• Title/Summary/Keyword: Sung Bong Park

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Current Status of KASI Solar Radio Observing System

  • Bong, Su-Chan;HwangBo, Jung-Eun;Park, Sung-Hong;Jang, Be-Ho;Lee, Chang-Hoon;Baek, Ji-Hye;Cho, Kyung-Suk;Park, Young-Deuk;Gary, Dale E.;Lee, Dae-Young
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.82.1-82.1
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    • 2011
  • Korea Astronomy and Space Science Institute (KASI) operates 2 solar radio observing facilities, e-CALLISTO (Earthwide network of Compound Astronomical Low-cost Low-frequency Instrument for Transportable Observatory) station and Korean Solar Radio Burst Locator (KSRBL). Although e-CALLISTO tracking system improvement.is underway, at least 6 new events were observed in this year. Software development for KSRBL is in progress. The antenna calibration software was updated and flux calibration software was developed. Also the automatic daily overview spectrum monitoring system is now operational. We found solutions to several problems including spurious data and FPGA board communication. However, a few minor unsolved hardware problems still persist. Meanwhile, at least 6 new events were observed by KSRBL in this year, and a comparative study with HXR is currently underway.

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Ni-Grain Size Dependent Growth of Vertically Aligned Carbon Nanotubes by Microwave Plasma-Enhanced Chemical Vapor Deposition and Field Emission Properties

  • Choi, Young-Chul;Jeon, Seong-Ran;Park, Young-Soo;Bae, Dong-Jae;Lee, Young-Hee;Lee, Byung-Soo;Park, Gyeong-Su;Choi, Won-Bong;Lee, Nae-Sung;Kim, Jong-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.231-234
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    • 2000
  • Vertically aligned carbon nanotubes were synthesized on Ni-coated Si substrates using microwave plasma-enhanced chemical vapor deposition. The grain size of Ni thin films was varied with the RF power density during the RF magnetron sputtering process. It was found that the diameter, growth rate, and density of carbon nanotubes could be controlled systematically by the grain size of Ni thin films. With decreasing the grain size of Ni thin films, the diameter of the nanotubes decreased, whereas the growth rate and density increased. High-resolution transmission electron microscope images clearly demonstrated synthesized nanotubes to be multiwalled. The number of graphitized wall decreased with decreasing the diameter. Field emission properties will be further presented.

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Mechanisms Underlying the Effects of LPS and Activation-induced Cytidine Deaminase on IgA Isotype Expression

  • Park, Seok-Rae;Kim, Hyun-A;Chun, Sung-Ki;Park, Jae-Bong;Kim, Pyeung-Hyeun
    • Molecules and Cells
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    • v.19 no.3
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    • pp.445-451
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    • 2005
  • Activation-induced cytidine deaminase (AID) is needed for Ig class switch recombination (CSR). We explored the effect of LPS on the expression of AID during B cell differentiation, and the role of AID in IgA isotype expression. In normal spleen B cells, LPS increased AID transcription up to 48 h post-stimulation, i.e. around the time of Ig CSR. TGF-${\beta}1$ and AID were required for IgA expression, and LPS contributed to $TGF{\beta}1$-induced IgA production largely by inducing AID. Interestingly, LPS repressed AID transcription in $sIgA^+$ B cells but still stimulated IgA production mainly by increasing the rate of IgA secretion. Our data indicate that LPS contributes to $TGF{\beta}1$-induced IgA isotype expression in at least two ways: by stimulating AID transcription before CSR and by enhancing the IgA secretion rate after CSR.

Radiation Heat Flux and Combustion Characteristics of Inverse Diffusion Flame Burner Using Synthesis Gas, Part 1 : Air-Fuel Combustion (합성가스를 이용한 역확산버너의 연소 및 복사열전달 특성, Part 1 : 공기-연료 연소)

  • Lee, Pil-Hyong;Park, Chang-Soo;Lee, Jae-Young;Park, Bong-Il;Hwang, Sang-Soon;Lee, Sung-Ho;Anh, Yong-Soo
    • Journal of the Korean Society of Combustion
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    • v.14 no.4
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    • pp.33-40
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    • 2009
  • Waste Thermal Pyrolysis Melting process was proposed and has been studied in order to prevent air pollution by dioxin and fly ash generated from combustion process for disposal of waste. In this study, applicability as the fuel of diffusion burner of synthesis gas formed from Waste Thermal Pyrolysis process was addressed. Results showed that there is no big difference in the flame shape between MNDF and SNDF, and lift off was detected in MIDF but flame is more stable in SIDF which contains hydrogen with high combustion velocity as flow rate in first nozzle is increased. And radiation heat flux in inverse diffusion flame of synthesis gas was found to be more by 1.5 times than that in inverse diffusion flame of methane because of higher mole fraction of $CO_2$ with high emissivity in product gas.

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Comparison between Superconducting Thin Films Fabricated by Using the Sputtering and the Evaporation Method (스퍼터링 법과 증발 법으로 제작한 초전도 박막의 비교)

  • Cheon, Min-Woo;Park, No-Bong;Yang, Sung-Ho;Park, Yong-Pil;Kim, Hye-Jeong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.04a
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    • pp.39-42
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    • 2004
  • The $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin film fabricated by using the sputtering method was compared with the $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin film fabricated by using the evaporation method. In doing the ultra-low deposition because each element can exist on the substrate surface, both the sputtering method and the evaporation method could easily fabricate single phase of the Bi2212 phase. Also, it is cofirmed that by optimizing the deposition condition, each single phase of the Bi2201 phase and the Bi2212 phase can be fabricated, the sticking coefficient of Bi element is clearly related to the changing of substrate temperature and the formation of the Bi2212 phase.

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Burst Locating Capability of the Korean Solar Radio Burst Locator (KSRBL)

  • Hwangbo, Jung-Eun;Bong, Su-Chan;Park, Sung-Hong;Lee, Dae-Young;Cho, Kyung-Suk;Lee, Jaejin;Park, Young-Deuk
    • Journal of Astronomy and Space Sciences
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    • v.32 no.1
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    • pp.91-99
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    • 2015
  • The Korean Solar Radio Burst Locator (KSRBL) is a solar radio spectrograph observing the broad frequency range from 0.245 to 18 GHz with the capability of locating wideband gyrosynchrotron bursts. Due to the characteristics of a spiral feed, the beam center varies in a spiral pattern with frequency, making a modulation pattern over the wideband spectrum. After a calibration process, we obtained dynamic spectra consistent with the Nobeyama Radio Polarimeter (NoRP). We compared and analyzed the locations of bursts observed by KSRBL with results from the Nobeyama Radioheliograph (NoRH) and Atmospheric Imaging Assembly (AIA). As a result, we found that the KSRBL provides the ability to locate flaring sources on the Sun within around 2'.

An Efficient Software Reliability Testing Method for the Model based Embedded Software (모델 기반 내장형 소프트웨어의 효율적 신뢰성 시험 기법)

  • Park, Jang-Seong;Cho, Sung-Bong;Park, Hyun-Yong;Kim, Do-Wan;Kim, Seong-Gyun
    • Journal of the Korea Society for Simulation
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    • v.27 no.1
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    • pp.25-32
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    • 2018
  • This paper presents an efficient software reliability testing method for the model based auto-generated code and reify a dynamic test procedure. The benefits of executing the model-based each static/dynamic reliability test before the code-based static/dynamic reliability test are described. Also, The correlations of code/model based reliability test are demonstrated by using model testing tool, Model Advisor and Verification and Validation, and the code testing tool, PolySpace and LDRA. The result of reliability test is indicated in this paper.

Dual Sink Nodes for Sink Node Failure in Wireless Sensor Networks (무선 센서 네트워크에서의 싱크노드 실패에 대비한 이중 싱크노드 장치)

  • Kim, Dae-Il;Park, Lae-Jeong;Park, Sung-Wook;Lee, Hyung-Bong;Moon, Jung-Ho;Chung, Tae-Yun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.6
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    • pp.369-376
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    • 2011
  • Since wireless sensor networks generally have the capability of network recovery, malfunction of a few sensor nodes in a sensor network does not cause a crucial problem paralyzing the sensor network. The malfunction of the sink node, however, is critical. If the sink node of a sensor network stops working, the data collected by sensor nodes cannot be delivered to the gateway because no other sensor nodes can take the place of the sink node. This paper proposes a TDMA-based wireless sensor network equipped with dual sink nodes, with a view to preventing data loss in the case of malfunction of a sink node. A secondary sink node, which synchronizes with a primary sink node and receives data from other sensor nodes in normal situations, takes the role of the primary sink node in the case of malfunction of the primary sink, thereby eliminating the possibility of data loss. The effectiveness of the proposed scheme is demonstrated through experiments.

Modulation of Kex2p Cleavage Site for In Vitro Processing of Recombinant Proteins Produced by Saccharomyces cerevisiae

  • Mi-Jin Kim;Se-Lin Park;Seung Hwa Kim;Hyun-Joo Park;Bong Hyun Sung;Jung-Hoon Sohn;Jung-Hoon Bae
    • Journal of Microbiology and Biotechnology
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    • v.33 no.11
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    • pp.1513-1520
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    • 2023
  • Kex2 protease (Kex2p) is a membrane-bound serine protease responsible for the proteolytic maturation of various secretory proteins by cleaving after dibasic residues in the late Golgi network. In this study, we present an application of Kex2p as an alternative endoprotease for the in vitro processing of recombinant fusion proteins produced by the yeast Saccharomyces cerevisiae. The proteins were expressed with a fusion partner connected by a Kex2p cleavage sequence for enhanced expression and easy purification. To avoid in vivo processing of fusion proteins by Kex2p during secretion and to guarantee efficient removal of the fusion partners by in vitro Kex2p processing, P1', P2', P4, and P3 sites of Kex2p cleavage sites were elaborately manipulated. The general use of Kex2p in recombinant protein production was confirmed using several recombinant proteins.

Summer Algal Flora of Dadohae National Park, Southwestern Coast of Korea (한국 남서해안 다도해 해상국립공원의 하계 해조상)

  • Park, Chan-Sun;Lee, Kon-Woong;Cho, Yong-Sung;Kim, Gwang-Bong;Oh, Jang-Geun;Hwang, Eun-Kyoung
    • Korean Journal of Environmental Biology
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    • v.27 no.3
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    • pp.252-260
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    • 2009
  • The summer algal flora and community of 9 islands in Dadohae National Park, southwestern coast of Korea, were investigated from June to September 2008. A total of 81 species (13 green, 22 brown and 46 red algae) of marine algae were identified. Among 9 islands, the number of species observed was the highest as 65 species at Jindo and the least as 37 species at Hongdo. The dominant species were Enteromorpha compressa, Ulva pertusa, Sargassum thunbergii, Gelidium amansii, Caulacanthus okamurae, Gloiopeltis furcata, and Symphyocladia latiuscula. The algal zonation of intertidal zone was figured out by Gloiopeltis furcata, Ishige okamurae, Caulacanthus okamurae-Enteromorpha compressa, Sargassum thungergii-Gelidium amansii, Symphyocladia latiuscula from upper to lower zone. The flora investigated could be classified into six functional groups such as coarsely branched form (38.1%), filamentous form (24.7%), sheet form (11.3%), thick leathery form (13.9%), jointed calcarious form (6.3%) and crustose form algae (5.7%). R/P and (R+C)/P values were 2.2 and 2.8, respectively. A cluster analysis of species occurrence was suggested that the number of marine algal species was different from greatly among the sampling sites.