• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.154-156
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• 1987

An important aspects of power system design involves consideration of service reliability requirements of load to be supplied and service reliability provided by any proposed system. This paper shows the investigation of the 1984 KEPCO service reliability to the large electric consumer whose contracted maximum demand is over 500 kw. 68 customers of the total 111 investigated are located in Myungdong area and Yuido in Seoul. Of the customers are included hotel Lotte, Giobo and Seoul national University Hospital. The average service reliability of Myungdong area customers is 316min/yr/customer and about 7 times/yr/customer, and 160 min, 6 times for Yuido. Which the service reliability the interruption and the interruption frequency which caused by the customers receiving facilities were showed. The investigation is telling that the service reliability of the underground distribution area are very superior to the other area reliability. The investigated reliability seem not appropriate to be improved by change of distribution System as well as equipments and facilities improvement in the near future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.312-314
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• 2000

The electric wave propagation characteristics of electromagnetic field by induction current shows a nonlinear distinction in the metal but linear on air. This paper is written about the magnetic transmission distinction in the metalic tube, which wrapped the center axis by the same direction. The electromagnetic field made by the transmission signal is transferred from the transmission coil area toward the receiving coil by the magnetic diffusion. So, it is different magnetic flux around the coil with one in the remote field area. Analyzing such a complex magnetic characteristic, we verified this theory by the vector analysis and presented eddy current mechanism and analytical model about magnetic distribution in the remote field area. This magnetic distribution rate in metal body will be very useful in the nondestructive inspection of the eddy current in remote field which is recently rising as a new technology.

• 지질공학
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• 제20권3호
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• pp.339-348
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• 2010

국내 해안 지역에 위치한 3곳의 천연가스 인수기지의 향후 발생 지진에 대한 대책 수립의 일환으로 기지 영역 내 자유장 부지들 4개소와 저장 탱크 지지 기초 말뚝 1개에 대한 지진 가속도 계측 시스템을 구축하였다. 천연가스 인수기지에서의 계측 시스템의 성공적 설치와 운영을 위하여 특별히 몇 가지 부가 장치들이 고안 적용되었다. 계측된 자료로부터 산출되는 최대지반가속도 기반 의사 결정이 가능한 종합적 지진경보 소프트웨어 시스템을 개별 기지 영역 뿐만 아니라 중앙관리 부서에서의 지진 신속 대응 목적으로 개발하였다. 또한, 전국 최대지반가속도 자료 연계 프레임을 중앙 통합 지진경보 시스템 내에 탑재하여 다양한 향후 확대 활용이 가능토록 구현하였다. 이 연구에서 개발한 천연가스 인수기지에 대한 가속도 계측 기반의 지진경보 시스템은 지반 조건 변화가 심할 수 있는 해안 지역의 시설 영역에 대한 프레임으로 매우 유용하게 이용될 수 있을 것이다.

• Journal of Advanced Marine Engineering and Technology
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• 제38권4호
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• pp.437-443
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• 2014

본 논문에서는 국내 DGPS 내륙 기준국의 전파 환경을 측정하고 기준국별 서비스 영역과 DGPS 수신 신호의 품질을 분석하였다. DGPS 기준국별로 동절기와 하절기에 전파되는 DGPS 신호의 수신 전계레벨과 신호대 잡음비를 측정하여 서비스 영역이 낮은 기준국의 영향과 영역을 향상하기 위한 방안을 모색하였다. 산악지형과 대지 도전율이 낮은 기준국을 제외한 기준국의 서비스 영역은 약 80 % 이상의 설계 기준 서비스 영역을 제공하고 있으며, 평탄한 지형과 대지 도전율이 양호한 대지의 기준국 설치운영과 송신 안테나의 효율 향상을 통하여 서비스 영역의 향상을 기대할 수 있다.

• Current Photovoltaic Research
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• 제11권1호
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• pp.34-37
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• 2023

Solar energy had become the main energy industry of renewable energy along with hydroelectric power generation. One of the technologies that contributed to the popularization of photovoltaic power and the decrease in the unit price of photovoltaic modules was the large-area solar cell. However, as the area increased, the light receiving area increased and the current value increased accordingly. Since power loss occurs when the current value was large, the number of busbar was increased to increase the current collection rate, and a technology to lower the current value through half-cutting was developed. The bus bar of the solar cell served as a passage through which the generated current was transmitted. This was because when the number of busbar decreases, the moving distance of electrons increased, so the amount of power generation decreases and when it increases, shadows occured. An important aspect of the electrode design was the optimal balance of these busbars and number of fingers. Therefore, in this study, the characteristics of the solar cell according to the number of front bus bars of the large-area solar cell were simulated using Griddler 2,5 pro. After selecting the number of busbar with the best characteristics, the difference was compared by varying the number of fingers and a better direction for the number of cutting was presented.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1998년도 학술발표대회 논문집 제17권 1호
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• pp.323-326
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• 1998

The paper describes a theoretical and experimental study on the speed of the torsional elastic waves propagating in an axisymmetirc waveguide whose cross-sectional area varies periodically as an harmonic function of the axial coordinate. The approximate solution of the phase speed has been obtained using the perturbation technique for sinusoidal modulation of small amplitude. The experiment verifying the theoretical result consists of transmitting and receiving torsional waves by magnetostriction and measuring the wave speed in the waveguides with threaded surfaces.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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• pp.42-43
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• 2001

Ecotoxicology is a research area for adverse effect of chemicals to ecosystem. While toxicology is directly related to human health, relation between ecotoxicology and human health is indirect. In this connection, public awareness of environmental effect has been rather behind that for health effects. Historically the first concern in ecotoxicology was adverse effect of pollution on organisms in waters receiving industrial wastewater. (omitted)

• 방송공학회논문지
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• 제21권1호
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• pp.97-104
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• 2016

본 논문에서는 지상파 Digital TV(Television) 방송의 난시청 지역 해소를 위하여 동일 채널 DTV ICS(Interference Cancellation System) 극소출력 중계기를 이용한 필드 테스트 분석을 통한 효과를 입증하였다. 전국적으로 산재한 난시청 지역(자연적) 및 건물(인위적)중에서 7개소를 필드 테스트 지역으로 선정하고, 각 방송국(KBS1, KBS2, EBS, MBC, SBS)에 대하여 ICS 극소출력 중계기의 설치 전, 후의 수신 전계 강도와 SNR(Signal to Noise Ratios)을 측정하고, 또한 수신율 개선 현황을 통하여 ICS 극소출력 중계기의 효과를 검증하고, 향후 ICS 타입 극소출력 중계기의 확산을 위한 연구 기반을 제공하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.222-225
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• 2001

In urban environments, the surface land impermeability fundamentally related to urban growth emphasizes the environmental problems such as the storm water peak flow (so-called the urban flooding) and the pollution. The conventional urban drainage system provides a number of temporary reservoirs intercepting and retaining surface-derived pollutants following their introduction to and deposition upon the impermeable surface. Gully-pots are common features in urban drainage systems in Korea, which were installed for draining rainwater to prevent regurgitation in rainy season and retaining larger particles, hence minimizing pipe blockage problems. When the road runoff conveying sediment enters a gully-pot, the sediment mixes with the gully liquor causing direct pollution of receiving waters. The characteristics of local sediment contamination are usually related to the types of land use activities that take place or have taken place within the area., This study was undertaken to evaluate the spatial and temporal variations of the contamination of gully-pot sediments in Seoul with respect to heavy metals such as As, Cd, Co, Cr, Ni, Pb, Cu and Zn. The heavy metal data were examined according to the land use type. In this paper, sampling sites in Seoul were divided into six groups (commercial area, industrial area, residental area, motor way, rural area, and local pollution).

• 한국환경보건학회지
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• 제31권6호
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• pp.467-474
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• 2005

The runoff characteristics of combined sewer overflow(CSO) in the urban area of Jeonju were investigated and analyzed by using the SWMM (Storm Water Management Model) and GIS. From August to November 2004, investigations on two rainfall events were performed and flowrate, pH, BOD, COD, SS, T-N and T-P were measured. these data were used for model calibration. Using GIS technique, watershed characteristics of study area were calculated. that is, divide into sub_basin, total width, slope, make soil map etc. On the basis of the measured data and the simulation results by SWMM, it could be known that the $80-90\%$ of pollution load are discharged in early-stage storm runoff. SMC(site mean Concentration) for combined sewer system area were BOD 28.1, COD 31.5, SS 186 ppm etc. this is shown that during the rain fall, high concentration of waste was loaded to receiving water. Unit loads of combined sewer system area were BOD 306, COD 410, SS 789, T-N 79, T-P 6.8 kg/ha/yr.