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901.
This article uses a demographic approach and data from the Health and Retirement Survey, a nationally representative sample of the U.S. population, to investigate sex differences in the length of life lived with heart disease and after a heart attack for persons in the United States age 50 and older. On average, women live longer than men with heart disease. At age 50 women can expect to live 7.9 years and men 6.7 years with heart disease. The average woman experiences heart disease onset three years older and heart attacks 4.4 years older than men. 相似文献
902.
903.
This paper examines the relationship between subjective well-being and domain satisfactions. In the past different models have been specified. The most commonly applied model is the bottom-up model in which domain satisfactions affect subjective well-being. The more recent top-down model suggests a reversed relationship. Finally there is the supposition that the correlations between these variables can be spurious due to the effect of personality characteristics. Empirical research has shown that different models are found for different domains and in different countries. Focussing on the effects of the domain satisfactions of finances, housing and social contacts it has been found that subjective well-being is mainly affected by satisfaction with social contacts in Western developed countries and by satisfaction with finances in East European countries. The question we should like to answer in this study is whether a similar pattern obtains for the factors which influence subjective well-being among the different race groups in South Africa. Interestingly, coloured people and Asians did indeed show the expected effects but the groups with the most extreme living conditions did not. Evaluation of life circumstances by black and white South Africans was determined by expectations for the future rather than by current living conditions. This surprising result is discussed in the light of the political situation in South Africa. 相似文献
904.
Drawing on Delgado and Yosso’s counterstory, Yosso’s community cultural wealth, and Alsup’s borderland discourses, the authors, who are women of color academics, use narratives from their lives to discuss the ways in which they draw on resources in managing and reconfiguring their multiple identities within the academy. These include identities of scholars, mentors, teachers, community members, mothers, and partners. They suggest that rather than merely being socialized into cultural reproduction, as much of the literature oriented toward women of color advises them to do in order to become successful, they seek to actually engage in transforming their roles and that of the academy by consciously and repeatedly making present and visible facets of identity that have previously been more-or-less absent in higher education. By presenting these counter-narratives the authors attempt to engage with ways of self-positioning that are, especially for women of color in academia, not frequently discussed or presented. 相似文献
905.
Two heuristics based on branch and bound (B&B) are developed to solve closed-loop material requirements planning (MRP) lot-sizing problems that have general product structures and variable costs. A “look ahead method'’(LAM) heuristic allows for variable production/purchasing costs and uses a single-level B&B procedure to rapidly improve lower bound values; thus, LAM efficiently uses computer-storage capacity and allows solution of larger problems. The “total average modification'’(TAM) heuristic uses B&B, applied level by level, and modified setup and carrying costs to solve the variable production/purchasing costs MRP lot-sizing problem. LAM and TAM are tested on problems and compared to heuristics in the literature. TAM may be used to solve large MRP lot-sizing problems encountered in practice. 相似文献
906.
Scientific techniques for inventory management typically are applied to systems containing many items. Such techniques require an estimation of the demand variance (and mean) of each item from historical data. This research demonstrates a significant potential for improvement in system cost performance from using least-squares regression fits of a variance-to-mean functional relation instead of the standard statistical variance estimate. Even when there is a moderate degree of heterogeneity among items and when the form of the variance-to-mean relation is misspecified, substantial cost savings may be realized. The cost of statistical uncertainty may be reduced by half. The research also provides evidence that system cost is fairly insensitive to the number of items used to fit the regression. This paper provides the underlying reason why a regression-derived variance estimator yields lower cost: it is less variable than the usual individual item variance estimator. 相似文献
907.
This paper develops a warning zone approach to make variance investigation decisions for a multiperiod process. The assumed cost generation process varies between an in-control and out-of-control state. These states cannot be directly observed, but must be inferred from the reported cost variances. Using the warning zone method of inference, the manager investigates the process whenever an upper threshold is exceeded or a lower threshold is exceeded for two consecutive periods. A four-state Markov chain models the resulting decision process. Steady state probabilities are derived for this chain and are used to obtain explicit formulas for the effectiveness and efficiency of the decision process. These formulas permit computation of the cost savings attainable by the warning zone method. Compared to other decision rules, the warning zone method is much simpler than the theoretically optimal Bayesian revision method, but uses more information than the Markovian control limit method. Numerical comparison of results shows that the warning zone method usually captures most of the available cost savings, even in cases where the Markovian control limit method does not perform well. 相似文献
908.
Robert Schoen Nancy S. Landale Kimberly Daniels Yen‐Hsin Alice Cheng 《Journal of marriage and the family》2009,71(2):384-395
Social background has historically been recognized as a major factor influencing family behavior, though recent work has largely emphasized racial/ethnic influences. Here we use 1994 – 1995 and 2001 – 2002 Add Health data to examine the cohabitation, first marriage, and first birth experience of young women. In a multistate life table context, hypothetical cohorts specified in terms of race and mother’s education are followed, from age 11 to age 24, as they move through 6 family‐related statuses. The results indicate that, for both Black and White women, a higher level of maternal education is generally associated with less cohabitation, less marriage, fewer first births, and a higher percentage of women who experience none of those transitions before age 24. Racial and social background differences are conceptually and empirically distinct. Because mother’s education is associated with substantially different trajectories of early family behavior for both Blacks and Whites, we argue that social background merits increased attention in research on contemporary American family patterns. 相似文献
909.
We explored the influences of women's social learning, marital resources and constraints, and exposure to norms about women's family roles on their views about wife hitting or beating among 5,450 participants in the 2005 Egypt Demographic and Health Survey. One half justified wife hitting or beating for some reason. Women from rural areas who were exposed to domestic violence more often justified such acts. Dependent wives whose husbands had more schooling, were blood relatives, and were coresident more often justified such acts. In settings where women tended to marry at older ages, women less often justified such acts. Women's resources and constraints in marriage accounted for the largest share of the variability in their attitudes about domestic violence against women. 相似文献
910.
We consider the fraction of pairs of m distinct alternatives on which a social welfare function f may be nondictatorially independent and Pareto when the domain of f satisfies the free k-tuple property. When k = 4 we improve the existing upper bound to . When there are at least 26 alternatives and we obtain an original upper bound, . To obtain these results we define and analyze the graph formed from the nondictatorial independent and Pareto pairs and
combine the results of this analysis with known results from extremal graph theory.
The authors extend special thanks to the two reviewers and the editor for their comments. 相似文献