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141.
S'inspirant de Cohen et de Merton, les auteurs enoncent l'hypothese que la delin-quence feminine pourrait etre la consequence de l'ensemble des difficultes que percoivent les jeunes filles dans la poursuite et la realisation de leur desir de se marier. Un groupe experimental d'adolescentes delinquentes et un groupe-con-trole de filles frequentant deux ecoles superieures furent utilisees. Elles durent remplir un questionnaire comportant un index de difficultes et trois echelles distinctes de delinquence, d'angoisse et d'anomie. Les resultats demontrent le fait suivant: bien que les delinquentes pergoivent moins d'obstacles que les autres par rapport a un mariage eventuel, elles manifestent tout de meme plus d'angoisse et plus d'anomie. On essaie d'expliquer ce resultat inattendu.
Inspired by Cohen and Merton the authors hypothesize that female delinquency may be the result of difficulties perceived by girls in the fulfillment of their marital goal. A test group of delinquent girls and a control group of high school girls were administered a questionnaire with an obstacle index, and three separate scales on delinquency, anxiety, and anomie. The findings revealed that although delinquent girls perceived fewer obstacles to their marital goal, they showed higher delinquency, greater anxiety, and higher anomie. The possible explanations are discussed. 相似文献
Inspired by Cohen and Merton the authors hypothesize that female delinquency may be the result of difficulties perceived by girls in the fulfillment of their marital goal. A test group of delinquent girls and a control group of high school girls were administered a questionnaire with an obstacle index, and three separate scales on delinquency, anxiety, and anomie. The findings revealed that although delinquent girls perceived fewer obstacles to their marital goal, they showed higher delinquency, greater anxiety, and higher anomie. The possible explanations are discussed. 相似文献
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Hongmin Li Stephen C. Graves Donald B. Rosenfield 《Production and Operations Management》2010,19(2):142-155
The replacement of an existing product with a new one presents many challenges. In particular, uncertainties in a new product introduction often lead to extreme cases of demand and supply mismatches. This paper addresses inventory planning decisions for product upgrades when there is no replenishment opportunity during the transition period. We allow product substitution: when a company runs out of the old product, a customer may be offered the new product as a substitute. We show that the optimal substitution decision is a time‐varying threshold policy and establish the optimal planning policy. Further, we determine the optimal delay in a new product introduction, given the initial inventory of the old product. 相似文献
145.
Adolescents with high sensation-seeking tendencies often seek out thrill seeking experiences to satisfy their need for stimulation and sensation. In many cases, sensation-seeking adolescents fulfill their need for stimulation and sensation by using illicit substances. However, not all high sensation seekers use drugs, although the factors that prevent or buffer sensation seeking remain unexplored. This study fills this gap in extant research by examining the role of authoritative parenting as a protective factor that prevents or buffers cigarette and marijuana use by adolescents with high sensation-seeking tendencies. Data from 1461 adolescents attending 6th through 8th grades in central Colorado were gathered during a semester-long classroom-based intervention to prevent the onset or further use of cigarettes. Results indicate that authoritative parenting moderated the effect of sensation seeking on adolescent marijuana attitudes, intentions, and peer influence but not behaviors. Further, authoritative parenting was a stronger influence than sensation seeking on cigarette-related outcomes with just the opposite effect observed for marijuana-related outcomes. 相似文献
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Donald W. K. Andrews Xiaoxia Shi 《Econometrica : journal of the Econometric Society》2013,81(2):609-666
In this paper, we propose an instrumental variable approach to constructing confidence sets (CS's) for the true parameter in models defined by conditional moment inequalities/equalities. We show that by properly choosing instrument functions, one can transform conditional moment inequalities/equalities into unconditional ones without losing identification power. Based on the unconditional moment inequalities/equalities, we construct CS's by inverting Cramér–von Mises‐type or Kolmogorov–Smirnov‐type tests. Critical values are obtained using generalized moment selection (GMS) procedures. We show that the proposed CS's have correct uniform asymptotic coverage probabilities. New methods are required to establish these results because an infinite‐dimensional nuisance parameter affects the asymptotic distributions. We show that the tests considered are consistent against all fixed alternatives and typically have power against n−1/2‐local alternatives to some, but not all, sequences of distributions in the null hypothesis. Monte Carlo simulations for five different models show that the methods perform well in finite samples. 相似文献
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In many situations it is necessary to test the equality of the means of two normal populations when the variances are unknown and unequal. This paper studies the celebrated and controversial Behrens-Fisher problem via an adjusted likelihood-ratio test using the maximum likelihood estimates of the parameters under both the null and the alternative models. This procedure allows the significance level to be adjusted in accordance with the degrees of freedom to balance the risk due to the bias in using the maximum likelihood estimates and the risk due to the increase of variance. A large scale Monte Carlo investigation is carried out to show that -2 InA has an empirical chi-square distribution with fractional degrees of freedom instead of a chi-square distribution with one degree of freedom. Also Monte Carlo power curves are investigated under several different conditions to evaluate the performances of several conventional procedures with that of this procedure with respect to control over Type I errors and power. 相似文献
150.
Results from classical linear regression regarding the effects of covariate adjustment, with respect to the issues of confounding, the precision with which an exposure effect can be estimated, and the efficiency of hypothesis tests for no treatment effect in randomized experiments, are often assumed to apply more generally to other types of regression models. In this paper results pertaining to several generalized linear models involving a dichotomous response variable are given, demonstrating that with respect to the issues of confounding and precision, for models having a linear or log link function the results of classical linear regression do generally apply, whereas for other models, including those having a logit, probit, log-log, complementary log-log, or generalized logistic link function, the results of classical linear regression do not always apply. It is also shown, however, that for any link function, covariate adjustment results in improved efficiency of hypothesis tests for no treatment effect in randomized experiments, and hence that the classical linear regression results regarding efficiency do apply for all models having a dichotomous response variable. 相似文献