• Title/Summary/Keyword: Doo-Jong Kim

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Research for fabricating micro-size PMMA beads using Electro-hydrodynamic process (Electro-hydrodynamic 프로세스를 이용한 PMMA 마이크로 비드 제조방법에 대한 연구)

  • Park, Jong-Ha;Lee, Jun-Hee;Kim, Wan-Doo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1509-1514
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    • 2008
  • To fabricate microsized poly(methyl methacrylate)(PMMA) beads of uniform size and density on poly(ethylene terephthalate) (PET) fis, we introduce an electro spraying technique that uses a target electrode applied with an ac electric fid. Using the apparatus and various material properties, we could obtain uniform size PMMA beads which were deposited on the thin PET film. The optical properties, transmittance and light diffusivity of the fis electro sprayed with the PMMA were characterized. The results show that the sprayed beads appear to act as a good optical diffuser, like microlenses. To understand the effect of process variables, applied field conditions and rheological properties, the morphological pictures of the deposited particles were investigated through the optical and scanning electron microscope.

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Fabrication of a Dual-Gap Substrate Using the Replica-molding Technique for Transflective Liquid Crystal Displays

  • Kim, Yeun-Tae;Hong, Jong-Ho;Cho, Seong-Min;Lee, Sin-Doo
    • Journal of Information Display
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    • v.10 no.2
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    • pp.68-71
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    • 2009
  • A replica-molding method of fabricating a dual-gap substrate for transflective liquid crystal (LC) displays is demonstrated. The dual-gap substrate provides homeotropic alignment for the LC molecules without any surface treatment and embedded bilevel microstructure on one of the two surfaces to maintain different cell gaps between the transmissive and reflective subpixels. The proposed transflective LC cell shows no electro-optic disparity between two subpixels and reduces the panel thickness and weight by 30% compared to the conventional transflective LC cell, which has two glass substrates.

Electric Field Distribution Simulation of the Cable Joint Materials (케이블 접속재료의 전계분포 시뮬레이션)

  • Kim, Hyung-Joo;Byun, Doo-Gyoon;Shin, Jong-Yeol;Lee, Duk-Jin;Lee, Chung-Ho;Hong, Jin-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.601-604
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    • 2001
  • The insulation materials of cables used for underground power transmission requires a higher insulating capability. and the most popular method to examine the cable is partial discharge test due to applying variation voltage. In the thesis. air void. silicone oil. of which may possibly exist real cables. are simulated by Electra 2D program. Also the relations between calculated field strength and the void defect type in the cable joint materails. In the modeling. electic field inner to the cable joint material composed by XLPE and EPDM is modeling simulated. We obtained the electric field distribution in void due to two conditions.

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Dynamic Local-Partition Using VML in MMORPG (MMORPG에서 VML를 이용한 동적 지역분할)

  • Lee, Jeong-Jin;Won, Dong-Ki;Kim, Beob-Kyun;Doo, Gil-Soo;Ann, Dong-Un;Chung, Seung-Jong
    • Annual Conference of KIPS
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    • 2005.11a
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    • pp.1487-1490
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    • 2005
  • 오늘날의 MMORPG 환경에서 수만~수십만 명의 유저들이 동시 접속하여 게임을 즐기고 있다. 수많은 인원이 같은 맵 상에서 활동하기 때문에 최근의 게임시스템들은 맵의 영역에 따라 유저를 분할하여 처리하고 있다. 이를 위해 맵 분할 시스템에 대한 연구가 다양하게 이루어지고 있으나 기존 맵 분할 시스템은 유동적인 유저들에 대해 대처하기엔 문제점을 가지고 있다. 본 논문에서는 기존 맵 분할 방법들에 대한 구조적 단점을 보완하고, 부하에 능동적으로 대처할 수 있도록 VML를 이용한 동적 맵 분할 방법을 제안한다.

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State synchronization using MigAgent in Seamless Game (MigAgent를 이용한 Seamless 게임에서의 상태 동기화)

  • Won, Dong-Kee;Lee, Jeong-Jin;Kim, Beob-Kyun;Doo, Gil-Soo;Ann, Dong-Un;Chung, Seung-Jong
    • Annual Conference of KIPS
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    • 2005.11a
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    • pp.1495-1498
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    • 2005
  • 오늘날의 MMORPG 환경에서 수만${\sim}$수십만 명의 유저들이 동시 접속하여 게임을 즐기고 있다. 수많은 인원이 같은 맵 상에서 활동하기 때문에 최근의 게임 서버들은 맵의 영역에 따라 유저를 분할하여 처리하고 있다. 이를 위한 방안으로 Seamless 게임 서버 방식이 이슈가 되고 있으며 이 방식에서는 PC의 서버간 이동시 필연적으로 지연이 발생하게 된다. 본 논문에서는 이를 최소화하기 위해 MigAgent 를 이용하여 Field Server간 통신 및 PC와 Field Server간 통신을 효율적으로 관리하기 위한 방법을 제안한다.

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Purification and Glycosylation Pattern of Human L-Ferritin in Pichia pastoris

  • Lee, Jong-Lim;Yang, Seung-Nam;Park, Cheon-Seok;Jeoung, Doo-Il;Kim, Hae-Yeong
    • Journal of Microbiology and Biotechnology
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    • v.14 no.1
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    • pp.68-73
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    • 2004
  • Ferritin is an iron storage protein found in most living organisms. For expression and industrial use, human light chain ferritin (L-ferritin) was cloned from human liver cDNA library and expressed in Pichia pastoris strain GS115. The recombinant L-ferritin in Pichia pastoris was glycosylated. In a fed-batch culture, the cell mass reached about 57 g/l of dry cell weight, and the L-ferritin in the cell was increased to about 95 mg/l after 150 h. In an atomic absorption spectrometry analysis, the intracellular content of iron in the L-ferritin transformant was measured as $1,694{\pm}85\;\mu\textrm{g}g/g$, which is 5.4-fold more than that of the control strain. This L-ferritin transformant could serve as iron-fortified nutrients in animal feed stock.

Effect of Expanded Rice Husk Medium on Rice Seedling for Machine Transplanting

  • Ko Jonghan;Kim Doo Yeol;Sa Jong Gu;Lee Byun Woo;Lee Youn Su
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.1
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    • pp.55-59
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    • 2005
  • Rice farmers can save labor and expenses by using expanded rice husk (ERH) as a seedling medium since ERH is lighter and cheaper than other commercial seedling media (CSM). This study was carried out to develop a method for rice seedling cultivation using ERH as a seedling medium. It is suggested that a mixture of $60\%$ of ERH and $40\%$ of a CSM could be used as a seedling medium; the planting densities would be 240g per tray for infant seedlings and 200 g for young seedlings; and nitrogen (N) would be applied at a rate of 1g per tray for infant seedlings prior to planting and 2g per tray for young seedlings with division. Great care should be taken to use $CO(NH_2)_2$ as an N-source fertilizer. These results would lay a foundation for the rice seedling cultivation with ERH as a medium.

The Implementation of XML Web Service for Wireless Internet Platform Environment (무선 인터넷플랫폼 환경에서의 XML웹서비스구현)

  • Kwon, Doo-Wy;Kim, Jong-Ryul;Do, Kyeong-Hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.184-187
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    • 2007
  • XML웹서비스는 인터넷 상에서 표준화된 오픈 네트워크를 통해 기업내 및 기업 상호간의 모든 컴퓨터 시스템을 결합하려는 새로운 분산 컴퓨팅 패러다임으로서, 이를 통해 기업의 수익증대와 비용절감의 효과를 얻을 수 있을 것으로 기대된다. 특히 모바일 매쉬업을 위해서는 XML웹서비스의 처리가 필수적인데, 본 논문에서 개발한 WIPI 기반의 XML표준 기술과 모바일 웹서비스 표준 기술을 통해 이러한 응용 개발이 가능하며 이러한 XML웹서비스를 실현하는데 표준 기술에는 XML과 HTTP가 있다. 본 논문에서는 WIPI 환경에서 사용할 수 있는 간단한 XML 파서를 구현하고 HTTP 통신이 가능하도록 하여 XML 웹서비스의 서비스 개발에 적용함으로써 모바일 환경에서의 XML 웹서비스 인터페이스를 구현하였다. 또한 이에 대한 실제 응용으로서 WIPI용 Java언어를 기반으로 학사지원시스템에 적용하였다.

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Acitve Noise Control via Walsh Transform Domain Genetic Algorithm (월쉬변환영역 유전자 알고리즘에 의한 능동소음제어)

  • Yim, Kook-Hyun;Kim, Jong-Boo;Ahn, Doo-Soo
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.11
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    • pp.610-616
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    • 2000
  • This paper presents an active noise control algorithm via Walsh transform domain controller learned by genetic algorithm. Typical active noise control algorithms such as the filtered-x lms algorithm are based on the gradient algorithm. Gradient algorithm have two major problems; local minima and eigenvalue ratio. To solve these problems, we propose a combined algorithm which consist of genetic learning algorithm and discrete Walsh transform called Walsh Transform Domain Genetic Algorithm(WTDGA). Analyses and computer simulations on the effect of Walsh transform to the genetic algorithm are performed. The results show that WTDGA increase convergence speed and reduce steady state errors.

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Transform domain algorithm for Improving Convergence Speed of Broadband Active Noise Control (광대역 능동소음제어의 수렴속도개선을 위한 변환영역 알고리듬)

  • Ahn, Doo-Soo;Kim, Jong-Boo;Lee, Tae-Pyo;Yim, Kook-Hyun
    • Proceedings of the KIEE Conference
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    • 1998.07b
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    • pp.644-646
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    • 1998
  • The main drawback of filtered-X LMS(FXLMS) algorithm for the ANC of broadband noises is its low convergence speed when the filtered reference signals are strongly correlated, producing a large eigenvalue spread in correlation matrix. This correlation can be caused either by autocorrelation of the signals of the reference sensors, or by coupling between the error path which introduces intercorrelation in the filtered reference signals. In this paper, we introduce a transform domain FXLMS(TD-FXLMS) algorithm that has a high convergence speed by orthogonal transform's decorrelation properties.

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