An Efficient Operator for the Change Point Estimation in Partial Spline Model

In bioinformatics application, the estimation of the starting and ending points of drop-down in the longitudinal data is important. One possible approach to estimate such change times is to use the partial spline model with change points. In order to use estimate change time, the minimum operator in terms of a smoothing parameter has been widely used, but we showed that the minimum operator causes large MSE of change point estimates. In this paper, we proposed the summation operator in terms of a smoothing parameter, and our simulation study showed that the summation operator gives smaller MSE for estimated change points than the minimum one. We also applied the proposed approach to the experiment data, blood flow during photodynamic cancer therapy.     

The Challenges of Governing Biotechnology in Korea

This paper explores the development of biotechnology governance and current challenges to its improvement in Korea. It aims to identify what element would be crucial to foster an effectively working system of biotechnology governance in Korea. The analysis is focused on two cases, the legislation of the Bioethics and Biosafety Act, and the development of ethical, legal, and social implications (ELSI) research. Our analysis finds that communication and consensus building between scientists and bioethics advocates in a broader sense is critical for improved governance. During the prolonged dispute over this legislation, the stakeholders advocating scientific advancements and those emphasizing the importance of ethics did not reach an agreement, which was reflected in the limitations of the act. The nascent ELSI research attempted to facilitate interdisciplinary communication and understanding between biotechnology scientists and those in humanities and social sciences, but was met with only limited success. Good governance of biotechnology requires scientists and other stakeholders to willingly comply with regulations and internalize certain norms. Based on our experience in ELSI research, a few suggestions are made to contribute to this end.     

A Comparison of Likelihood-Based Spatiotemporal Monitoring Methods Under Non-Homogenous Population Size

This article discusses the spatiotemporal surveillance problem of detecting rate changes of Poisson data considering non-homogenous population sample size. By applying Monte Carlo simulations, we investigate the performance of several likelihood-based approaches under various scenarios depending on four factors: (1) population trend, (2) change magnitude, (3) change coverage, and (4) change time. Our article evaluates the performance of spatiotemporal surveillance methods based on the average run length at different change times. The simulation results show that no method is uniformly better than others in all scenarios. The difference between the generalized likelihood ratio (GLR) approach and the weighted likelihood ratio (WLR) approach depends mainly on population size, not change coverage, change magnitude, or change time. We find that changes associated with a small population in time periods and/or spatial regions favor the WLR approach, but those associated with a large population favor the GLR under any trends of population changes.     

Product evaluation bias under minimal group situations

The present study was designed to identify the source of product evaluation bias. Three experiments were conducted to see if the evaluation bias occur in the minimal group situation defined by [Tajifel, H., Billig, M., Bundy, R., & Flament, C. (1971). Social categorization and intergroup behavior. European Journal of Social Psychology, 1, 149–178], and to determine the factors responsible for making evaluation bias. Relative measure of product evaluation played a major role in producing an evaluation bias in minimal group situation. Similarly, relative measure of distribution was a critical factor affecting distribution bias. The possible boundary condition of [Tajifel, H., Billig, M., Bundy, R., & Flament, C. (1971). Social categorization and intergroup behavior. European Journal of Social Psychology, 1, 149–178] minimal group situation in evaluation bias were also discussed.     

Structural determinants of team performance: the mutual influences of learning culture,creativity, and knowledge

This study examined the effects of supportive learning culture, team creativity, and collaborative knowledge creating practices on team performance. A survey was used to collect data from a total of 228 knowledge workers from nine Korean organizations. Analyses included measuring item internal consistency, validating proposed constructs, and examining structural relationships using Structural Equation Modelling. The proposed research model was validated in terms of item internal consistency and a model-fit in the Korean business context. Supportive learning culture had a positive and direct influence on team creativity and on the teams' collaborative knowledge creation practices; however, it had an indirect influence on the team performance through the variables of team creativity and knowledge creation practices. In the conclusion, limitations, implications, and further research suggestions are discussed.     

An iterative sparse algorithm for the penalized maximum likelihood estimator in mixed effects model

In this paper, we propose a new iterative sparse algorithm (ISA) to compute the maximum likelihood estimator (MLE) or penalized MLE of the mixed effects model. The sparse approximation based on the arrow-head (A-H) matrix is one solution which is popularly used in practice. The A-H method provides an easy computation of the inverse of the Hessian matrix and is computationally efficient. However, it often has non-negligible error in approximating the inverse of the Hessian matrix and in the estimation. Unlike the A-H method, in the ISA, the sparse approximation is applied “iteratively” to reduce the approximation error at each Newton Raphson step. The advantages of the ISA over the exact and A-H method are illustrated using several synthetic and real examples.     

Accuracy of regularized D-rule for binary classification

We consider a regularized D-classification rule for high dimensional binary classification, which adapts the linear shrinkage estimator of a covariance matrix as an alternative to the sample covariance matrix in the D-classification rule (D-rule in short). We find an asymptotic expression for misclassification rate of the regularized D-rule, when the sample size $n$ and the dimension $p$ both increase and their ratio $p∕n$ approaches a positive constant $\gamma$. In addition, we compare its misclassification rate to the standard D-rule under various settings via simulation.     

Importance of Family Values Differences Between Husbands and Wives in Determining Depression in Foreign Wives in Korean Multicultural Families: Examining the Moderating Effect of Social Support

Differences in value systems are often grounds for conflict in relationships. This is particularly the case for international marriages where spouses hold potentially different family values. This study thus investigated the effect of family values differences between Korean husbands and foreign wives on depression of the wives. It also attempted to examine the moderating effect of family, friend, and formal support. Findings showed that family values differences affected the wives' depression and family support had a significant moderating effect. Researchers recommended that practitioners should be attentive to values differences between the spouses when working with multicultural families.     

Trailblazing women in academia: Representation of women in senior faculty and the gender gap in junior faculty's salaries in higher educational institutions

This study examines how women's representation at different levels of an organizational hierarchy predicts gender equity in assistant professors’ salaries at four-year universities. This study suggests that women's proportion at the full professor rank is positively associated with improved gender equity in assistant professors’ salaries, while women's proportion at the associate and assistant ranks is not significantly associated with improved gender equity. Institutions with a female president, however, have a greater wage gap. Overall, the results imply that the presence of women who blazed the trail of tenure and promotion contributes to the improved gender equity for their junior colleagues.     

The Culture of White Space,the Racialized Production of Meaning,and the Jamband Scene

This study critically examines the subculture of the jamband scene, particularly that of the band Phish, through the notion of “white space.” We demonstrate the existence of colorblind racism and denial of white privilege in the white space of Phish subculture, which is also emblematic of the jamband subculture at large. This study utilizes content analysis drawing from social media comments that react to an article written by Headcount, a political organization in the jamband subculture, titled “Phish Scene is So White: Let's Talk.” The most salient themes we found were colorblind racism and particular online forms of colorblind racetalk through emotional deflection and sarcasm—that we term NIMBY. Our findings add to our understanding of how colorblind racism operates in online versions of subcultural white spaces. We conclude by considering the importance of sociologists to urgently map the social and cultural contours by which white spaces are (re)produced, particularly through cultural processes of meaning-making.