“That's So Gay!”: Examining the Covariates of Hearing This Expression Among Gay,Lesbian, and Bisexual College Students

Abstract

Objective: The investigators examined the health and well-being correlates of hearing the popular phrase “that's so gay” among gay, lesbian, and bisexual (GLB) emerging adults. Participants: Participants were 114 self-identified GLB students aged 18 to 25 years. Methods: An online survey was distributed to students at a large public university in the Midwest during winter 2009. Results: Participants’ social and physical well-being was negatively associated with hearing this phrase, specifically feeling isolated and experiencing physical health symptoms (ie, headaches, poor appetite, or eating problems). Conclusions: College professionals and student leaders must acknowledge that the phrase is a form of heterosexist harassment. As such, policies addressing diversity and harassment should address students’ use of this phrase, aiming to reduce its use. Additionally, colleges and universities should develop practices that counteract poorer well-being associated with hearing the phrase.     

秦皇岛市高中生体育消费行为的调查

通过秦皇岛市5所高中621名学生的调查问卷,对高中生的体育消费行为进行调查。结果表明,秦皇岛市高中生体育消费的年级差异显著,在消费动机方面性别差异显著。高中生的体育消费受到家庭、学校、媒体信息等多种因素的影响。     

基于RiskMetrics模型的单个期货合约保证金比例设计

为了规避价格波动风险,期货交易所应该采取动态保证金设置方式。本文对单个期货合约的日收益序列建立了基于RiskMetrics的VaR模型,用滚动样本预测下一交易日的VaR值,而LR检验表明所建立的VaR模型能较好地测度价格波动风险。因此,下一交易日保证金比例可以设置为预测的VaR值和所规定的涨跌停板率的最小值,这样就能以相应的概率抵御该交易日价格波动带来的风险。     

陕西上市公司GDP贡献及可持续发展研究

选取陕西省在上海和深圳证券交易所的上市公司为样本.利用Eviews5.0对1997-2006年陕西GDP和所选上市公司净资产收益率、每股收益以及主营业务增长率进行了ADF单位根检验、Johansen协整检验和格兰杰(Granger)因果检验,发现陕西省经济发展数据和上市公司指标都是一阶平稳序列,且存在两个协整关系,上市公司的每股收益与GDP还具有反常的Granger因果关系.在陕西经济持续稳定增长的同时,上市公司的每股收益却逐年下降,可持续发展能力匮乏.     

基于企业社会责任的闭环供应链超网络均衡模型

文章为研究企业社会责任对闭环供应链总体效率及决策行为的影响,考虑到多层多成员多目标决策的闭环供应链网络中同层非合作竞争决策者,以利润最大、排放废气最小、风险最小为目标,构建了由供应商、制造商、零售商、需求市场和回收商组成的超网络模型.该模型利用均衡理论及变分不等式的方法分析各层决策者的独立决策行为及其相互作用,并通过改进的投影梯度算法求得均衡点.通过三个算例分析得出企业社会责任水平对产品的交易平衡和价格水平的影响.     

Bayesian analysis of a multiple-recapture model

In the Bayesian analysis of a multiple-recapture census, different diffuse prior distributions can lead to markedly different inferences about the population size N. Through consideration of the Fisher information matrix it is shown that the number of captures in each sample typically provides little information about N. This suggests that if there is no prior information about capture probabilities, then knowledge of just the sample sizes and not the number of recaptures should leave the distribution of Nunchanged. A prior model that has this property is identified and the posterior distribution is examined. In particular, asymptotic estimates of the posterior mean and variance are derived. Differences between Bayesian and classical point and interval estimators are illustrated through examples.     

An adaptive sampling scheme guided by BART—with an application to predict processor performance

The evaluation of new processor designs is an important issue in electrical and computer engineering. Architects use simulations to evaluate designs and to understand trade‐offs and interactions among design parameters. However, due to the lengthy simulation time and limited resources, it is often practically impossible to simulate a full factorial design space. Effective sampling methods and predictive models are required. In this paper, the authors propose an automated performance predictive approach which employs an adaptive sampling scheme that interactively works with the predictive model to select samples for simulation. These samples are then used to build Bayesian additive regression trees, which in turn are used to predict the whole design space. Both real data analysis and simulation studies show that the method is effective in that, though sampling at very few design points, it generates highly accurate predictions on the unsampled points. Furthermore, the proposed model provides quantitative interpretation tools with which investigators can efficiently tune design parameters in order to improve processor performance. The Canadian Journal of Statistics 38: 136–152; 2010 © 2010 Statistical Society of Canada     

A general approximation to quantiles

For many continuous distributions, a closed-form expression for their quantiles does not exist. Numerical approximations for their quantiles are developed on a distribution-by-distribution basis. This work develops a general approximation for quantiles using the Taylor expansion. Our method only requires that the distribution has a continuous probability density function and its derivatives can be derived to a certain order (usually 3 or 4). We demonstrate our unified approach by approximating the quantiles of the normal, exponential, and chi-square distributions. The approximation works well for these distributions.     

Maximum likelihood estimation of the bimodal failure rate for censored and tied observations

DIMITROV, RACHEV and YAKOVLEV ( 1985 ) have obtained the isotonic maximum likelihood estimator for the bimodal failure rate function. The authors considered only the complete failure time data. The generalization of this estimator for the case of censored and tied observations is now proposed.