• 생물정신의학
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• 제9권1호
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• pp.34-41
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• 2002

Background:Since serotonin neurotrasnmission plays an important role in the pathophysiology of depression, the drug that acts on serotonin transporter can be an effective antidepressant. The aim of this study was to investigate the relationship between serotonin transporter polymorphisms(5-HTTLPR) and the long-term effect of the antidepressant treatment. Method:The 175 depressive patients, who met DSM-IV criteria for major depressive disorder or dysthymic disorder were enrolled into three year study. The genotypes of the patients were investigated by polymerase chain reaction of genomic DNA with promoter regions of the serotonin transporter gene. The patients were assessed by the Clinical Global Impression Scale, at the 1st visit, 8th week, 16th week, 1st year, 2nd and 3rd year after the antidepressant treatment. Result:The genotypes of 138 patients were investigated and 128 of them finished this 1st year study and 107 remained in the study after 2-year treatment, and, 97 completed this 3-year study. The therapeutic response of each subset was not different at 8th, 16th week, but the subset with homozygote(l/l) of long variant showed a better antidepressant therapeutic response than heterozygote(l/s). The heterozygote(l/s) showed a better response than the subset with homozygote(s/s) of short variant at 1st, 2nd and 3rd year after the antidepressant treatment in CGI-global improvement score. Conclusion:This result shows that the serotonin transporter polymorphism may be related to the long-term effect of antidepressant treatment and there may be also ethnic difference.

• 벤처창업연구
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• 제12권1호
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• pp.133-144
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• 2017

본 연구는 1999년부터 2015년까지 상장기업을 대상으로, 순위프로빗 모형을 이용하여 신용등급 관련 이해관계자 중 하나인 기업의 관점에서 신용등급에 영향을 미치는 요인을 투자등급과 투기등급으로 구분하여 분석하였다. 투자등급의 경우 영업이익률, 매출액, 시장가/장부가, 배당지급, 자본적 지출 비율, 유형자산 비율이 양(+)의 계수를, 장 단기 부채비율, 베타, 고유위험이 음(-)의 계수를 보였다. 투기등급의 경우 배당지급, 유보이익률, 자본적 지출 비율이 양(+)의 계수를, 장 단기 부채비율과 연구개발비가 음(-)의 계수를 가졌다. 글로벌금융위기 이후 "신용정보의 이용 및 보호에 관한 법률"이 강화된 2009년 전 후를 기준으로 분석한 결과, 투자등급에서 자본적 지출 비율, 현금비율, 유형자산 비율이 2009년 이전에는 양(+)의 계수를 보였으나 2010년 이후에는 유의하지 않았다. 투기등급의 경우 2009년 이전에 단기부채보다 장기부채가 더 유의한 음(-)의 계수를 보였으나 2010년 이후에는 장기부채보다 단기부채가 더 유의한 음(-)의 계수를 보였다. 흥미롭게도 연구개발비가 2010년 이후 투자등급과 투기등급 모두 유의한 음(-)의 계수를 보였다. 이는 연구개발에 대한 투자가 기업의 성장기회를 높여 더 많은 현금흐름을 창출하며 이것이 신용등급을 상승시킬 것이라는 선행연구와 일치하지 않는다.

• 디자인학연구
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• 제19권5호
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• pp.335-350
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• 2006

산업기술의 발달, 소비자의 행동변화, 업계경쟁 심화 등으로 인해 강력한 브랜드를 구축하는 일이 점점 더 힘들어지고 있다. 더욱이 브랜드는 고정 불변된 자산이 아니라 살아있는 생명체와 같아서 브랜드 수명주기에 따라 노화되기 마련이다. 따라서 끊임없이 소비자와의 관계를 통해서 자기 존재를 확인 시킬 수 있는 자기변화와 변혁이 필요하다. 즉, 시간의 흐름과 함께 또는 시장상황의 변화로 인해 진부해진 브랜드를 다시금 소비자의 인식선상으로 되돌리기 위하여 재활성화 작업이 필요하다. 본 연구에서는 단기적 과제로써 디자인 리뉴얼에 대한 효과를 측정하는 것에서 벗어나, 브랜드 수명주기에 따른 장기적 의미의 브랜드 관리에 초점을 맞추고 성공적인 브랜드 재활성화의 사례 분석과 연구 분석 대상 선정을 통한 소비자 의식도 분석결과를 종합하여 효과적인 재활성화의 시기와 방안에 관하여 규명하고자 하였다. 본 연구결과를 통하여 예측 가능한 환경의 변화에 미리 대응하기 위하여 단행하는 시기적절한 브랜드 재활성화는 브랜드 에쿼티의 하락을 미연에 방지하고 브랜드의 수명을 연장할 수 있는 중요한 방법으로 파악되었다. 또한 브랜드 재활성화는 단기적 매출 상승을 위한 전술의 개념보다는 장기적인 브랜드 관리전략으로써 BLC곡선이 하락하는 시점에서 지속적으로 실행되어야하며, 단기간에 졸속으로 이루어져 겉포장만 바꾸는 식의 외형적 측면의 디자인 리뉴얼에만 연연해서는 안 된다는 것을 확인할 수 있었다.

• 한국환경과학회지
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• 제17권6호
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• pp.591-599
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• 2008

In order to support the development of wind farms in Jejudo, a wind resource database for Jejudo has been established using a meteor-statistical analysis of KIER(Korea Institute of Energy Research) met-mast measurements and KMA(Korea Meteorological Administration) weather data. The analysis included wind statistics, tower shading, an exposure category classification using satellite images, the effect of atmospheric stability on the wind profile exponent, and a correlation matrix of wind speed to gain an understanding of the meteorological correlation between long-term weather observation stations and short-term met-mast measurements. The wind resource database for Jejudo, is to be provided as an add-on to Google $Earth^{TM}$, which is expected to be utilized as a guideline for the selection of an appropriate reference site for long-term correction in the next wind farm development project.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권1호
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• pp.57-62
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• 2005

Grid-connected photovoltaic (PV) systems were installed and monitored at the field demonstration test center (FDTC) in Korea in October 2002. Before long-term field testing of installed PV systems, the performances of PV components were evaluated and compared through short-term performance tests of each of the PV system components such as power conditioning system and PV module under standard test conditions. A data acquisition system has been constructed for measuring and analyzing the performance of PV systems to observe the overall effect of environmental conditions on their operation characteristics. Performances of PV systems have been evaluated and analyzed not only for component perspective (PV array, power conditioning unit) but also for global perspective (system efficiency, capacity factor, electrical power energy) by review of the field test and loss factors of the systems. These results indicate that it is highly imperative to develop an optimum design technology of grid connected PV systems. The objective of this paper is not only to evaluate and analyze the performance of domestic PV systems application through long-term field testing at FDTC but also to develop evaluation, analysis and optimum technology for long-term stability and reliability of grid-connected PV systems in Korea.

• The Journal of Asian Finance, Economics and Business
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• 제7권7호
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• pp.15-25
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• 2020

This empirical research aims to identify the relationship between fiscal and financial macroeconomic fundamentals and the volatility of government bonds' borrowing cost in an emerging country - Vietnam. The study covers the period from July 2006 to December 2019 and it is based on a sample of 1-year, 3-year, and 5-year government bonds, which represent short-term, medium-term and long-term sovereign bonds in Vietnam, respectively. The Generalized AutoRegressive Conditional Heteroskedasticity (GARCH) model and its derivatives such as EGARCH and TGARCH are applied on monthly dataset to examine and suggest a significant effect of fiscal and financial determinants of bond yield volatility. The findings of this study indicate that the variation of Vietnam government bond yields is in compliance with the theories of term structure of interest rate. The results also show that a proportion of the variation in the yields on Vietnam government bonds is attributed to the interest rate itself in the previous period, base rate, foreign interest rate, return of the stock market, fiscal deficit, public debt, and current account balance. Our results could be helpful in the macroeconomic policy formulation for policy-makers and in the investment practice for investors regarding the prediction of bond yield volatility.

• Journal of Astronomy and Space Sciences
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• 제20권1호
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• pp.11-20
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• 2003

A method for estimating the NORAD SGP4 atmospheric drag term from minimum osculating orbit states, i.e., two osculating orbits, is developed. The first osculating orbit state is converted into the NORAD TLE-type mean orbit state by iterative procedure. Then the converted TLE is propagated to the second orbit state using the SGP4 model with the incremental SGP4 drag term. The iterative orbit propagation procedure is finished when the difference of the two osculating semi-major axes between the propagated orbit and the given second orbit is minimized. In order to minimize the effect of the short-term variations of the osculating semi-major axis, the osculating argument of latitude of the second orbit is propagated to the same argument of latitude of the first orbit. The method is applied to the estimation of the NORAD-type TLE for the KOMPSAT-1 spacecraft. The SGP4 drag terms are estimated from both NORAD SGP4 orbit propagation and the numerical orbit propagation results. Variations of the estimated drag terms are analyzed for the KOMPSAT-1 satellite orbit determination results.

• 정보학연구
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• 제9권4호
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• pp.75-85
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• 2006

This study is to test the influence of stock option granting information on the firm's performance. The important issue in stock option is that agent cost is the important determinant factor for the long term performance. The agent cost arises between the manager and shareholders. So many study are concentrated in diminishing the agent cost, and develop some substitute tools to measure the agent cost. The event study about stock option analyzes returns around event date at a time. Event study provides estimation periods and cumulative returns. Announcements about stock option are generally associated with positive abnormal returns in short term period, but not showing positive effect in long term period. It is important to investigate the responses of stocks to new information contained in the announcements of stock option. Therefore it is important to study the long term performance in the case of stock option. The event time portfolio approach exists the CAR model, BHAR model and WR model. And the calendar time portfolio approach has the 3 factor model, 4 factor model, CTAR model, and RATS model. This study is forced to develop and arrange two approach method in evaluating the performance, the event time portfolio approach and calendar time portfolio approach.

• Journal of Biosystems Engineering
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• 제40권3호
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• pp.178-185
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• 2015

Purpose: This research suggests a method of establishing criteria for working area and operating cost for a long-term lease of agricultural machinery. Methods: Eight crops were selected-three food crops and five open-field vegetables-and agricultural machines used for sowing, transplanting, and cultivation in dry-field farming were analyzed. Results: The break-even acreage for agricultural machinery under a long-term lease was found to differ by agricultural machine, ranging from 1.0 to 5.8 ha. In terms of arable land area, the break-even acreages for harvesting machinery and transplanters were 15.6 to 26.1 ha and 6.1 to 8.6 ha, respectively. The working area lessees should secure was divided into two cases: (1) 2.0 to 11.6 ha when leasing individual agricultural machines (sowing and transplanting) for a long-term period, and (2) more than 10 ha when farmers who cultivate beans, potatoes, garlic, onions, and so on lease sowing and transplanting machines as a set. When agricultural machinery was leased for a long term, the operating cost and working time were reduced by 27.6 to 74.4% and 2.5 to 21.6%, respectively, indicating considerable effect. Conclusions: A long-term lease project needs to be promoted to overcome the limitation of short-term leases of agricultural machinery. The local government should lead this project and facilitate the mechanization of dry-field farming. The department in charge of agricultural machinery lease projects needs to set the working area to cover the rate and maintenance cost for farmers who lease agricultural machinery for the long term.

• 한국시스템다이내믹스연구
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• 제7권2호
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• pp.21-34
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• 2006

Korean Government has carried out various support policies for small and midium size enterprises(SMEs). However, effect of the policy might not be realized in short term or the policy has turned out in fail. We found out the time of support is also important. Thus we propose that government should figure out the proper time to support funds according to the companies status(Technology, Production, Marketing) based on System Thinking.