• Title/Summary/Keyword: Choi Dong Hoon

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A Study on Correction of Airborne Laser Scanning Intensity Data (항공레이저스캐닝(ALS) 반사강도의 보정에 관한 연구)

  • Shin, Dong-June;Chang, Hoon;Choi, Nak-Hoon
    • 한국공간정보시스템학회:학술대회논문집
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    • 2005.05a
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    • pp.267-272
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    • 2005
  • 최근 항공레이저스캐닝(ALS)은 높은 정확도와 경제성을 이유로 지형정보를 획득하는 탁월한 수단으로 주목받고 있다. ALS에 의해 수집되는 고도자료는 DSM, DEM 제작에 유용하게 이용된다. ALS는 고도자료 이외에 지표면의 물질적 특성을 나타내는 반사강도를 획득한다. 그러나 반사강도는 노이즈로 인해 널리 이용되지 못하고 있으며, 노이즈의 주원인은 반사각으로 알려져 있다. 따라서 본 연구는 센서 위치정보와 ALS 고도자료를 이용하여 반사각을 이용하여 반사강도를 보정하는 방법을 제안하였다 여기에는 ${\theta}$의 각도로 입사한 레이저의 강도는 수직으로 입사한 레이저의 강도보다 $sin{\theta}$만큼 감소한다는 물리학적 원리가 이용되었다 반사각은 지표면과 레이저가 이루는 각으로, 센서와 측정점 사이의 각과 지표면의 경사각의 두 단계로 나누었다. 방법의 적합 여부를 확인하기 위해 적외선 영역에서 분리도가 잘 이루어지는 아스팔트, 휴경지(토양), 콘크리트, 수목의 네 가지 검증영역을 선정하여 보정된 반사강도와 보정 전의 반사강도를 비교하였다. 모든 영역에서 반사강도가 증가하였으며 특히 콘크리트와 수목에서의 증가가 두드러졌다. 보정을 통해 네 영역에서 반사강도의 분리도가 향상됨을 물론 그 크기가 '아스팔트<토양<콘크리트<수목'으로 나타나는 이론적인 경향과 유사함을 확인할 수 있다.

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Irrational Belief and Psychopathology of Highschool Students (고등학교(高等學校) 재학생(在學生)들의 비합리적(非合理的) 신념(信念)과 정신병리(精神病理))

  • Kim, Sang-Hoon;Choi, Hoon-Dong;Kim, Hack-Ryul
    • Korean Journal of Psychosomatic Medicine
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    • v.3 no.1
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    • pp.28-38
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    • 1995
  • The purpose of this study is to investigate the relationship between irrational belief and psychopathology. The Korean version of Symptom Check List-90-R and Irrational Belief Test were administered to 621 high school students in group. The author used Pearson correlation coefficiency and multiple regression analysis to seek the regression patterns of the irrational belief. The results were as follows. 1) Most of the subscales of the SCL-90-R and Irrational Belief Test were correlated significantly. 2) In multiple regression analysis, the irrational belief associated with anxious overconcern was the most predictable variable for psychopathology.

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Evaluation of Optimal Transfer Capability in Power System interconnection (연계된 계통간의 최적 송전용량 산정)

  • Son, Hyun-Il;Choi, Ah-Reum;Lee, Sung-Hoon;Kim, Jin-O;Jeon, Dong-Hoon
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.195_196
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    • 2009
  • As the electrical power industry is restructured, the electrical power exchange is becoming extended. One of the key information used to determine how much power can be transferred through the network is known as available transfer capability (ATC). To calculate ATC, traditional deterministic approach is based on the severest case, but the approach has the complexity of procedure. Therefore, novel approach for ATC calculation is proposed using cost-optimization method in this paper, and is compared with well-being method and risk-benefit method. This paper proposes the optimal transfer capability of HVDC system between mainland and a separated island in Korea through these three methods. These methods will consider production cost, wheeling charge through HVDC system and outage cost with one depth (N-1 contingency).

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PHOTOINDUCED PHASE TRANSITION BEHAVIOR OF LIQUID CRYSTALLINE COPOLYMERS CONTAINING AZO CHROMOPHORE

  • Kang, Suk-Hoon;Samui, Asit-Baran;Choi, Dong-Hoon
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.04a
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    • pp.28-31
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    • 1998
  • Photoresponsive polymers are being intensely investigated over last two decades, which can be attributed to both fundamental and applied significance. Presently the attention is being directed to these materials in view of their possible application in nonlinear optics and optoelectronics. It was demnstrated quite early that by covalent fixation of both photochromic group and the mesogenic group to the same polymer main chain high concentration of photochromic group can be attained.(omitted)

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Hybrid Passivation for Organic-Thin Film Transistor on Plastic

  • Han, Seung-Hoon;Kim, Yong-Hee;Kim, Sung-Hoon;Kim, Chang-Hyun;Jeon, Tae-Woo;Lee, Sun-Hee;Choi, Min-Hee;Choo, Dong-Jun;Jang, Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.979-982
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    • 2008
  • We studied hybrid passivation using parylene-C, metal, photoacyl and indium zinc oxide for pentacene OTFT to assure stability in subthreshold region. After the passivation, the changes in S and $V_{on}$ of OTFT were negligible and $I_{off}$ maintained its initial value of ${\sim}10^{-12}$ A. Therefore, the hybrid passivation is suitable for practical applications based on OTFT.

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플라스틱 미세 성형 기술과 생물학적 응용

  • Jung, Chan-Il;Jang, Jun-Geun;Han, Dong-Chul;Na, Kyung-Hwan;Park, Hoon-Jae;Choi, Tae-Hoon;Kim, Seung-Soo;Cho, Han-Sang;Jung, Seok;Kim, Joong-Kyung;Lee, Yong-Gu;Park, Jun-Ha
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.05a
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    • pp.6-6
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    • 2004
  • 마이크로 / 나노 바이오 기술은 생명공학 및 의약기술의 발전을 가능하게 하고 생체시스템 관련 연구를 위한 마이크로 및 나노 기기를 제작할 수 있게 함으로써 새로운 기술적 영역으로 부각되고 있다. 이러한 기술은 1990년대 초에 랩온어칩(Lab-on-a-chip)의 개발을 가능하게 하였다. 랩온어칩은 실험실(Lab)을 하나의 소자(Chip)에 올려놓는다(On)는 말로 쉽게 설명된다. 즉, 생물학이나 생화학 실험실에서 주로 연구되는 단백질, 세포 등 인체에 영향을 주는 다양한 물질들이 체내외에서 나타내는 반응을 쉽게 검출, 분석하는 일련의 과정들을 빠르고 정확하게 수행할 수 있도록 도와주는 도구인셈이다.(중략)

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High-transmittance Multi-domain Vertical Alignment Liquid Crystal Device with Protrusion Structure

  • Kim, Ki-Han;Jeon, Eun-Young;Park, Byung Wok;Choi, Sun-Wook;Song, Dong Han;Kim, Hoon;Shin, Ki-Chul;Kim, Hee Seop;Yoon, Tae-Hoon
    • Journal of the Optical Society of Korea
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    • v.16 no.2
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    • pp.166-169
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    • 2012
  • We propose a high-transmittance multi-domain vertical alignment liquid crystal device with a protrusion structure. Disclination lines, which inevitably appear at the boundaries of domains in a multi-domain structure, can be reduced by adding a protrusion structure on the top substrate. The transmittance was improved by 11% using the proposed structure with no change of either the dark state or the operating voltage.

Synthesis and Photoisomerization Properties of Polynorbornenes with Azobenzene Chromophores

  • Kang, Suk-Hoon;Shin, Hee-Deuk;Oh, Cha-Hwan;Choi, Dong-Hoon;Park, Ki-Hong
    • Bulletin of the Korean Chemical Society
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    • v.23 no.7
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    • pp.957-963
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    • 2002
  • We successfully synthesized the addition-type polynorbonenes (PNB) exhibiting photochromic properties and excellent thermal stability. Three norbornene-based monomers with different azobenzene moiety (R=NO2, H,OCH3) were synthesized by transesterification method. The corresponding PNB copolymers were synthesized by transition metal-catalyzed addition polymerization method, and characterized by GPC, UV-Vis spectroscopy, NMR, and thermal analysis. For comparison of the photochromic properties depending on the rigidity of polymer backbone, we prepared the polymethylmethacrylate (PMMA) copolymer with the corresponding azobenzene moiety. We investigated the photoisomerization behavior by means of optical muitichannel analyzer with Xe lamp as well as real-time UV-Vis spectroscopy with high-pressure mercury lamp. Among three PNB copolymers, a polymer with azobenzene (R=H) was the most adaptable for observation of photoisomerization behavior. It was found that the rate of photoisomerization and relaxation depended on the structure of azobenzene chromophore, rather than that of polymer backbone.

Threshold Voltage Shift in (4-pentylphenylethynyl)-dithienyl-anthracene Organic Thin-film Transistor with Self-assembled Monolayer

  • Lee, Sun-Hee;Kim, Sung-Hoon;Han, Seung-Hoon;Choi, Min-Hee;Jeong, Yong-Bin;Choo, Dong-Joon;Jang, Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.858-860
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    • 2009
  • We have applied self-assembled monolayer to make high performance and stable OTFT on the organic gate dielectric. The ${\beta}$-phenethyltrichlorosilane (SAM) was coated on the organic gate dielectric and then active layer was printed. Significant improvements in on-currents and threshold voltage shift were achieved for the SAM treated devices compared to device without SAM.

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