• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1523-1525
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• 2003

Due to the rapid development of wireless networking system, researches on the communication devices are mainly focus on microwave frequency devices such as filters, resonators, and phase shifters. Among them, Film bulk acoustic resonator (FBAR) has been paid extensive attentions for their high performance. In this research, ZnO thin films were deposited by RF-magnetron sputtering on Al/$SiO_2$/Si wafer and then crystalline properties and surface morphology were examined. To measure crystalline structure and surface morphology X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) were employed. It was showed that crystalline properties of ZnO thin films were strongly dependant on the deposition conditions. As increasing the deposition temperature and the deposition pressures, the peak intensities of ZnO(002) plane were increased until $300^{\circ}C$, then decreased rapidly. At the sputtering conditions of RF power of 213 W and working pressure of 15 m Torr, ZnO film had excellent c-axis orientation, surface morphology, and adhesion to the substrate. In conclusion we optimized smooth surface with very small grains as well as highly c-axis oriented ZnO film for FBAR applications.

• Journal of Information Science Theory and Practice
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• v.7 no.4
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• pp.33-44
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• 2019

Altmetrics measure the frequency of references about an article on social media platforms, like Twitter. This paper studies a variety of factors that affect the popularity of articles (i.e., the number of article mentions) in the field of psychology on Twitter. Firstly, in this study, we classify Twitter users mentioning research articles as academic versus non-academic users and experts versus non-experts, using a machine learning approach. Then we build a negative binomial regression model with the number of Twitter mentions of an article as a dependant variable, and nine Twitter related factors (the number of followers, number of friends, number of status, number of lists, number of favourites, number of retweets, number of likes, ratio of academic users, and ratio of expert users) and seven article related factors (the number of authors, title length, abstract length, abstract readability, number of institutions, citation count, and availability of research funding) as independent variables. From our findings, if a research article is mentioned by Twitter users with a greater number of friends, status, favourites, and lists, by tweets with a large number of retweets and likes, and largely by Twitter users with academic and expertise knowledge on the field of psychology, the article gains more Twitter mentions. In addition, articles with a greater number of authors, title length, abstract length, and citation count, and articles with research funding get more attention from Twitter users.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.533-538
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• 2003

It has been shown that ion implantation produces remarkable improvements in surface-sensitive physical and chemical properties as well as other mechanical properties, in polymers. In this study, ion implantation was performed onto polymer, PC(polycarbonate), in order to investigate surface hydrophilic property through contact angle measurement using distilled water. PC was irradiated with N, Ar, Xe ions at the irradiation energy of $20\;{\sim}\;50keV$ and the dose range of $5{\times}10^{15},\;1{\times}10^{16},\;7{\times}10^{16}\;ions/cm^2$. The contact angle of water has been reduced with increasing fluence and ion mass but increased with increasing implanted energy. The changes of chemical and structural property are discussed in view of infrared spectroscopy and FT-IR, XPS, which shows increasing C-O bonding and C-C bonding. The root mean square of surface roughness examined by means of AFM changed smoothly from 0.387nm to 0.207nm and the change of wettability was discussed with respect to elastic and inelastic collisions obtained as results of TRIM simulation. It was found that wettability of the modified PC surface was affected on change of functional group and nuclear stopping or linear energy transfer(LET, energy deposited per unit track length per ion) that causes chain scission by displacing atom from polymer chains, but was not greatly dependant on surface morphology.

• Korean Journal of Applied Biomechanics
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• v.18 no.3
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• pp.51-59
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• 2008

The objective of this study is to kinematically analyze forehand & backhand strokes of abscission handicap wheelchair table tennis athletes. The participant of this study were picked out of national athletes who have abscission handicap. Forehand stroke movement was expected to show a throw like motion. However, external rotation and internal rotation of the right arm created a backswing and an impact. Backhand stroke was expected to show a push like motion, and as expected, proximal part of the body didn't participate in the stroke motion, but the distal part, the right arm, rotated internally to backswing and external rotated to impact to form a push like motion. Forehand swing was expected to show throw like motion according to the Link Segmental System principle. However, abscission handicap athlete didn't show clear linking structure connecting proximal and distal parts. Successful strokes were dependant only on the angle of arm rotation.

• The Journal of Korean Society for School & Community Health Education
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• v.12 no.2
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• pp.43-67
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• 2011

Objectives: The purpose of this study was to analyze factors affecting school life adjustment of athletes in middle and high school. Methods: The data in this study came from the survey which conducted to 500 students of physical education high school athletes and elite athletes in general school from the beginning of December 2009 to the end of January 2010 in Seoul and Kyunggi. Finally 436 cases was used. The dependant variable in this study was school life adjustment. And the independent variables were socio-demographic factors, stress and depression factors, social support factors. The analysis methods were T-test, ANOVA, correlation analysis, stepwise multiple regression analysis by using SPSS Ver. 12.0. Results: First, there was a statistically significant result between school life adaptation and sex, family circumstances, life satisfaction variables Second, there was a negative correlation between social support and stress, depression. Third, there was a negative correlation between school life adjustment and some stress factors, all depression factors. Also relationship between school life adjustment and social support showed a positive correlation. Fourth, Taking a look at the impact on school life adjustment, family factors and practical environmental factors in the stress factors and the feeling of worthlessness in the depression factors appeared to influence negatively. Also teachers' support in the social support factors showed positive effects. Explanatory power of the final regression model was 25.6%. Conclusions: The first step in order to improve the school life adjustment of athletes in middle and high school is the teachers' support. Athletes in middle and high school can have capability, responsibility, initiatives through teachers' attention and affection. The effective prevention education and health education programs on stress and depression should be introduced and carried out in the health education programs actively for student athletes to be free from stress, depression.

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.77-88
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• 2006

The purpose of this study is to Propose the time dependent K-least time path algorithm applicable to a real-time based operation strategy in multi-modal transportation network. For this purpose, we developed the extended method based on entire path deletion method which was used in the static K-least time path algorithm. This method was applied to time dependent K-least time path algorithm to find k least time paths in order based on both time dependant mode-link travel time and transfer cost In particular, this algorithm find the optimal solution, easily describing transfer behavior, such as walking and waiting for transfer by applying a link-based time dependent label. Finally, we examined the verification and application of the Proposed algorithm through case study.

• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.490-497
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• 2007

A Combined sewer overflows (CSOs) are themselves a significant source of water pollution. Therefore, the control of urban drainage for CSOs reduction and receiving water quality protection is needed. Examples in combined sewer systems include downstream storage facilities that detain runoff during periods of high flow and allow the detained water to be conveyed by an interceptor sewer to a centralized treatment plant during periods of low flow. The design of such facilities as stormwater detention storage is highly dependant on the temporal variability of storage capacity available (which is influenced by the duration of interevent dry periods) as well as the infiltration capacity of soil and recovery of depression storage. As a result, a continuous approach is required to adequately size such facilities. This study for the continuous long-term analysis of urban drainage system used analytical probabilistic model based on derived probability distribution theory. As an alternative to the modeling of urban drainage system for planning or screening level analysis of runoff control alternatives, this model have evolved that offer much ease and flexibility in terms of computation while considering long-term meteorology. This study presented rainfall and runoff characteristics of the subject area using analytical probabilistic model. This study presented the average annual COSs and number of COSs when the interceptor capacity is in the range $3{\times}DWF$ (dry weather flow). Also, calculated the average annual mass of pollutant lost in CSOs using Event Mean Concentration. Finally, this study presented a decision of storage volume for CSOs reduction and water quality protection.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1321-1326
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• 2006

Total ginsenosides were purified and their antioxidant, antibacterial and anticancer activities were measured. The crude extracts of ginseng, which were extracted with 75% ethanol by ultrasonification method, were firstly purified on AB-8 macroporous adsorption column to remove water soluble impurities, and decolored on Amberlite IRA 900 Cl anion-exchange column. Then, they were purified on Amberlite XAD16 adsorption column to delete the non-polar impurities. Total ginsenosides contents of the purified extracts were 79.4%, 71.7% and 72.5% in cultured wild ginseng, red ginseng and white ginseng, which were significantly increased than those of crude extracts. All of the three extracts showed concentration-dependant scavenging activities against DPPH radicals, among which white ginseng showed the most powerful activity. Cultured wild ginseng roots showed strongest effect against both B. subtilis PM 125(Gram-positive) and E. coli D31 (Gram-negative) bacteria, while red ginseng and white ginseng only showed the activity against B. subtilis. According to the result of the MTT assay, ail of the three extracts inhibited the growth of U-937 human hohistiocytic lympma cell, which were significantly different (p < 0.05) when compared to the control.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1249-1253
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• 2006

The fractions of Capsosiphon fulvescens were studied to verify the anticancer and immunostimulating activity. The fractions from the ethanol extract of C. fulvescens were prepared by the systematic extraction procedure with the solvents such as hexane, ethyl ether, methanol, butanol and H$_2$O. The cytotoxic effects of C. fulvescens fractions against human leukemia cell line U937, mouse neuroblastoma cell line (NB41A3), human hepatoma cell line (HepG2)and rat glioma cell line (C6) were investigated. Ethyl ether fraction of C. fulvescens showed the highest cytotoxicity against all four cell lines tested. In addition, H$_2$O fraction also showed relatively high cytotoxicity. Dose dependent patterns were observed on all four cell lines. The immune-stimulating effects of C. fulvescens fractions on rat macrophage cell line (RAW 264.7) were also investigated. All five fractions of C. fulvescens extract stimulated NO production with concentration dependant manner. These results suggest that C. fulvescens may be a useful candidate for a natural antitumor and immune-stimulating agent.

• Journal of Fashion Business
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• v.14 no.6
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• pp.84-99
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• 2010

The aim of this study is to understand the wedding planners' general perceptions on Hanbok as a ceremonial dress in wedding ceremonies. Moreover, the study explores the aesthetic understanding of wedding planners on Hanbok which both influences their choice of recommendation and purchasing decisions. In the process of organizing the structure of weddings for clients, planners have naturally acquired the position of being able to influence the sales of the Hanbok industry. Moreover, brides-to-be are heavily dependant on wedding planners in sketching the outlines of their whole wedding. Therefore, in order to analyze the opinions of both subjects, a research survey was launched which involved three hundred participants from two groups: first, wedding planners who were free lancers working in the Chungdam District, and second, wedding planners who were working for wedding consulting firms. The survey method was based on one precedent study, in which a preliminary survey was conducted by interviewing companies in the Hanbok industry and wedding consulting firms, and an additional survey in the form of questionnaires. The STATA 11.0 program was used for analyzing the recruited data for frequency analysis and cross-tabulations analysis on career. The conclusion of this research may be used as substantial preliminary data in prospering the Hanbok industry, enhance and newly shape its marketing strategies and the conclusion is as follows. 1. Wedding planners have a more profound understanding on Hanbok and prioritize the significance of formative constituents in the order of color, material, style, size, and decoration. 2. The prospects of promoting the image of Hanbok through wedding planners is promising. According to surveys, this goes to show that the persuasion of wedding planners have brought a positive effect on choice of Hanbok and as wedding planners become more specialized, their involvement in preparing Hanbok with brides is increasing. 3. Wedding planners believed that the main reasons why future brides do not select Hanbok as a ceremony dress are that the cost is too high relative to practicality and that there are not enough opportunities to wear them.