• Title/Summary/Keyword: Byung-cheon Park

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Comparative Study on Performance of Grid-Connected Photovoltaic Modules in Tropical Monsoon Climate under Thailand condition (태국 열대몬순기후 조건에서 PV모듈 기술별 성능특성 비교 연구)

  • Kim, Seung Duck;Koh, Byung Euk;Park, Jin Hee;Cheon, Dae In
    • New & Renewable Energy
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    • v.10 no.3
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    • pp.39-46
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    • 2014
  • The performances of three different types of photovoltaic (PV) module technologies namely, copper-indium-diselenide (CIGS), mono-crystalline silicon (mo-Si) and amorphous silicon (a-Si) have been comparatively studied in the grid-connected system for more than a year under the tropical monsoon climate of Thailand. The yields, performance ratios and system efficiencies for the respective PV module technologies have been calculated and a comparison is presented here. The performance ratios of the initial operation year for CIGS showed highest among the compared technologies under Thailand climate conditions by marking 97.0% while 89.6% for a-Si and 81.5% for mo-Si. Although mo-Si has shown highest efficiencies all over the period, under the testing conditions, the operating efficiency of mo-Si was down-graded from its reference value mainly due to high operating temperature and the efficiency of the tested CIGS module was also found as high as that of mo-Si in the study. Accordingly, outdoor assessment shows that CIGS modules have demonstrated high performance in terms of yields and performance ratios in Thailand climate conditions.

Pipe Support Modeling & Fabrication Drawing Generation on GSCAD (Pipe Support Modeling 및 제작도 작성 GSCAD 적용 사례)

  • Min, Byung-Cheon;Park, Jung-Hyun;Kang, Young-Min;Kim, Eun-Sub
    • Special Issue of the Society of Naval Architects of Korea
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    • 2009.09a
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    • pp.40-46
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    • 2009
  • The GSCAD (Global Shipbuilding CAD) System used in Samsung Heavy Industries is based on the Relation and Rule. The design area where excellence of these Relation & Rule can be used fully is pipe support modeling. That's because, many rules are required to place a pipe support and it's supported by hull structural object. Samsung Heavy Industries has been customizing the Relation and Rule supported by SmarMarine3d(R) to model pipe support easily and satisfies standard. Also, the pipe support fabrication drawing program was developed to generate a drawing for the pipe support customized. This paper reviews the characteristics of pipe support modeling on GSCAD and the Rules customized also, fabrication drawing program will be introduced.

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Robust Active LED Driver with High Power Factor and Low Total Harmonic Distortion Compatible with a Rapid-Start Ballast

  • Park, Chang-Byung;Choi, Bo-Hwan;Cheon, Jun-Pil;Rim, Chun-Taek
    • Journal of Power Electronics
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    • v.14 no.2
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    • pp.226-236
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    • 2014
  • A new active LED driver with high power factor (PF) and low total harmonic distortion (THD) compatible with a rapid-start ballast is proposed. An LC input filter is attached to the ballast to increase PF and reduce THD. A boost converter is then installed to regulate the LED current, where an unstable operating region has been newly identified. The unstable region is successfully stabilized by feedback control with two zeroes. The extremely high overall system of the 10th order is completely analyzed by the newly introduced phasor transformed circuits in static and dynamic analyses. Although a small DC capacitor is utilized, the flicker percentage of the LED is drastically mitigated to 1% by the fast controller. The proposed LED driver that employs a simple controller with a start-up circuit is verified by extensive experiments whose results are in good agreement with the design.

Extracardiac Uptake of Thallium-201 during Myocardial Perfusion Imaging with Pharmaeologic Vasodilation (심근관류 스캔중에 나타난 Thallium-201의 심장외 국소적 섭취)

  • Choi, Chung-Il;Kwak, Dong-Suk;Chung, Byung-Cheon;Park, Moo-Keun;Lee, Jae-Tae;Lee, Kyu-Bo
    • The Korean Journal of Nuclear Medicine
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    • v.26 no.1
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    • pp.65-71
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    • 1992
  • Myocardial perfusion imaging with $^{201}Tl-chloride$ following exercise or vasodilator-induced hyperemia has been effective in detecting the presence of coronary artery disease. An increased lung uptake of thallium has been reported as a sensitive marker of severe and extensive coronary artery disease and associated with poor prognosis. Thallium has also been noted to concentrate in a variety of malignant lesions. We report 5 cases of extracardiac uptake of thallium during myocardial perfusion scan with pharmacologic vasodilation. Accumulation of thallium was found in the lesions of a breast cancer, a lung cancer, a Castleman's disease and 2 cases of thymoma. We believe that the presence of focal extracardiac uptake of thallium during myocardial perfusion scan should suggest the need for further clinical evaluation to detect the tumor and must differentiate the increased lung uptake of thallium due to left ventricular dysfunction in coronary artery disease.

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Automated Molding Design Methodology to Optimize Multiple defects in Injection Molded Parts

  • Park, Jong-Cheon;Kim, Byung H.
    • International Journal of Precision Engineering and Manufacturing
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    • v.1 no.1
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    • pp.133-145
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    • 2000
  • Plastic molding designers are frequently faced with optimizing multiple defects in injection molded parts. these defects are usually in conflict with each other, and thus a tradeoff needs to be made reach a final compromised solution. In this study, an automated injection molding design methodology has been developed to optimize multiple defects of injection molded parts. Two features of the proposed methodology are as follows: one is to apply the utility theory to transform the original multiple objective optimization problem into single objective optimization problem with utility as objective function, the other is an implementation of a direct search-based injection molding optimization procedure with automated consideration of process variation. The modified complex method is used as a general optimization tool in this research. The developed methodology was applied to an actual molding design and the results showed that the methodology was useful through the CAE simulation using a commercial injection molding software package. Applied to production, this study will be of immense value to industry in reducing the product development time and enhancing the product quality.

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In-Situ Observation of New Extra-Vascular Threadlike Structure of Mouse Using a Fluorescence Stereoscopic Microscope

  • Sung, Baeck-Kyoung;Lee, Ja-Woong;Lee, Byung-Cheon;Johng, Hyun-Min;Baik, Ku-Youn;Nam, Tae-Jeong;Park, Dae-Hun;Soh, Kyeong-Sun;Soh, Kwang-Sup
    • Journal of Pharmacopuncture
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    • v.7 no.3
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    • pp.73-76
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    • 2004
  • We report the new threadlike structures outside the blood vessels of mice. For this, we developed an in-situ searching method of the structure by vital staining with the dye of acridine orange and using a fluorescent stereomicroscope designed specifically for this purpose. We consider that the newly found threadlike structure might be rediscovery of the extra-vascular Bonghan duct which was reported in 1963 by Bonghan Kim.

Molecular Characterization and Mitogenic Activity of a Lectin from Purse Crab Philyra Pisum

  • Na, Jong-Cheon;Park, Byung-Tae;Chung, Woo-Hyuk;Kim, Ha-Hyung
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.4
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    • pp.241-244
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    • 2011
  • A lectin from the hemolymph of purse crab, Philyra pisum, was found to have anti-proliferative activity on human lung cancer cells by our laboratory. In this study, P. pisum lectin (PPL) was molecularly characterized including molecular mass, amino acid sequences, amino acid composition, and the effects of metal ions, temperature, and pH on the activity. We found that PPL showed mitogenic activity on human lymphocytes and BALB/c mouse splenocytes. The mitogenic activity (maximum stimulation index, $SI=9.57{\pm}0.59$) of PPL on human lymphocytes was higher than that of a standard well-known plant mitogen, concanavalin A (maximum $SI=8.80{\pm}0.59$). The mitogenic activity mediated by PPL is required for optimum dosing, and higher or lower concentrations caused decreases in mitogenic response. PPL also induced mitogenic activity on mouse splenocytes, however, the maximum SI ($1.77{\pm}0.09$) on mouse splenocytes of PPL was lower than that ($2.14{\pm}0.15$) of concanavalin A. In conclusion, PPL is a metal ion-dependent monomer lectin with mitogenic activity, and could be used as a lymphocyte or splenocyte stimulator.

Liquidity and Mechanical Properties of Concrete by Fluidity Retention Agent Mix Rate Change (유지제 혼입율 변화에 따른 콘크리트의 유동성 및 역학적 특성)

  • Park, Byung-Kwan;Choi, Sung-Yong;Pei, Chang-Chun;No, Dong-Hyun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.11a
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    • pp.89-92
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    • 2008
  • This research analyzed the basic characteristics of unhardened concrete and the compression strength characteristics of hardened concrete according to liquidity retention agent mix rate change to improve the liquidity fluidity retention performance of high performance concrete, and produced the following results. The moment fluidity retention agent is added according to fluidity retention agent mix rate change, which increased fluidity retention agent mix rate, slump flow decreased, and in the case of slump flow according to the progress time change by the fluidity retention agent mix rates, the more fluidity retention agent mix rate increased, the lower slump flow change rate became. The moment fluidity retention agent is added according to fluidity retention agent mix rate change, fluidity retention agent mix rate increased compared to non-mixture of fluidity retention agent, and the air amount by progress time change by the fluidity retention agent mix rates slightly increased, however target range is still met and unit volume mass is inversely proportional to air amount. Compression strength according to age progress by the fluidity retention agent mix rates was shown to increase slightly with increase in fluidity retention agent mix rate, and yet the difference was not significant.

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Electrical performance and contact resistance with the substrate temperature in the pentacene organic thin-film transistors

  • Lee, Cheon-An;Jang, Kyoung-Chul;Kim, Sung-Won;Ryoo, Ki-Hyun;Jin, Sung-Hun;Lee, Jong-Duk;Shin, Hyung-Cheol;Park, Byung-Gook
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1317-1319
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    • 2005
  • Bottom contact pentacene organic thin-film transistors are fabricated at three different substrate temperatures, $70^{\circ}C$, $80^{\circ}C$ and $90^{\circ}C$. The maximum effective mobility was obtained at $80^{\circ}C$. The contact resistance was extracted by applying two different methods, TLM method and channel-resistance method, and the value shows the minimum at $80^{\circ}C$, which is thought to be the important reason for the best performance.

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High voltage MOSFET fabricated by using a standard CMOS logic process to drive the top emission OLEDs in silicon-based OELDs

  • Lee, Cheon-An;Kwon, Hyuck-In;Jin, Sung-Hun;Lee, Chang-Ju;Lee, Myung-Won;Kyung, Jae-Woo;Cho, Il-Whan;Lee, Jong-Duk;Park, Byung-Gook
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.981-983
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    • 2003
  • Using the conventional standard CMOS logic process, the high voltage MOSFET to drive top emission OLEDs was fabricated for the silicon-based organic electroluminescent display. The drift region of the conventional high voltage MOSFET was implemented by the n-well of the logic process. The measurement result shows a good saturation characteristic up to 50 V without breakdown phenomena.

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