Changes of Landscape Structure for the Recent 20 Years in the Wangsuk Stream Basin of the Central Korea

Lee, Chang-Seok,Cho, Yong-Chan,Shin, Hyun-Chul,Lee, Seon-Mi The Ecological Society of Korea 2006 Journal of Ecology and Environment Vol.29 No.4

Landscape changes for 20 years between 1981 and 2001 in the Wangsuk stream basin located on the central Korea were investigated on the basis of physiognomic vegetation map made from the aerial photograph interpretation and field check. Changes of landscape structure were noticeable in agricultural field and forest landscape elements. Changes in the agricultural fields due to transformation of agricultural pattern into the institutional agriculture dominated landscape change, although urbanization also contributed to such change. The former change due to change of food production structure originated from socio-economic development during this period and the latter to the overpopulation of Seoul. As energy sources for heating and cooking, fertilizer, and fodder for livestock transform from plant materials to fossil fuel, manufactured one, and grain, succession of forest escaped from direct human disturbance dominated change of landscape structure in forested land. Differently from the positive landscape change in the upper area, change in the lower area deteriorated landscape quality by increasing artificial land. It was estimated that such landscape deterioration in the Wangsuk stream basin would influence water quality of the stream. In order to realize sustainable land-use against such environmental degradation, systematic environmental management based on landscape ecological perspective such as "an eco-plan for creating riparian vegetation belt," which is under preparation by Ministry of Environment, was recommended.

Vegetation change and emerging research feedback for Korean National Long Term Ecological Research (KNLTER)

Cho, Yong-Chan,Lee, Chang-Seok,Cho, Hyun-Je,Lee, Kyu-Song,Park, Pil-Sun The Ecological Society of Korea 2011 Journal of Ecology and Environment Vol.34 No.1

Various responses of forest ecosystems to climate change underscore the need to improve our understanding of the environmentally-driven changes in forests, most effectively by long-term monitoring protocols. We have explored vegetation dynamics based on changes in community structure, species composition, diversity and demographics in four Korean National Long Term Ecological Research (KNLTER) sites--Mt. Nam, Mt. Jeombong, Mt. Worak, and Mt. Jiri--between 2004 and 2009. Most of the sites and forests studied exhibited increments in total basal area, but this was not observed in Quercus mongolica forests in Mt. Nam and Mt. Worak. Stem density exhibited various changes. Altitude gradient was the representative factor in differences in species composition. Two patterns of compositional change--convergence and divergence--were detected. The vegetation of Mt. Nam and Q. mongolica community of Mt. Work showed relatively larger changes in composition. However, in the other sites, few changes were observed. Changes of species richness were not notable except for Mt. Nam, where three species were added in the pine forest, whereas one species disappeared in the oak forest. In the oak forests, mortality rate was as follows (in descending order): Mt. Nam (25.5%), Mt. Jeombong (24.3%), Mt. Worak (16.4%) and Mt. Jiri (0.8%). In the pine forest, the recruitment rate was as follows (in descending order): Mt. Nam (63.7%), Mt. Worak (12.9%), Mt. Jeombong (7.6%) and Mt. Jiri (7.3%). The mortality rate and change rate of basal area were strongly negatively correlated (r = -0.9, P = 0.002), and the recruitment rate and change rate of density were positively correlated (r = 0.77, P = 0.026). In the KNLTER sites, larger vegetation changes were attributed to anthropogenic activities such as salvage logging. Suppression or competition for resources would also affect these changes. Research suggestions such as monitoring to clarify the causes of species mortality were discussed.

Impacts and Countermeasures of Climate Change on Food Supply

Kim Chang-gil,Jeong Hak-kyun,Han Suk-ho,Kim Jeong-seung,Moon Dong-hyun 한국농촌경제연구원 2013 한국농촌경제연구원 기본연구보고서 Vol.- No.-

Climate change has become a megatrend that will lead to significant changes in future society. Korean and overseas agencies specializing in climate forecasts predict that average global temperatures will continue to rise. While climate change may potentially have certain positive impacts for crop yields, the overall impact is predicted to be negative for environment and food security. In this context, our study aims to suggest a plan for systematically establishing a stable food supply system in Korea in respose to climate change. Various analytical models were employed, including: a response analysis based on questionnaire for farmers, panel-based analysis of the causes of pests and diseases in rice production, a random-effects model for panel data of extreme weather impact, and an analysis of food supply effects using the Simulation Model for Climate-Agriculture Relations (SIMCAR) integrated model in conjunction with the Crop Estimation through Resource and Environment Synthesis (CERES) model of the Korea Agricultural Simulation Model (KASMO). An analysis was made of major grain yields by means of the KREI-KASMO. This revealed reduced yields and area in comparison with the baseline in 2050, resulting in a reduction of rice production by 17.8%p in the RCP8.5 scenario, and reduction of soybean by 21.2%p and reduction of barley by 13.7%p in the A2 scenario. Self-sufficiency ratio of major grains in 2050 drawn from the SIMCAR revealed that the climate change scenario for rice showed 55.0% to be reduced by 18.3% in comparison with the baseline. It is predicted that selfsufficiency ratio in rice will drop to 50% which means a half of consumed rice should be imported. Key tasks for building a stable food supply system to cope with climate change were developed based on the domestic production capacity, the buffering capacity to climate change, import capacity from other countries, and policy performance capacity with reference to the empirical analysis. First, the suggested key tasks for improving the domestic production capacity include developing and disseminating adaptation technology, conserving farmland and expanding arable land, practicing climate-smart agriculture by using fusion technology, and modernizing infrastructure for agriculture. Second, key tasks for improving buffering capacity to climate change are improving resilience and biodiversity, building a risk management system, and further improving storage of food in Korea and other countries. Third, major tasks for improving the import capacity from other countries are constructing overseas food bases, effectively using the international grain market, and enhancing international cooperation with relevant countries. Finally, key tasks for improving policy performance capacity are refining and applying the climate change impact analysis model with respect to policies, expanding investments in research and development, building a vulnerability assessment system, enhancing education and training, and installing Climate Change Response Center for Agriculture (tentative). In this study, several key challenges were presented in the four different areas related to building a stable food supply system which can help overcome the challenges of climate change. It is expected that the nature of the policies that need to be prioritized and promoted, given the constraints of budget, organization and information will be addressed in future research. Also, in order for the solutions for key challenges to work properly in the field such that policy outcomes will be maximized, a consortium of research bodies in the related fields of agriculture, agricultural meteorology and agricultural economics should be created. As preparation for specific action programs. Furthermore, follow-up studies should be conducted to verify the expenses required for developing reliable climate change impact assessment models and the effectiveness of the enforced policies. Such fie

최빈국 지역정부의 기후변화적응계획 수립을 위한 기술적 가이드라인 개발 연구

장훈 ( Hoon Chang ),송영일 ( Young-il Song ),심창섭,문지원,이명주 한국환경정책평가연구원 2016 기후환경정책연구 Vol.2016 No.-

전 세계적으로 기후변화가 가속화됨에 따라 이로 인한 영향과 피해가 더욱 심각해지고 있다. 선진국보다는 최빈국이 기후변화에 의한 위험에 더욱 취약함에 따라 유엔기후변화협약에서 는 최빈국을 대상으로 기후변화로 인한 피해 저감을 위하여 기후변화적응계획 수립을 권고하였다. 유엔개발계획, 유엔기후변화협약 등의 국제기구 혹은 몇몇 국가에서는 기후변화적응계획 수립 가이드라인을 마련하여 최빈국의 적응계획 수립을 지원하고 있으나 현재까지 적응계획의 수립은 저조한 상황이다. 2010년 COP16에서부터 기후변화적응계획 수립을 권고하였으나 48개 최빈국 중 현재까지 다섯 국가에서만 적응계획 수립을 완료하였다. 한편 유엔자본 개발기금5)에서는 최빈국 지자체의 기후변화적응 능력 향상을 위해 LoCAL 프로젝트를 추진하고 있으며, KEI는 국내에서의 기후변화적응계획 수립 노하우를 토대로 동 프로젝트에 기술적 측면의 지원을 하고 있다. 이러한 KEI 지원의 일환으로 본 연구에서는 최빈국 지역정부의 기후변화적응계획 수립을 위한 가이드라인을 개발하고 이를 최빈국 중 하나인 부탄에 적용하였다. 본 연구에서 제안하는 가이드라인의 세부적인 내용은 다음과 같다. 중앙정부뿐만 아니라 지자체에서도 활용 가능하도록 국내외 기후변화적응계획 수립 관련 가이드라인을 검토하여, 절차별 방법이나 특성을 파악하였다. 그리고 부탄 및 캄보디아와 같은 일부 최빈국을 방문하여 현지 조사를 통해 가이드라인의 개발 방향을 정립하였다. 본 연구에서 제안하고 있는 기후변화적응계획 수립의 절차는 국내 기초지자체의 계획 수립 절차를 참고하였고, 절차별 과학적인 평가 방법은 필요한 자료의 유무나 질을 고려하여 정성적 또는 정량적 측면의 방법을 총 8단계로 나누어 제안하였다. 지역의 일반 현황과 기후변화 현황을 분석하고, RCP 시나리오 기반의 기후변화 전망을 분석하여 향후 기온이나 강수량이 기후변화로 인해 어떻게 변화하는지 예측하는 방법을 제안하였다. 그리고 이해당사자를 대상으로 기후변화적응에 대한 니즈를 파악하여 우선적으로 고려해야 할 사항이 무엇인지 판단하고, 과거 구축된 자료를 바탕으로 기후변화로 인한 재해 및 영향이 무엇인지 분석하는 방안을 제안 하였다. 취약성 평가는 수행 여건에 따라 정량적, 정성적 방법으로 평가될 수 있으며, 리스크는 3회에 걸친 전문가 설문을 통해 정성적인 방법으로 분석하도록 하였다. 이와 같이 분석된 종합적인 평가 결과를 기존의 최빈국 개발사업(investment menu)과 비교하여 적응계획 이행을 위하여 우선적으로 추진해야 할 사업을 선정하고, 체계적인 평가 및 모니터링 전략을 구축하는 등 전반적인 적응계획 수립 및 이행에 걸친 방안을 제안하였다. Due to accelerated climate change, its impacts and devastations are increasing day by day. As developing countries are more vulnerable to climate change compared to developed countries, UNFCCC recommended the development of a climate change adaptation plan in order to reduce their exposure to risks derived by climate change. Since COP 16, 2010, developing countries were encouraged to establish National Adaptation Plans(NAPs). Including UNDP and UNFCCC, many organizations proposed guidelines to assist the development of NAPs. yet only 5 out of 49 countries have officially submitted them. Meanwhile, UNCDF has been supporting the developing countries to foster their climate change adaptation capacities through LoCAL projects, while the Korea Environment Institute(KEI) has been providing technical elements for the projects. In alignment to such activities, this research have employed the guideline for the formation of the adaptation plans for local governments in Bhutan as a pilot program. The guideline is comprised by the study of various climate change adaptation planning guidelines and its attributes of each procedures. As case studies, field missions were carried out in Bhutan and Cambodia to enhance the understanding of the research. In regards of the process on composing the National Adaptation Plans, this research referred to the Korean national adaptation plans of the local governments. In consideration of the availability and quality of statistical information, the scientific procedures has been comprised in eight qualitative and qualitative steps. Through the analysis of the region`s general circumstances, climatic factors and RCP based scenario examinations, this research presents how to estimate the shift of temperature and precipitation altered by climate change. Moreover it raises the necessity of the needs of climate change adaptation to be prioritized through stakeholders and added on to the accumulated data and reviewed in the aspects of climate change disasters. For the vulnerability assessment, depending on the circumstances, both qualitative and quantitative methods may be applied and the risk evaluation will be conducted by three stages of expert surveys. The outcome derived by such methodologies will be assessed with prior LDC investment menus and considered when selecting the priority projects for initiating the adaptation plans.

조직문화 변화 상황에서 구성원 태도와 행동 변화의 영향요인

현창혁(Hyun, Chang Hyuk),이호선(Lee, Hosun) 한국인사관리학회 2013 조직과 인사관리연구 Vol.37 No.2

본 연구에서는 조직문화 변화 상황에서 구성원의 태도와 행동 변화에 초점을 두었다. 즉 기업이 새로운 조직문화를 구축하기 위해 행동지침으로서의 공유가치를 조직 내에 정착시키는 데 있어서 구성원이 변화에 참여하고 지원하는 행동에 영향을 미치는 요인이 무엇인지를 구명하려 하였다. 구체적으로는 Herscovitch & Meyer(2002)의 변화몰입과 변화지지행동의 개념을 적용하여 구성원의 공유가치 실천 행동에 영향을 미치는 요인을 분석하였다. 그리고 변화몰입에 영향을 미치는 요인을 상사의 변혁적 리더십 요인과 구성원 자신이 지각하는 변화관련 인지적 요인으로 구분하고, 인지적 요인은 다시 변화관련 자기효능감, 변화결과 호의도, 조직의 변화준비성 등으로 세분화하여 영향의 정도를 파악하고자 하였다. 분석 결과, 변혁적 리더십과 지각된 변화관련 인지적 요인(변화관련 자기효능감, 변화결과 호의도, 조직의 변화준비성)이 모두 정서적 변화몰입과 공유가치실천 행동에 정의 영향을 미치는 것으로 드러났다. 아울러 정서적 변화몰입이 변혁적 리더십과 공유가치실천 행동 간의 관계를 매개하며, 변화관련 인지적 요인과 공유가치실천 행동 간의 관계에서도 매개효과가 있음이 밝혀졌다. This study is focused on attitudinal and behavioral changes of organizational members under context of organization cultural changes. That is, it tries to identify the factors that affect organizational members' behavior for participating and supporting in relation to organization changes when companies plan to settle down shared values as the code of conduct into the organizations so as to establish new organization culture. Data were collected from 748 full-time employees during Sep. and Oct. 2011, but 702 questionnaires were used to for analysis. Results indicate both transformational leadership and cognitive factors related to changes(change-related self-efficacy, positive expectancies to change outcome, and readiness for organizational change) have positive influence on organizational members' emotional commitment to organization change and behaviors of practicing shared values. Furthermore, organizational members' emotional commitment to organization change has mediating effect on the relationships between transformational leadership and their behaviors of practicing shared values. It also has mediating effect on the relationships between cognitive factors related to changes and organizational members' behaviors of practicing shared values. Finally, some implications of these findings are discussed and directions for future research are suggested.

대표농도경로 (RCP) 시나리오에 따른 회야강 유역의 미래 유출 및 유사 변화 분석

황창수(Hwang, Chang Su),최철웅(Choi, Chul Uong),최지선(Choi, Ji Sun) 대한공간정보학회 2014 대한공간정보학회지 Vol.22 No.3

본 연구는 미래 기후변화 및 토지피복변화가 유역 내 유출량과 유사량의 거동에 가져올 영향을 분석하는데 목적이 있다. 기상자료는 IPCC 5차 평가보고서를 위해 새롭게 논의된 RCP 시나리오 중 서로 상반되는 4.5 및 8.5 시나리오의 기후전망 (2011~2100년) 이 사용되었으며, 토지피복지도는 RCP 4.5 및 8.5 시나리오의 사회ㆍ경제 스토리라인과 로지스틱 회귀모형 (LR)을 이용하여 개발 된 모델에 의해 구축되었다. 기후변화만 고려한 경우, 토지피복변화만 고려한 경우, 기후변화 및 토지피복변화 모두 고려한 경우의 세 가지 시나리오를 설정하고, 각 시나리오에 따른 유출량 및 유사량을 모의한 결과 계절적으로 매우 명확한 변화를 나타내었다. 기후변화는 봄과 겨울에 유출량을 증가시키고 여름과 가을에 유출량을 감소시키는 것으로 나타났으며, 유사량 역시 유출량과 동일한 변화의 양상을 보였다. 토지피복변화는 유출량을 증가시키는 반면 유사량은 감소시키며, 이는 도시화로 인한 불투수 면적의 증가에 의한 것으로 판단된다. 토지피복변화는 기후변화에 비해 유출량에 적은 영향을 끼치나, 기후변화에 의해 초래된 유출량 문제를 더욱 극대화 시킬 수 있다. 따라서 지속적인 수자원 관리를 위하여 기후변화의 잠재적 영향을 파악하고, 토지피복변화에 따른 적절한 수자원 대응 정책 마련이 필요할 것으로 판단된다. This study is analyze future climate and land cover change affects behaviors for amount of streamflow and sediment discharge within basin. We used the climate forecast data in RCP 4.5 and 8.5 (2011-2100) which is opposite view for each other among RCP scenarios that are discussed for 5th report for IPCC. Land cover map built based on a socialㆍeconomic storyline in RCP 4.5/8.5 using Logistic Regression model. In this study we set three scenarios: one scenario for climate change only, one for land cover change only, one for Last both climate change and land cover change. It simulated amount of streamflow and sediment discharge and the result showed a very definite change in the seasonal variation both of them. For climate change, spring and winter increased the amount of streamflow while summer and fall decreased them. Sediment showed the same pattern of change steamflow. Land cover change increases the amount of streamflow while it decreases the amount of sediment discharge, which is believed to be caused by increase of impervious Surface due to urbanization. Although land cover change less affects the amount of streamflow than climate change, it may maximize problems related to the amount of streamflow caused by climate change. Therefore, it"s required to address potential influence from climate change for effective water resource management and prepare suitable measurement for water resource.

스포츠생리학 : 운동중지가 비만남자청소년의 콜레스테롤 대사에 미치는 영향

윤석창(YoonSeok-Chang),성봉주(SungBong-JU) 한국체육학회 2000 한국체육학회지 Vol.39 No.4

본 연구는 8주 수영 training 후 8주 운동중지(detraining)가 비만청소년의 콜레스테롤 대사에 미치는 영향을 파악하기 위하여 체지방율이 30% 이상인 비만 남자청소년(n=12)을 대상으로 6명씩 두 집단(운동집단, 통제집단)으로 나누었다. 운동집단(n=6)에게는 자발적 식이제한(2,000kcal/day)을 병행한 수영을 8주간 실시하게 한 후, 8주간 식이 제한과 운동처치를 하지 않았다 통제집단(n=6)은 16주 동안 아무런 처치를 하지 않았다. 운동집단의 수영 Training 은 주당 3일, 1회 60분, 운동강도는 분당심박수가 130~160(회/분)으로 설정하여 실시하였다. 측정은 처치 전, 4주, 8주, 12주, 16주 후에 5번 실시하였고, 측정항목은 신장(Height), 체중(Body Weight), 총콜레스테롤(TC), 중성지방 (TG), 저밀도지단백콜레스테롤(LDL-C), 고밀도지단백콜레스테롤(HDL-C), 지단백분획치 (TC/HDL-C) 등의 항목으로 한정하였으며, 실험결과 다음과 같은 결론을 얻었다.첫째, 운동그룹은 8주 수영 Training 후 TC에서 유의한 변화가 나타나지 않았다. 또한 연이은 8주 Detraining 후에도 TC에서 유의한 변화가 나타나지 않았다.둘째, 운동그룹은 8주 수영 Training 후 TG에서 유의한 변화가 나타나지 않았다. Detraining 후에는 4 · 8주에서 TG의 유의한 증가가 나타났다.셋째, 운동그룹은 8주 수영 Training 후 LDL-C에서 유의한 변화가 나타나지 않았다. 8주 Detraining 후에도 LDL-C에서 유의한 변화가 나타나지 않았다.넷째, 운동그룹은 8주 수영 Training 후 HDL-C에서 유의한 변화가 나타나지 않았고 8주 Detraining 후에도 유의한 변화가 나타나지 않았다.다섯째, 운동그룹은 8주 수영 Training 후 TC/HDL-C에서 유의한 변화가 나타나지 않았고 8주 Detraining 후에도 유의한 변화가 나타나지 않았다.자발적 식이제한을 동반한 8주 수영 운동 후 8주 운동중지는 콜레스테롤 대사에서 유의한 변화가 나타나지 않았다. 그러나 중성지방에서만 민감한 변화를 나타내었다. The purpose of this study is to investigate the effect of 8-week detraining after 8-week swimming on the spontaneous caloric restriction and the changes of the cholesterol metabolism in obese adolescents. 12 males were selected as the experimental objects for this study. They were over 30% Body fat, without risk factor during training and never attended in any obese therapy course before. The exercise regimen was composed of the spontaneous caloric restriction and the schedule of swimming program, 1 hrs/day, 3 days/week The intensity of the swimming program was respectively at 60~80%HRmax(130~160 beat/min).. The calorie restrict regimen was about 2,000kcal/day. The variable was measured to the TC, TG, HDL-C, LDL-C, TC/HDL at pre-test 4W, 8VV, 12W(4-week detraining), 16W(8 weeks detraining). The Independant & Paired t-test Measure was used and Tukey was treated for the post hoc testing(p<0.05).The results was as following;(1) The TC of the exercise group after 8-week swimming was not changed significantly. The TC after 8-week detraining was not changed significantly.(2) The TG of the exercise group after 8-week swimming was not changed significantly. The TG after 4 and 8-week detraining was increased significantly.(3) The LDL-C of the exercise group after 8-week swimming was not changed significantly. The LDL-C after 8-week detraining was not changed significantly.(4) The HDL-C of the exercise group after 8-week swimming was not changed significantly. The HDL-C after 8-week detraining was not changed significandy.(5) The TC/HDL-C of the exercise group after 8-week swimming was not changed significantly. The TC/HDL-C after 8-week detraining was not changed significantly.8-week detraining after 8-week swimming on the spontaneous caloric restriction dose not give significant change in cholesterol metabolism. But the TG level showed sensitive change.

대학생의 성교육 효과측정을 위한 기초 연구

장순복,최연순,강희선,박소미,Chang, Soon-Bok,Choi, Yun-Soon,Kang, Hee-Sun,Park, So-Mi 대한간호협회 1997 대한간호 Vol.36 No.2

This study was performed to provide preliminary data for the development of a useful instrument to measure the effect of sex education. The study was conducted with the voluntary participation of 155 college students enrolled in the course "Sexuality and Relationship" at Y university in Seoul. At the end of that course, they were asked to write freely about the change they had experienced on sexuality. All meaningful statements were elicited and classified into 7 categories; "Change of Knowledge", "Enlightenment", "Change of Attitude on Sexuality", "Buildup of Ability", "Buildup of. Identity", "Change of Emotion", "Change of Behavior:' There were significant changes in the areas of knowledge(28. 6%), enlightenment(27.4%), and attitudes(20.3%) about sexuality among these 7 categories. The Change of Knowledge category consists of 3 areas: "concretion of knowledge", "increase of information", and "correction of misunderstanding." In the category of Enlightenment, total 12 areas are included: "sex role", "erception of lack of knowledge", "importance of family", "life plan", "parent role", "value of life", "equality", "sexual autonomy", "importance of sexuality", "freedom of sexuality", "perception of sexual problem", and "meaning of love." The Attitude Change category consists of 8 areas. These are "being natural", "being progressive", "being sensitive", "being truthful", "being expressive", "being cautious", "being responsible", and "being confident". The category of Buildup of Ability includes 4 areas: "problem solving", "sex education", "relationship", and "communication". The category of Buildup of Identity includes "sexual identity", and "value of sexuality". The Emotional Change category includes 3 areas: "positive feeling", "negative feeling", and "breaking from negative feeling on sexuality". The Behavior Change category includes "sex-related behavioral change". In conclusion, up to now most researches on sex education effect measures only changes of knowledge, attitude, and behavior. But we believe the changes in "Enlightenment", "Buildup of Ability", "Buildup of Identity", "Change of Emotion", should be included in addition to knowledge, attitude, and behavior in the development of an instrument to measure the sex education effects. And the effect of sex education should measure the degree of learning of autonomy, enlightenment, and ability of behavior and so on rather than studying the simple changes in sexuality.enment", "Buildup of Ability", "Buildup of Identity", "Change of Emotion", should be included in addition to knowledge, attitude, and behavior in the development of an instrument to measure the sex education effects. And the effect of sex education should measure the degree of learning of autonomy, enlightenment, and ability of behavior and so on rather than studying the simple changes in sexuality.ng the simple changes in sexuality.

논문 : 배당의 미래이익 예측력과 외국인투자자

강태구 ( Tae Goo Kang ),이창우 ( Chang Woo Lee ),남혜정 ( Hye Jeong Nam ) 명지대학교 금융지식연구소 2013 금융지식연구 Vol.11 No.3

본 연구는 배당의 미래이익 예측력이 외국인 투자자들의 지분율에 따라 어떻게 달라지는지 검증하였다. 일반적으로 배당지급은 기업의 미래이익을 예측하는 데 유용한 정보로 여겨지고 있으나, 이에 대한 실증연구결과들은 혼재되어 있다. 또한 배당의사결정과 관련된 연구들은 투자자들의 배당선호현상에 따라 기업의 배당의사결정이 영향을 받고 있음을 제시하고 있으며, 특히 우리나라의 경우, 배당의사결정에 외국인투자자가 미치는 영향이 매우 높게 나타나고 있다. 이는 특정투자자집단의 배당요구가 높은 경우, 기업의 배당의사결정이 미래이익에 대한 사적정보의 전달수단이기 보다는 단기적으로 배당에 대한 투자자들의 요구를 반영한 결과로 나타날 수 있음을 보여준다. 나아가 이러한 배당의사결정은 배당의 미래이익 예측력을 낮게 만들 것으로 예측된다. 본 연구는 배당의 미래이익 예측력을 재검증하고, 나아가 외국인지분율에 따라 배당의 미래이익예측력이 달라지는지 검증하였다. 먼저, 배당의 미래이익 예측연구들은 자기자본이익률(ROE)의 평균회귀(mean reverting)현상과 배당증가 또는 배당감소가 이익변화에 미치는 비대칭적 영향을 고려하고 있으나, 이익변화에 영향을 미치는 여러 가지 변수들을 통제하지 않고 있다. 따라서 본 연구는 선행연구에서 제시되고 있는 기업규모(SIZE), 성장성(SGR), 부채비율(LEV), 그리고 연도더미를 추가하여, 이를 통제하고 난 후에도 배당의 미래이익예측력이 여전히 존재하는지 검증하였다. 둘째, 배당의 미래이익 예측력이 기업의 배당의사결정에 영향을 미치는 특정집단에 의하여 달라지는지 검증하였다. 2000년부터 2007년까지 배당지급을 한 6,720 기업-년 표본을 대상으로 분석한 결과, 기본 모형뿐만 아니라 여러 통제변수를 포함한 모형에서도 우리나라 기업들의 배당변화는 미래 1년 뒤의 이익변화와 유의한 양의 관계를 나타냈으나, 미래 2년 뒤의 이익변화와는 유의하지 않았다. 또한 이익변화에 영향을 미치는 변수들을 추가한 모형의 설명력(R2=0.46)이 기본모형의 설명력(R2=0.28)보다 급격히 증가함을 알 수 있었다. 그러나 이러한 관계는 외국인지분율을 통제할 경우, 유의하지 않게 나타났다. 이는 기업의 배당의사결정이 미래전망에 근거하여 이루어지기보다는 특정투자자집단의 배당요구를 반영하는 수단으로 사용되고 있음을 보여준다. 즉 우리나라의 경우, 배당의사결정이 외국인투자자들의 배당요구를 반영하여 이루어짐을 알 수 있다. 본 연구는 대부분의 선행연구들이 외국인투자자와 배당성향간의 동시적인 관계에 대한 결과들을 제시한 반면에, 외국인투자자가 우리나라 기업들의 배당의사결정에 미치는 영향과 함께 배당의 미래이익예측력의 관점에서 살펴보았다는 점에 의의가 있다. This paper investigates whether the dividend payout predicts future earnings and the predictability varies depending on the proportion of investors. Specifically, this paper examines the effect of foreign investors on the relationship between dividend change and the predictability of future earnings in Korean firms. Reasoning from the hypothesis that dividend changes convey new information about a firm`s future profitability, a dividend increase is seen as a positive signal about the firm`s future earnings and profitability. However, the results from prior studies are controversial. Some papers have suggested that dividend changes would mean different things depending on a firm`s dividend policy and the motives behind its managers` decision to pay dividends. In addition, a firm`s governance is considered as one of important factors that affects dividend policy. In the Korean security market, foreign investors owned about 38% of the stock in 2007. As the percentage of foreign ownership had grown, many researchers have analyzed the effect of this ownership on dividend policy. However, prior studies found mixed results and have focused on the association between foreign investors and the level of the dividend or dividend change. They also suggest that predictability of dividend on future earnings is influenced by applied assumption on earnings and other factors like governance as well. We revisit the dividend signaling issue in the light of the catering theory of dividends suggested by Baker and Wurgler (2004). Lintner (1956) argued that managers unwilling to change payout ratio without any important change on the firm`s future performance. Won and Kim (1992) report that managers are more likely to be concerned about the internal factors such as net income, divisible surplus, predicted future performance, and the shareholders` preference for dividend policy. More importantly, several studies suggest that the foreign investors have a significant effect on the Korean market. Park (2004) reports that foreign investors` participation in firms generally pushes up the dividend payments while pulling down investments made in facilities no matter which industry a company is in. Sul and Kim (2006) show that those companies whose majority shareholders are foreign investors tend to pay higher dividends than others whose majority shareholders are domestic investors. In contrast to negative effect of foreign investor, there are empirical studies claiming positive impact of foreign investor in Korean market. Ahn, Shin, and Chang (2005) suggest that foreign investors prefer firms with lower information asymmetry. The study also shows that foreign investors can effectively monitor the management of firm in lessening information asymmetry. Similarly, Park and Lee (2006) suggest that foreign investors` participation in investment of domestic firms can help them make more efficient management decision by improving their corporate governance. Thus, Park and Lee claim that it is problematic to generalize the negative role of foreign investors in the Korean market. Based on this argument, we predict that if foreign investors play an effective monitoring role in a dividend policy, dividend change for firms with higher level of foreign investors is a good indicator in predicting future earnings than for firms with lower level of foreign investors. However, if foreign investors play a negative role in dividend decision process, predictability of dividend decreases. We test this prediction by using the modified model with several control variables that can affect earnings changes. Using 6,720 observations from 1993 to 2007, we find that the dividend change predicts future earnings for next one year relative to the dividend change year. Specifically, the coefficient on RDIV is 0.045 (t=6.85) and this indicates the dividend increases is a good indicator in predicting future earnings. When it comes to model specification, adjusted R2 of modified model is greater than that of the basic model, which means that the modified model is well specified in explaining earnings changes. The result of the effect of foreign investors on predictability of dividend is not significant. This finding implies that managers, on average, decide to pay dividend as a response to demand from foreign investors.

Brain SPECT 영상의 Attenuation Correction 방법들에 대한 비교

조진우,김창호,나수경,이귀원,Jo, Jin U,Kim, Chang Ho,Na, Soo Kyung,Lee, Gui Won 대한핵의학기술학회 2012 핵의학 기술 Vol.16 No.2

이 연구의 목적은 Brain SPECT (Single Photon Emission Computed Tomography)의 Non-attenuation correction (AC-non) 영상에 대한 attenuation correction(AC) 방법 중 Chang's method와 CT based attenuation correction(AC-CT) 사이의 count를 비교하기 위함이다. phantom study는 증류수로 채워진 hoffman 3D phantom에 $^{99m}Tc$ 37Mbq을 투여하였고, patient study는 normal volunteer에 $^{99m}Tc$-HMPAO 750Mbq를 정맥주입하고 Siemens사의 Symbia T6로 Brain SPECT 영상을 획득하였고 뇌 정량 분석을 하였다. 각각의 방법들을 적용한 transverse image는 같은 위치에서 재구성 되었으며 각각 10, 20, 30번째 slice에서 6개의 region of interest(ROI)를 그려 AC-non 과 AC-CT 그리고 Chang's method의 count를 비교하였다. phantom study에서 AC-non, AC-CT, Chang's method의 각각 평균 count는 $4606.8{\pm}511.3$, $16794.6{\pm}2429.4$, $8752.6{\pm}896.5$이었으며 patient study에서 $5460.8{\pm}519.6$, $15320{\pm}1171.6$, $12795{\pm}1422.1$이었다. phantom study에서 AC-CT와 AC-non 사이의 비는 3.70이고 Chang's method와 AC-non 사이의 비는 1.92였으며 patient study에서는 각각 2.85, 2.38이었다. 우리는 이 연구를 통하여 AC-CT가 Chang's method보다 더 높은 AC을 해준다는 걸 알 수 있었다. 그리고 Chang's method는 patient study에서의 AC 값이 phantom study에서의 AC값보다 더 높다는 것을 알 수 있었다. brain SPECT/CT를 시행하는 경우 scatter correction을 같이 시행하고 bone에 의한 감쇠 정보를 반영할 수 있는 AC-CT가 chang's method보다 정확하다 할 수 있겠다. Purpose : The purpose of this study was to compare count between Chang's method and CT-based attenuation correction (AC-CT) among the attenuation correction (AC) methods for non-attenuation correction (AC-non) images of Brain SPECT (Single Photon Emission Computed Tomography). Materials and Methods : We injected $^{99m}Tc$ 37Mbq in a Hoffman 3D phantom filled with distilled water in the phantom study, and injected intravenously $^{99m}Tc$-HMPAO 740Mbq in a normal volunteer in the patient study, and then obtained Brain SPECT images with Symbia T6 of Siemens and conducted quantitative brain analysis. Transverse images to which each method was applied were rebuilt at the same position, and 6 regions of interest (ROI) were drawn on each of Slice No. 10, 20 and 30 and then the counts of AC-non, AC-CT and Chang's method were compared. Results : The mean counts of AC-non, AC-CT and Chang's method were $4606.8{\pm}511.3$, $16794.6{\pm}2429.4$, and $8752.6{\pm}896.5$, respectively, in the phantom study and $5460.8{\pm}519.6$, $15320{\pm}1171.6$ and $12795{\pm}1422.1$, respectively, in the patient study. In the phantom study, the ratio of AC-CT to AC-non was 3.70 and the ratio of Chang's method to AC-non was 1.92, and in the patient study, they were 2.85 and 2.38, respectively. Conclusion : From this study, we found that AC-CT makes higher AC than Chang's method. In addition, when Chang's method was used, AC in the patient study was higher than that in the phantom study. These results need to be considered also in other examinations.