• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.48-58
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• 2013

The stock market is constantly changing and sometimes a slump or a sudden rising in stocks happens without any special reason. So the stock market is recognized as a complex system and it is hard to predict the change on stock prices. In this paper we consider the stock market to a network consisting of stocks. We analyzed the dynamics of the Korean stock market network and evaluated the changing of the correlation between shares consisting of the time series data of 137 companies belong to KOSPI200. Our analysis shows that the stock prices tend to plummet when the correlation between stocks is very high. We propose a method for recommending the stock portfolio based on the analysis of the stock market network. To show the effectiveness of the recommended portfolio, we conducted the simulated stock investment and compared the recommended portfolio with the efficient portfolio proposed Markowitz. According to the experiment results, the rate of return of the portfolio is about 10.6% which is about 3.7% and 5.6% higher than the average rate of return of the efficient portfolio and KOSPI200 respectively.

• Journal of Intelligence and Information Systems
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• v.20 no.1
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• pp.103-119
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• 2014

In this paper, we investigate intellectual reaction differences among market participants to various corporate information announcements and the main information prompting investors to trade. Our research is based on IPO companies listed on the KOSDAQ exchange from January 2000 to September 2012 and concentrates on three information disclosures - bonus issue, seasoned equity offer, and new investment in facilities announcements. We find that intellectual market participants react positively to bonus issues and seasoned equity offers, but negatively to new investment announcements. Market trading volume increases before the positive events and all cgroups actively buy shares during these periods. For the negative events, only institution participants show active selling. Overall, institutions act as momentum traders, and individuals and foreigners as contrarian traders. We also discuss the implications of this study.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.4_1
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• pp.293-298
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• 2014

Recently, the direct georeferencing has been becoming a common method in the aerial photogrammetry. As this direct georeferencing method using converged sensor of the digital photogrammetry camera and GPS(Global Positioning System)/INS(Inertial navaigation System), more rapid and accurate aerial photogrammetry has improved following advanced performance in photogrammetry. Since the accuracy of EO parameters from the direct georeferencing is determined by GPS/INS accuracy, it is significant to calculate the exact attitude information using values of INS rotations. For following calculations, the misalignment, such as INS rotation and the gap of GPS/INS, has to be decided. Because the number of ground control points are used for tirangulation and boresight calibration, those results should be different according to array and location of ground control points. In the study, those location and array of ground control points were tested to be used boresight calibration. As a result, there is no significant change of misalignment and exterior orienation parameters in the case when ground control points were at all course. On the contrarily, the difference has been shown in the case of no ground control point at course.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.4
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• pp.407-417
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• 2018

In this study, the antioxidant, cytoprotective and antimicrobial activities of 50% ethanol extract of Polygoni multiflori Radix (PMR) and its ethyl acetate fraction were evaluated to confirm the applicability as a functional ingredient. The activities of the major constituent of PMR were verified and 2, 3, 5, 4′-tetrahydroxystilbene 2-O-${\beta}$-D-glucoside (THSG) was confirmed to be the main component of extract and fraction using HPLC-DAD, LC-EIS-MS analysis. The phenolic and THSG contents of the ethyl acetate fraction were 11.1- and 3.0-folds higher than those of the ethanol extract, respectively. As a result of the DPPH assay and that of luminol dependent chemiluminescence assay in $Fe^{3+}$-EDTA/H2O2 system. the ethylacetate fraction was superior to the ethanol extract in free radical and ROS scavenging activities. Especially, the ethyl acetate fraction and THSG exhibited the similar scavenging activity like L-ascorbic acid in ROS scavenging activity. The ethyl acetate fraction perceived the most potent cytoprotective effect against oxidative damage of erythrocytes induced by photosensitization reaction, followed by the ethanol fraction, THSG and that of (+)-${\alpha}$-tocopherol, which was used as a positive control. Antimicrobial activities were evaluated by disc diffusion and broth microdilution assay against S. aureus, E. coli, P. aeruginosa and C. albicans. In particular, the antibacterial activity of the extract and fraction against S. aureus was superior to that of methyl paraben. Taken together, our results suggest that PMR could be used as a natural ingredient for antioxidant, cytoprotective and antimicrobial activities.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.685-687
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• 1999

기존 교수 연수체제는 전이 효과가 떨어지며 교사의 업무에 지장을 초래하게 된다. 이에 선정된 컴퓨터교육내용을 원격교육체제로 전환하여 기존 교사 연수의 단점을 극복하여, 효율성을 기할 수 있다. 컴퓨터교육내용을 원격 교육체제로 구축함에 있어서 다양한 원격교육매체의 특징과 가능한 학습 활동, 컴퓨터교육 내용의 특징에 따라서 원격 컴퓨터교육의 모형을 탐색하여 보았다. 그 모형은 자기주도적 학습활동에 기반한 코스웨어 모형, 토의 학습활동에 기반한 토의학습 모형, 대체 학습모형으로 일체학습 모형, 원격 교육의 모든 매체를 활용할 수 있는 문제결학습모형으로 분류하여 제시하여 보았다.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.304-306
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• 2005

This paper presents the RTDS training course on using passive filters for control of harmonic currents. The course can show harmonic currents in porer system, which is occurred by function generators, with Fourier analysis function of RTDS and the effect of passive filters implemented in RTDS to eliminate harmonics. In addition to, With Jeju-Haenam HVDC system, we have simulated the effect of passive filters on harmonic currents occurred by massive power conversion system of HVDC.

• 한국정보교육학회:학술대회논문집
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• 2004.01a
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• pp.260-267
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• 2004

언론보도에 따르면 우리나라 어린이들의 사망률이 인구 10만명당 25.6명으로 OECD회원국 가운데 가장 높은 것으로 나타나고 있다. 모든 위험상황으로부터 최우선적으로 보호되어야 할 대상인 어린이들이 우리 사회에서는 상당한 위험에 노출되어 있는 것이 현실이다. 지난 30년간의 급속한 산업화로 인해 물질의 풍요는 누렸지만 그 이면에 나타난 각종 안전사고는 점차 증가 추세이며 더욱 늘어날 것으로 예상되고 있다. 어린이의 귀중한 생명과 재산을 보호하기 위해서는 무엇보다도 어릴적부터 철저한 안전교육을 통한 안전 습관화와 함께 범 국가적인 차원의 안전대책이 마련되어야 할 것이다. 이에 우리나라도 올해를 어린이 안전 원년의 해로 정하여 각종 안전대책을 마련하고 있으며 학교안전 교육의 중요성이 부각되면서 안전교육을 위한 프로그램의 개발 보급이 요구되고 있다. 이전의 안전교육용 프로그램이 한국산업안전공단, 교통안전공단 둥 주로 외부기관에 의해 제작되어 초등학교 현장에 직접 투입하기에는 적절치 않아 초등학생들의 발달단계와 교육과정 분석을 통해 초등학교 학생들의 수준에 알맞은 내용으로 재구성하여 본 프로그램을 설계하게 되었다.

• 발명특허
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• v.30 no.6 s.348
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• pp.36-39
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• 2005

복개되었던 청계천을 살리기 위한 서울시의 정책추진으로 청계고가가 철거되고, 그 위를 뒤덮었던 콘크리트 도로들이 사라지면서 청계천이 사람들의 눈앞에 모습을 드러냈다. 오래도록 도로 아래 묻혀있던 청계천은 그 복원을 계기로 많은 이들에게 생활하천이던 청계천의 옛 모습을 기억하게 했다. 삼삼오오 둘러앉아 빨래를 하거나 멱을 감는 아련한 추억으로, 혹은 빛바랜 사진으로 말이다. 추억 속 그 시절은 사람이 많이 살지 않고 빨래나 멱을 감는 것이 큰 하수가 아니었지만, 도시가 개발되고, 사람들이 많아지고, 생활하수가 늘어나면서 하수처리의 문제는 오늘날 도시계획 속에 포함될 만큼 중요한 문제가 되었다. 사람이 사는 곳이라면 어디든지 하수가 생기기 마련이다. 생활하수이건 산업하수이건 그로 인해 생겨나는 오염된 물, 오수인 하수는 불결하기 마련이다. 이 하수가 제대로 배수되지 않으면 전염병의 원인이 되기도 하고 생활 주변환경을 심각하게 오염시키는 결과를 초래하게 된다. 그렇기 때문에 하수는 신속하게 사람들이 살고 있는 환경 주변에서 배제되어져야 하며 하수도는 그 하수들을 처리하는 과정으로 하수도관과 종말처리장, 유수지 배수펌프장으로 구분된다. 이 하수를 처리하기 위해 하수관이 시가지 안의 도로 아래에 그물모양으로 어지럽게 깔려 있는데 도로 아래 매립되어 있기 때문에 견고한 시공이 필수적이다.

• Cross-Cultural Studies
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• v.21
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• pp.87-111
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• 2010

This research examines the concept of 'homo sovieticus' by reviewing the sociological essay novel homo sovieticus written by Zinoviev who was one of the well-known dissident in Soviet Union period, and attempts to have critical understanding of the concept. It is an interesting research topic that current Russia and Russians who get through the historical layers from Soviet to post-Soviet regime at the time current trend that allows to have various academic discussions of post-Soviet. It is required to examine the past of Russia and Russian to make precise estimation of their current and future. Therefore, it is necessary to re-examine the term of 'homo sovieticus' which is conventionally accepted. This research aims at broad comprehension of homo-sovieticus by focusing on the Zinoviev's own understanding instead of the habitual use of the term which only contains ideological and political intention.

• Management & Information Systems Review
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• v.28 no.1
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• pp.25-44
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• 2009

This study examines long term performance of initial public offerings(IPO) after book building was introduced in KOSDAQ market. We use event time portfolio approach and calendar time portfolio approach to test if the performance of IPO is fair or not in long term. We estimate the performance by using the BHAR(buy and hold abnormal return), CAR(cumulative abnormal return), WR(wealth relatives) model in event time portfolio approach. And we calculate the performance by using Fama-French three factor model, CTAR(calendar time abnormal return), RATS(Return Across Time and Securities approach) model in calendar time portfolio approach. This study shows that the long term performance of IPO is positive with statistical significance as the results of the analysis through the various research method and all windows in all kinds of firms and total firms.