• Title/Summary/Keyword: Lee Bum Sung

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Success Rate Analysis in GPS Attitude Determination Using a Unscented Kalman Filter (GPS반송파를 이용한 자세결정에서 UKF적용을 통한 성공률 변화 분석)

  • Kwon, Chul-Bum;Chun, Se-Bum;Lee, Eun-Sung;Kang, Tae-Sam;Jee, Gyu-In;Lee, Young-Jae
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.3
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    • pp.222-227
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    • 2005
  • Resolving the integer ambiguity of GPS carrier phase measurements is the most important routine in precise positioning. In this paper, success rate is analyzed when using baseline information in the process of determining attitude. The result is verified through the simulation. Determining the initial position for the ambiguity resolution is estimated by using code measurement and baseline constraint. Success rate is estimated using covariance of the formed initial position. UKF has been used to overcome the nonlinear baseline condition during the process so that the higher success rate has been obtained compared with the general attitude determination.

A Study on Expansion of Back Fire Limit Equivalence Ratio of the Hydrogen Fueled Engine (수소기관의 역화한계당량비 확장에 관한 연구)

  • Paik, Sung Ho;Park, Jae Bum;Kim, Yun Young;Lee, Jong Tae
    • Transactions of the Korean hydrogen and new energy society
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    • v.8 no.3
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    • pp.111-119
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    • 1997
  • In this study, feasibility of expansion of BFL equivalence ratio are examined with change of injection location of hydrogen gas in intake pipe, coolant temperature, spark timing and amount of residual gas. As the results, BFL equivalence ratio is increased when injection location has some distance from intake valve. And it is decreased in accordance with increasing of coolant temperature and advance of spark timing. The amount of residual gas has little effect on BFL equivalence ratio.

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Characteristic Comparison with respect to Doubly salient Types (이중돌극기의 종류에 따른 특성 비교)

  • Kim, Youn-Sung;Jin, Chang-Sung;Kim, Seung-Joo;Lee, Ho-Joon;Kim, Koung-Bum;Lee, Ju;Jung, In-Sung
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.766_767
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    • 2009
  • Generally, the Doubly Salient Machine such as Switched Reluctance Motor doesn't have Permanent Magnet, it sometimes adopts permanent magnet or DC filed winding for high efficiency or adjustable speed control. In this paper, adjustable speed range is compared for Doubly Salient Permanent Magnet Machine (DSPM), Brushless Doubly Fed Doubly Salient Machine (BDFDS) and Hybrid Excited Doubly Salient Machine (HEDS). Especially, air-gap flux density to the DC field current is shown and the operating speed as the field-weakening is estimated.

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Highly Efficient Phosphorescence Emitting Materials and Applications to Organic Light Emitting Diode

  • Sung, Lee-Bum;Yun, Jung-Sang;Nam, Byun-Ki;Sung, Yu-Han;Lee, Yoo-JIn;Kim, Sung-Hyun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1143-1146
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    • 2005
  • Novel series of electron-transporting hosts, pentavalent aluminum complexes containing 8 hydroxyquinoline ligands and various phenolato ligands were synthesized, and organic light-emitting diodes (OLEDs) were fabricated using these complexes as host materials of phosphorescent emitting device and the fabricated phosphorescent emitting device showed low driving voltage, high efficiency at high current density and good stability under conventional driving condition.

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Studies on the Conducting Cells in the Haustorium of Cuscuta australis R. Brown (실새삼(Cuscuta australis R. Brown) 흡기(吸器)에서의 통도세포(通導細胞)에 관한 연구)

  • Lee, Kyu-Bae;Park, Jong-Bum;Lee, Chai-Doo
    • Applied Microscopy
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    • v.17 no.1
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    • pp.161-168
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    • 1987
  • The elongated filamentous haustorial cells, hyphae, of Cuscuta australis R. Brown penetrated into the vascular tissues of the host plant Trifolium repens L. were studied by the light and electron microscopes. The hyphae reached the host xylem were invaded into the host vessels and then they grew within the host vessels. Finally these hyphae were differentiated into the water conducting elements, xylary hyphae, by thickening of the secondary walls. The hyphae reached the host phloem were branched at the apical regions. These hyphae possessed thin-layered cytoplasm involving the typical features of sieve elements such as the parallel arrays of smooth endoplasmic reticulum, plastids with the clusters of fine starch granules, and mitochondria with the dilated cristae. It was indicated that these hyphae were differentiated into the nutrients conducting elements, phloic hyphae. The structures described were compared with those of other parasitic plants and were discussed in view of the translocation of materials from host to parasite.

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