Noninformative priors for linear combinations of the normal means

In this paper, we develop noninformative priors for linear combinations of the means under the normal populations. It turns out that among the reference priors the one-at-a-time reference prior satisfies a second order probability matching criterion. Moreover, the second order probability matching priors match alternative coverage probabilities up to the second order and are also HPD matching priors. Our simulation study indicates that the one-at-a-time reference prior performs better than the other reference priors in terms of matching the target coverage probabilities in a frequentist sense.     

Probabilistic modeling of percutaneous absorption for risk-based exposure assessments and transdermal drug delivery

Chemical transport through human skin can play a significant role in human exposure to toxic chemicals in the workplace, as well as to chemical/biological warfare agents in the battlefield. The viability of transdermal drug delivery also relies on chemical transport processes through the skin. Models of percutaneous absorption are needed for risk-based exposure assessments and drug-delivery analyses, but previous mechanistic models have been largely deterministic. A probabilistic, transient, three-phase model of percutaneous absorption of chemicals has been developed to assess the relative importance of uncertain parameters and processes that may be important to risk-based assessments. Penetration routes through the skin that were modeled include the following: (1) intercellular diffusion through the multiphase stratum corneum; (2) aqueous-phase diffusion through sweat ducts; and (3) oil-phase diffusion through hair follicles. Uncertainty distributions were developed for the model parameters, and a Monte Carlo analysis was performed to simulate probability distributions of mass fluxes through each of the routes. Sensitivity analyses using stepwise linear regression were also performed to identify model parameters that were most important to the simulated mass fluxes at different times. This probabilistic analysis of percutaneous absorption (PAPA) method has been developed to improve risk-based exposure assessments and transdermal drug-delivery analyses, where parameters and processes can be highly uncertain.     

Not so great expectations: sex and housewives in Hong Kong

The study explores the life of married women who are being described as having "good," "normal," "blessed" sexuality. The case of si-nais (housewives) in Hong Kong shows that we can never assume that married women (or any social category) are privileged by virtue of their status on the sexual hierarchy. The blessings of social respectability apparently enjoyed by these women may work to enable or hinder women's expression of their erotic desires and sexual fulfillment, depending on their special social circumstances. These women's imagination and experience of good sex is composed of a multitude of components. Women may feel good because they can achieve other psychological and social aims that are important in their lives (which could be related to the maintenance of marriage or the peace of the family). Women may feel good because of the erotic satisfaction that they derive from different pursuits including interests, leisure or other intimate relationships, rather than sexual fulfillment in terms of orgasm or physical pleasure. Women may reformulate their pleasure variously at different stages of their lives. Social respectability, orgasm, emotional intimacy, or any other specific element, may all enter or leave the formula for good sex.     

Stagnation as a Distinct Clinical Syndrome: Comparing 'Yu' (Stagnation) in Traditional Chinese Medicine with Depression

Background: Depression was translated into Chinese as yiyu,with reference to the yu syndrome in traditional Chinese medicine.Literally meaning ‘not flowing, entangled or clogged’,yu, or ‘stagnation’ in English, is, however, a constructdistinct from depression. Objective: The study aimed to explorethe construct of stagnation through scale development. Method:A concept-driven approach was adopted to generate candidateitems for the Stagnation Scale. Other measures were a validitychecking item, a Beck Depression Inventory (BDI) and a twelve-itemGeneral Health Questionnaire (GHQ-12). Respondents were recruitedby convenience and snowball sampling, resulting in 602 questionnairesbeing completed by adults between the ages of eighteen and sixty-five.Results: Exploratory factor analysis provided a three-factor,sixteen-item solution. The three factors were named Overattachment,Body-Mind Obstruction and Affect-Posture Inhibition. Cronbach’salphas of the entire scale and subscales ranged from 0.82 to0.91. Correlations of the scale total with the validity checkingitem, BDI and GHQ-12 were 0.71, 0.53 and 0.48, respectively.Stagnation showed a pattern of associations with demographicvariables different from depression. Conclusion: The StagnationScale has good psychometric properties, and has meaningful factorstructures. The evidence supports the contention that stagnationis a clinical syndrome distinct from depression. The new concepthas important implications for social work practice.     

Adolescent Residents Negotiate the Construction of Social Problems in a Low-Income Community: Making Claims on the “City of Sadness”

The social constructionist approach to research on social issues provides a conceptual means in understanding how specific problems are generated and handled by institutional claims-makers, including the state and mass media. In neighborhood research, the voice of adolescent residents is seldom heard, let alone the value of their claims in relation to the state's construction. This article endeavors to address this in several steps: by outlining the specific developmental trajectory of low-income community in Hong Kong; by examining the dominant state discourse on the nature and “solution” of community problems; and by analyzing the voice of adolescent residents. Empirically, 54 Chinese adolescents (aged 12 to 17 years) were recruited to participate in eight focus groups to express how they saw community conditions. Furthermore, a random sample of 22 parents of the participants was surveyed as comparison. Finally, the article suggests that adolescents' constructions provide significant opportunities developing more critically informed, “bottom-up” agendas for community revitalization.     

Hong Kong men's stories of intra-national cross border romances

This article explores experiences of gender, love, sex and family during the present period of complex social transformation in Hong Kong (HK) and the mainland through the narratives of five HK men and their adventures across the border. Whilst initially rose-tinted, their adventures encountered unexpected problems and brought about unforeseen needs. The article explores the emotions and responsibilities these men needed to contend with as they tried to exploit the opportunities that the mainland presented and argues for the need for services and support for the increasing number of men who frequently cross the border to achieve their goals.     

Altruism Within the Family: A Comparison of Father and Mother Using Life Happiness and Life Satisfaction

Studies on intra-household allocation of resources show that exogenous increase in mothers’ income has larger effect on children’s outcomes than the same increase in fathers’ income, suggesting gender differences may exist in parents’ altruism towards their children. Using self-reported life happiness and life satisfaction, we investigate the differences by gender in mutual altruism between father and child as well as mother and child dyads in Singapore. We found that mutual altruism exists between mother and child, but not between father and child. These findings are robust to the measure of self-reported well-being. Further, we find that gender difference in altruism of fathers and mothers is not driven by the difference in the extent of future old age support desired by fathers and mothers from their children.     

A heuristic approach for component scheduling on a high-speed PCB assembly machine

The collect-and-place machine is one of the most widely used placement machines for assembling electronic components on the printed circuit boards (PCBs). Nevertheless, the number of researches concerning the optimisation of the machine performance is very few. This motivates us to study the component scheduling problem for this type of machine with the objective of minimising the total assembly time. The component scheduling problem is an integration of the component sequencing problem, that is, the sequencing of component placements; and the feeder arrangement problem, that is, the assignment of component types to feeders. To solve the component scheduling problem efficiently, a hybrid genetic algorithm is developed in this paper. A numerical example is used to compare the performance of the algorithm with different component grouping approaches and different population sizes.     

非农业户籍会使人更幸福吗

中国的户籍制度相对比较特殊,它曾衍生了大量“农转非”等户口买卖现象,这使人不禁产生疑问：非农业户籍会使人更幸福吗？本文基于北京大学CFPS数据,构建了一个影响幸福程度的包括户籍因素在内的有序因变量模型。我们不但详述了户籍类型与居民幸福程度的内在联系机制,同时还分析众多主客观因素对幸福的影响。研究发现,户籍类型转变的实质是社会行动者基于户籍制度功能而做出的理性选择行为,不同时间和空间的户籍制度功能会引起幸福程度的差异;生活态度、人际和教育等因素也会显著影响幸福程度。因此,户籍制度改革过程中,重视户籍制度的功能而非形式是明智之举;同时,完善农村就业机制、增强个人自信心是提升社会行动者幸福程度的有效手段。     

Flexible mixture modelling using the multivariate skew-t-normal distribution

This paper presents a robust probabilistic mixture model based on the multivariate skew-t-normal distribution, a skew extension of the multivariate Student’s t distribution with more powerful abilities in modelling data whose distribution seriously deviates from normality. The proposed model includes mixtures of normal, t and skew-normal distributions as special cases and provides a flexible alternative to recently proposed skew t mixtures. We develop two analytically tractable EM-type algorithms for computing maximum likelihood estimates of model parameters in which the skewness parameters and degrees of freedom are asymptotically uncorrelated. Standard errors for the parameter estimates can be obtained via a general information-based method. We also present a procedure of merging mixture components to automatically identify the number of clusters by fitting piecewise linear regression to the rescaled entropy plot. The effectiveness and performance of the proposed methodology are illustrated by two real-life examples.