• 한국시스템다이내믹스연구
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• 제2권2호
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• pp.25-40
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• 2001

This paper describes the forecast of power plant construction in a competitive korean electricity market. In Korea, KEPCO (Korea Electric Power Corporation, fully controlled by government) was responsible for from the production of the electricity to the sale of electricity to customer. However, the generation part is separated from KEPCO and six generation companies were established for whole sale competition from April 1st, 2001. The generation companies consist of five fossil power companies and one nuclear power company in Korea at present time. Fossil power companies are scheduled to be sold to private companies including foreign investors. Nuclear power company is owned and controlled by government. The competition in generation market will start from 2003. ISO (Independence System Operator will purchase the electricity from the power exchange market. The market price is determined by the SMP(System Marginal Price) which is decided by the balance between demand and supply of electricity in power exchange market. Under this uncertain circumstance, the energy policy planners such as government are interested to the construction of the power plant in the future. These interests are accelerated due to the recent shortage of electricity supply in California. In the competitive market, investors are no longer interested in the investment for the capital intensive, long lead time generating technologies such as nuclear and coal plants. Large unclear and coal plants were no longer the top choices. Instead, investors in the competitive market are interested in smaller, more efficient, cheaper, cleaner technologies such as CCGT(Combined Cycle Gas Turbine). Electricity is treated as commodity in the competitive market. The investors behavior in the commodity market shows that the new investment decision is made when the market price exceeds the sum of capital cost and variable cost of the new facility and the existing facility utilization depends on the marginal cost of the facility. This investors behavior can be applied to the new investments for the power plant. Under these postulations, there is the potential for power plant construction to appear in waves causing alternating periods of over and under supply of electricity like commodity production or real estate production. A computer model was developed to sturdy the possibility that construction will appear in waves of boom and bust in Korean electricity market. This model was constructed using System Dynamics method pioneered by Forrester(MIT, 1961) and explained in recent text by Sternman (Business Dynamics, MIT, 2000) and the recent work by Andrew Ford(Energy Policy, 1999). This model was designed based on the Energy Policy results(Ford, 1999) with parameters for loads and resources in Korea. This Korea Market Model was developed and tested in a small scale project to demonstrate the usefulness of the System Dynamics approach. Korea electricity market is isolated and not allowed to import electricity from outsides. In this model, the base load such as unclear and large coal power plant are assumed to be user specified investment and only CCGT is selected for new investment by investors in the market. This model may be used to learn if government investment in new unclear plants could compensate for the unstable actions of private developers. This model can be used to test the policy focused on the role of unclear investments over time. This model also can be used to test whether the future power plant construction can meet the government targets for the mix of generating resources and to test whether to maintain stable price in the spot market.

• 디지털융복합연구
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• 제18권9호
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• pp.423-431
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• 2020

본 연구는 무용수업 참여 정도가 사회성발달과 또래 관계에 어떠한 영향을 미치는지 알아보는 데 그 목적이 있으며 다음과 같은 결과가 나왔다. 첫째, 인구통계학적 특성에 따른 사회성발달과 또래 관계의 차이에서는 성별에서 또래 관계의 하위요인 경쟁심은 남학생이 높게 나타났으며, 학년에 따른 또래 관계의 하위요인 중 자신감은 2학년 학생이 높게 나타났다. 둘째, 중학생의 무용수업 참여 정도에 따라 사회성발달에 미치는 영향을 살펴본 결과, 무용수업 참여기간은 사회성 하위요인 자율성, 성취성, 협동성에 유의한 영향을 주며 참여빈도는 책임성, 활동성에 유의한 영향을 주는 것으로 나타났다. 이러한 결과는 무용수업 참여 기간이 증가할수록 사회성발달에 발달한다는 것을 알 수 있다. 셋째, 중학생의 무용수업 참여 정도가 또래 관계에 미치는 영향성을 살펴본 결과 무용수업 참여 기간이 높을수록 또래 관계 하위요인들이 긍정적인 영향을 미치는 것으로 나타났고, 참여 기간이 증가할수록 적대감이 감소한 결과가 나타났다. 즉 참여 시간, 참여빈도, 참여 기간 모두 증가할수록 또래 관계에 영향을 미친다는 것을 알 수 있었다.

• 한국조사연구학회지:조사연구
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• 제6권2호
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• pp.75-101
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• 2005

본 논문은 1997년과 2000년 이차에 걸쳐서 출간된 $\ll$한국 민간단체 총람\gg$ 자료를 소개하고, 이 자료의 분석을 통해 한국 시민단체의 성장에 대한 양적 연구를 수행한다. 시민단체 성장에 대한 주요 지표가 될 수 있는 회원수 정보와 설립연도 정보의 질을 데이터에 나타난 결측율을 중심으로 검토한다. 회원수 정보를 통해서 1996년에서 1999년 사이의 회원수 변화를 활동 분야에 따라 알아보고 그 결과를 시민단체의 성장이라는 측면에서 논의한다. 분석 결과 우리나라 시민단체 성장의 주축이라고 여겨지고 있는 시민사회 분야에서, 특히 전국적 규모의 단체들을 중심으로 많은 회원 감소가 있었던 것으로 보인다. 설립되는 단체 수의 지속적인 증가 추세와 맞물려, 이 결과는 계속적으로 그 숫자가 증가하고 있는 시민단체들 사이에 제한된 자원을 둘러싼 경쟁이 있음을 반영한다고 본다. 이러한 경향을 생태학적 조직이론에 근거해서 논의하고, 1945년부터 1996년까지 시민단체의 수적 성장 패턴을 설립연도 정보를 이용하여 간접적으로 확인한다. 이 의사 성장 곡선(pseudo-growth curve)을 생태학적 조직 이론에 근거해서 로지스틱 성장 곡선 모형으로서 제시하고, 비선형적 회귀분석을 통해 활동 범위와 분야별로 단체들의 수적 증가 추이를 비교해 본다.

• 디자인학연구
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• 제18권1호
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• pp.253-262
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• 2005

급변하는 멀티미디어시대에 백화점은 지역 소비자들의 문화적 욕구를 충족시키는 장소역할 뿐 아니라 새로운 라이프스타일의 추구와 소비패턴의 연출장소로도 활용되고 있어 소비자들의 구매 욕구를 불러일으키기 위한 비주얼머천다이징의 중요성은 더욱 더 커지고 있다. 본 논문은 백화점 화장품매장에서 여성고객이 화장품을 구매할 때 비주얼머천다이징 전략이 어떠한 영향력이 있는지 그 선호도를 설문조사하여 분석하였는데 그 결과를 보면 다음과 같다. 매장디자인 연출구성에 있어서 색채와 P.P(Point of Sale Presentation)의 선호도가 일반요인인 상품의 품질, 가격, 직원서비스 다음으로 중요한 것으로 나타남에 따라 화장품기업들은 비주얼머천다이징전략을 시행할 때 제품의 판매촉진을 위해 각 브랜드의 차별화 된 트레이드컬러의 제시와 P.P 즉, 분류된 상품의 판매 포인트를 상품정보와 함께 표현, 연출하는 것이 무엇보다 중요하다고 할 수 있다.

• Animal cells and systems
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• 제13권1호
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• pp.71-78
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• 2009

To clarify the reproductive function of vibration signals in Hynobius, which has externally fertilized eggs, we quantitatively analyzed the body and tail undulations of male Korean salamanders (Hynobius leechii) in sixteen mating events. One large and one small male, and one female were used in each mating event. We analyzed behaviors recorded over a total of 3 hrs for each mating event; 2 hrs before and 1 hr after female's oviposition. Males touched females using their snouts or body trunk throughout the entire mating periods, but females touched males increasingly more after approximately 1 hr before oviposition. Males conducted body undulations more than 50 times per 10 minutes at a mean frequency of 0.64 Hz. Large males conducted more body undulations than small males, particularly on the tree twig where females attached their egg sacs. Males responded to other males' body undulation throughout the mating period by orienting their head towards, approaching, and touching the undulating male. Females only responded for about 10-20 min before ovipositing, and most responses were directed to the large male's body undulation. Males conducted tail undulations 3.0 times per 10 min at a mean frequency of 1.7 Hz and most tail undulations occurred after one male bit the other male. These results suggest that body undulations function in both male-female and male-male interactions, while tail undulations mainly functions in male-male competition. Also, male H. leechii appear to actively attract females, while females respond to the males only at times close to oviposition.

• Journal of Ecology and Environment
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• 제44권2호
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• pp.62-71
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• 2020

Understanding vegetation structure and the relationship with environmental factors has been crucial for restoration and conservation of riparian zones. In this study, we conducted field survey in a riparian zone of Namhan River in South Korea both before and after flooding in order to understand temporal and spatial variations of riparian vegetation. There were significant temporal and spatial variations in species composition, and distribution patterns of vegetation were different along a gradient of elevation above the water level. At low elevation, Zizania latifolia was dominant throughout the field survey periods, and Bidens frondosa began to grow late and dominated both in post-flooding 1 and 2. Prior to flooding, Scirpus radicans and Polygonum thunbergii were widely distributed at middle elevation, while Artemisia vulgaris, Phragmites australis, and Miscanthus sacchariflorus were dominant at high elevation. After flooding, P. thunbergii was dominant at middle elevation with most other species decreasing, and more invasive or pioneer plants, including Artemisia princeps, H. scandens, and Sicyos angulatus, were observed at high elevation. Species composition and distribution patterns were homogeneous at low elevation, whereas dynamic variations of vegetation were observed both temporally and spatially at higher elevations. Elevation and distance from the water front were the most principal factors governing vegetation structure. Furthermore, soil physicochemical properties were also found to determine species composition and distribution patterns. These results indicate that vegetation structure in the riparian zones is formed by the combined effects of hydrological regime and soil physicochemical properties, inherent characteristics of species, and interspecific competition. Understanding of temporal and spatial variations of riparian vegetation may provide useful insights into ecological restoration and conservation of the vegetation within the riparian zones.

• 대한한의학회지
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• 제35권1호
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• pp.145-156
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• 2014

Objectives: Korean medicine hospitals, since they first emerged in the early 1970s, have rapidly become a new member of the hospital population. As it was a new organizational frame for traditional medicine, we tried to analyze the changes of Korean medicine hospitals coping with institutional environment and their relative positioning in the whole health care sector. Methods: On the basis of Scott and his colleagues' identification of the three components of institutional environments, changes in organizational logics, actors, and governance of Korean medicine hospitals during the period from 1971 to 2010 were analyzed. Results: First, Similar to previous literature on institutional eras of Korean health sector, three distinct periods were characterized: the foundation of Korean medicine hospitals to consolidate the legal status(1971~1986), a rapid increase of entrepreneurial hospitals through cultural-cognitive legitimacy(1987~2001), and the reinforcement of specialization and competition(2002~present). Conclusions: Results suggested that: (1) changes in institutional environments hada heavy impact on structural and behavioral changes among Korean medicine hospitals, but the pace was slower than that of western medicine hospitals. (2) In structure, Korean medicine hospitals have positioned themselves as unofficial long-term care hospitals, focusing on chronic diseases(e.g. cerebrovascular disease). Our study demonstrated that organizational theories can provide useful framework for the analysis of Korean medicine and related policies. Indeed, one of the most important implications of this study is that understanding changes in institutional environments is important to understand the process of how members of the health care sector live, grow, change, decline and survive.

• 한국의류학회지
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• 제16권3호
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• pp.233-242
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• 1992

This study primarily concentrates on the Fashion Style of the New Generation which has come into being in 1980 with reference to the contents of the newspaper and magazine in 1950's. . The New Generation has undergone the social and cultural change under the effect of mass communication, mass consumption brought by the economic development, sports boom promoted during the period of Asian Games and Seoul Olympic Games and the adoption of the policy for the autonomous school uniform. In the process of the social and cultural change, they have the common peculiarity such as sensitivity, anthoritarianism and polarity and they have taken an important part in the development of the 'Young Fashion' The characteristics of their fashion styles are divided into three periods as follows; 1. The rising period (1980-1982): The most important pecuriality of the first step can be sum up to the following point. The free fashion style replaced the formal one such as T-shirt or casual wear comes into as a everyday dress. Moreover, many people become interested in the New Fashion which is gradually diversified and high-qualified. As a natural consequence, the lively interest of the people has brought into the appearance and competition of the New Brand in fashion industry 2. The growing period (1983-1986): Mannish Look, so-called 'New Fashion' gained the summit of the fashion and change over conservatively. However, 'Mannish Look' have great effect on the Fashion Style until now on. Specially in Korea, 'Punk Style'and 'Androgynous Look' can be an example among many. 3. The diversifying period (1987-1989): The Fashion Style has developed variously even though the Reactionism takes the lead as the main current of the Korean Fashion. Moreover, it is noticeable that man comes into the stage as a new fashion group and the fashion market begins to dear in various lines of goods with moderate and low prices. These various aspects can be regarded as diversification in the Fashion Style as the needs in the times and society.

• 한국농공학회논문집
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• 제60권5호
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• pp.55-67
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• 2018

The objectives of this study were to monitor organic farming upland compared with conventional upland field and to evaluate nutrient loads reduction of surface cover effect with long-term historical climate data. APEX(Agricultural Policy Environmental eXtender) model was validated with experimental data and used for assessing surface cover scenarios for 30-year simulation periods. The validated values of RMSE(Root Mean Square Error), RMAE(Root Mean Absolute Error), $R^2$ and E(Nash-Sutcliffe efficiency) for runoff were 1.17-1.37 mm/day, 0.28-0.45 mm/day, 0.88-0.90 and 0.82-0.94 in two treatments, respectively. Those for water quality (nitrogen) were 0.05-0.16 kg/ha, 0.52-0.75 kg/ha, 0.67-0.72 and 0.32-0.70 in two treatments, respectively, and therefore the validated model showed good agreement with the observed runoff and nitrogen load for the study period. When decreasing the surface cover rate of organic farming field to 75%, 50%, 25%, and 0% (conventional field), average annual runoff increased by 7%, 15%, 23% and 31%, respectively. Under same condition of decreasing the surface cover rate, average annual nitrogen loads increased by 1.4 times, 1.7 times, 2.0 times, and 2.3 times compared with organic farming field, respectively. This study showed that it is possible to present an appropriate surface cover ratio to maintain conventional production and minimize nonpoint sources pollution for organic farming system, although long-term monitoring is needed to determine its effects on environmental concerns, crop competition, and other uncertainty.

• 한국수산과학회지
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• 제54권4호
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• pp.434-444
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• 2021

The decrease in fatness of the Pacific oyster Crassostrea gigas, which consequently results in decrease in the profit of aquaculture industry, has become a source of serious concern in southeast coast of Korea. The ratio of flesh (edible portion) to total oyster weight, commonly called edible portion yield ("suyul" in Korean), have been used as a fatness index for the healthy and valuable state of oyster from the early stage of oyster farming in Korea. More than 360 data sets were collected from early culturing periods (in the 1970s) to the present from approximately 15 published literatures to evaluate the long-term fatness trend of oyster, reared particularly in submerged longline culturing system in Gyeongsangnam-do province. Slight decrease in oyster fatness during the 1970s to 1990s was detected in Tongyeong and Geoje Bays; however, from the 1990s to the present, clear decreasing trends were observed with a decrease of 0.04-0.08% year^-1, especially during harvest season. Oyster mass production per unit area almost doubled within a short period in the early 2000s; however, changes in coastal environment factors inhibited the fattening of shellfish from the mid 1990s. These results indicate that the severe competition in feeding and low biological production in water column might be some convincing reasons for the decrease in fatness of oyster from the 1990s, in Tongyeong and Geoje Bays, Korea.