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991.
Jaesin Sa PhD Dong-Chul Seo PhD Toben F. Nelson ScD David K. Lohrmann PhD 《Journal of American college health : J of ACH》2013,61(8):454-467
Abstract Objective and Participants: This study explored (1) the prevalence of cigarette smoking among South Korean international college students in the United States, (2) differences in smoking between on- and off-campus living arrangements, and (3) predictors of an increase in smoking over time in the United States Methods: An online survey was completed by 1,201 students at 52 4-year US universities (34% response rate). Results: The overall smoking prevalence was 43.5%. The smoking rate (29.0%) of female students was higher than that (4%) of female college students in South Korea. Sex, living place, living situation, length of stay as a student in the United States, home smoking rules, campus-wide tobacco-free policies, and levels of acculturative stress, anxiety, and depression were significantly associated with an increase in smoking (p < .05). Conclusions: Given the high smoking prevalence among the South Korean students on US college campuses, targeted prevention efforts for these students may be warranted. 相似文献
992.
This paper describes the development of a model for the determination of optimal mean part delivery dates in a stochastic assembly system for the objective of minimizing the expected cost of subassembly and part inventory. Parts are assembled at each station to a subassembly. The part delivery and processing times at assembly stations follow known probability distributions. An approximate solution technique based on the optimization of individual stations in isolation is developed. The approximation applies a correction factor, as a function of the variability in part delivery and processing time, cost parameters and number of stations, to the decisions from the single station solutions to compensate for interdependence between stations. Results indicate that this is an effective approach and yields good near-optimal solutions with very little computational effort. Insights regarding the effect of the type of distribution used, random processing times, variance of the distribution used and cost parameter values on part delivery dates are also reported. 相似文献
993.
In this paper, we revisit the problem of combining estimates of location considered by Cohen (1976). Our results unify and strengthen the results of Cohen (1976), Bhattacharya (1981) and Akai (1982). 相似文献
994.
Approximated QDF misclassification probabilities have been derived for bivariate normal populations with known parameter values. Tne effect of unequal covariances and population distance on the misclassification probabilities are examined 相似文献
995.
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997.
Per Engström 《Social Choice and Welfare》2011,37(1):139-147
The article extends Ng’s (Am Econ Rev 77(1):186–191, 1987) model of optimal taxation of diamond goods—goods that are valued solely for their costliness. We extend his findings by analyzing how other goods should be taxed in
the presence of pure diamond goods; modified Ramsey rules are derived in a basic single-type model as well as in a two-type
model with redistribution. One key finding, that may be surprising and rather provoking, is that close complements (hip hop
music) to diamond goods (bling bling) should be heavily subsidized. 相似文献
998.
We derive a theoretical and parametrized form for a two-way contingency table by using matrix calculus and Kronecker products. 相似文献
999.
Birgitta Törnkvist 《统计学通讯:模拟与计算》2013,42(4):1247-1264
In modelling a system structure it is often important to test the constancy of the structural parameters. If the hypothesis of constant parameters is rejected we wish to characterize the parameter variation. In this paper we examine the usefulness of the MOSUMSQ test statistics for locating and characterizing the parameter variation in linear regression models. The means and the variances of the test statistics are given for non-random parameter variation. The observed path of the MOSUMSQ test statistics provides valuable knowledge about the time of the onset of the parameter change and whether it is instantaneous or gradual. 相似文献
1000.
This note presents an extension of Q-method of analysis for binary designs given by Rao (1956) to n-ary balanced and partially balanced block designs. Here a linked n-ary block (LNB) design is defined as the dual of balanced n-ary (BN) design. Having a note on Yates’ (1939, 1940) method of P-analysis, we further extend the expressions for binary linked block (LB) designs given by Rao (1956) to linked n-ary block (LNB) designs which admit easy estimation of parameters for these type of all n-ary designs. 相似文献