Gender,race, and subjective social class and their association with leisure preferences

Abstract

This study examines the leisure preferences of subgroups defined by gender, race, and subjective social class. The multiple hierarchy stratification perspective and the class polarization perspective provided the theoretical rationale for the study, and a secondary data set from a national probability telephone survey was used. The interviews obtained information regarding the leisure preferences of adults age 21 to 65. From 2,148 contacts, 1, 711 interviews were completed. The results provide partial support for the study's hypotheses. Poor‐working‐class Black women were distinct from White men and women and middle‐class Black men, but they were similar to the other Black groups. As hypothesized, the leisure preferences of middle‐class Black and White men were similar. However, contrary to the study's hypothesis, Black men of different classes did not exhibit greater dissimilarity when compared with Black women of different classes.     

小商品市场发展与义乌社会阶层分化

浙江是市场大省、民营经济大省,专业市场和产业集群相结合的发展模式下,浙江新世纪以来,社会转型加速,新的社会阶层快速成长,并在经济社会生活中占据重要地位;社会各阶层结构在经济建设大潮中界限渐趋模糊,人员阶层归属多元化;非阶层组织相对活跃,现有阶层类别共性弱化、差异性增大。义乌是浙江经济发展的缩影,义乌新世纪社会转型特征和社会阶层分化状况部分反映着浙江全貌,并预示着社会阶层进一步分化的趋势。     

中国农村居民家庭医疗消费支出的影响因素及弹性分析

文章基于QUAIDS模型,采用2010年全国农村固定观察点截面数据,探讨农村居民家庭医疗消费支出的影响因素及其需求弹性,并进一步分析不同收入农户医疗消费的价格弹性。结论显示,家庭规模、家庭收入对医疗消费支出有正向影响,家庭劳动力人数、地区差异对其有负向影响;医疗服务大体上仍属于生活必需品,但随着收入的增加,农户将增加对医疗服务的消费;对农户进行收入补偿,能够减少食品消费价格上升对医疗消费支出的负向影响;相对于高收入农户,其他消费品价格的提高对低收入农户医疗消费的影响较大。     

"模糊、层次、综合评价"优化配置水资源

配置水资源是社会、政治、经济、环境、生态等多元、庞大完整、错综复杂的系统工程，进行配置时，应使其所涉及问题的综合目标最大化，据此，用“模糊、层次、综合评价”方法配置水资源是合适有效的。     

防渗墙作用下堤防保护区地下水动态数值模拟分析工：模型、参数及分析方法

介绍了能够考虑水文气象过程的饱和非饱和非稳定地下水流运动数学模型。以全封闭和半封闭式防渗墙为重点研究埘象，以长江重要堤防为背景概化得到典型二元和多元结构堤基、堤身断面及土层的饱和非饱和渗流参数；以实测资料为基础概化得到较典型的水文气象过程，提出降雨入渗和蒸发排泄边界处理方式以及初始条件确定方法；提出根据二维模型模拟结果用有无对比法分析防渗墙对地下水动态的影响，根据三维模型模拟结果分析防渗墙端部绕渗对地下水流场动态的影响。模型和参数具有典型性，研究方法合理、有效。     

The Impact of Surface Heat Flux and Wind on Thermal Stratification in Portage Lake,Michigan

Portage Lake is situated near the center of the Keweenaw Peninsula and is connected to Lake Superior via lengthy (> 7 km) navigation channels. Using moored thermistor records and meteorological data, we examine how changes in lake stratification are related to surface winds and heat flux. Frequent episodes of full water column mixing are observed throughout the summer. Convective mixing through surface cooling appears to be an important agent responsible for these events, as all occur during cold air outbreaks and when the net heat flux is directed out of the lake (negative). However, wind-induced mixing is also implicated in contributing to some vertical mixing events, as evidenced by two events initiated during a period of strong winds and declining, but not yet negative, heat fluxes. Our analysis indicates that each time the water column restratifies, it tends to become more susceptible to convectively-driven overturn during cold air outbreaks. This tendency is quantified by the estimated time over which surface cooling due to a specified set of conditions, characteristic of a cold air outbreak, would reduce the temperature contrast between the upper and lower layers by half. This time declines by more than an order of magnitude for successive restratification events observed in the summer of 1999. Our analysis also reveals successive formation and dissolution of a diurnal surface mixed layer in an otherwise homogeneous water column during a 10-day period of August 1999. This is attributed to the combination of relatively light winds and negative daily net heat fluxes.     

Seasonal stratification and mixing in a recently flooded mining void in tropical Australia

Enterprise Pit Lake is a water-filled mining void located in Australia's wet/dry tropics south of Darwin in the Northern Territory (13°49.6'S, 131°49.8'E). In the mid-1990s, the void was rapidly filled by the artificial diversion of the nearby Pine Creek watercourse. Profile data and surface water quality data were collected in the lake on a monthly basis from November 1998 to October 1999. Analysis of this data showed that Enterprise Pit Lake was strongly stratified for most of the year with deep mixing occurring once during the middle of the cool, dry season ( August, 1999 ). The relatively small volume of its epilimnion and its low productivity allowed significant oxygen concentrations to remain in the hypolimnion of the lake when it was strongly stratified. Low pH values in a layer of water with a depth of approximately 35 m and located in the lake's hypolimnion might be associated with several factors, including enhanced sulphide oxidation on the walls of the pit in this region.     

Analysis of treatment response data from eligibility designs

In this paper, we develop and compare two alternative approaches for calculating the effect of the actual intake when treatments are randomized, but compliance with the assignment in the treatment arm is less than perfect for reasons that are correlated with the outcome. The approaches are based on different identification assumptions about these unobserved confounders. In the first approach, which stems from [Sommer, A., Zeger, S., 1991. On estimating efficacy in clinical trials. Statistics in Medicine 10, 45–52], the unobserved confounders are modeled by a discrete indicator variable that represents subject-type, defined in terms of the potential intake in the face of each possible assignment. In the second approach, confounding is modeled without reference to subject-type in the spirit of the Roy model. Because the two models are non-nested, and model comparison and assessment of the approaches in a real data setting is one of our central goals, we formulate the discussion from a Bayesian perspective, comparing the two models in terms of marginal likelihoods and Bayes factors, and in terms of inferences about the treatment effects. The latter we calculate from a predictive perspective in a way that is different from that in the literature, where typically only a point summary of that effect is calculated. Our real data analysis focuses on the JOBS II eligibility trial that was implemented to test the effectiveness of a job search seminar in decreasing the negative mental health effects commonly associated with job loss. We provide a comparative analysis of the data from the two approaches with prior distributions that are both reasonable in the context of the data and comparable across the model specifications. We show that the approaches can lead to different evaluations of the treatment.     

A General Algorithm for Univariate Stratification

This paper presents a general algorithm for constructing strata in a population using  X , a univariate stratification variable known for all the units in the population. Stratum  h  consists of all the units with an  X  value in the interval   [ b _{h −1},  b_h )   . The stratum boundaries   { b_h }   are obtained by minimizing the anticipated sample size for estimating the population total of a survey variable  Y  with a given level of precision. The stratification criterion allows the presence of a take-none and of a take-all stratum. The sample is allocated to the strata using a general rule that features proportional allocation, Neyman allocation, and power allocation as special cases. The optimization can take into account a stratum-specific anticipated non-response and a model for the relationship between the stratification variable  X  and the survey variable  Y . A loglinear model with stratum-specific mortality for  Y  given  X  is presented in detail. Two numerical algorithms for determining the optimal stratum boundaries, attributable to Sethi and Kozak, are compared in a numerical study. Several examples illustrate the stratified designs that can be constructed with the proposed methodology. All the calculations presented in this paper were carried out with stratification , an R package that will be available on CRAN (Comprehensive R Archive Network).     

高速铁路路基填筑分层规划技术

沪昆高速铁路DK219+469～DK221+319段为路基地段,受工程地质条件差异性变化影响,基底高程相差很大。结合施工单位的地质钻探勘验资料、设计地质文件,描绘出更为详细的地质断面图,再根据路基基底、过渡段的处理要点及基底高程来划分路基填筑过程中每层的起终点里程与层数,最终形成整段路基各个区段的填筑分层规划图,最直接地体现设计意图。路基填筑分层规划技术是指导路基填筑施工的主要技术措施,是路基填筑施工管理的核心内容。