• Title/Summary/Keyword: Doo-Jong Kim

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A Study on Analysis of Distributed Parameter Systems via Fast Walsh Transform (고속 월쉬 변환을 이용한 분포정수계의 해석에 관한 연구)

  • Kim, Tai-Hoon;Kim, Jin-Tae;Chae, Young-Moo;Lee, Hae-Gi;Kim, Jong-Boo;Ahn, Doo-Soo
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2084-2086
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    • 2001
  • This study uses distributed parameter systems as the spatial discretization technique, modelling in lumped parameter systems, and applies orthogonal transform and the Picard's iteration method to high order partial differential equations and matrix partial differential equations. In exercising optimal control of distributed parameter systems, excellent consequences are found without using the existing decentralized control or hierarchical control method.

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Inhibitory Action of Phenylpropanoids on Arthus Reaction, Plaque Forming Cells and Hemagglutinin titer

  • Lee, Ji-Yun;Kim, Youn-Joung;Lee, Jin-Hee;Kim, Tae-Doo;Sim, Sang-Soo;Kim, Chang-Jong
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.195.1-195.1
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    • 2003
  • Many kinds of phenylpropanoids(PP), C6-C3 compounds, are widely distributed in many plants. In this experiments, effect of PP on sheep red bood cells (sRBC)-induced Arthus reaction (AR) were studied in ICR male mice. SRBC were challenged by i.p. injection two weeks after sensitization of Lp. injection of sRBC. Five days after the challenge of antigen, paw edema induced 3 hours after the last challenge by AR. (omitted)

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Inhibitory Action of Cinnamic Acid Derivatives on Reversed Cutaneous Anaphylasis and Hemolysin Titer

  • Kim, Tae-Doo;Lee, Ji-Yun;Kim, Youn-Joung;Lee, Jin-Hee;Sim, Sang-Soo;Kim, Chang-Jong
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.196.1-196.1
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    • 2003
  • Cinnamic acid derivatives(CAD) originating from vegetable kingdom have some biological activity. Effect of CAD on reversed cutaneous anaphylaxis (RCA) and hemolysin (HY) titer were studied in rats. Experiments were carried out to determine RCA as the skin edema induced at 2 hours after injection of 0.05 $m\ell$/site of anti-rat serum rabbit serum. Drugs were orally administered at one hour before antigen challenge. (omitted)

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Inhibitory Action of Phenylpropanoids on Histamine Release from Rat Peritoneal Mast Cells

  • Lee, Jin-Hee;Lee, Ji-Yun;Kim, Youn-Joung;Kim, Tae-Doo;Yoon, Mi-Yun;Sim, Sang-Soo;Kim, Chang-Jong
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.194.1-194.1
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    • 2003
  • Phenylpropanoids originating from vegetable kingdom have some biological activity. In this experiments, effect of phenylpropanoids on the histamine release from mast cells were studied in vitro. Rat peritoneal mast cells were isolated by the discontineous gradients of Percoll and their histamine release by stimulation of compound 48/80 and A23187 at a concentration of 6.0 $\mu\textrm{g}$/$m\ell$ were determined. (omitted)

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Analysis of Thermal Characteristics for the Fire Risk Assessment According to Partial Disconnection on the VCTF and IV Electric Wire (VCTF와 IV전선의 반단선에 의한 화재위험성 평가를 위한 열적특성 해석)

  • Kim, Doo-Hyun;Kim, Sung-Chul;Lee, Jong-Ho;Park, Jong-Young;Park, Young-Ho;Lee, Hyung-Jun
    • Journal of the Korean Society of Safety
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    • v.23 no.4
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    • pp.47-52
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    • 2008
  • Many researches on fire risk for normal electric wiring have been pursued in advanced countries such as the USA and Japan, but comparative studies of the partial disconnection and normal state of electric wires have not been conducted. Detection system for the cause of partial disconnection is not developed and prevention countermeasure for electrical fire by the cause is not effective. Therefore, in this paper, partial disconnection characteristics on electric wires were derived and analyzed by experiment and electrical-thermal finite element method(Flux 3D) on the model wires which consist of VCTF(PVC insulated PVC sheathed Cap Tyre Flexible Cord, KS C 3304) and IV(lndoorwire PVC, KS C 3302). VCTF is used in wiring portable electric appliances and the IV is used indoors. Interrelationships between partial disconnection premonitory symptom and current were derived and analyzed by the characteristics based on experiments and thermal analysis for electric wire according to current under normal state and 200% overload state of rated current.

Preparation of Bipolar Plate for Fuel Cell Using CNT/Graphite Nano-Composite

  • Choi, Jong-Min;Kim, Tae-Jin;Hyun, Min-Soo;Peck, Dong-Hyun;Kim, Sang-Kyung;Lee, Byung-Rok;Park, Jong-Soo;Jung, Doo-Hwan
    • Carbon letters
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    • v.6 no.3
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    • pp.181-187
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    • 2005
  • Bipolar plates require some specific properties such as electrical conductivity, mechanical strength, chemical stability, and low permeability for the fuel cell application. This study investigated the effects of carbon nanotube (CNT) contents and process conditions of hot press molding on the electrical and physical properties using CNT 3~7 wt% added graphite nano-composites in the curing temperatures range of 140~$200^{\circ}C$ and pressure of 200~300 kg/$cm^2$. Bulk density, hardness and flexural strength increased with increasing CNT contents, curing pressure and temperature. With the 7 wt% CNT added noncomposite, the electrical resistance improved by 30% and the flexural strength increased by 25% as compared to that without CNT at the temperature of $160^{\circ}C$ and pressure of 300 kg/$cm^2$. These properties were close to the DOE reference criteria as bulk resistance of 13 $m{\Omega}cm$ and tensile strength of 515 kg/$cm^2$.

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Stability Analysis of the Ignition Coil using Partial Discharge (부분방전법을 이용한 점화코일의 안정도 해석)

  • Park, Hee-Doo;Kim, Tag-Yong;Shin, Hyun-Taek;Kim, Weon-Jong;Shin, Jong-Yeol;Hong, Jin-Woong
    • Journal of the Korean Society of Safety
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    • v.21 no.1 s.73
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    • pp.53-58
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    • 2006
  • This paper has been addressed on the discharge characteristics of the ignition coil by Weibull function. It analyzed discharge number and amount of discharge using Weibull distribution to know the inter-relationship between partial discharge and mileage. We detected the discharge which happens for 10 seconds. The applied voltage increased by 0.5[kV] at discharge inception voltage. We diagnosed failure rate using the shape parameters. As a result, we confirmed that the failure rate was increased, because the shape parameter showed the value of 5 according to increasing mileage degradation. Also, it is considered to increase the degradation of inner insulator of ignition coil. Because failure rate of virgin was increased from 0[%] to 25[%] after degradation, stability analysis of the ignition coil using Weibull analysis is possible.

Oenanthe javanica extract accelerates ethanol metabolism in ethanol-treated animals

  • Kim, Jong-Yeon;Kim, Ki-Hoon;Lee, Youn-Ju;Lee, Seung-Ho;Park, Jong-Cheol;Nam, Doo-Hyun
    • BMB Reports
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    • v.42 no.8
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    • pp.482-485
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    • 2009
  • The effect of water dropwort (Oenanthe javanica DC) extract in eliminating ethanol was evaluated in New Zealand white rabbit and ICR mice. When a hot-water extract of water dropwort extract and ethanol was injected into New Zealand white rabbit, the plasma ethanol level was rapidly reduced, similar to metadoxine treatment. Specifically, the n-butanol fraction of hot-water extract was the strongest in eliminating plasma alcohol in ICR mice. When ethanol was orally ingested, administration of the hot-water extract eliminated up to 44% of the plasma ethanol in mice while the n-butanol fraction eliminated around 70%. Alcohol removal behaved in a dose-dependent manner in response to 50-200 mg/kg of n-butanol fraction. These data show O. javanica extract is effective in overcoming alcohol intoxication by the accelerating ethanol metabolism.

NUMERICAL METHOD FOR TWO-PHASE FLOW ANALYSIS USING SIMPLE-ALGORITHM ON AN UNSTRUCTURED MESH (비정렬격자 SIMPLE 알고리즘기반 이상유동 수치해석 기법)

  • Kim, Jong-Tae;Park, Ik-Kyu;Cho, Hyung-Kyu;Kim, Kyung Doo;Jeong, Jae-Jun
    • Journal of computational fluids engineering
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    • v.13 no.4
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    • pp.86-95
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    • 2008
  • For analyses of multi-phase flows in a water-cooled nuclear power plant, a three-dimensional SIMPLE-algorithm based hydrodynamic solver CUPID-S has been developed. As governing equations, it adopts a two-fluid three-field model for the two-phase flows. The three fields represent a continuous liquid, a dispersed droplets, and a vapour field. The governing equations are discretized by a finite volume method on an unstructured grid to handle the geometrical complexity of the nuclear reactors. The phasic momentum equations are coupled and solved with a sparse block Gauss-Seidel matrix solver to increase a numerical stability. The pressure correction equation derived by summing the phasic volume fraction equations is applied on the unstructured mesh in the context of a cell-centered co-located scheme. This paper presents the numerical method and the preliminary results of the calculations.

An integrated elastomer substrate with a lens array and pixel elements for three-dimensional liquid crystal displays

  • Hong, Jong-Ho;Kim, Yeun-Tae;Kim, Yun-Hee;Lee, Byoung-Ho;Lee, Sin-Doo
    • Journal of Information Display
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    • v.13 no.2
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    • pp.55-59
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    • 2012
  • In this paper, a concept of an integrated elastomer substrate for a three-dimensional (3D) liquid crystal display based on the integral-imaging method is presented. The elemental lens array and columnar spacers were integrated into one of the two substrates, an elastomer substrate, through an imprinting process. The integrated elastomer substrate was capable of maintaining the uniform liquid crystal (LC) cell gap and promoting homeotropic LC alignment without any surface treatment. The monolithic approach reported herein will provide a key component for 3D displays with enhanced portability through a more than 40% weight reduction compared with the conventional integral-imaging method.