• 제목/요약/키워드: Kim Sang-Ik

검색결과 1,128건 처리시간 0.041초

Preparation and characterization of nanosized hollow silica in the presence of aluminum isopropoxide

  • Nguyen, Ngoc Anh Thu;Kim, Hyun-Ik;Kim, Sang Hern
    • 한국응용과학기술학회지
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    • 제33권3호
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    • pp.421-427
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    • 2016
  • Nanosized hollow silica was prepared by $St{\ddot{o}}ber$ method in the presence of aluminum isopropoxide. The mixture of polyelectrolytes such as poly(sodium 4-styrene sulfonate)(PSS) and polyacrylic acid(PAA) were used as templates. Tetraethylorthosilicate(TEOS) and aluminum isopropoxide were used as precursors for silica and alumina, respectively. The function of aluminum isopropoxide is to increase the porosity of silica shell. The characterizations of hollow silica were examined by TEM(transmission electron microscopy), TGA(thermogravimetric analysis), BET(Brunauer Emmett Teller), Energy-dispersive X-ray spectroscopy(EDS), and FT-IR spectrum. It was found that the shell thickness of hollow silica was around 8 nm and the core diameter was around 20 nm by TEM.

Apparatus and Method of Visual Lifetime Measurement of Organic Light Emitting Devices

  • Yang, Yong-Suk;Chu, Hye-Yong;Oh, Ji-Young;Lee, Jeong-Ik;Kim, Gi-Heon;KoPark, Sang-He;Hwang, Chi-Sun;Kim, Mi-Kyung;Do, Lee-Mi;Chung, Sung-Mook;Ko, Young-Wook
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.623-624
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    • 2004
  • The coating and estimation of gas and moisture barriers on polymer and glass substrates are receiving very much attention in passivation of organic light emitting devices (OLEDs). In this study, the encapsulation and lifetime measurement techniques of OLEDs were presented. The degradation mechanisms of bare and encapsulated OLEDs were investigated by the visual lifetime measurement (VLM) system with the parameters such as a pixel luminance(L), a luminance rms roughness(dL), a brightness area ratio(R), an edge degradation depth(D), etc.

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Box-Behnken법을 이용한 매입형 영구자석 동기전동기의 회전자 구조 최적설계 (Optimal Design of the Rotor Structure by using Box-Behnken Method for IPMSM)

  • 한정호;김원호;장익상;김미정;이기덕;이재준;이주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.949-950
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    • 2011
  • There are various ways of optimizing rotor design of Interior Permanent Magnet Synchronous Motors(IPMSM). In this paper, the best optimized design value was found by varying the Bridge thickness of PM in the rotor and changing Rib. The set design values were torque, 5 harmonics, 7 harmonics, and safety factor. Also, in order to make practical design value easily and quickly for optimization, Box-Behnken of Response Surface Method(RSM) method was used. Therefore, IPMSM resulted an optimized design model with high torque, low harmonics, and constant value of safety factor.

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매입형 영구자석 동기 전동기의 파라미터 측정법 비교 (A Comparison of parameters measurement of IPMSM)

  • 장익상;김원호;김미정;이기덕;이재준;이주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.832-833
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    • 2011
  • Interior Permanent Magnet Synchronous Motor (IPMSM) produces two kind of torque that Magnetic and Reluctance torque. The permanent magnet linkage flux and d-axis and q-axis inductances have an important influence on the torque characteristic of IPMSM. Thus their accurate prediction is essential for predicting performance aspect such as the torque and flux-weakening capabilities. In this paper, is calculated by LC resonance method with FEM. The results are validated by comparison the calculated by another method.

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집중권 IPMSM의 고속 운전을 위한 연구 (Study on High Speed Operation of IPMSM with Concentrated Winding)

  • 이기덕;김원호;장익상;김미정;이재준;이주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.854-855
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    • 2011
  • In this paper, Interior permanent magnet synchronous motor(IPMSM) with concentrated winding for 110cc electric motorcycle is introduced. Optimum design is performed so as to satisfy wide speed operation range. And output characteristics is analyzed according to shoe height in many variables. Because partial magnetic saturation in shoe affects the harmonics, output characteristics of motor could be confirmed that a significant change. As a result, the new shape and the optimal design parameters considering the partial magnetic saturation is obtained. Compared with the base model, wide operating range was confirmed.

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영구자석 형상에 따른 전기 스쿠터용 IPMSM 특성 고찰 (Study of IPMSM characteristic for electric scooter according to the shape of permanent magnet)

  • 김미정;김원호;장익상;이기덕;이재준;한정호;정태철;채웅찬;이주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.856-857
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    • 2011
  • 최근 레저와 이동수단으로 전기를 이용한 스쿠터와 자전거가 많이 연구 개발되고 있다. 이러한 어플리케이션에 사용되는 모터의 경우은 설계 및 제어 비용이 저렴하면서도 소음이 작고, 출력밀도와 효율이 요구가 된다. 대부분의 경우 BLDC가 전동기 및 제어기 제작 단가가 저렴하여 자전거 및 스쿠터의 전기 추진용으로 많이 사용되었지만 소음 및 효율등의 성능면에서는 요구사항을 만족하지 못하고 있다. 이러한 단점을 보완하기 위해서 현재 출력밀도와 효율이 높은 IPMSM이 많이 연구 개발되고 있다. 본 논문에서는 전기 스쿠터용 IPMSM의 영구자석 형상에 따른 특성을 연구하였다.

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동맥류를 동반한 양측성 관상동맥-폐동맥루의 외과적 교정 - 1예 보고 - (Surgical Treatment of Bilateral Coronary to Pulmonary Artery Fistulae with a Saccular Aneurysm - A case report -)

  • 김상익;김병훈;노정섭
    • Journal of Chest Surgery
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    • 제40권12호
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    • pp.851-854
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    • 2007
  • 흉부 압박감과 심계항진, 흉통을 주소로 내원한 76세 여자 환자로 동맥류를 동반한 양측성 관상동맥-폐동맥루로 진단되었다. 수술은 심폐우회 및 심정지하에 이루어 졌는데 주폐동맥 주변의 동정맥루 혈관 및 동맥류 절제 그리고 폐동맥 내부에서 동정맥루의 출구를 봉합하였다. 술 후 결과는 양호하였으며 문헌고찰과 함께 보고한다.