• Title/Summary/Keyword: YoungChu

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A Study on Low Emission Pulverized Coal Combustion in the 2 Staged Coaxial Cyclone Combustor (2단 동축형 Cyclone 연소기를 이용한 저공해 미분탄 연소특성 연구)

  • Choi, Sang-Il;Park, Chu-Sik;Kim, Sung-One;Kim, Ho-Young
    • Journal of the Korean Society of Combustion
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    • v.4 no.1
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    • pp.67-83
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    • 1999
  • The objective of this study is development of low emission pulverized coal combustor for reducing pollutant emission generated from coal combustion. Low emission combustion technology for reducing NOx and fly ash was investigated by using 2 stage coaxial cyclone combustor. Staged combustion was employed for NOx reduction and high temperature slagging combustion was also studied for fly ash removal in the combustor. The result of this study shows that the low emission combustion system can reduce the amount of atmospheric pollutions with improved boiler efficiency and performance.

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Operating Characteristics of D-DOT Probe for Nanosecond High-Voltage Pulse Measurements (고전압 나노초 펄스 측정을 위한 D-DOT 프로브의 동작특성)

  • Lim, Soo-Won;Cho, Chu-Hyun;Kim, Jong-Soo;Kim, Young-Bae;Ryoo, Hong-Je;Jin, Yun-Sik
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1594-1596
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    • 2011
  • 고전압 펄스 성형회로의 출력 펄스를 측정하기위한 D-DOT 프로브를 설계 제작하고 그 동작 특성을 조사하였다. 이 프로브는 고전압 펄스 전송선의 외함에 전계방향과 병렬로 설치되었다. 프로브의 중심도체는 지름 4.6 mm의 구리선이고, 바깥도체는 안지름 15 mm의 알루미늄이며, 이들 도체사이에 동축의 테플론 절연체가 삽입되었다. 프로브에서 출력되는 신호는 고전압 펄스신호의 미분된 형태의 신호가 측정되므로 오실로스코프의 적분기능을 사용하였다. 실제 제작한 프로브의 교정비는 $7.7{\times}10^{12}$였으며, 컴퓨터 시뮬레이션을 통하여 얻은 교정비는 $7.38{\times}10^{12}$였다.

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Larval Development of Balanus trigonus Darwin(Cirripedia: Thoracica: Balanidae) reared in the laboratory

  • LEE Chu;KIM Chang-Hyun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.6
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    • pp.457-467
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    • 1990
  • Sessile barnacle, Balanus trigonus Darwin, was collected from the intertidal rocks and the external shells of bivalve Mylius coruscus. The nauplius and cyprid larvae were cultured in a constant temperature cabinet at a temperature of $20^{\circ}C$ and a light regime of 14 h light and 10 h darkness. Larval development includes the six nauplius stages and a cyprid stage prior to settlement and metamorphosis to the young adult. Morphological characteristics including antennules, antennae and mandibles are described and illustrated. All nauplius larvae have trilobed labra typical in balanoides. The developmental time taken from newly hatched nauplius I to cyprid was $9\~13$ days and averaged 11 days.

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NaCl Content in Korean Storage Foods (우리나라 저장식품중의 NaCl 함량)

  • Park, Young-Ran;Park, Bong-Ock
    • Journal of Nutrition and Health
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    • v.7 no.1
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    • pp.25-29
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    • 1974
  • In order to help food habits of Korean, major foods of side dishes in Korean foods were analyzed by Mohr's Silver Nitrate Method. The kinds of foods were Kanchang (Sa)Sauce) Kochuchaag(Redpepperbean paste), Doeuchang(Soy bean Paste) and Kimchies, and selected into 3 areas in Korea; Seoul (city area), Kyung Puk Province (Fishery area) and Chun-Puk Province (Farming area). The results are as follows; Average NaCl content of Kan-chang is 26.04g/dl ranged from 24.27 to 28.22g/dl and among them Farming area is the highest content. In Ko-chu-chang, average content is 11.36g% ranged from 10.77 to 11.60g%. Doen-chang has an average 15.89% ranged from 13.28 to 18.54g% and in Kimckies they were resulted 3.36g%.

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10kW Charger consist of Grid-connected inverter and 2-stage DC-DC converter for EV (계통연계인버터와 2단 DC-DC 컨버터로 구성한 전기자동차용 10kW급 충전기)

  • Kim, Kyeong-Tae;Jeong, Jong-Kyou;Chu, Kyeong-Ho;Park, Seung-Hui;Seo, An-Sik;Lee, Seul-Gi;Lee, Jun-Young
    • Proceedings of the KIPE Conference
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    • 2011.07a
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    • pp.553-554
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    • 2011
  • 환경오염의 의한 지구온난화가 세계적 이슈가 되고 있으며 화석연료의 고갈 등으로 기존의 자동차들이 점점 설 자리를 잃어 가는 게 현재 상황이다. 따라서 화석연료 자동차를 대체해야하는 많은 새로운 형태의 자동차가 제시 되고 있는데 그중에 현재 가장 경쟁력과 경제성을 가진 전기자동차가 대두되고 있는 시점에 이를 충전하기 위한 여러 장치들이 나오고 있다. 그중에 우리는 3상계통 인버터와 고효율 DC-DC 컨버터로 구성 된 충전기를 소개하고자한다.

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The effect of Rh/Ce/Zr additives on the redox cycling of iron oxide for hydrogen storage (산화철의 환원-산화 반응을 이용한 수소저장에 미치는 Rh/Ce/Zr의 효과)

  • Lee, Dong-Hee;Cha, Kwang-Seo;Park, Chu-Sik;Kang, Kung-Soo;Kim, Young-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.49-52
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    • 2007
  • We investigated hydrogen storage and production properties using redox system of iron oxide($Fe_{3}O_{4}$ + $4H_{2}$ ${\leftrightarrows}$ 3Fe + $4H_{2}O$) modified with rhodium, ceria and zirconia under atmospheric pressure. Reduction of iron oxide with hydrogen(hydrogen storage) and re-oxidation of reduced iron oxide with steam(hydrogen evolution) was carried out using a temperature programmed reaction(TPR) technique. On the temperature programmed studies, the effects of amounts of cerium and zirconium on the re-oxidation rate of partial reduced iron oxides were increased with increasing metal additives amount, but the rhodium amount showed little effect on the re-oxidation rate. On the thermal studies, the re-oxidation rates were enhanced with increasing temperature(300 $^{\circ}C$ < 350 $^{\circ}C$).

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Servo Design for High-TPI Hard Disk Drives Using a Delay-Accommodating State Estimator

  • Kim, Young-Hoon;Chu, Sang-Hoon;Kang, S.W.;Oh, D.H.;Han, Y.S.;Hwang, T.Y.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.134-139
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    • 2002
  • This paper presents a servo design method for high track-density hard disk drives, in which the plant time delay, mainly due to the processor computation time, is taken into account. The key idea behind the proposed design method is to incorporate the delay model into the output equation of the state-space representation for the plant model; thereby, the delay is accounted for by a standard state observer in a natural manner, with simplified state equations as compared to those for conventional methods. The results from practical application confirm that the proposed method is quite effective in realizing a high-bandwidth servo system in hard disk drives.

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Case Studies on the Electric Power Loss Reducing Methodology for Transformer Installation in Sewage Treatment Plant (하수처리장 변압기 설치사례 연구를 통한 전력손실 저감방안)

  • Kim, Chu-Young;Choi, Chang-Gyu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.1
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    • pp.70-77
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    • 2011
  • Sewage treatment plants, consuming 1,756[GWh] which is 0.53[%] of national wide electricity consumption, is one of the electricity consuming facilites. At the research of electricity consumption and power quality analysis on sewage treatment plants, average utilization of transformer was less than 40[%] because peak load was very lower than its capacity due to excess capacity. So reduction of power loss can be achieved by transformer design optimization. The achievement in this research, is to meet reduction of power loss through optimizing the capacity and to improve as high efficiency-low loss transformer while the transformer is operating.

Shrink-Wrapped Boundary Face Algorithm for Mesh Reconstruction from Unorganized Points

  • Koo, Bon-Ki;Choi, Young-Kyu;Chu, Chang-Woo;Kim, Jae-Chul;Choi, Byoung-Tae
    • ETRI Journal
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    • v.27 no.2
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    • pp.235-238
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    • 2005
  • A new mesh reconstruction scheme for approximating a surface from a set of unorganized 3D points is proposed. The proposed method, called a shrink-wrapped boundary face (SWBF) algorithm, produces the final surface by iteratively shrinking the initial mesh generated from the definition of the boundary faces. SWBF surmounts the genus-0 spherical topology restriction of previous shrink-wrapping-based mesh generation techniques and can be applied to any type of surface topology. Furthermore, SWBF is significantly faster than a related algorithm of Jeong and others, as SWBF requires only a local nearest-point-search in the shrinking process. Our experiments show that SWBF is very robust and efficient for surface reconstruction from an unorganized point cloud.

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