• 대한전기학회논문지:전력기술부문A
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• 제53권9호
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• pp.507-512
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• 2004

HTS (High Temperature Superconducting) Transformer has the several useful characteristics in the viewpoints of technical and economical. Especially, an HTS transformer replaces the copper wire coils in a conventional transformer with lower loss HTS wire. In addition, inexpensive, environmentally benign liquid nitrogen replaces the conventional oil as the electrical insulation (dielectric) and provides the necessary cooling for the HTS transformer Therefore, the Life-cycle cost of an HTS transformer is much more attractive than conventional because it is more energy efficient, lighter in weight, smaller in size, and environmentally compliant. HTS transformer can be the best way to replace with conventional transformer in the future. In these days, companies world-wide have conducted researches on HTS transformer. A development project for a 154kV HTS transformer is proceeding at a research center and university in Korea. In this paper, we investigate the expected price of HTS transformer to have a merit in viewpoint of economic aspect. First, life-cycle cost of conventional transformer is calculated and based on this, the expected price of HTS transformer is evaluated. which HTS transformer is competitive against conventional transformer.

• 전기학회논문지
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• 제67권11호
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• pp.1455-1462
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• 2018

As the interests in eco-friendly energy has increased, the interests in Electric Vehicles(EVs) are increasing as well. Moreover, due to the government's economic support for EVs, penetration level of it has rapidly increased. These sharp increases, however, induce various problems in distribution system, such as voltage/frequency variations, peak demand increasement, demand control, etc. To minimize these possible matters, lots of research have conducted. Nevertheless, most of it assumed extremely important factors, such as numbers and charging patterns of EVs. It inevitably results in errors in their research, and thus make it difficult to prevent the possible matters from EVs. In this paper, therefore, we use actual EVs charging data from KEPCO, and analysis and deduction of it were conducted. The simulations were carried out for four aspect(season, region, purpose).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.109-109
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• 2006

Screen printing (SP) metal contact is typically applied to the solar cells for mass production. However, SP metal contact has low aspect ratio, low accuracy, hard control of the substrate penetration and unclean process. On the other hand, photo lithograpy (PL) metal contact can reduce defects by metal contact. In this investigation, PL metal contact was obtained the multi-layer structure of Ti/Pd/Ag by e-beam process. We applied SP metal contact and PL metal contact to single crystalline silicon solar cells, and demonstrated the difference of conversion efficiency. Because PL metal contact silicon solar cell has Jsc (short circuit current density) better than silicon solar cell applied SP metal contact.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.353-357
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• 2004

현재 우리나라의 철골공사에서 생산성은 철골부재의 중량으로 되어있다. 그러나 철골공사의 생산성은 부재의 중량보다는 피스 수에 더 많은 영향을 받는다. 이에 따라 새로운 철골공사의 생산지수가 필요하다. 본 연구에서는 우리나라 철골공사의 문제점을 분석하고 문제점을 개선할 수 있는 새로운 생산지수를 개발하고자 한다. 이를 통해 전 과정을 통일된 수치화하고 이 수치를 관리함에 따라 복잡한 관리를 보다 효과적으로 통합관리 할 수 있도록 한다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 추계 학술논문 발표대회 논문집
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• pp.151-154
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• 2006

It is generally referred that life cycle of concrete construction is depend on whether durability of concrete is obtained or not. Nevertheless, it has not been yet applied that new material and technology to improve durability of concrete such as seaside concrete construction. In this study, chemical agent which is capable of improving durability added to 2 types seaside concrete mixs and evaluated engineering properties such as slump, air content, setting time and compressive strength. Besides shrinkage crack with an restraint condition and chloride ion penetration tests were executed to measure resistance of concrete added chemical agent and then compared non-added. It was appeared that engineering properties and resistant for chlorides was possible to improved. But resistant for shrinkage crack was not noticeable improvement than non-added. Therefore it is necessary that more consideration and following study to improve durability aspect to shrinkage crack and chlorides resistant.

• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1438-1449
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• 2018

The importance of power system stability has been emphasized with an increase of wind energy penetration in the power system. Accordingly, the guarantee on various control capabilities, including active and reactive power control of wind farms, was regarded as the most important aspect for the connection to the grid. To control the wind farm active power, the wind farm controller was introduced. The wind farm controller decides the power set points for each wind turbine generating unit and each wind turbine generating unit controls its power according to the set points from the wind farm controller. Therefore, co-relationship between wind farm controller and wind turbine controllers are significantly important. This paper proposes some control methods of wind farm active power control based on modified wind turbine control for power system stability and structures to connect wind turbine controllers to wind farm controller. Besides, this paper contributes to development of control algorithm considering not only electrical components but also mechanical components. The proposed contributions were verified by full simulation including power electronics and turbulent wind speed. The scenario refers to the active power control regulations of the Eltra and Elkraft system in Denmark.

• 한국산학기술학회논문지
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• 제22권5호
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• pp.502-508
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• 2021

포화된 연약 점성토 지반에서 침하량을 예측하는 것은 연약 지반 설계 시 매우 중요하다. 이 연구에서는 낙동강 지류 인접 지역인 김해진영 지구를 대상으로 피에조콘 관입시험을 실시한 지반조사 자료를 참고하여 침하량 산정의 신뢰성을 향상시킬 수 있는 방법에 대하여 고찰하였다. 해당 지역의 지반을 두 가지 Robertson Chart(1986, 1990)에 따라 분류하고 대표적인 지반 침하량 산정 공식인 Terzaghi(1925) 침하량 산정 공식 및 Sanglerat(1972) 침하량 산정 공식에 의해 이론 침하량을 산정하였다. 산정된 이론 침하량을 실제로 측정한 계측 침하량과 SPSS 상관분석을 통해 비교함으로써 보정계수를 산정하였다. 연구결과 이론 침하량과 계측 침하량의 평균오차율은 각각 17.28% 및 26.96%로 나타났다. 또한 이 지역의 경우 Terzaghi(1925) 방법에 의한 이론 침하량 산정결과가 Sanglerat(1972) 방법으로 구한 이론 침하량보다 계측 침하량에 더 근접한 것으로 나타나 Terzaghi(1925) 침하량 산정 방법이 더 정밀한 것으로 나타났다. 또한 산정된 보정계수를 사용하면 이 지역의 침하량 예측의 신뢰성을 향상시킬 수 있을 것으로 판단된다.

• 한국의류학회지
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• 제17권2호
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• pp.265-279
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• 1993

The channel of distribution exists for the purpose of moving product from the manufactuerer to the final consumer. In order to satisfy consumer needs, channels provide for the those products to arrive at the right place, at the right time and in the quantity, quality and price desired. Currently, there has been an emerging interest in the improvement of distribution system in many areas of industries and Korean government because of a market liberalizatiion begun at 1989 and still has processed step by step. In the wave of market liberalization, an understanding of the channel of distribution and structure would be very crucial when developing the opportunities of competitive advantages in Korean apparel industry. The purposes of this study were to investigate the determinants of the distribution channel and to identify how to respond to the market liberalization for developing the possible future strategies in the apparel industry. Data for this study were obtained from interviews with managers in apparel company in addition to a questionnaire mailed to over 106 middle management position of apparel company. Data were analyzed by using descriptive statistics. The results of this study were summarized as follows. 1. In the distribution channel of the apparel industry, a vertical marketing system, comprising producer, apparel company, retailer, prevailed without intermediaries such as wholesalers or vendors. Especially, the apparel company controlled marketing channel members. This type of system may reflect added product cost and may be not advantageous to retailers and consumers because most apparel companies are responsible for its own transfortation, storage and stocks after season. 2. In the view of market liberalization, most apparrel companies showed double-edged viewpoints. In terms of positive aspect, it would give stimulus to broaden variety of fashion merchandise and to improve product quality of fashion merchanise which were the most disadvantageous factors in competing with oversea's brands. In terms of negative aspect, it would bring the bankruptcy of small or medium sized apparel firms and the foreign products' penetration in domestic market. From this study, severel recommedations were suggested forward to improve the present condition in apparel industry. They included eliminating the power of apparel company and reinforcing middlemen for more efficient distribution system and for satisfying consumer needs in rapidly changing environment. Also it included government supports, reinforcement of information system, improvement in channel structure, and career development program in conjunction with apparel companies and academic society for improving scientific management and future potential strategies in Korean apparal industry.

• 만화애니메이션 연구
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• 통권47호
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• pp.439-461
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• 2017

중국 고대사회에 있어 효 문화는 가부장제도 아래에서 도덕규범의 실천적 원리였다. 조아(曹娥)는 중국의 대표적인 효의 상징인물로, 원래 무녀(巫女)였으나 한대의 주류 사상인 유가철학의 전파와 함께 효녀의 형상으로 전환되었으며, 이후 지역문화의 발전과 함께 민간의 신앙과 접목하여 수신(水神)의 개념으로 재탄생하기도 하였다. 조아설화의 전파과정 중, 구전과 문학적 가공은 상호적인 작용을 통해 영향을 주고받으며, 미화되거나 신성화되고 체계화 되었는데, 조아도상은 이러한 인류가 추구하는 보편적이며 온전한 사유적 형상의 체현이다. 예컨대, 현대사회에 있어 문화적 정체성과 함께 그 이면의 근본적인 내적 함의의 인식이 중요하다. 그러므로 조아의 효를 주제로 한 사회기반의 문화콘텐츠의 창작과 이를 통해 효가 가진 문화적 핵심가치를 찾는 것은 의미 있는 일이다. 본문은 조아설화와 효사상 그리고 문화원형을 사례중심으로 서술하였으며, 조아의 민간신앙적 신성화 측면에서 문학으로부터 파생된 가공과 도상의 형성 사이의 관계를 이해하고, 이미지의 변화와 조형성을 통한 문화콘텐츠로서의 가능성을 살펴보았다.

• Journal of Welding and Joining
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• 제33권6호
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• pp.27-35
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• 2015

Laser welding sector in the automotive industry has been widely recognized as one of the most important bonding processes, such as parts welding. Efforts to improve productivity and weld quality have been progressing steadily. In addition, laser welding is suitable for welding process that can produce high-quality welds suitable for flexible production and small quantity batch productions. In order to ensure the rigidity of the material, high strength material are applied to more than 1 GPa class body parts and automotive bumper beams. However, not only the situation is that the trend of domestic research, but also development is based on product molding considering freedom of shape where reinforcement is applied to meet the safety regulations and high-speed crash performance, despite the use of high strength materials. The tendency for heat-affected zone (HAZ) softening phenomenon common in areas of laser welded high tensile steel welding confirmed the occurrence of weld softening effect according to the process parameters. Based on this, range of process parameters could be selected for ensuring weld quality.