon-type rank-sum statistics to detect possible shifts of a monitored process. Exact formulae for the alarm rate, the run length distribution, and the average run length (ARL) are all derived. A key advantage of these charts is that, due to their nonparametric nature, the false alarm rate (FAR) and in-control run length distribution is the same for all continuous process distributions. Tables are provided for the implementation of the charts for some typical FAR values. Furthermore, a numerical study carried out reveals that the new charts are quite flexible and efficient in detecting shifts to Lehmann-type out-of-control situations.  相似文献   
8.
The Color Additives Scientific Review Panel considered whether there was information sufficient to perform a carcinogenic risk assessment on the colors D&C Red No. 19 (R-19), D&C Red No. 37 (R-37), D&C Orange No. 17 (O-17), D&C Red No. 9 (R-9), D&C Red No. 8 (R-8) and FD&C Red No. 3 (R-3) and to evaluate the assessments sent to FDA as part of the petitions for use of the colors for drug and external uses by the Cosmetic, Toiletry and Fragrance Association (CTFA). There is a lack of human data concerning the colors for making a human health assessment, so the assessments are based upon the extrapolation of animal data. The risk assessments are determined for exposure to single chemicals. Excluded from consideration are possible effects from exposure to multiple chemicals, such as co-carcinogenesis, promotion, synergism, antagonism, etc. In the light of recent efforts in establishing a consensus in risk assessment, the Panel has determined that the CTFA assessments for R-10, O-17, and R-9 are consistent with present acceptable usages, although it questions some of the assumptions used in the assessments. The Panel identified a number of general assumptions made, and discusses their validity, their impact on total uncertainty, and the potential options to address the gaps in understanding that necessitate the assumption. The Panel also derived revised risk estimates using more "reasonable" assumptions than "worst-case" situations, for 90th percentile and average exposure. For those assumptions that are easily quantifiable, the Panel's estimates are less than an order of magnitude lower than the CTFA risk estimates, indicating that the underestimates and overestimates of the CTFA risk estimates tend to balance each other. The impact of most of the assumptions is not quantifiable. The assessment for R-3 is complicated by the fact that there is no good skin penetrance study for this color. It was assumed that the penetrance is similar to that of another water-soluble xanthene color, R-19. It is expected that the absorption of the color is not likely to exceed that of the smaller molecule, R-19. Therefore, the risk estimates are similar to the CTFA estimates, but with different reasoning. The estimates for R-8 and R-37 are different from the others in that there is a lack of any exposure or toxicological information on these colors.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
9.
This paper deals with the construction of optimum partitions of for a clustering criterion which is based on a convex function of the class centroids as a generalization of the classical SSQ clustering criterion for n data points. We formulate a dual optimality problem involving two sets of variables and derive a maximum-support-plane (MSP) algorithm for constructing a (sub-)optimum partition as a generalized k-means algorithm. We present various modifications of the basic criterion and describe the corresponding MSP algorithm. It is shown that the method can also be used for solving optimality problems in classical statistics (maximizing Csiszárs -divergence) and for simultaneous classification of the rows and columns of a contingency table.  相似文献   
10.
There has been much discussion about the factors underlying inflation in the health care sector and the means to moderate increases in health expenditures. This paper identifies various costcontainment strategies and synthesizes research findings that may be helpful in evaluating their effectiveness. The review demonstrates the complexity of the issues and relationships that must be confronted and understood in cost containment. The delivery system is shown to be not well-suited to improving efficiency and restraining health care expenditure. Any single strategy, whether it involves restructuring the market or more direct regulation, cannot in itself accomplish the combination of expenditure control and adequacy of services that is socially desirable. A number of mutually reinforcing strategies are required. Finally, more empirical and analytical information on incentives, provider and regulatory decisionmaking, costs of regulation, and the dynamics of negotiation, is essential for the design of an effective costcontainment program.  相似文献   
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