股市危机中股指期货应该限制交易吗——基于2015年股市危机的实证分析

利用上证50、沪深300和中证500股指期货合约及其相应指数的高频数据,克服了传统BEKK和DCC模型的不足,通过建立VECM-DCC-VARMA-AGARCH模型考察股市危机期间中国股指期货市场与股票市场之间的信息传导关系与风险传染效应。研究结果表明,股市危机期间股指期货具有很强的价格引导和风险传染效应,股指期货的持续波动加剧了股票市场的进一步波动。因此,提出风险传染效应与市值规模相关、非对称效应和非预期冲击效应与市值规模负相关、波动的风险传染效应与市值规模正相关。危机时期,应抑制股指期货市场上的过度投机,对股指期货采取限制开仓、提高交易保证金和交易手续费都是正确和切实可行的措施。建议监管当局健全股指期货和股票市场交易制度。     

The impact of age,BMI and sex hormone on aging males’ symptoms and the international index of erectile function scores

Objective: To analyze the impact of age, BMI and sex hormone on aging males’ symptoms (AMS) and the 5-item version of the international index of erectile function (IIEF-5) scores in middle-aged and elderly Chinese men.

Methods: A population-based cross-sectional study was conducted in Jiashan County. A total of 969 men, aged between 40 and 80 years old, were admitted. Physical examination and the sex hormones were measured, and AMS and IIEF-5 scores were assessed.

Results: The oneway ANOVA analysis indicated older age groups had higher AMS total-scores, somatic and sexual sub-scores, and lower IIEF5 scores (all p?r_pairwise) analyses showed the significant associations between AMS and age or sex hormone (cFT, Bio-T, SHBG, and LH) levels, and similar for IIEF5. However, when age was adjusted, the correlation coefficients (r_partial) weakened, and correlation significance disappeared, except LH (for AMS: r_partial?=?0.096, p?=?.009; for IIEF-5: r_partial?= ?0.140, p?=?.001). Multiple linear regressions confirmed the influence of increased age and LH on the AMS and IIEF5 scores.

Conclusion: CFT, Bio-T and SHBG failed to yield any additional predicting information when age was adjusted. To improve the male reproductive health, future research should pay more attention on aging-related comorbidities and how to improve general wellness.     

An M/G/1 clearing queueing system with setup time and multiple vacations for an unreliable server

This paper studies an M/G/1 clearing queueing system with setup time and multiple vacations, in which all present customers in the system are served simultaneously and breakdowns may occur in busy or setup period. We investigate the stationary distribution of system size and the Laplace–Stieltjes transform of sojourn time. In addition, various performance measures are discussed, such as the mean system size at arbitrary time and the mean length of a vacation circle. Moreover, a cost analysis is carried out for this queueing system. Numerical results are presented to study the sensitivity of the system parameters on the expected cost function and system performances.     

An Extended Single‐index Model with Missing Response at Random

An extended single‐index model is considered when responses are missing at random. A three‐step estimation procedure is developed to define an estimator for the single‐index parameter vector by a joint estimating equation. The proposed estimator is shown to be asymptotically normal. An algorithm for computing this estimator is proposed. This algorithm only involves one‐dimensional nonparametric smoothers, thereby avoiding the data sparsity problem caused by high model dimensionality. Some simulation studies are conducted to investigate the finite sample performances of the proposed estimators.     

城市管理导向的居民幸福指数测评研究——以安徽省为例

提高居民的幸福指数是新常态下城市管理的重点工作。在综述以往研究的基础上，以需要层次论作为理论依据，整合2015年度安徽省统计年鉴数据完整、准确的指标，构建了安徽省城市居民幸福指数体系，经过数据收集、统计、分析和综合，得出16个城市居民综合幸福指数、基本需求幸福指数、发展需求幸福指数、享受需求幸福指数分值，对结果及其应用价值进行了讨论。     

Stakeholder Performance Measurement in Nonprofit Organizations

According to recent findings, nonprofit organizations should address the relationships of nonprofit service quality, satisfaction, loyalty, and organizational identification when planning and evaluating donor surveys. This article presents a donor satisfaction barometer that can be used to gain insights into the strength of these key relationships and thereby establish a basis for calculated relevant indices. With such indices, nonprofit organizations can compare stakeholder performance over time and benchmark themselves against other organizations. Data from 2,599 blood donors to one section of the German Red Cross, collected through the proposed donor satisfaction barometer, show that service quality drives satisfaction, and donor satisfaction and organizational identification both exert significant positive effects on donor loyalty. Therefore, nonprofit organizations should use a combined strategic approach that improves both donor satisfaction and organizational identification to increase donor loyalty. The successful application of the donor satisfaction barometer also suggests its value for other nonprofit industries and offers important insights for managers.     

Discovering hidden statistical issues through individual-level models in ecological studies

ABSTRACT

In ecological studies, individual inference is made based on results from ecological models. Interpretation of the results requires caution since ecological analysis on group level may not hold in the individual level within the groups, leading to ecological fallacy. Using an ecological regression example for analyzing voting behaviors, we highlight that the explicit use of individual-level models is crucial in understanding the results of ecological studies. In particular, we clarify three relevant statistical issues for each individual-level models: assessment of the uncertainty of parameter estimates obtained from a wrong model, the use of shrinkage estimation method for simultaneous estimation of many parameters, and the necessity of sensitivity analysis rather than adhering to one seemingly most compelling assumption.     

Construction of closed interval for process capability indices Cpu,Cpl, and Spk based on Boole’s inequality and de Morgan’s laws

ABSTRACT

Considerable effort has been spent on the development of confidence intervals for process capability indices (PCIs) based on the sampling distribution of the PCI or the transferred PCI. However, there is still no definitive way to construct a closed interval for a PCI. The aim of this study is to develop closed intervals for the PCIs C_pu, C_pl, and S_pk based on Boole's inequality and de Morgan's laws. The relationships between different sample sizes, the significance levels, and the confidence intervals of the PCIs C_pu, C_pl, and S_pk are investigated. Then, a testing model for interval estimation for the PCIs C_pu, C_pl, and S_pk is built as a powerful tool for measuring the quality performance of a product. Finally, an applied example is given to demonstrate the effectiveness and applicability of the proposed method and the testing model.     

第三方物流外包服务综合绩效评估模型的构建

本文根据全面性、特殊性、可比性、可操作性原则,参考评价第三方物流企业的一般评价指标的选取原则,选取了包括运力资源利用率、固定资产周转率、订单完成率、配送资源利用率等20个具有代表性的指标,详细地构建了第三方企业物流系统综合评价指标体系,并采用主成分因子分析法对企业物流系统进行了综合评价。     

Using institutional ethnography's ideological circle to portray how textually mediated disability discourse paralysed a Supreme Court of Canada ruling

Persons with disabilities created through texts as damaged goods are being ‘cured’ by workplace accommodation, a textually mediated work process. Prior to 1999, workplace accommodation in the Canadian federal public service signified the adjustments necessary to enable a disabled worker to fit into a workplace designed for able-bodied workers. In 1999, a Supreme Court of Canada (SCC) ruling known as Meiorin turned this accommodation provision on its head. Instead of being focused on individual-level fixes so that a disabled worker could be accommodated in an existing workplace, this legislation required employers to transform their workplaces so as to make them ready to receive as many different types of workers as reasonably possible from the outset. Using Dorothy E. Smith's institutional ethnography, I use my experiences as a disability rights activist employed in the Canadian federal public service to explicate how textually mediated disability discourse paralysed this groundbreaking SCC ruling.