On a class exhibiting trend change in average failure rate

Abstract

Weak convergence and moment convergence issues are investigated for the New Better than Average Failure Rate (NBAFR) family (introduced by Loh (1984 Loh, W. Y. 1984. A new generalization of the class of NBU distributions. IEEE Transactions on Reliability R-33 :97–113[Crossref], [Web of Science ®] , [Google Scholar])). We explore the validity of these results in the context of a more general ageing class that we introduce. We prove some new properties of this class and derive its interrelationships with other non-monotonic ageing families. Reliability and moment bounds are obtained and an interesting characterization of exponentiality is proved. Special cases of our results lead to new theorems for the NBAFR class. Finally weak convergence and related issues are established for this class.     

交往理性：哈贝马斯的理性重建

哈贝马斯是在分析交往行为和生活世界的过程中建构起交往理性概念的。他是以工具理性和交往理性二元分立为基点,赋予交往理性以对抗工具理性的使命,通过“交往理性”这种新理性观的确立,解除了意识哲学的“先验主体”和“先验理性”的设定,摒弃了主、客体二元对立的思维方式,从而取消了主体中心主义的独裁,从根本上否定了狭隘的传统的“理性”观,也为现代人逃离现代性困境提供了一个可能的方向。     

A Bayesian Analysis for Accelerated Lifetime Tests Under an Exponential Power Law Model with Threshold Stress

In this paper, we present a Bayesian methodology for modelling accelerated lifetime tests under a stress response relationship with a threshold stress. Both Laplace and MCMC methods are considered. The methodology is described in detail for the case when an exponential distribution is assumed to express the behaviour of lifetimes, and a power law model with a threshold stress is assumed as the stress response relationship. We assume vague but proper priors for the parameters of interest. The methodology is illustrated by a accelerated failure test on an electrical insulation film.     

The econometrics of female labor supply and children

This is a survey of applied econometric research on the effects of children on female labor supply. Reasons for interest in the topic, and a basic model and terminology, are reviewed. Concerns are raised about the possible endogeneity of child status variables, and about the instrumental variables approach for dealing with this problem. Alternative ways of conceptualizing and estimating child status effects are considered, together with selected empirical evidence. Relevant developments from the household demand literature are summarized. Basic issues of model choice are also discussed.     

李白与杜甫面面观

围绕李白与杜甫的生平行事及其诗歌创作,从八个层面进行对比论述,所谓“以诗证史,有裨于知人论世”。文中既综合了当代的研究成果,也提出了一些新的见解。     

池莉“人生三部曲”的男性形象和女性意识

池莉的"人生三部曲"虽以男性为主要描写对象,但透过这些男性形象与对应的女性形象的关系可以看出,池莉自始至终都以女性意识来关照其作品中的人物:呼唤男子汉的女性意识增强了男性的角色意识;要求丈夫尊重、重视、认同的意识使男主人公更加清醒地认识现实、承担责任;女性主体意识的张扬使男人从男性中心幻觉中跌落,自觉地修炼自身、确立自己.     

Interfamily economic exchange: A function of culture or economics?

This study explores differences in inter-household exchange of goods and services in Anglo- and Mexican-American families controlling for income level and for ethnicity. The extent of such exchange, its perceived importance to the family's quality of life, satisfaction with the exchange, and the relation of persons in the exchange process are examined. Significant differences are found more often between higher income Anglo- and Mexican-Americans than between low-income families, both in the family providing goods and services for others and in the receipt of them. Higher income Mexican-American families are more likely than their Anglo- counterparts to exchange with relatives. Ethnic effects are more prevalent in higher income households than in low-income households. Economic effects are more predominant than ethnic effects.This study contributes to interregional Agricultural Experiment Station Research Project NC-128, Quality of Life as Influenced by Area of Residence. Cooperating states: Arizona, California, Colorado, Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, Nevada, Ohio, Texas.Flora L. Williams' current research interests include income adequacy, financial problems, and indicators of change in economic well-being. She is an Associate Professor, Consumer Sciences and Retailing, Purdue University, West Lafayette, IN 47907.     

Who Cares About Your Big Day? Impact of Life Events on Dynamics of Social Networks

With online social networking having revolutionized the way in which individuals communicate and interact with each other, there is heightened research interest in the dynamics of social networks. This article seeks to contribute to this stream of research by addressing the key question of the impact of major life events, such as getting married or graduating from college, on social network evolution. Consistent with prior studies on the evolution of individuals’ social networks, we specifically focus on two key attributes of an individual's network: indegree of ties and relational embeddedness. By longitudinally analyzing the network activities of a large‐scale online social network, we find that the indegree of ties increased significantly following a major life event, and that this impact was stronger for more active users in the network. Interestingly, we also find that the broadcast of major life events served to revive dormant ties as reflected by a decrease in embeddedness following a life event. We also found that one‐time life events such as weddings had a greater impact than recurring life events such as birthdays on the evolution of a user's social network. From a research perspective, our study contributes to existing research by focusing on a user's communication network as opposed to friendship network and by emphasizing how exogenous life events add a different dimension to user communication patterns. The importance of life events on social network evolution has important implications for practice as well by providing insights to advertisers as well as to social networking sites.     

新生代农民工城市融入的困境与出路——基于厦门市的调查

新生代农民工是中国现代产业工人的主体,是社会稳定与进步的重要影响因素。新生代农民工的文化程度相对较高,生活方式与老一代农民工有明显差别,他们的"城市梦"更执着。厦门是新生代农民工聚集的城市,在实证研究基础上,分析厦门新生代农民工当前面临的困境,以社会工作视角从宏观、中观和微观层面提出解决对策,以期更好地服务新生代农民工,团结新生代农民工,共同推进厦门市文明城市建设。