Modified linear discriminant analysis using block covariance matrix in high-dimensional data

Among many classification methods, linear discriminant analysis (LDA) is a favored tool due to its simplicity, robustness, and predictive accuracy but when the number of genes is larger than the number of observations, it cannot be applied directly because the within-class covariance matrix is singular. Also, diagonal LDA (DLDA) is a simpler model compared to LDA and has better performance in some cases. However, in reality, DLDA requires a strong assumption based on mutual independence. In this article, we propose the modified LDA (MLDA). MLDA is based on independence, but uses the information that has an effect on classification performance with the dependence structure. We suggest two approaches. One is the case of using gene rank. The other involves no use of gene rank. We found that MLDA has better performance than LDA, DLDA, or K-nearest neighborhood and is comparable with support vector machines in real data analysis and the simulation study.     

Tolerance of Uncertainty: Links to Happenstance,Career Decision Self‐Efficacy,and Career Satisfaction

This study investigated the extent to which tolerance of uncertainty affects the relationship between happenstance skills and career satisfaction via career decision self‐efficacy. Moderated mediation analysis was conducted on data collected from 321 graduates (175 men, 146 women) of Korean universities making the school‐to‐work transition. Results showed that career decision self‐efficacy fully mediated the relationship between happenstance skills and career satisfaction. Furthermore, the moderation effect of tolerance of uncertainty had a significant impact on the relationship between happenstance skills and career decision self‐efficacy. Tolerance of uncertainty should be considered an important variable in happenstance career theory and intervention. Unplanned influences should also be considered important factors in the career decision‐making process.     

Intergenerational income mobility and inequality in South Korea

Using data from the Korean Labor and Income Panel Study (KLIPS), recent trends in intergenerational income mobility were explored, examining the relationship between income mobility and income inequality in South Korea. The study found that the intergenerational elasticity of income is about 0.2 and there is no clear‐cut trend in intergenerational income mobility. In addition, this study showed that there is no systematic relation between rising income inequality and intergenerational income mobility in contemporary Korea. Overall, the results indicate that intergenerational income mobility is irresponsive to the income inequality the respondents experienced growing up. It is assumed that education and welfare transfer programs might offset the consequences of income inequality by leading to upward mobility for children from low‐income households.     

使用汞分析器检测矿渣及水泥中的汞

以矿渣和水泥作为研究对象,采用汞分析器对其中的汞进行检测。水泥是一种建筑过程中广泛使用的高凝结材料。由于汞具有较大的毒性,因此必须严格检测建筑材料中汞的含量以降低其对人体的损害。作为水泥的替代物,矿渣具有许多的优点,例如价格低廉、毒性较小等。     

Impacts of child development accounts on parenting practices: evidence from a randomised statewide experiment

ABSTRACT

This study examines the impact of Child Development Accounts (CDAs) on parenting practices of mothers with young children in a statewide randomised experiment conducted in the United States. The experiment included 2704 primary caregivers of children born in Oklahoma during 2007: 1358 were randomly assigned to the treatment group and 1346 to the control group. Structural equation modelling suggests that the punitive-parenting score among treatment participants was .12 standard deviations smaller than that among control participants (p < . 05). Findings indicate that CDAs reduce punitive parenting, and may serve as an additional tool for positive parent–child interactions.     

Small-dollar children's saving accounts and children's college outcomes by race

This is paper three of four in the Small-Dollar Children Accounts series that studies the relationship between children's small dollar savings accounts and college enrollment and graduation. The series uses different subsamples to examine three important research questions: (a) Are children with savings of their own more likely to attend or graduate from college? (b) Does dosage (no account, only basic savings, savings designated for school of less than $1, $1 to $499, or $500 or more) matter? And (c) is designating for school more predictive of college enrollment or graduation than having basic undesignated savings alone? Using propensity score weighted data from the Panel Study of Income Dynamics and its supplements we created multi-treatment dosages of savings accounts and amounts to answer these questions separately for black (n = 404) and white (n = 453) children. White children's savings are not significantly related to their college outcomes. Differently, compared to black children without savings accounts, black children are three times more likely to enroll in college when they have school savings of less than $1 and six times more likely when they have school savings of $1 to $499. Further, black children with school savings of $1 to $499 are four times more likely to graduate from college and black children with school savings of $500 or more are three-and-a-half times more likely to graduate from college, compared to those with no savings account. We suggest Child Development Accounts (CDAs) may be a promising tool for helping black children get to and through college.     

The Effects of Depressive Symptoms on Work Activities and Welfare Exit of Welfare Recipients in Korea1

The purpose of this research is to examine the link between depressive symptoms of welfare recipients and their work activity and welfare exit using a secondary dataset, entitled the Korean Welfare Panel Study. In 2000, the National Basic Livelihood Security System (NBLSS) was introduced to (i) ensure a basic standard of living for households in poverty, and (ii) promote work activity and welfare exit of the recipients. A considerable body of literature has reported that the policy outcome of the NBLSS is not a success. However, the reason for the low success rate is unclear. In contrast to studies in the USA, few studies in Korea investigated the effect of depression on welfare‐to‐work transitions. To bridge the gap in the literature, we examine the association between depression, work activity, and welfare exit using a logistic regression analytic method. The analytic results show that the level of depression (total score on the Center for Epidemiological Studies Depression Scale) was negatively associated with welfare recipients’ work activity and welfare exit, suggesting that depressive symptoms may be a significant barrier to promoting economic self‐sufficiency. Implications of the study findings are further discussed.     

Insights on medical tourism: markets as networks and the role of strong ties

Despite a huge amount of speculation and expectation surrounding medical tourism, hard empirical evidence is only now beginning to emerge. This paper widens the focus of discussion by contrasting two country experiences (UK and Korea) which on the surface illustrate the diversity of medical tourism and little else. However, considered more comparatively, the accounts contribute toward wider, albeit tentative, theoretical understandings, and insights. The paper is drawn from two broad programs of empirical study conducted over three years in UK and Korea, respectively. The article is structured in three parts: first, a brief overview of policy, legislative, and accreditation frameworks that exist to govern medical tourist flows. Second, we present evidence around flows, demographics, treatment, and medical tourism for Korea and UK (both for supply and demand). Third, we examine conceptual and theoretical implications of this evidence. We argue that viewing medical tourism as a global market is problematic; some medical tourist markets are best viewed as networks with long-term exchange relationships; some specific areas of activity do function more strongly as price-related; decision making around medical tourism frequently involves a range of information and social networks (economic action as embedded social structure); and medical tourism is a function of globalization.