• 대한전기학회논문지
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• 제36권10호
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• pp.695-702
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• 1987

Nowadays as the power systems have been more complicated and have grown to ultra high voltage, it requires a accurate and high speed relaying scheme to improve the reliability and stability of power systems for a harmonious power supplying. For this purpose voltage and current have to be measured at the location of the protective device and the short circuit impedance must be determined. This paper presents the application methods and some results of digital distance relaying scheme which is based upon the theouy of real-time symmetrical components. Usually the symmetrical component have been used to solve the transient systems as well as the steady state systems under unbalanced systems. But, real-time symmetrical component frequently have not been applied to on-line control region of the large power system. We have tried to apply this method to deal with the various type of faults on artificial transmission line. And experimental results demonstrate the validity of the proposed techniques. Therefore, this study is expected that it is contributed to improve the reliability of power supplying, searching for the fault location rapidly and exactly in power system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.965-968
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• 2003

This paper describes the PWM-VSI controller of three-phase UPS system using stationary reference frame. This controller meets the specification the UPS inverter output voltage even under the unbalanced or nonlinear load. This controller is also constructed with duble control loop of the outer voltage control loop and the inner current control loop. For the fast response of the output voltage control, yhr inner current control loop of the capacitor current os used. To get the good property against overshoot, the If controller us used. The outer voltage controller is designed with P controller and the high gain transfer function is used for the zero steady state error. All control gains of both controller is designed base on the CDM method.

• 한국수학사학회지
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• 제16권2호
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• pp.103-116
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• 2003

Now we have faced to two fundamental population problems: The one is over-population problem in proportion to the nation's total area, 99,434 $km^2$, and the other is unbalanced population distributions in the provincial districts of administration (16th local governments). For example, the population density of Seoul city is 16,335 persons, and the nations population density of South Korea is 464 persons for 1 km$^2$. At the first part of this study, we introduced the origins and historical back grounds of Formal Demorgraphy. And the second part, we suggest some useful indicators of urbanization of rural populations in terms of Gini's Coefficients of Concentration. As the result, we can show that the ecological Gini's Coefficients of Concentration, during the periods covered by this study, have been increasing extraordinary: 0.349, 0.433, 0.532, 0.581, 0.633 and 0.626 in 1970, 1980, 1985, 1990, 1995, 2000 A.D. respectively. However, the trend of urbanization (concentration of population) of Korean population has been the relative equilibrium state of 0.63 from 1995 to 2000 A.D.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1871-1873
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• 2000

There are many electrical accidents between bare wire and line post insulator which is degraded by long time using, causing leakage current on the surface of insulator. In this paper it is presented that the 22.9 Kv-y distribution lines are protected by binding cover which is needed from fog or rainy moisture, surges occurring by switching or lightening pulse. It is analyzed to investigate the unbalanced transfer characteristics and reflection coefficient by using binding cover and non-cover. It was tested the radio interference voltage in the test room and electric field strength by calculation between binding cover and non-cover. In the factory the leakage current causing on the surface of insulator was tested in the state of light load and heavy load.

• 대한전기학회논문지:전력기술부문A
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• 제49권12호
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• pp.602-607
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• 2000

This paper presents the new simulation algorithms using network methods to analysis the steady-state train voltage distribution characteristics in ac auto-transformer fed railroads. In general, the supply system of railroads is composed of non-symmetrical and unbalance transmission line. Therefore, the general method using simplified old algorithms have the self-contradictory errors because the supply line of train railroads is completely unbalanced. In this paper, the simulation results of new developed algorithms is compared with those of EMTP to confirm the effectiveness.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.305-308
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• 2007

본 논문에서는 전력품질 향상용 전력전자기기의 제어에 중요한 정보인 전원의 위상각을 검출하는 기존의 방법들에 대해서 먼저 알아보고, 그 중 불평형한 전원단 전압조건에서도 정확한 위상각을 검출할 수 있는 전차원 상태관측기를 이용한 정상분 전압 추출 PLL(Phase Locked Loop) 방법을 제안한다. 제안된 PLL 방법은 기존의 전역 통과 필터(APF, All Pass Filter)를 이용한 정상분 전압추출기 대신 전차원 상태관측기를 사용함으로써 불평형사고 발생 시 과도상태 응답특성을 개선하였다. 기존의 정상분 전압 추출 PLL 방법과 본 논문에서 제안된 PLL 방법의 성능을 비교하기 위해, 전원단 전압에 불평형 사고 발생시 위상각을 검출하는 모의실험과 실험을 하였고, 이를 통해 기존의 전역 통과 필터를 이용한 정상분 전압 추출 PLL 방법보다 제안된 전차원 상태관측기를 이용한 정상분 전압 추출 PLL 방법의 과도상태 응답특성이 개선됨을 입증하였다.

• 한국소음진동공학회논문집
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• 제13권3호
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• pp.172-179
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• 2003

Linear matrix Inequality based $H_\infty$ robust controller is designed to control the motion of a 4-axis unbalanced rigid asymmetric rotor supported and controlled by two active magnetic bearings in this paper. To this end, the equations of motion of the system are derived via Hamilton's variational principle and transformed to a state-space form for the standard $H_\infty$ control problem. LMI-based controller, which does not require additional assumptions beyond the usual stabilizability and detectability assumptions, is designed based upon the pole place weighting function and loopshaping technique. The obtained results are compared with those reported in the available literature and the efficiency of the proposed LMI-based $H_\infty$ control is revealed.

• 한국사회정책
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• 제25권4호
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• pp.3-38
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• 2018

본 연구는 2000년대 이후 한국 복지국가의 성장이 재분배적 측면에서 어떤 영향을 미치고 있는지, 복지국가의 성장으로부터 소외된 계층이 없는지에 관해 분석하였다. 분석 결과 한국 복지국가의 성장은 발전주의/생산주의의 제도적 유산인 사회보험 중심 제도 환경 속에서, 사회보험 확대를 통해 복지수혜를 보편화하는 방향으로 이루어졌음을 확인하였다. 복지수혜의 보편화가 재분배적 측면에서 미친 영향을 분석한 결과 노인인구의 경우 국민연금은 상대적으로 역진적 효과를 갖지만, 기초연금 도입의 영향으로 전체 노인 뿐 아니라 저소득 노인들의 상황도 개선되었음을 확인하였다. 그러나 근로연령대 인구의 경우 저소득층에 대한 복지혜택은 상대적으로 뿐 아니라 절대적으로도 개선되지 않았으며, 복지국가가 불평등을 거의 개선하지 못했다. 한국 복지국가의 성장에서 가장 소외된 계층은 이들 근로연령대 저소득 가구로, 가구주 연령이 높고, 취업하지 못했거나 불안정한 일자리에 머무르고 있으며, 상대적으로 가구원 수가 적고 여성 가구주 비중이 높은 집단이다. 지난 10여년 간의 복지국가 성장에도 불구하고 이들에 대한 복지국가의 혜택이 개선되지 못했다는 점은 한국 복지국가의 성장이 불균등한 성격을 가지고 있었음을 보여준다. 앞으로 한국 복지국가가 그간의 성장에서 소외된 집단을 포괄하기 위해서는 사회보험 중심 소득보장 프로그램의 다원화, 사회보험의 포괄성 개선, 소득-고용-훈련의 연계 강화, 보편적 복지와 선별적 표적화의 결합이 필요하다.

• 기본간호학회지
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• 제4권2호
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• pp.217-228
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• 1997

According to industralization the percentage of working women with children is on the continuous increase. There has been a growing concern over important health problems of middle-aged women, especially with working women. But we didn't know how to care of themselves yet even if it was importment to fint out that. So this reseach was an attempt to identify the nature of experience of their health management so that it is to be contributed to be knowledge development of women' health management strategy. The phenomenological approach in qualitative studies was used to serve this purpose. Subjects were 10 middle-aged working women having children in well-being state. The result of this study was as follows : 'Diet pattern' was to unbalanced and irregular but they tried to correct balanced and harmony dietary life. 'Exercise' was very simple and irregular. They have closed-minded of kinds of exercise. 'Controlling the environment and their minds' was to obtain emotional stability and be free from stress. They put emphasis on refraining from being overtiring and watching their condition carefully. They always tried to keep the peaceful mind. 'Reducing fatigue' was to be bathing, hot streamed-bath, finger pressure therapy, massage, singing, communication with others and maintenance of personal relationships. 'Identification of self-esteem' was very key point to maintain their health. Working regulary gave them to please and value of the life. 'Work oriented life pattern' was to be harm their health state so that it need to be available clinics to check up their health state after work. The rest of this study showed that it need to be social support for working women to work with comfort. Further study regarding working women engaging in the lower level is nesessary.

• 건축역사연구
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• 제29권3호
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• pp.15-24
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• 2020

As China enters the 21st century, China is strengthening its position as a world power in an international position. However, there are still problems with Three Agricultural(Agricultural, Rural, Farmer) and unbalanced urban and rural villages. China, as one of the largest and most populous nations, values the development of three farms. Strategies such as "The Construction Of New Socialist Countryside" were a policy to solve rural problems, But they were not enough to achieve breakthrough results. In order to achieve more effective results, the Central Committee of THE STATE COUNCIL proposed The Document No.1 of "Opinion on the Implementation of The Rural Revitalization Strategy" in February 4, 2018 and published "The Rural Revitalization Strategy (2018-2022 )". The Yanbian region, which is the subject of this study, is the home of Korean-Chinese tribes and the Korean autonomous region. As a minority of Chinese ethnic minorities, the Korean-Chinese has their own unique culture, and Yanbian has distinct regional characteristics. As The Rural Revitalization Strategy was raised, Villages is showing positive change in accordance with policy implementation in Yanbian. This study analyzed the current status of policy implementation of The Rural Revitalization Strategy in Yanbian area and analyzed the policy contents and performances based on the of Yanbian Daily News. Based on the results of the analysis, I would like to help in suggesting a more rational development direction and building the villages.