• 한국화재소방학회논문지
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• 제31권1호
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• pp.1-9
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• 2017

본 연구에서는 거실제연설비가 설치된 철도 지하환승통로에 현장성능평가시험인 제연 TAB(Test, Adjusting, Balancing)를 실시하여, 제연설비 성능 확보에 미치는 영향을 분석하고 개선방안을 도출하였다. 제연 TAB는 지하환승통로의 제연설비 설계자료 분석, 제연덕트 누기테스트, 제연송풍기와 덕트의 풍량 및 풍속 측정, Smoke test로 나누어 진행되었다. 제연덕트 누기시험을 통해 누기율을 측정하여 덕트의 기밀성을 확인하였고, 흡입측 덕트 정압손실로 인한 제연풍량 부족의 문제점을 개선하여 송풍기의 성능을 확보하였다. 또한, Smoke test을 통해 예상제연구역별 제연댐퍼 동작 시 자연풍, 열차풍 영향으로 인한 문제점을 분석하고 개선하여 예상 제연구역 내 제연이 원활하게 이루어짐을 확인하였다.

• 한국정보통신학회논문지
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• 제26권8호
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• pp.1248-1254
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• 2022

스쿨존에서 교통사고를 사전에 예방하려고 노력하고 있다. 하지만, 스쿨존 내 교통사고는 계속 발생하고 있다. 운전자가 어린이보호구역 내 상황 정보를 미리 알 수 있으면, 사고를 줄일 수 있다. 본 논문에서는 스쿨존 내 사각지대를 없애는 카메라, 사전 교통정보를 수집할 수 있는 번호인식 카메라 시스템을 설계한다. 차량속도 및 보행자를 인식하는 LIDAR 시스템을 개선하여 설계한다. 카메라 및 LIDAR에서 인식된 보행자 및 차량 영상 정보를 수집하고 가공하여, 인공지능 시계열 분석 및 인공지능 알고리즘을 적용한다. 본 논문에서 제안한 딥러닝으로 학습된 인공지능 교통사고 예방 시스템은, 스쿨존 진입 전 차량 내 모바일 장치에 스쿨존의 정보를 운전자에게 전달하는 강제 푸시서비스를 한다. 그리고 LED 안내판에 스쿨존 교통정보를 알람으로 제공한다.

• 전력전자학회논문지
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• 제21권4호
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• pp.283-289
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• 2016

Islanding protection of a grid-connected photovoltaic (PV) inverter is a key function for standards compliance. Unintentional islanding results in safety hazards, reliability, and many other issues. Therefore, many anti-islanding schemes have been examined. However, existing anti-islanding schemes have poor power quality and non-detection zone issues. Moreover, most schemes have problems that deteriorate the performance of islanding detection under parallel operation. Therefore, this paper proposes a novel anti-islanding scheme that has negligible power quality degradation and has no non-detection zone and islanding detection under a parallel operation. Both simulation and experimental results validate the proposed scheme.

• 한국표면공학회지
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• 제51권5호
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• pp.316-324
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• 2018

Harsh seawater environment is subdivided into marine atmosphere, splash zone, tidal zone, submerged zone and bottom of sea depending on the exposed part. Since corrosion rate depends on the conditions of the exposed parts, proper protection and maintenance for each parts are essential for long-term use of steel structures in seawater environment. For steel structures which were installed in Shiwha Lake, a special maintenance system is required to guarantee its long-term durability and safety. As the tidal power plant has recently been operated, the salinity has risen due to the rapid influx of seawater upstream into Sihwa Lake and the corrosion tendency of the structure is variable according to the water level fluctuation. In this study, corrosion properties of steel structures under water level fluctuation was evaluated by corrosion rate measurement, visual inspection and natural potential measurement and their durability and life management were discussed in view of the effect of variation in of seawater level fluctuations in Shihwa Lake.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.755-758
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• 1999

Reinforced concrete is in general known as high durability construction material under normal environments due to strong alkalinity of cement. Marine and harbour concrete in the tidal and the splash zone at seashore are exposed to cyclic wet and dry saltwaters which cause to accelerate corrosion of reinforcing steel in concrete. If corrosion resistance of concrete gets to weaken due to carbonations and cracks in cover concrete, furthermore, concrete durability rapidly decreases by corrosion of reinforcement steel embedded in concrete. The objective of this study is to develop appropriate corrosion protection systems so as to enhance the durability of concrete by controlling the cover depth of concrete and by using corrosion inhibitors as concrete admixtures.

• Journal of Electrical Engineering and Technology
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• 제3권1호
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• pp.29-35
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• 2008

With long time setting, zone 3 impedance relays are considered insensitive to power swings, and their operation condition during power swings is seldom analyzed. Instead of ti me-consuming simulation to the swing loci, their operation condition is directly quantified by polynominal functions in this paper to find the critical swing angle and frequency for relay operation under different relay settings and system parameters. It is found: (1) the swing loci are more densely populated inside than outside of the protection region, which corresponds to long residence time and possible relay operations; (2) the relays may be sensitive to load encroac hments and stable power swings with different relay settings and system parameters; (3) the critical swing frequency may be in the range of low-frequency power swings.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.821-826
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• 2000

Reinforced concrete is in general known as high durability construction material under normal environments due to strong alkalinity of cement. Marine concrete specimens in the tidal and the splash zone at seashore have been exposed to cyclic wet and dry saltwaters which cause to accelerate corrosion of reinforcing steel in concrete. If corrosion resistance of concrete gets to weaken de to carbonations and cracks in cover concrete, furthermore, concrete durability rapidly decreases by the corrosion of reinforcement steel embeded in concrete. The objective of this study is to develop appropriate corrosion protection systems of marine concrete so as to enhance the durability of concrete by establishing pertinent cover depth of concrete and by using corrosion inhibitors as concrete admixtures.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.893-895
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• 1998

This paper presents the adaptive setting method of distance relay under the single line ground fault. The apparent impedance measured at the relaying point and actual impedance is different because of fault resistance and various prefault loading condition. For a resistance earth fault detection, relay setting zone is adaptively changed with measured load current and bus voltage at the relaying point to avoid maloperation.

• 산업기술연구
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• 제9권
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• pp.3-19
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• 1989

Shoreline have been changed from time immemorial continuously, three-quarters of the population of the world live by the sea. It is not too much to say that all of us who live in Han penisular live by coastal zone because we can reach in the beach within only for hours. In this way effectual use and menagement of coastal zone is very importent problems in side of protection of marine resources as well as land use. But it has problems which change of shoreline have to be surveyed and to be predictived. This study the pattern and characteristics of the East sea coast including investigations of the shoreline changes of the East sea. This report gives a description of the method for implementing the seawall boundary condition in the shoreline change numerical model. Such analytical solutions can provide a simple and economical means to make a quick qualitative evaluation of shoreline response under a wide range of environmental and engineering conditions.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• 제1호
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• pp.120-126
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• 2001

The Haidian Garden of Zhongguancun Science and Technology Zone is an area with high intellectual intensity. It is therefore known as China's Silicon Valley. The Summer Palace, a World Heritage Site, sits in the northwest part of it. 250 years ago, the construction of imperial gardens in this area, including the Summer Palace, gave birth to the appearance and prosperity of the town of Haidian. This will also provide various opportunities for the growth of the science and technology. Today the green space, the cultural and ecological environment of the Summer Palace, and its 3-kilometer buffer zone are becoming one important strategic factor for the Haidian Garden to attract talents, improve international competitiveness and realize sustainable development. How to taking advantage of the favorable resources, to achieve balance between protection of the environment around the Summer Palace and urban development, will be of great importance in the future plans of the science and technology.