Yonsei University

About: Yonsei University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Cancer. The organization has 50162 authors who have published 106172 publications receiving 2279044 citations. The organization is also known as: Yonsei.

Internet Addiction and Psychiatric Symptoms Among Korean Adolescents

Abstract: Background: The aims of this study were to identify the independent factors associated with intermittent addiction and addiction to the Internet and to examine the psychiatric symptoms in Korean adolescents when the demographic and Internet-related factors were controlled. Methods: Male and female students (N = 912) in the 7th-12th grades were recruited from 2 junior high schools and 2 academic senior high schools located in Seoul, South Korea. Data were collected from November to December 2004 using the Internet-Related Addiction Scale and the Symptom Checklist-90-Revision. A total of 851 subjects were analyzed after excluding the subjects who provided incomplete data. Results: Approximately 30% (n = 258) and 4.3% (n = 37) of subjects showed intermittent Internet addiction and Internet addiction, respectively. Multivariate logistic regression analysis showed that junior high school students and students having a longer period of Internet use were significantly associated with intermittent addiction. In addition, male gender, chatting, and longer Internet use per day were significantly associated with Internet addiction. When the demographic and Internet-related factors were controlled, obsessive-compulsive and depressive symptoms were found to be independently associated factors for intermittent addiction and addiction to the Internet, respectively. Conclusions: Staff working in junior or senior high schools should pay closer attention to those students who have the risk factors for intermittent addiction and addiction to the Internet. Early preventive intervention programs are needed that consider the individual severity level of Internet addiction.

Modeling consumer adoption of mobile shopping for fashion products in Korea

Abstract: This study explores the potential of a consumer technology adoption model in examining structural relationships among mobile commerce characteristics, perceived value, and intention to adopt mobile shopping for fashion products. Through an online survey method, the 511 valid questionnaires obtained from Korean users of a mobile Internet service identified perceived m-commerce characteristics consisting of four factors: usefulness, enjoyment, ease of use, and instant connectivity. The first three factors were positively related to perceived value, whereas instant connectivity was negatively related. Moreover, estimated structural equation modeling described the important function of perceived value as mediating the effect of m-commerce characteristics on the consumers' intention to adopt mobile fashion shopping. Managerial implications for practitioners and researchers are discussed in the context of m-commerce. © 2009 Wiley Periodicals, Inc.

The UV-Optical Galaxy Color-Magnitude Diagram. III. Constraints on Evolution from the Blue to the Red Sequence

Abstract: We introduce a new quantity, the mass flux density of galaxies evolving from the blue sequence to the red sequence. We propose a simple technique for constraining this mass flux using the volume-corrected number density in the extinction-corrected UV-optical color-magnitude distribution, the stellar age indexes Hδ_A and D_n(4000), and a simple prescription for spectral evolution using a quenched star formation history. We exploit the excellent separation of red and blue sequences in the NUV − r band Hess function. The final value we measure, ρ_T = 0.033 M_⊙ yr^(−1) Mpc^(−3), is strictly speaking an upper limit due to the possible contributions of bursting, composite, and extincted galaxies. However, it compares favorably with estimates of the average mass flux that we make based on the red luminosity function evolution derived from the DEEP2 and COMBO-17 surveys, ρ_R = +0.034 M_⊙ yr^(−1) Mpc^(−3). We find that the blue sequence mass has remained roughly constant since z = 1 (ρ_B ≃ 0.01 M_⊙ yr^(−1) Mpc^(−3)), but the average on-going star formation of ρ_(SF) ≃ 0.037 M_⊙ yr^(−1) Mpc^(−3) over 0 < z < 1 is balanced by mass flux off the blue sequence. We explore the nature of the galaxies in the transition zone with particular attention to the frequency and impact of active galactic nuclei (AGNs). The AGN fraction peaks in the transition zone. We find circumstantial, albeit weak evidence that the quench rates are higher in higher luminosity AGNs.