• Tribology and Lubricants
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• 제20권4호
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• pp.183-189
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• 2004

The floating ring seal is used in an oxidizer and a fuel pump of the turbo pump unit in the liquid rocket engine to optimize a leakage without rubbing phenomenon. The damper floating ring seal, one of the floating ring seals, is with round hole pattern surfaces. It can reduce the leakage by increased friction factor that obtained from experimental data. In this paper, the leakage test about floating ring seal and damper floating ring seal was conducted. The test result showed the leakage performance of damper floating ring seal was better than the leakage performance of floating ring seal. With the leakage test the lock-up and rotation test about seal was conducted and that position is measured. The relatively large lock-up eccentric ratio was obtained from the test result of damping floating ring seal. The attitude angle of seal increases with increasing of shaft rotation.

• 한국정밀공학회지
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• 제16권12호
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• pp.60-70
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• 1999

An efficient automatic inspection system for Floating Seal is developed, The proposed system consists of a high resolution line scan camera, microcomputer, and PLC (Programmable Logic Controller). In order to perform rapid inspection, The ROI (Region of Interest) is extracted from the original image. There are types of defects; shape defects and surface defects. Each features of defects are captured by edge detect, segmentation, morphological operation, and threshold analysis. PLC controller is used to synchronize the whole system and store the inspection results temporarily to reduce the overhead of microcomputer. As a result, the system is being utilized successfully in a teal inspection line.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.526-527
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• 2008

본 논문은 MOSFET을 스위칭 소자로 사용한 350W급 2MHz 병렬공진 DC-AC 컨버터를 제안한다. 제안된 DC-AC 컨버터는 스위치의 전압스트레스 크기가 입력전압과 동일한 값으로 주어져 기존의 절연형 컨버터들 중에서 가장 낮은 전압 스트레스 값을 가지고 입력전압의 크기와 출력전력의 크기를 고려하여 풀-브리지 컨버터 토폴로지를 채택하였다. MOSFET 게이트 구동펄스는 50% 시비율이며, 구동트랜스포머를 사용하여 DC-AC 컨버터의 플로팅 스위치를 구동하였다. DC-AC 컨버터의 입력 전압은 50V, 부하저항은 $500{\Omega}$의 무유도 저항을 이용했다. 출력전압과 출력전류의 실효치는 각각 430V, 800mA 이고 효율은 82.5%에 도달하였다.

• 한국항해항만학회지
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• 제37권3호
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• pp.315-320
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• 2013

According to climate change, deficiency of usable land, large water portion of the Earth surface, and improvement of income level, floating architecture is emerging as a strong & attractive alternative. The aim of this study is to suggest some related applying ways for new building projects around waterside. New paradigm of architecture can be described as a new model and/or system of architecture with new concept and Zeitgeist like sustainability and green building. Floating building is already a new paradigm of architecture comparing with the preconception of building only on the land and current building regulations. New paradigm features from the sample projects can be summarized as new concepts of building, application of various renewable energy resources(water, solar, wind), modular construction, use of local raw material, dual purpose usage, long term and relocatable usage, and special building materials for green building.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.214-215
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• 2011

일반적으로 멀티레벨 인버터는 고조파 저감을 위하여 출력전압의 레벨 수에 비례하는 다수의 플로팅(floating)된 입력 전압원 또는 다수의 절연 변압기를 필요로 하므로 시스템이 복잡하고 가격이 높은 단점을 갖는다. 이를 위해 본 논문에서는 단 한 개의 입력 전압원 만으로 원하는 만큼의 출력전압 레벨 수를 획득할 수 있는 Charge Pump 방식의 멀티레벨 인버터를 제안한다. 제안된 인버터는 시스템 구성이 매우 간단하여 제작단가 및 전력변환 효율을 개선시킬 수 있는 장점을 가진다. 최종적으로 제안 인버터의 특성에 대한 이론적 분석과 모의실험을 통해 그 우수성을 검증한다.

• 한국농공학회지
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• 제42권6호
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• pp.63-71
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• 2000

The purpose of this study is to derive optimal design floods by the Wakeby distribution model using the probability weighted moments. Parameters for the Wakeby distribution were estimated by the probability weighted moments for the annual flood flows of the applied watersheds. Design floods obtained by the Wakeby and GEV distributions were compared by the relative mean errors, relative absolute errors and root mean square errors. In general, it has shown that the design floods by the Wakeby distribution using the methods of the probability weighted moments are closer to those of the observed data in comparison with those obtained by the GEV distribution.

• 한국관개배수논문집
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• 제4권1호
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• pp.34-50
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• 1997

This study was conducted to derive optimal design floods by Log Pearson Type III distribution model of the annual maximum series at five watersheds along Geum, Yeong San and Seom Jin river systems. Design floods obtained by different methods for evaluatio

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2011년도 추계학술대회
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• pp.131-132
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• 2011

수리학적인 모형실험을 이용하여 플로팅 구조물의 변위를 영상기반으로 관측할 수 있다. 디지털 캠코더 파일로부터 취득된 영상에 프레임 영상 추출, 특징점 추출 및 정합을 수행하였다. 정확한 결과 산출을 위하여 향후 개선된 실험환경에서 동영상 취득을 수행할 예정이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.199-202
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• 2004

NFGM(Nano-Floating Gate Memory) is a very prospective candidate memory for the next generation with MRAM, PRAM, PoRAM. Among these memory devices for the next generation, NFGM has a lot of merits such as a simple low cost fabrication process, improved retention time, lower operating voltages, high speed program/erase time and so on. Therefore, many intensive researches for NFGM have been performed to improve device performance and reliability, which depends on the ability to control particle size, size distribution, crystallity, areal particle density and tunneling oxide quality. In this paper, we investigate the researches for NFGM up to recently.

• 전기학회논문지
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• 제64권1호
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• pp.143-148
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• 2015

In this paper a new method is proposed for realizing active floating inductors from voltage differencing transconductance amplifier(VDTA) which is being studied nowadays. This proposed method employs only one VDTA and one transconductance for designing an active inductor from a passive floating inductor and implementing it to integrated circuits. The number of CMOS transistors can be considerably reduced from 6~18 as 1~3 gm circuits can be eliminated and even without R the design can be made, which can help in reducing the size of the circuit and power consumption. The proposed VDTA floating inductor was successfully used in constructing 1 MHz second order biquad active bandpass filter and bandwidth could be adjusted from 77kHz~1.59MHz by the changes made in gm from 6uS~20uS.