Inference and optimal design of multiple constant-stress testing for generalized half-normal distribution under type-II progressive censoring

The generalized half-normal (GHN) distribution and progressive type-II censoring are considered in this article for studying some statistical inferences of constant-stress accelerated life testing. The EM algorithm is considered to calculate the maximum likelihood estimates. Fisher information matrix is formed depending on the missing information law and it is utilized for structuring the asymptomatic confidence intervals. Further, interval estimation is discussed through bootstrap intervals. The Tierney and Kadane method, importance sampling procedure and Metropolis-Hastings algorithm are utilized to compute Bayesian estimates. Furthermore, predictive estimates for censored data and the related prediction intervals are obtained. We consider three optimality criteria to find out the optimal stress level. A real data set is used to illustrate the importance of GHN distribution as an alternative lifetime model for well-known distributions. Finally, a simulation study is provided with discussion.     

基于遗传算法的装备采购决策优化研究

在装备采购中，由于需求单位地域分布和担负的任务各不相同，对装备的品种、数量、时限要求也就不一样，如何使装备采购科学化、合理化，是一个涉及多变量、多目标的复杂系统问题。在综合考虑装备采购各项因素的基础上，构建多约束条件下的多目标模糊指派模型，提出了基于遗传算法的解决方案，最后通过案例进行仿真实验，验证该算法的可行性和有效性，解决了采用传统优化方法难以解决的装备采购优化决策问题。     

Childbearing and Marriage: Investigating the Importance of Context for Meaning-Making of First-Time Marriage

Previous research reveals that the temporal ordering of childbearing and marriage can have an impact on the meaning of first-time marriage. This article aims to obtain a deeper understanding of meaning-making of first-time marriage in relation to childbearing. Narrative interviews with 16 brides and grooms in 8 couples in Sweden were conducted. The material was analyzed in relation to the temporal ordering of childbearing and marriage. The study reveals that the construction of meaning of marriage does not only relate to the temporal context. Social factors such as social class or family formation might also be relevant for how meaning is constructed. This article contributes to a deeper understanding of meaning-making as a relational process constructed within particular contexts.     

Gender Differences in Union Formation in Mexico: Evidence From Marital Search Models

Although increasingly appreciated for their explanatory power in developed societies, marital search models have yet to be widely applied to developing nations. This article evaluates the applicability of marital search models to marriage timing in Mexico. The analysis compares separate models of union formation for men and women that include individual and marriage market predictors. Results show that union formation is closely linked to the uncertainties surrounding the transition to adulthood and the availability of marriageable partners. Improvements in women's economic position do not diminish the attractiveness of marriage, as female independence arguments would suggest. Instead, they are a central force behind the stability of marriage behavior in Mexico. A central transformation identified in the analysis is the reduction in sex differences in age at marriage as women expand their education and labor force participation.     

春秋时期的媵制及其盛行原因

媵制指一个贵族男子娶妻 ,这个妻的侄、娣 (妹 )也随同她一同陪嫁 ,这侄娣随姑、姊同嫁一夫的婚俗 ,在春秋时期的诸侯和士大夫中相当盛行 ,对春秋时期的政治联盟、社会稳定和婚姻外交起过十分重要的作用。这种制度的盛行 ,不仅与史前文化的遗存及西周春秋时期的宗法继承制有关 ,而且与春秋时期特殊的历史背景和现实需要有关     

社会性别与深层道德结构--择偶、性的道德模式

在男权文化占主导地位的社会环境中,男女在择偶和性的道德模式上存在着完全不对等的规范,男女占有不同的社会资源,这些被长久地视为自然而然、合情合理的现象。文章试图从社会性别视角来探究隐藏在择偶和性风俗习惯背后的不平等的道德模式。     

探析蒙古考验婚史诗与好汉三项比赛

好汉三项比赛从萨满教祭祀仪式演变成为衡量好汉的价值标准之后 ,渐渐渗透于蒙古英雄史诗之中 ,在原有完成任务式考验婚史诗的基础上 ,出现了复合式考验婚史     

Statistical Distributions of Daily Breathing Rates for Narrow Age Groups of Infants and Children

Children may be more susceptible to toxicity from some environmental chemicals than adults. This susceptibility may occur during narrow age periods (windows), which can last from days to years depending on the toxicant. Breathing rates specific to narrow age periods are useful to assess inhalation dose during suspected windows of susceptibility. Because existing breathing rates used in risk assessment are typically for broad age ranges or are based on data not representative of the population, we derived daily breathing rates for narrow age ranges of children designed to be more representative of the current U.S. children's population. These rates were derived using the metabolic conversion method of Layton (1993) and energy intake data adjusted to represent the U.S. population from a relatively recent dietary survey (CSFII 1994–1996, 1998). We calculated conversion factors more specific to children than those previously used. Both nonnormalized (L/day) and normalized (L/kg-day) breathing rates were derived and found comparable to rates derived using energy estimates that are accurate for the individuals sampled but not representative of the population. Estimates of breathing rate variability within a population can be used with stochastic techniques to characterize the range of risk in the population from inhalation exposures. For each age and age-gender group, we present the mean, standard error of the mean, percentiles (50th, 90th, and 95th), geometric mean, standard deviation, 95th percentile, and best-fit parametric models of the breathing rate distributions. The standard errors characterize uncertainty in the parameter estimate, while the percentiles describe the combined interindividual and intra-individual variability of the sampled population. These breathing rates can be used for risk assessment of subchronic and chronic inhalation exposures of narrow age groups of children.     

宋明理学与中华民族精神

宋明理学是中国古代社会后期别具特色和风格的哲学思维形态。它被统治阶级奉为官方哲学,长达六七百年之久,支配着我国经济、政治以及文化思想的发展。由于它构建了一套严谨的极具思辨性的理论体系,把先前儒家所提出的伦理纲常上升到宇宙本体论的高度,从而强化了爱国主义,反映了时代的共同价值取向,提升了中华民族对于崇高精神境界的追求,正是这些承担并体现了形成与发展中的中华民族精神,是锤炼和塑造当代中华民族精神的文化土壤。     

对第二语言习得中“年龄小优势论”的辩证分析

多数人认为:在第二语言习得过程中,年龄小的人比年龄大的人学得好;儿童比成年人学得好。通过对大量的有关年龄因素如何影响"第二语言习得"(SLA)的资料的辩证分析,肯定了在自然条件下,就语音和语法方面而言,年龄越小,学得越好,但年龄大的人在读写方面的优势以及成年人比儿童能够更快地习得第二语言语法的事实证明了:在"第二语言习得"中,年龄小的人并非总是比年龄大的人学得好,从而论证了"年龄小优势论"具有一定的片面性。