• Title/Summary/Keyword: H.283

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A Design of DVR's Control Algorithm (DVR제어알고리즘 개발)

  • Lee, S.D.;Lee, S.J.;Kim, M.C.;Lee, H.W.;Kim, J.H.
    • Proceedings of the KIEE Conference
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    • 2001.05a
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    • pp.283-286
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    • 2001
  • 본 논문은 전력 품질개선장치인 DVR(Dynamic Voltage Restorer)시스템의 제어알고리즘 개발에 관한 것이다. DVR은 배전전계통에 직렬변압기를 통해 설치되어 전원의 순간전압강하(Voltage sag)를 보상하는 장치이며 전력변환장치 직렬변압기 에너지저장장치, 충전장치, 보호장치등으로 구성된다. 지락사고, 비선형부하의 순간투입, 뇌서지등 여러 요인에 의해 3상전원에서 발생하는 다양한 형태의 전압sag 보상이 가능한 제어알고리즘 모델을 제시하고 컴퓨터시뮬레이션을 통해 기본성능을 확인한 후 소형 DVR을 제작해 시험하였으며 이시험결과를 실 용량 DVR시제품의 설계에 이용하였다.

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A study on the design and manufacture technique for 765kV T/L pipe steel tower. (765kV 송전용 강관철탑설계 및 제조기술에 관한 연구)

  • Kim, J.B.;Lee, D.I.;Park, T.D.;Lee, I.H.;Shin, S.S.;Kim, H.R.
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.281-283
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    • 1993
  • We have studied and researched about the pipe steel tower. Which can be designed briefly with fewer members and due to electrical supported with single member economically and safely as higher structure and bigger load is required for 765kv T/L and it is difficult to transmit the electricity with good quality Safely and economically by the traditional steel tower composed of single angle.

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Study on the corrosion of A/C condenser in the ship (선박용 해수 열교환방식 A/C 응축기의 부식원인)

  • Baek, S.M.;Yang, J.H.;Kim, K.J.;Moon, K.M.;Lee, M.H.
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.283-284
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    • 2006
  • The ship performs heat exchange using seawater to keep main engine and auxiliary machinery at optimum temperature. In heat exchanger, refrigerant located outside of copper tube is cooled by seawater flowing through inside of copper tube. On the other hand, seawater erosion and corrosion nay occasionally cause the corrosion of the copper tube in A/C(Air Conditioner) condenser. This corrosion of copper tube makes seawater and refrigerant mixed, seriously damaging A/C system. In this study, accordingly, the exact ive mechanism of the corrosion on the condenser entailing serious problems occasional is investigated through the electrochemical polarization experiments on the condenser's component materials. According to the experiments, the corrosive procedures on the copper tube was verified by the fact that passive film of the copper tube surface which is destroyed by the pressure of sucked seawater, is damaged by the corrosive ingredients in the seawater.

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Effects of Composts and Soil Amendments on Physicochemical Properties of Soils in Relation to Phytophthora Root and Crown Rot of Bell Pepper

  • Kim, Ki-Deok;Nemec, Stan;Musson, George
    • The Plant Pathology Journal
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    • v.16 no.5
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    • pp.283-285
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    • 2000
  • Two field tests were conducted in 1995 to examine the effects of composts and soil amendments on physicochemical properties of soil in relation to Phytophthora root and crown rot of bell pepper. Chitosan, crab shell waste, humate, sewage sludge-yard trimmings, and wood chips were applied to test plots, some of which affected the levels of P, K, Mg, pH, and H. Physicochemical properties were not related with disease incidence, but percent organic matter, estimated nitrogen release, K, and Mg were correlated with total microbial activity. The elements K and Mg were especially responsible for the increased soil microbial activity that could affect development of root and crown rot of pepper.

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Electrical characteristics of 30MHz resonator using $PbTiO_3$ system ceramics ($PbTiO_3$계 세라믹스을 이용한 30MHz 레조네이터의 전기적특성)

  • Oh, D.O.;Yoo, J.H.;Park, C.Y.;Yoon, H.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05c
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    • pp.71-74
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    • 2002
  • In this study, resonant characteristics of $Pb_{0.88}(La_{0.6}Nd_{0.4})_{0.08}(Mn_{1/3}Sb_{2/3})_{0.02}Ti_{0.98}O_3$ ceramics were investigated with the variations of electrode radius size for manufacturing the best 30MHz SMD type ceramic resonator with the size of $3.7{\times}3.1{\times}0.255mm^3$. Physical properties were proper for appling for 30MHz SMD type ceramic resonator. In third overtone thickness vibration mode, with increasing electrode radius size, resonant resistant($Z_r$) was decreased gradually. Mechanical quality factor($Q_{mt3}$) and dynamic range(D.R) showed the maximum value of 2,283, 47.1dB respectively, at 0.74mm electrode radius size.

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A Study of Selection of Existing A.C. Transmission Facilities for Use with D.C. (기존 교류선로의 직류변환 송전방식에 있어서 선정기법에 관한 연구)

  • Kim, D.J.;Moon, Y.H.;Lee, D.I.;Yoon, J.Y.;Yang, K.H.
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.283-285
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    • 2002
  • The paper describes a study of selection of existing a.c. Transmission facilities converted fur use with d.c. system. In order to increasing the power transfer capability of existing a.c. transmission facilities, d.c. is one of good alternatives. Some advantages and disadvantages of this method are discussed, and the selection method of existing transmission facilities for use with d.c. considering economics and stability is presented in this paper.

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Egg Development and Mitotic Interval (τ0) in Black Plaice, Pleuronectes obscurus (Herzenstein)

  • Park, In-Seok;Im, Soo-Yeon
    • Fisheries and Aquatic Sciences
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    • v.13 no.4
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    • pp.278-283
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    • 2010
  • Black plaice, Pleuronectes obscurus (Herzenstein), were collected and fertilized to observe egg development, temperature-related cleavage rates, and mitotic intervals (${\tau}_0$). Fertilized egg was demersal, adhesive, and did not contain oil globules. After 1.75 h, the blastodisc formed, and hatching took place 121 h after fertilization at $14^{\circ}C$. The hatched larvae were $3.5{\pm}0.16\;mm$ in total length. At higher temperatures, eggs developed faster and underwent further identical developmental processes. Additionally, ${\tau}_0$ and water temperature were strongly negatively correlated at all temperatures (Y=-2.6981X+98.767, $R^2$=0.9831, where Y is ${\tau}_0$, and X is temperature) for black plaice.

Identification of hemolysin as one of the important virulent factors in vibrio anguillarum V7

  • Choe, Young-Chool;Jeong, Gajin
    • Journal of Microbiology
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    • v.33 no.4
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    • pp.283-288
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    • 1995
  • We have identified hemolysin rendering virulency of Vibrio anguilarum grown at 23.deg.C which was evaluated on human RBCs. Hemolysin itself was separated as a single band on non-denaturing gel electrophoresis. Vibrio hemolysin was destroyed by trypsin and proteinase K and was heat labile. Optimal pH for activity was around pH 6 while pI of the molecule was recognized as 5.7, with relative distance (R$\sub$f/) on non-denaturing gel was 0.7. Addition of EDTA and FeCI$\sub$3/ drew the possibility that the production of hemolysin was mainly induced to overcome iron deficiency inside host animalsd infection.

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Effect of reduction Temperature on the Skeletal Isomerization of iso-butene over Pt/MoO3/SiO2 Catalyst (환원온도가 Pt/MoO3/SiO2 촉매에서 iso-butene 의 골격 이성질화반응에 미치는 영향)

  • Cho Sae Jung;Kim Seong Mi;Kim Dong Hei;Kim Seong-Soo;Kim Jin Gul
    • Proceedings of the KAIS Fall Conference
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    • 2004.11a
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    • pp.280-283
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    • 2004
  • Effect of H2 spillover rate as function of reduction temperature on reaction kinetics was evaluated. Reaction kinetics including yield, conversion, activation energy and selectivity of 1-butene isomerization over Pt/HxMoO/SiO were measured as reaction temperature was increased. While conversion of 1-butane was decreased, yield of iso-butene was increased. Two kinds of reaction mechanism were proposed from the change of selectivity as function of temperature.

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A Study on the Light Stimulus of Organic Thin Films (유기박막의 광 자격에 관한 연구)

  • 김성진;이경섭
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.283-286
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    • 2000
  • In this paper, generation form of displacement current was compared and measured induce monolayers which 8A5H with Pure azobenzene. Light response of two monolayers which compared and measured though they are the same isomer. The experimental results are as following; In case of ultraviolet($\lambda_1$) and visible($\lambda_2$) irradiation on 8A5H induce monolayers depositioned on board the peak of current was detected about 10[fA]. but light irradiation on pure azobenzene any particular reaction for detailed. This is the reason of hydrophobicity construct in molecule structures its molecule dynamic behaviour in cis and trans was not due to activated.

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