• Title/Summary/Keyword: 코라

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Development of 7m-off-Long-Distance Wireless Power Transfer System (7m 원격 무선전력전송 개발 사례)

  • Choi, Bo H.;Lee, Eun S.;Kim, Ji H.;Rim, Chun T.
    • Proceedings of the KIPE Conference
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    • 2014.07a
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    • pp.7-8
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    • 2014
  • 본 논문은 다이폴 코일 공진방식(DCRS, Dipole Coil Resonant System)을 사용한 원격 무선전력전송 개발 사례를 소개한다. 제안된 다이폴 코일 공진방식은 기존의 자기결합 공진방식(CMRS, Coupled Magnetic Resonance System)에 비하여 송신, 수신코일로만 이루어진 간단한 코일 구조와 작은 부피를 가지며, 공진도 Q를 100이하로 설계하여 주변 환경 변화에 강인한 전력전달 특성을 가진다. 본 논문에서는 원전 중대사고 시 격납건물 필수계측기용 소형 비상전원으로 개발된 10W급 7m 원격 무선전력전송 장치의 구성 및 설계과정을 제시한다.

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Optimal Design Methodology of a 500 W Wireless Power Transfer Converter (500 W급 무선 전력 전송용 컨버터의 최적설계 방법에 관한 연구)

  • Kim, Mina;Kim, Katherine A.;Jung, Jeehoon
    • Proceedings of the KIPE Conference
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    • 2015.07a
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    • pp.19-20
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    • 2015
  • 본 논문은 동작 주파수에 따른 임피던스 분석을 통해 무선 전력 전송 컨버터의 최적 설계 방법을 제안한다. 기존의 무선 전력 전송에는 크게 4가지의 토폴로지가 있는데 본 논문은 SS 토폴로지에 대한 최적 설계 방법을 제시한다. 무선 전력 전송이 가지는 근본적인 특징인 코일 간의 낮은 커플링 계수로 인해 컨버터 설계 시 많은 제약 사항들을 고려해야 한다. 일반적인 변압기와 달리 코일 간의 커플링 계수가 0.2 안팎이므로 충분한 자화 인덕턴스를 가지기 위해서는 코일의 턴 수를 늘리는 방안이 있으나 턴 수에 따라 코일 저항이 늘어나, 도통 손실이 증가하는 문제가 있다. 또한 낮은 자화 인덕턴스는 높은 자화전류에 의한 컨버터의 1차 측 전류의 상승을 야기하며, 도통손실을 증가시킨다. 따라서 본 논문에서는 무선 전력 전송용 컨버터의 최적 설계를 임피던스 변화의 관점에서 수학적인 분석을 통해 제안하고, 그에 따른 시뮬레이션으로 검증하고자 한다.

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Face Component Extraction Using Multiresolution Image (다해상도 영상을 이용한 얼굴 구성요소 추출)

  • Jang, Kyung-Shik
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.12
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    • pp.3675-3682
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    • 1999
  • This paper proposes the method to extract face components without using the color information and the motion information in a gray image. A laplacian pyramid of the original image is built. Eye and nose candidates are extracted using only the gray information in a low resolution laplacian image and pairs are found that consist of two eye candidates and a nose one. At full resolution, horizontal and vortical edges are found in the regions of face components which are established using the candidates. Using those edge informations, face components are extracted. The experiments have been performed for images with various sizes and positions of face, and show very encouraging result.

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A Study on Power Control Algorithm for Load Shedding and Energy Saving Effect (LED 조명의 목표전력량 제어 알고리즘과 에너지절감 효과에 관한 연구)

  • Jung, Jae-Yong;Han, Ki-Jung;Park, Ki-Woong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2012.11a
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    • pp.351-354
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    • 2012
  • 본 연구는 LED 조명제어시스템(LMS)을 이용해서 관리자가 원하는 목표전력량과 LED 조명의 구역별 중요도에 따라 Priority 를 설정 후 실시간으로 전력량을 측정해서 Overload(목표전력량 80% 이상 초과 1 단계, 90% 이상 2 단계) 상황 발생 시 자동으로 LED 조명전력을 차단 또는 디밍함으로써 정전에 대비하고 에너지절감도 가능한 알고리즘과 실증결과에 관한 연구내용을 소개한다.

A Level 2 Middleware for Steel Plant Control (철강플랜트 제어를 위한 레벨 2 미들웨어)

  • Kim, DoHun;Hwang, Hwa-Won;Choi, Ja Young;Ko, JaeHoon;Kim, Chee-Ha
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.2
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    • pp.86-92
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    • 2011
  • In this paper, we proposed a level 2 middleware with common services for controlling steel plants, which is named POSMOS. POSMOS supports eight middleware services currently, but, this paper described in detail two representative services of the common services: file service and external communication service and their respective measured performance. In the experiment section, we described the performance of the two representative services and a case using our middleware which shows better response time than the existing commercial middleware by about 32%.

4Q Local Controller for the ITER CS, VS1, CC AC/DC Converter

  • Suh, J.H.;Oh, J.S.;Kim, B.C;Choi, J.W.;Shin, H.K;Yoo, M.H.;Park, H.J.;Jo, S.M.;Kim, C.W.;Lee, Y.S
    • Proceedings of the KIPE Conference
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    • 2018.11a
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    • pp.111-112
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    • 2018
  • 4Quadrant 동작하는 ITER CS, VS1, CC AC/DC Converter Local Controller는 전압제어 모드로 동작하며 초전도 코일에 제어된 전류를 충전, 유지, 방전하며 제어기 내외부 조건에 의한 보호 동작이 요구된다. 코일 전류가 제로 영역에 있을 때 플라즈마 붕괘로 인한 코일 전류 blocking을 방지하기 위한 순환전류 모드가 요구 되며 코일 전류에 따른 컨버터 브릿지의 동작모드가 결정된다. 본 논문은 RTDS를 이용하여 제어기의 성능을 검증한 내용을 논의하고자 한다.

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Evaluation of Effectiveness of Concrete Coated with Bacterial Glycocalix under Simulated Sewage Environments (유사 하수환경에서 글라이코 캘릭스 코팅 콘크리트의 효율성 평가)

  • Yoon, Hyun-Sub;Yang, Keun-Hyeok
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.1
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    • pp.97-104
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    • 2020
  • The present study conducted mock-up tests under the simulated sewage environments to examine the practical significance and limitation of coating materials that were previously developed on the basis of the bacterial glycocalix as a protection of concrete structures exposed to microbiological and sulphate attacks. The variations of the compressive strength and mass of the concrete due to the sulphate attack were measured using cylinder specimens. The bacteria growth and glycocalix formulation were calculated from the samples extracted from the sewage pipes. The next generation sequencing analysis was also conducted for environmental damage assessment due to the use of Rhodobacter capsulatus in the simulated sewage environments. The mock-up tests revealed that the developed coating materials have a good potential in resisting the sulphate attack, indicating no reduction on compressive strength and mass of the coated concrete under the sewage environment. At the age of 91 days, the concentrations of viable bacteria and glycocalix measured from the hardened coating materials were 1.4×104cell/mL and 67.5mg/㎤, respectively. Moreover, harmful strains were not observed in the sewage water including glycocalix-coated concrete pipes. This implies that Rhodobacter capsulatus used in the coating materials does not influence negatively the microorganism cluster in the sewage environments.

Effectiveness of 32-element Surface Coil Array for Accelerated Volume-Targeted Breath-Hold Coronary MRA (체적 지향형 호흡정지 자기공명 조영술의 가속화에 대한 32채널 코일 어레이의 효용성)

  • Lee, Hyun-Yeol;Suh, Jin-Suck;Park, Jae-Seok
    • Investigative Magnetic Resonance Imaging
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    • v.13 no.2
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    • pp.137-145
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    • 2009
  • Purpose : To compare 12 and 32-element surface coil arrays for highly accelerated coronary magnetic resonance angiography (MRA) using parallel imaging. Materials and Methods : Steady state free precession coronary MRA was performed in 5 healthy volunteers at 1.5 T whole body MR scanner using both 12 and 32-element surface coil arrays. Left anterior descending and right coronary artery data sets were acquired for each volunteer. Data sets were sub-sampled for parallel imaging using reduction factors from 1 to 6. Mean geometry factor (g-factor), maximum g-factor, and artifact level were calculated for each of the two coil arrays. Results : Over all reduction factors, the mean and maximum g-factors and artifact level were significantly reduced using the 32-element array compared to the 12element array (P << 0.1). The mean g-factor was sensitive to the imaging orientations of coronary arteries while the maximum g-factor and artifact level were independent of orientation. Conclusion : The 32-element surface coil array significantly improves artifact and noise suppression for highly accelerated coronary MRA using parallel imaging. The increased acceleration factors made feasible with the 32-element array offer the potential to enhance spatial resolution or increase volumetric coverage for 3D coronary MRA.

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Studies on the Physicochemical properties in Processing of Accelerated Low Salt-Fermented Anchovy by adding koji (코오지를 이용한 속성 저식염 멸치젓의 성분)

  • 백승화;임미선;김동한
    • The Korean Journal of Food And Nutrition
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    • v.9 no.4
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    • pp.385-391
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    • 1996
  • To produce low salt fermented anchovy by an accelerated method with Asp. oryzae and Bacillus sp. koji and change of physicochemical properties in the fermentation during 60 days were examined. The contents of moisture, crude protein, ash and salinity of salted anchovy changed little during the fermentation with 62.5~63.8%, 12.0~14.1%, 12.8~13.8%, and 12.8~13.8%, respectively. but crude lipid decreased from 15.5~15.8% initially to 13.1~13.9% finally. The p during the fermentation decreased slowly until day 50 and increased afterwards. Acidity increased remarkably on day 10 and changed little afterwards. This increase in acidity was particularly observed in the use of Asp. oryzae koji. Amino nitrogen contents sharply increased until day 20 wit 686.0~756.0mg% and then increased slowly. Ammonia nitrogen contents in the use of koji increased until day 40 or 50 and decreased after that ; while those without koji steadily increased until day 60. The TBA values for all the samples reached the highest point on day from 20 to 30 and decreased afterwards. The TBA values and ammonia nitrogen contents were higher in Bacillus sp. koji than in Asp. oryzae koji. The alcohol contents of anchovy paste a little decreased during 10 days, increased slowly after that until day 50, and then decreased. The content of alcohol was higher in the use of koji than in the non koji.

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