The empirical analysis of the -bilateral optimized combinatorial auction model

This study proposes a new and highly efficient dynamic combinatorial auction mechanism—the N-bilateral optimized combinatorial auction (N-BOCA). N-BOCA is a flexible iterative combinatorial auction model that offers more optimized trading for multiple suppliers and purchasers in the supply chain than one-sided combinatorial auction. We design the N-BOCA model from the perspectives of market architecture, trading rules, and decision strategy for winner determination, the decision strategy for winner determination needs flexible optimization modeling capability. Thus rule-based reasoning was applied for reflecting the flexible decision strategies. We also show the viability of N-BOCA through Paired Samples T-test experimentation. It shows that N-BOCA yields higher purchase efficiency and effectiveness than the one-auctioneer to multi-bidders (1-to-N) combinatorial auction mechanism.     

Predictive factors of acculturation attitudes and social support among Asian immigrants in the USA

This study examines acculturation attitude and its relation to social support among Asian immigrants. The data were collected from 242 Korean, Indian and Filipino immigrants in the USA using the Acculturation Attitude Scale and the Social Support Index. Findings showed that Koreans had a less positive attitude toward acculturation than did Indian and Filipino participants. Acculturation attitude was positively correlated with educational level and English fluency. This study also found a negative correlation between acculturation attitude and social support. Social support from friends and English fluency were identified as significant predictor variables in determining the level of acculturation attitude. These findings not only contribute to social work education and practice, but also increase cultural sensitivity and awareness in working with these populations.     

Bayesian variable selection approach to a Bernstein polynomial regression model with stochastic constraints

This paper provides a Bayesian estimation procedure for monotone regression models incorporating the monotone trend constraint subject to uncertainty. For monotone regression modeling with stochastic restrictions, we propose a Bayesian Bernstein polynomial regression model using two-stage hierarchical prior distributions based on a family of rectangle-screened multivariate Gaussian distributions extended from the work of Gurtis and Ghosh [7 S.M. Curtis and S.K. Ghosh, A variable selection approach to monotonic regression with Bernstein polynomials, J. Appl. Stat. 38 (2011), pp. 961–976. doi: 10.1080/02664761003692423[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]]. This approach reflects the uncertainty about the prior constraint, and thus proposes a regression model subject to monotone restriction with uncertainty. Based on the proposed model, we derive the posterior distributions for unknown parameters and present numerical schemes to generate posterior samples. We show the empirical performance of the proposed model based on synthetic data and real data applications and compare the performance to the Bernstein polynomial regression model of Curtis and Ghosh [7 S.M. Curtis and S.K. Ghosh, A variable selection approach to monotonic regression with Bernstein polynomials, J. Appl. Stat. 38 (2011), pp. 961–976. doi: 10.1080/02664761003692423[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]] for the shape restriction with certainty. We illustrate the effectiveness of our proposed method that incorporates the uncertainty of the monotone trend and automatically adapts the regression function to the monotonicity, through empirical analysis with synthetic data and real data applications.     

We Don’t Belong Here: Adolescents of North Korean Refugee Families and Their Suicidal Behaviors

Despite the increasing number of studies that examine the link between immigration and suicide in Korean youths, most have focused on self-harming behaviours among adolescents in multicultural families, while much less attention has been directed towards those in North Korean (NK) refugee families. This paper addresses this gap by comparing three determinants of suicidal behaviours across three groups of Korean adolescents. Data are drawn from the KYRBS, a nationally representative sample of students in middle and high schools, and the results indicate that NK youths were 87.2 per cent more likely to have suicidal ideation than their South Korean peers, that they are 3.7 times more likely to experience suicidal plans and 4.1 times more likely to attempt suicide. These results clearly suggest that immigrant youths, including NK refugees, are confronting significant difficulties with assimilation, and those disadvantages lead to a higher propensity of self-threatening behaviours.     

INVESTMENT SHOCKS,CONSUMPTION PUZZLE,AND BUSINESS CYCLES

A mass of recent research shows that investment shocks are primary driving forces of business cycles. A thorny issue, however, arises due to countercyclical consumption behavior following the investment shocks. This article contributes to the literature by resolving this anomalous issue in a model that features time inconsistency, modeled as naïve hyperbolic discounting. The proposed model delivers positive responses of consumption to an investment shock and thus produces comovement of key macroaggregates, which is in line with the observed U.S. business cycles. Furthermore, this article also substantiates the validity of the proposed model by producing comovement following an investment news (or anticipated investment) shock. Additional analyses on changes in model structure and parameter value do not reverse the main finding. (JEL E3, E7)     

Impact of older adults' mobility and social participation on life satisfaction in South Korea

South Korea has been experiencing rapid population aging. In an aging society, the need for healthy lives is greater. Two of the fundamental factors to enable independent and active life for the elderly are mobility and social participation. The purpose of this study was to examine the relationship between older adults’ mobility, social participation, and quality of life in South Korea. We used data from the 2017 National Survey of Older Koreans conducted by the Ministry of Health and Welfare and the Korea Institute for Health and Social Affairs and applied hierarchical regression. The major finding was that older adults’ mobility had a positive impact on their life satisfaction. After controlling for older adults’ mobility, social participation was positively associated with life satisfaction regardless of the place of residence. The findings of this study not only make a valuable contribution to further research on mobility and social participation but also provide new insight into improving older adults’ quality of life.