Global Warming Likely Reduces Crop Yield and Water Availability of the Dryland Cropping Systems in the U.S. Central Great Plains

고종한,Lajpat R. Ahuja 한국작물학회 2013 Journal of crop science and biotechnology Vol.16 No.4

We investigated the impact of GCM-projected climate change on dryland crop rotations of wheat-fallow and wheat-cornfallowin the Central Great Plains (Akron in Colorado, USA) using the CERES 4.0 crop modules in RZWQM2. The climatechange scenarios for CO2, temperature, and precipitation were produced by 22 GCM projections for Colorado based on theA1B scenario. The climate change for years 2050 and 2075 was super-imposed on measured 30-year-baseline climate data(1989-2008). For all the cropping rotations and projection years, simulated yields of wheat and corn decreased significantly (P< 0.05) with increasing temperatures. The yield declines due to the elevated temperatures should be attributable to the shorteningof crop maturity duration and concurrent decreases in soil water and evapotranspiration. The model was also projected todecrease crop yields for the combined climate change scenarios of CO2, temperature, and precipitation in the dryland croppingrotations

벼 왕겨 추출물(抽出物)에서 상호대립억제작용(相互對立抑制作用) 물질(物質)의 생물검정(生物檢定) 및 동정(同定)

고종한,엄석현,김명조,유창연,이윤수,이완,지현소,함진관,김두열,김이훈 한국육종학회 1998 한국육종학회 학술발표회 발표요지 Vol.30 No.2

강원도 영동·서 지역 벼 주요품종의 물질생산과 광합성속도 차이에 관한 연구

고종한,정진안,김두열,조동하,김이훈 한국작물학회 1997 한국작물학회 학술발표대회 논문집 Vol.1997 No.2

Potential Impacts on Climate Change on Paddy Rice Yield in Mountainous Highland Terrains

고종한,김한용,정승택,안중배,최광용,강신규,John Tenhunen 한국작물학회 2014 Journal of crop science and biotechnology Vol.17 No.3

Crop models are suitable tools to assess the potential impacts of climate change on crop productivity. While the associated assessmentreports have been focused on major rice production regions, there is little information on how climate change will impact thefuture rice crop production in mountainous highland regions. This study investigated effects of climate change on yield of paddy rice(Oryza sativa) in mountainous highland terrains of Korea using the CERES-Rice 4.0 crop model. The model was first calibrated andvalidated based on observed data and then applied to simulations for the future projections of rice yield in a typical mountainous terrainwhich borders North and South Korea, the Haean Basin in Kangwon Province, Republic of Korea. Rice yield in the highland terrainwas projected to increase by 2050 and 2100 primarily due to elevated CO2 concentration. This effect of CO2 fertilization on yield(+10.9% in 2050 and +20.0% in 2100) was also responsible for increases in water-use efficiency and nitrogen-use efficiency. Withmanagement options, such as planting date shift and increasing nitrogen application, additional yield gains were predicted in responseto the future climate in this area. We also found that improving genetic traits should be another option to get further yield increases. Allin all, climate change in mountainous highland areas should positively influence on paddy rice productivity

SCIE 등재의 준비에 대하여

고종선(高宗宣) 전력전자학회 2008 전력전자학회지 Vol.13 No.6

상업계 특성화고등학교 학생에 대한 교사의 지지가 자기효능감을 매개로 직업기초능력에 미치는 영향

고종남 한국상업교육학회 2023 상업교육연구 Vol.37 No.2

Recently, students of specialized high schools in Korea have been losing their sense of efficacy in their studies and careers. Due to the prolonged online class, various activities are insufficient for student career development, and it has a negative effect on the improvement of basic vocational competency. In this regard, this study conducted an empirical analysis of how teacher support affects basic vocational ability through self-efficacy, targeting 326 students from 6 commercial Specialized high schools in the metropolitan area. As a result of the study, first, it was found that teacher support had a positive (+) effect on academic self-efficacy and career decision self-efficacy. Second, both academic self-efficacy and career decision self-efficacy had a positive (+) effect on basic vocational competency. Third, it was found that teacher support did not affect basic vocational competency, Fourth, it was found that academic self-efficacy and career decision self-efficacy had multiple mediating effects in the relationship between teacher support and basic vocational competency. Therefore, active teacher support plays an important role in improving the basic vocational competency and self-efficacy of students in commercial specialized high schools, The government's efforts to enhance teachers' competence and school level efforts to enhance students' self-efficacy are needed. Therefore, it suggests that teachers themselves are required to develop various educational activities that can enhance students' efficacy.

외환위기 전후 기업차원의 암묵세 변화 분석

고종권 ( Jong Kwon Ko ),박성원 ( Sung Won Park ),박희진 ( Hee Jin Park ) 한국회계학회 2014 회계학연구 Vol.39 No.6

본 연구는 외환위기라는 경제적 사건을 전후하여 기업차원의 암묵세의 크기를 추정하고 암묵세의 변화를 분석하였다. 암묵세의 변화는 기간별 변화 외에도 산업별 변화가 존재하는지를 분석하고 변화의 요인을 설명하였다. 분석 결과 암묵세 추정치는 외환위기 전 기간은 -0.261로 부(-)의 암묵세인 반면 외환위기 후 기간은 0.323으로 정(+)의 암묵세가 존재하는 것으로 나타나 외환위기 전에 비해 암묵세의 크기가 양(+)의 값으로 바뀌고 완전하지 않으나 암묵세가 실현되는 것으로 나타났다. 그리고 산업별 암묵세의 크기를 추정한 결과 외환위기 전과 후에 나타나는 기간별 암묵세의 변화는 모든 산업에 평균적으로 발생하는 것이 아니라 산업별로 차별적으로 발생하는 것으로 나타났다. 암묵세 증가에 영향을 미치는 요인을 산업경쟁력의 관점에서 분석한 결과 외환위기 전에 산업집중도가 산업 평균보다 높은 산업에서 외환위기 후에 경쟁의 강화에 따른 산업집중도 하락이 암묵세의 크기를 증가시킨 요인으로 나타나 산업집중도의 변화로 인해 암묵세가 나타난다는 증거를 제시한 것으로 보인다. 암묵세의 증가에 영향을 미치는 요인을 세무계획 측면에서 분석한 결과 외환위기 후 경쟁이 강화된 산업에서 암묵세가 나타났으나 산업별 조세혜택의 지속성은 하락하여 암묵세가 완전하게 실현되지 못하는 요인이 되는 것으로 보인다. 본 연구의 의의는 다음과 같다. 연도별 산업별로 암묵세를 추정하고 암묵세의 크기가 연도별산업별로 차별화된다는 증거를 제시하였고, 외환위기 전후 산업별 암묵세의 크기 변화가 산업경쟁력의 변화와 산업별 조세혜택의 변화에 기인한다는 증거를 제시하였다. 연도별 산업별로 암묵세를 추정하여 기존 연구를 확장하고 산업경쟁력과 산업별 조세혜택의 변화가 암묵세의 변화를 설명한다는 증거를 제시하였다는 점에 의의가 있다. 국내 선행연구는 외환위기 이전 세전조세혜택(PTTSE)과 세전수익률(PTROE)과의 관계가 양(+)의 값을 가지는 것에 대하여 암묵세 이론과 반대되는 현상이라고 언급하였을 뿐 명확히 해석하지 못하였으나 본연구는 암묵세의 크기 추정을 통해 외환위기 전 부(-)의 암묵세가 존재하였음을 제시하여 기존 연구결과에 대해 명확한 해석을 제공하였다. The main purpose of this paper is to investigate the extent of implicit taxes at the corporate level and the effect on implicit taxes before and after the Asian financial crisis. We analyse the change of implicit taxes not only cross-sectional variations but also industrial variations. In our analysis, we use Korean listed firms with available Korea Investors Services (KIS)-Vaule data from 1991 to 2012. We restrict the sample to non-financial, non-utility firms and have a december year-end. Additionally, firm-years with missing financial data and firm-years which can not estimate effective tax rates are excluded. We delete observations in which any continuous variable lies beyond the highest and lowest 1% of the distribution for that variable to control for outliers. These data requirements result in a sample of 7,838 firm-year observations which consist of 2,460 observations before the financial crisis(1991-1997) and 5,378 observations after the financial crisis(2000-2012). Using four alternative specifications including correlation, regression, and estimating the extent of implicit taxes, we provide strong evidence that before the financial crisis implicit taxes at the corporate level do not offset any of the variation in explicit taxes. Contrary to the economic theory, we find evidence of negative implicit taxes in this period. Firms with lower effective tax rates due to tax benefits had higher pretax return and higher after tax return, indicating that implicit taxes did not eliminate any of the firms`` tax benefits. One of our specifications estimates the extent of implicit taxes and finds that the average of implicit taxes is -0.261 in this period and this result indicates that variation in explicit taxes is not offset by variation in pre-tax income. But, after the financial crisis we observe an increase in the extent of implicit taxes at the corporate level. One of our specifications estimates the extent of implicit taxes and finds that the average of implicit taxes is 0.323 in this period. This result indicates that after the financial crisis about a third of the explicit tax advantage is offset by the pretax return disadvantage and a large increase in implicit taxes in this period. We also estimate the extent of implicit taxes at the industry level annually and finds that there is an inter-temporal variations in the extent of implicit taxes and the variations before and after the financial crisis appears differently by industry level. To investigate this possibility that the increase in implicit taxes after the financial crisis is due to a change in the intensity of competition faced by firms in our sample, we examine whether the level of competition in the industry level changed before and after the financial crisis. We use a Herfindahl index to measure average concentration ratio for each industry and finds that increase in implicit taxes was concentrated in industries with above mean concentration ratio before financial crisis, and was mainly due to the increase in competition after the financial crisis. To investigate the possibility that aggressive tax planning after the financial crisis may have contributed to the increase in implicit taxes at the corporate level, we examine the persistence of tax preferences and finds that there is a large volatility in tax preferences from one year to the next, and less persistent tax preferences after the financial crisis. This suggests that positive implicit taxes after the financial crisis was mainly due to the increase in competition in this period, and less persistent tax preferences at the industry level may affect negatively for the realization of implicit taxes. Next, by examining the role of firm-specific characteristics that have been found to be associated with tax planning, we find evidence that the change in pretax return associated with tax planning partly explain the realization of implicit taxes. This paper contributes to the implicit tax study as follows by providing an additional evidence of the extent of the implicit taxes. First, even though there are lots of implicit tax research focusing on the individual assets , only a limited studies of the existence of implicit taxes at the corporate level are exist due to a methodological issue. This paper focuses on overcoming the limit by analysing implicit taxes at the corporate level using industry mean return on equity as an equilibrium ROE as is suggested by Jennings e t al.(2012). Second, Almost implicit tax research at the corporate level only examine the relation between tax burden (or tax benefit) and pretax return, and do not directly estimate the extent of implicit tax at the corporate level. This paper extend the prior research by estimating the extent of implicit taxes at the corporate level using maximum likelihood estimation. Third, even though prior research only focus on the annual extent of implicit taxes, this paper additionally analyse the extent of implicit taxes by industry and finds evidence that the level of competition and the persistence of tax preferences in the industry level partly explain the change in implicit taxes before and after the financial crisis.

꾸준한 관찰과 관리, 기본이자 핵심

고종열,Go, Jong-Yeol 한국낙농육우협회 2017 낙농·육우 Vol.37 No.3

외란관측기와 파라미터 보상기를 이용한 PMSM의 정밀위치제어

고종선,이태훈 전력전자학회 2004 전력전자학회 논문지 Vol.9 No.1

This paper presents a new method of external load disturbance compensation using deadbeat load torque observer and gain compensation by parameter estimator. The response of the permanent magnet synchronous motor(PMSM) follows the nominal plant. The load torque compensation method is composed of a deadbeat observer. To reduce the noise effect, the post-filter implemented by moving average(MA) process is adopted. The parameter compensator with recursive least square method(RLSM) parameter estimator is suggested to make the new system work as same as the name plate system which in used to take gains. The proposed estimator is combined with a high performance load torque observer to resolve the problems. As a result, the proposed control system has a robust and precise system against the load torque and the parameter variation. A stability and usefulness are verified by computer simulation and experiment. 본 논문은 데드비트 외란 관측기를 사용한 외부 부하 외란 보상과 파라미터 추정기에 의한 보상 이득의 조정을 나타내고 있다. 결론적으로 PMSM의 응답은 지표 시스템을 따른다. 부하 토크 보상 방법은 데드비트 관측기로 구성된다. 노이즈 영향을 감소시키기 위해 MA 처리에 의해 구현된 후단 필터를 적용하였고, RLSM 파라미터 추정기를 가진 파라미터 보상기가 주어진 실제 시스템의 이득 계산시 사용된 파라미터로 가상 동작하여 이득이 오차가 없는 것처럼 동작하게 한다. 제안된 추정기는 문제를 풀기 위해 고성능 외란 관측기와 조합하여 사용한다. 제안된 제어 시스템은 부하토크와 파라미터 변화에 대해 강인하고 정밀한 시스템이 된다. 이상의 제안된 시스템의 안정성과 유용함이 컴퓨터 시뮬레이션과 실험을 통하여 확인되었다.

Nano-Confined Organic Semiconductors and Their Electrical Doping for Stable and Efficient Optoelectronic Applications

고종국,송지연,윤현식,이창희,차국헌 한국고분자학회 2017 한국고분자학회 학술대회 연구논문 초록집 Vol.42 No.2