• Title/Summary/Keyword: Byung-cheon Park

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Power Amplifier Compensation Technique based on Tapped Delayed Neural Networks (시간지연 신경망을 이용한 기지국용 전력증폭기의 보상기법)

  • HwangBo, Hoon;Nah, Wan-Soo;Yang, Youn-Goo;Park, Cheon-Seok;Kim, Byung-Sung
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2327-2329
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    • 2005
  • In this paper, we identify the memory effects of the RF high-power base station amplifiers with Vector Signal Analyzer (VSA). It is found that the model of power- amplifier using Tapped Delayed Neural - Networks with back-propagation algorithm shows very accurate modeling performance. Based on this behavioral modeling, we conducted inverse compensation process which also uses Neural Networks.

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Improvement of Early age Concrete Strength Using Blast Furnace Slag Powder (콘크리트의 초기강도 향상을 위한 고로슬래그 미분말의 사용에 관한 실험적 연구)

  • Yoo, Jang-Won;Lee, Ju-Sun;Park, Byung-Kwan;Pei, Chang-Chun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.05b
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    • pp.77-80
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    • 2009
  • The purpose of the study was to examine engineering characteristics due to fine particle cement and gypsum contents to improve early strength of concrete substituted blast furnace slag powder. The results were as follows. Above all, For fluidity, generally all mixtures had lower fluidity than Plain mixture and was not satisfied target scope, but for mixture substituted the gypsum showed a little increasing trend. For air content, generally all mixtures compared to Plain mixture had decreasing tendency. However, all mixtures were satisfied target scope. For compressive strength, long-term strength was better than early strength according to ternary blast furnace slag contents was increased. For complex mixture was better than individual use of gypsum and fine particle cement.

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Evaluation of Crack Control Performance of the Concrete with Fiber Combination (섬유혼입 조건에 따른 콘크리트의 균열제어 성능 평가)

  • Park, Jae-Yong;Lee, Myoung-Ho;Kang, Byung-Hoi;Kim, Kyoung-Hoon;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.11a
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    • pp.21-22
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    • 2013
  • Nowadays, the fiber which mixed with concrete matrix always has low adhesion with cement paste. It's difficult to use fiber to reinforce the structure. For more adding fiber in concrete would cause some problems as the low flowability and surface polishing. Further study is needed in fiber using. In this research, further study in fiber reinforced concrete has been invested. Various fibers with different properties have been used to prevent cracking. Fiber reinforced concrete's fundamental properties as slump, air content, compressive strength and tensile strength have been tested. Optimum type of the fiber and optimum addition ratio of fiber has been invested to increase the utility of the fiber which used in concrete.

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A Study on the Roadside Slope of the Parkway in Chi-Ri Mountain National Park (智異山 國立公園 道路비탈면에 對한 조사 硏究)

  • Seo, Byung-Soo;Kim, Sei-Cheon;Lee, Chang-Heon;Park, Choung-Min;Lee, Kyu-Wan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.18 no.3 s.39
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    • pp.39-56
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    • 1990
  • The purpose of this study is to analyze the roadside slope of mountainous Parkway. 48 sites were selected by Random Ranking Sampling. This study was researched on the slope condition with the cause of occurrence, the situation of fundamental engineering works and vegetation on slopes. The main results of this research are summarized as follow ; 1. Slope shapes are shown nine types in cut slope and four types in fill slope. 2. Generally, fill slopes are larger than cut slopes in slop area. 3. Grade is more steep than standard grade. 4. Main engineering works, which constructed for slope stability, are terracing, side-ditch wall, channel, concrete trellis works and wire fence. 5. Roundabout channel were many constructed within the sector of Ukmojeong-Deokdong, but were few constructed within the sector of Banseon-Seongsam pass and Cheoneun Temple-Seongsam pass. 6. Most. of side-ditch wall were constructed of concrete and wet-masonry. 7. In vegetation works, many exterior species were selected. 8. Planting pattern was not combinated with the national park landscape.

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Lips Detection by Probability Map Based Genetic Algorithm (확률맵 기반 유전자 알고리즘에 의한 입술영역 검출)

  • Hwang Dong-Guk;Kim Tae-Ick;Park Cheon-Joo;Jun Byung-Min;Park Hee-Jung
    • The Journal of the Korea Contents Association
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    • v.4 no.4
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    • pp.79-87
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    • 2004
  • In this paper, we propose a probability map based genetic algorithm to detect lips from portrait image. The existing genetic algorithm used to get an optimal solution is modified in order to get multiple optimal solutions for lips detection. Each individual consists of two chromosomes to represent coordinates x, y in space. Also the algorithm introduce a preserving zone in the population, a modified uniform crossover, a selection without individual duplication. Using probability map of H, 5 components, the proposed algorithm has adaptability in the segmentation of objects with similar colors. In experiments, we analyzed relationships of primary parameters and found that the algorithm can apply to the detection of other ROIs easily

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Modeling of pentacene MIS capacitors with admittance measurements and the effects of dispersive charge transport

  • Jung, Keum-Dong;Lee, Cheon-An;Park, Dong-Wook;Park, Byung-Gook;Shin, Hyung-Cheol;Lee, Jong-Duk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.67-69
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    • 2006
  • Capacitance and loss values of pentacene MIS capacitors with different thicknesses are measured as a function of frequency for the modeling of the devices. The equivalent circuit for the ideal MIS capacitor is adopted to model the obtained admittance, so the values of $C_i,\;C_d,\;C_b$, and $R_b$ are determined for each pentacene thickness. In the loss curve, broader loss peaks are observed in measurement than the modeling results regardless of the pentacene thickness. By considering the effects of dispersive charge transport in bulk semiconductor, more accurate modeling results are obtained.

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Performance improvement in bottom-contact pentacene organic thin-film transistors by the PMMA layer insertion

  • Lyoo, Ki-Hyun;Kim, Byeong-Ju;Lee, Cheon-An;Jung, Keum-Dong;Park, Dong-Wook;Park, Byung-Gook;Lee, Jong-Duk
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1139-1141
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    • 2006
  • For the bottom-contact pentacene organic thin-film transistors (OTFTs), the insertion of a thin PMMA layer $(20{\AA})$ between the pentacene and the electrode improves the electrical performances, such as carrier mobility and on-current magnitude, about 4 times larger than those of the devices without the PMMA. The performance enhancement is presumably due to the decreased contact resistance between metal and pentacene by inserting the thin PMMA layer.

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Triple Layer Passivation for Organic Thin-Film Transistors

  • Ryoo, Ki-Hyun;Lee, Cheon-An;Jin, Sung-Hun;Jung, Keum-Dong;Park, Chang-Bum;Lee, Jong-Duk;Shin, Hyung-Cheol;Park, Byung-Gook
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1310-1312
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    • 2005
  • Passivation of organic thin-film transistors (OTFTs) using organic and metal thin-film was presented. Parylene-C and titanium were used as an organic and metal layer, respectively. With the proposed passivation method the degradation of electric parameters of OTFTs was relieved compared with non-passivated devices. Several electric parameters such as on/off current, field-effect mobility, and threshold voltage were shown.

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Quality Changes in Concrete According to the Number of Use of Aluminum Form Surface Coating Material (알루미늄 거푸집 표면코팅재의 전용횟수에 따른 콘크리트의 품질변화)

  • Lee, Il-Sun;Park, Byung-Kwan;Baek, Dae-Hyun;Park, Jae-Soon;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.05b
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    • pp.123-126
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    • 2009
  • This study is analyzed the effects of the number of use of aluminum form surface coating material on surface quality of concrete. The results can be summarized as follows. Surface roughness showed larger values with increase in the number of use. Values were larger in UP and AL compared to PE. While found to have bad influence on concrete surface quality, PA and W showed most excellent values for roughness. The number of surface pores increased with increasing number of use, and the number of pores on concrete surface was reduced by applying a remover. In terms of type of surface coating material, PA and W showed smallest number of pores in comparison to PE. In order to comprehensively improve surface quality of concrete, parallel use of PA coating material and remover is deemed most appropriate.

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Correlation Analysis Study Between Spent Mushroom Substrate and Microbial Community (수확 후 버섯 배지와 미생물 군집의 상관관계 분석 연구)

  • In Kyu Lee;Hyun Seung Kim;Ji Min Woo;Won Jun Chang;Eun Jeong Byeon;Ki Byung Park;Youn Su Lee
    • The Korean Journal of Mycology
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    • v.52 no.1
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    • pp.61-71
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    • 2024
  • Next-generation sequencing of shiitake, oyster, and king oyster spent mushroom substrates collected from Chun-cheon, Yeo-ju, Hong-cheon, Gwang-ju, Ui-ryeong, and A-san was performed. Metabarcoding analysis using amplicon sequence variants was performed to confirm the microbial content ratio in the medium after harvesting the collected mushrooms; the ratio of the contents of various microorganisms in the medium after mushroom harvest varied depending on the materials added to produce the mushroom medium. The WPGMA analysis of the similarity between microbial communities, which was based on the β-diversity, confirmed that the microbial communities in the substrates of the different mushroom varieties were similar.