• Title/Summary/Keyword: Cheong-Dae

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Characteristics of water treatment plant sludges on raw water source (취수원별 정수장 슬러지의 물리화학적 특성)

  • Moon, Yong-Taik;Kim, Byung-Goon
    • Journal of environmental and Sanitary engineering
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    • v.21 no.3 s.61
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    • pp.37-43
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    • 2006
  • Recently, needs for reuse of sludge produced from WTP(water treatment plant) have been increased with shortage of landfill sites and difficulties of the treatment and disposal processes. Therefore, Reusing is becoming an Increasingly popular waste management alternative to divert waste from landfills. In order to research the characteristics of WTP sludges, we used the sludges of C WTP which intake the lake Dae-Cheong and the sludges of S WTP which intake Keum river, The specific surface area of C and S WTP sludges were $0.9986m^2/cc\;and\;1.874m^2/cc$, respectively. The gravity was about $2.0{\sim}2.4$ which are scope of peat or loamy clay. The major minerals of C WTP sludges were kaolinite(48.4%), muscovite(19.5%), and quartz(16.7%). Also, muscovite(31.6%), quartz(30.3%), and kaolinite(17.3%) in S WTP sludges were major minerals.

Dynamic Analysis for Performance Improvement of Line Center (라인센터의 성능향상을 위한 동특성 해석)

  • Cheong, Seon-Hwan;Choi, Seong-Dae;Kweon, Hyun-Kyu;Shon, Jae-Yool
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.2 no.2
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    • pp.75-83
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    • 2003
  • Recently, the machine tools have been needed for high speed and accuracy to increase productivity. The most Important thing to get a more stabilized machine is to know the frequency response which has an effect on manufacture a lot. This problem should be considered seriously by many researchers. There are many application programs about FEM but Just using FEM program to get information of the object is not enough to put our confidence in the stability of the machine tool design. Therefore, the purpose of this research is to make a study for proving one of the ways to design to produce stabilized a machine more efficiently by comparing FRT method and FEM. At these two tests, we can learn about the frequency response area causing resonance and we can reconfirm the result to trust.

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Fracture Behavior of the Cut Surface of a Flat Panel Glass according to Vibration Input (진동 인가에 따른 평판 유리 절단면의 파괴거동)

  • Choi, Seong-Dae;Cheong, Seon-Hwan;Kim, Gi-Man;Kweon, Hyun-Kyu;Jeon, Jae-Mock;Rho, Young-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.4 no.3
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    • pp.51-56
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    • 2005
  • This research presents a modeling and a manufacturing method of screw flow meter. This paper introduces the efficient design and manufacturing method of screw type flow meter using reverse engineering and test technology. The methods introduced this paper utilize the reverse engineering that is increasing accuracy of modeling and manufacturing of reverse model. And then it can be used in performance test with hydraulic test equipment. Hence this can be used in the basic document for development of the quite accurate flowmeter.

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Assessment of Insulation Condition for Hydro-generator (대용량 수치발전기의 절연진단에 의한 절연상태평가)

  • Lee, Kwang-Ho;Park, Jong-Jin;Kim, Ki-Won;Lee, Eun-Woong
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1810-1812
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    • 2002
  • This test was performed to assess the insulation deterioration condition of the stator winding of Chung-Ju hydrogenerator #4 and Dae-Cheong hydrogenerator #2 which had been in service after being constructed 1980. The insulation diagnostic tests include resistance polarization index(P.I.) AC current, dissipation factor(Tan ${\delta}$) and partial discharges ($Q_{max}$). The results of diagnostic tests were compared to factory test measurements.

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Construction of a T-Vector Using an Esterase Reporter for Direct Cloning of PCR Products

  • Lim, Ho-Dong;Cheong, Dae-Eun;Shin, Hyun-Jae;Kim, Geun-Joong
    • Journal of Microbiology and Biotechnology
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    • v.20 no.11
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    • pp.1481-1483
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    • 2010
  • We constructed an efficient T-vector, pTQEST216T that employed an engineered esterase as an indicator for direct cloning of PCR products. After ligation of the XcmI-digested vector with PCR products, this cloning system could easily discriminate positive clones owing to insertional inactivation of the esterase reporter. Additionally, PCR products were efficiently cloned into this vector without the gel purification steps, owing to the well-designed multi-cloning site that was in-frame fused at the circularly permutated gap of the reporter.

A Study on Electroluminescence Device with Polymer (고분자를 이용한 전계발광소자에 관한 연구)

  • Lee, Jong-Chan;Lee, Cheong-Hak;Park, Su-Gil;Lim, Kee-Joe;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1219-1221
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    • 1997
  • Poly(1,4-phenylene(1-methoxyenthylene)), organic water soluble PPV precursor was synthesized for polymer electroluminescence(EL) device. To control the molecular array, deposition method of emitter was Langmuir-Blodgett(LB). PPV precursor layer was treated thermally to conversion of PPV. Optical, electrical and EL properties of PPV LB thin film was estimated. Homogeneous light emission of greenish-yellow in PPV LB thin film can be easily confirmed under normal lighting even at low driving voltage. Polymer EL device using PPV LB thin film as emitter materials had a possibility to apply to next generation display device.

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Improvement of the Corrosion Fatigue Life of Metal Material by Shot Peening (쇼트피닝가공에 의한 금속재료의 부식피로수명 개선)

  • Nam Ji-Hun;Kou Dae-Lim;Lee Kook-Jin;Lee Dong-Sun;Cheong Seong-Kyun
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.716-721
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    • 2004
  • Corrosion highly affects to reduce lifetime and performance of machinery metallic components. The effects of shot peening on the fatigue life of metal material under corrosive environment are investigated in this paper. Experimental results show that the fatigue limit of shot peened specimen increases about 52$\%$. That means the fatigue life of metallic components is highly extended by shot peening. The corrosion greatly reduces the fatigue strength depending on the corrosive condition from one week up to one year. In case of shot peened specimen, the corrosion does not reduce the fatigue strength and fatigue life up to six months. It means that shot peening has superior effectiveness to reduce the influence of corrosion to the metallic materials.

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Catalytic Activity of Supported Rhodium(I) Complex for the Carbonylation of Nitrobenzene: Mechanism for Carbamate Formation

  • Kim, Jin-Hyung;Kim, Dae-Won;Cheong, Min-Serk;Kim, Hoon-Sik;Mukherjee, Deb Kumar
    • Bulletin of the Korean Chemical Society
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    • v.31 no.6
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    • pp.1621-1627
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    • 2010
  • The investigation of the catalytic activity of supported rhodium(I) complex [Rh(P-S)$(CO)_2$] (P-S; polymer anchored salicylic acid) toward the reductive carbonylation of nitrobenzene in DMF medium has been reported. Use of basic cocatalysts in the reaction medium enhanced the percentage of more useful phenyl carbamates. Spectroscopic studies indicate that the reaction proceeds through a dimer species [Rh(HS)(CO)(C(O)$OCH_3$)(${\mu}-OCH_3)]_2$ and phenyl isocyanate is formed as an intermediate. A plausible reaction mechanism based on the identification of reactive intermediates from the soluble rhodium variety has been proposed for the carbonylation process.

Morphological Characterization and Classification of Anuran Tadpoles in Korea

  • Park, Dae-Sik;Cheong, Seo-Kwan;Sung, Ha-Cheol
    • Journal of Ecology and Environment
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    • v.29 no.5
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    • pp.425-432
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    • 2006
  • The tadpoles of 12 Korean anuran species, including Bombina orientalis, Bufo gargarizans, B. stejnegeri, Hyla japonica, Kaloula borealis, Rana dybowskii, R. huanrenensis, R. coreana, R. nigromaculata, R. chosenica, R. rugosa, and R. catesbeiana, were classified based on their morphological characteristics. We collected eggs or tadpoles of the 12 Korean anuran species from Gangwon, Incheon, Chungcheong, and Gyeonggi districts in 2005 and 2006 breeding seasons. When the tadpoles reached at $27{\sim}37$ Gosner's developmental stages, we described morphological characteristics of the tadpoles of each anuran species and measured their physical parameters such as total length, body length, and body mass. After that, we chose 12 morphological characteristics to identify each species and to use them as classification keys such as eye location, caudal musculature pattern, spiracle location, oral disc morphology, and labial tooth row formula. In this paper, we presented classification keys, morphological characteristics, and drawings for the tadpoles of 12 anuran species.

A Technique for Removing Adjacent Induction Noise Mixed with Partial Discharge Signals of High Voltage Rotating Machines (고압 회전기 부분방전 신호에 혼합된 인접상 유도 잡음 제거 기법)

  • Youn, Young-Woo;Yi, Sang-Hwa;Hwang, Don-Ha;Choo, Young-Bae;Kang, Dong-Sik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.2
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    • pp.335-341
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    • 2009
  • Analysis of the partial discharge signal, a technique to diagnose the stator winding insulation is a key function for the diagnosis of high voltage rotating machines and requires high precision. To satisfy this requirement, various denoising techniques such as filtering and differential methods were proposed. However, these techniques can not eliminate a adjacent induction noise that decreases reliability of the diagnosis. A simple novel denoising algorithm, therefore, is proposed for removing the adjacent induction noise in this paper. The algorithm shows good performance in the real partial discharge signals measured by 13kV class capacitive couplers installed at hydro-generator in Dae-cheong Dam.