On some mixture models based on the Birnbaum-Saunders distribution and associated inference

In this paper, we consider three different mixture models based on the Birnbaum-Saunders (BS) distribution, viz., (1) mixture of two different BS distributions, (2) mixture of a BS distribution and a length-biased version of another BS distribution, and (3) mixture of a BS distribution and its length-biased version. For all these models, we study their characteristics including the shape of their density and hazard rate functions. For the maximum likelihood estimation of the model parameters, we use the EM algorithm. For the purpose of illustration, we analyze two data sets related to enzyme and depressive condition problems. In the case of the enzyme data, it is shown that Model 1 provides the best fit, while for the depressive condition data, it is shown all three models fit well with Model 3 providing the best fit.     

Tavern proximity,tavern density and socio-economic status as predictors of assault occurrence within New Zealand: a temporal comparison

This paper investigates how the associations between tavern proximity, tavern density and area unit socio-economic status with assault occurrence vary in a temporal sense. Using New Zealand Police data specifying the day, time and location of assaults in 2016 and Ministry of Justice data specifying the location of on-licenced taverns, we construct logistic regression models to determine how well tavern proximity, tavern density and socio-economic status predict the occurrence of assaults at peak (Fri 22:00–Sat 03:00 and Sat 22:00–Sun 03:00) and off-peak times. An equal-sized sample of traffic generators (public venues whose primary function is not the sale of alcohol) is constructed and similar procedures applied. We find that tavern proximity and tavern density are stronger predictors of assault occurrence at peak, compared to off-peak, times. Conversely, socio-economic status is a better predictor of assault occurrence at off-peak times. We also find that whilst tavern proximity and density are stronger predictors of assault occurrence relative to traffic generator proximity and density at peak times, the opposite is true at off-peak times. These results suggest that in order to minimise alcohol-related harm, there is a need for policy-makers to take into account the temporal nature of these relationships.     

Allocation strategies of standby redundancies in series/parallel system

This article deals with the topic of optimal allocation of two standby redundancies in a two-component series/parallel system. There are two original components C₁ and C₂ which can be used to construct a series/parallel system, and two spares R₁ (same as C₁) and R₂ (different from both C₁ and C₂) at hand with them being standby redundancies so as to enhance the reliability level of the system. The goal for an engineer is to seek after the optimal allocation policy in this framework. It is shown that, for the series structure, the engineer should allocate R₂ to C₁ and R₁ to C₂ provided that C₁ (or R₁) performs either the best or worst among all the units; otherwise, the allocation policy should be reversed. For the parallel structure, the optimal allocation strategy is just opposed to that of series case. We also provide some numerical examples for illustrating the theoretical results.     

A unified approach to stochastic comparisons of multivariate mixture models

In this paper, we consider a unified approach to stochastic comparisons of random vectors corresponding to two general multivariate mixture models. These stochastic comparisons are made with respect to multivariate hazard rate, reversed hazard rate and likelihood ratio orders. As an application, results are presented for stochastic comparisons of generalized multivariate frailty models.     

Coparenting and Children’s Adjustment to Divorce: The Role of Geographical Distance from Fathers

After divorce, shorter distances between parents’ homes are often seen as facilitating nonresident fathers’ involvement with their children, good coparenting practices, and children’s well-being. However, few studies have explored how geographical distance relates to coparenting and children’s adjustment. Moreover, the direction of causality remains unclear, as uninvolved fathers due to paternal disinterest, maternal gatekeeping, or interparental conflict are more likely to move farther away from their children. Based on a probability sample of 144 divorced mothers of school-aged children living in Geneva, Switzerland, this study explores how the distance between parents’ homes relates to maternal promotion of the father–child relationship (cohesive coparenting) and children’s emotional and behavioral outcomes. Results show that cohesive coparenting relates more to frequent father–child contacts by phone or e-mails than to residential proximity. Both cohesive coparenting and fathers’ residential proximity have positive and independent effects on children’s adjustment. Children whose fathers live nearby exhibit fewer behavioral difficulties and more prosocial behavior than children whose fathers live far away. These findings suggest that frequent contacts by phone or e-mail can substitute for distance in coparenting, but geographical proximity still matters for fathers’ contribution to children’s well-being. Overall, this study recommends that spatial and mobility dimensions should receive more attention in divorce research.     

基于组织视角的安全蔬菜生产者道德风险分析——以江苏省为例

从农业生产组织的视角,通过对江苏省490户安全蔬菜生产农户的调查,运用Logistic二元选择模型对影响生产者道德风险的因素进行了分析。研究结果表明,安全蔬菜生产农户参加的农业生产组织的类型、组织对农户生产安全蔬菜的检查、组织对农户农药购买和农药使用情况的监管、组织对农户违规生产的处罚以及处罚的严格度均对农户道德风险的防范有显著影响。     

语篇象似性与翻译

象似性存在于语言的各个层面上。在篇章中的象似性现象有重要的表意功能。因此,翻译不仅仅是语言符号之间的转换,同时也要受篇章象似性的制约。文章主要从距离象似性,语音象似性,形状象似性和对称象似性来讨论篇章象似性对翻译的制约。     

On the mean residual life of records

Suppose that a technical system is subject to shocks, e.g. peaks of voltages from a sequence of identically independent voltages having a lower limit value v>0$v>0$. We propose a new definition for the mean residual life of the records of the sequence and study its various properties.     

基于专利引用的国际性技术外溢实证研究

采用专利跨国引用作为国际性技术外溢的代理变量,基于美国国家经济研究局专利引用数据库分析中国发明专利技术的现状和特征;依据该数据库中6大类36个专利的细分类别,计算1985年～1999年中国与11个创新型国家(地区)的技术相似度;运用技术知识存量替代技术知识流量,测算中国1985年～2004年的对外技术依存度,综合分析技术相似性、对外技术依存度、地理距离和语言等因素对中国通过专利引用获取国际性外溢技术的影响,利用负二项回归方法对影响中国专利引用的相关因素进行计量研究。研究结果表明,技术相似度与跨国专利引用之间不存在显著性正相关关系,对外技术依存度、语言差异均与跨国专利引用显著负相关,地理距离与跨国专利引用显著正相关。     

Aging,Proximity to Death,and Religiosity

Considerable evidence has documented that the elderly are more religious and that religiosity is associated with better health and lower mortality. Yet, little is known about the reverse role of life expectancy or proximity to death, as opposed to age, for religiosity. This paper provides evidence for the distinct role of expected remaining life years for the importance of religion in individuals’ lives. We combine individual survey response data for more than 300,000 individuals from 95 countries over the period 1994–2014 with information from period life tables. Contrary to wide-held beliefs, religiosity decreases with greater expected proximity to death. The findings have important implications regarding the consequences of population aging for religiosity and associated outcomes.