• Title/Summary/Keyword: YoungChu

검색결과 773건 처리시간 0.037초

구조체 보호를 위한 고내화성 마감재 적용에 관한 실험적 연구 (Development of Inorganic Fire Protection Materials for High Strength Concrete)

  • 정석조;송훈;권춘우;김영엽;추용식;이종규
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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    • pp.885-888
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    • 2006
  • Nowaday, High strength concrete(HSC) has been mainly used in high rise building. HSC have superior property as well as improvement in durability compared with ordinary strength concrete. In spite of durability of HSC, explosive spalling in concrete front surface near the source of fire occurs serious problem in structural safety. Thus, this study is concerned with experimentally investigation fire resistance of the inorganic fire protection materials at high temperatures up to $800^{\circ}C$. From the test result, developed inorganic binder becomes general that with rising temperature the compressive strength of the material increases in tendency. Therefore, the results indicate that it is possible to fireproof panels, fire protection of materials, etc.

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$SO_3$ 함량 및 Sand Sulrry 입도조절에 따른 경량기포콘크리트(ALC)의 물리적 특성 (Improvement in Fundamental Properties of ALC Using $SO_3$ Ratio's and Sand Sulrry)

  • 김영엽;이종규;송훈;추용식;권춘우;정석조
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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    • pp.749-752
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    • 2006
  • Autoclaved lightweight concrete (ALC) have high water absorption, low compressive strength and popout the origin of the low surface strength in its properties. These properties make troubles under construction such as cracking and popout. Thus, this study is to improve the fundamental strength by control of $SO_3$ ratio's and Sand Sulrry grain size. From the test result, Improved ALC have a good fundamental properties. Compressive strength, and abrasion's ratio were improved depending on increasing $SO_3$ ratio's and Sand Sulrry grain size control.

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무전극 황방전등에서 고압 이원자 황($S_2$)의 자체 역전 효과 (Self Reversal Effect of the High-pressured Diatomic Sulfur in the Electrodeless Sulfur Discharge Lamp)

  • 추장희;구선근;박기준;이영우
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제49권11호
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    • pp.609-615
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    • 2000
  • A prototype electrodeless sulfur lamp was developed and investigated the spectroscopic characteristics. The emission spectra of $S_2$ in the microwave-discharged eletrodeless sulfur lamp (ESL) were studied at various input power. The emission spectra of the ESL shift to longer wavelength with increasing of the input power. We have shown that this is due to the self reversal effect in the high pressure gas discharge. We also show that the self reversal effect increases as the rotation of the discharged bulb. The spectral distribution of the ESL shifts about 45 nm toward visible region from UV region due to the rotation of the lamp bulb.

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서브 나노초 상승시간의 고전압 펄스 발생용 피킹 스위치 (A Peaking Switch to Generate a High Voltage Pulse of Sub-nanosecond Rise Time)

  • 노영수;진윤식;조주현;임수원
    • 전기학회논문지
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    • 제61권9호
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    • pp.1300-1305
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    • 2012
  • A triaxial Blumlein pulse forming line has been designed to generate a pulse whose voltage is ~300 kV, pulse duration is ~5 ns, and rise time is ~500 ps. It turns out, however, that the rise time of the pulse becomes much longer than 500 ps due to parasitic inductances and capacitances existing inside the system. A peaking switch has been developed to shorten the rise time of the pulse from Blumlein pulse forming line. In the peaking switch, a wedge-shaped dielectric material (MC 901 nylon) is employed to surround the electrode on the antenna side. This shape inhibits an abrupt change of the output impedance, thereby minimizing the reflection of the output pulse. Experimental results show that the peaking switch is capable of improving the rise time of the pulse at a level of 500 ps.

장애인을 위한 사용자 의도 파악 시스템 개발에 관한 연구 (Development of Intention Reading System for the Disabled)

  • 이영진;추길환;김재헌;정명진
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 G
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    • pp.3018-3020
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    • 1999
  • 본 논문에서는 손과 발을 자기의 의지대로 움직일 수 없는 장애인들이 전동 휠체어나 로봇 팔과 같은 보조 장치를 손, 발의 사용 없이 조작 할 수 있는 시스템 개발을 위한 연구에 대해서 소개한다. 손과 발을 사용하지 않고 전동 휠체어나 로봇 팔을 조작하려면 장애인의 의도를 파악하고 이 정보에 의한 구동 방식이 필요하게 된다. 본 연구에서는 장애인의 눈동자의 움직임과 머리의 움직임 그리고 음성 신호를 이용하여 보조 장치들을 구동시키고자 한다. 이를 구현하기 위해서는 시선의 방향을 측정할 수 있는 기술과 머리의 위치와 방향을 측정하는 기술, 그리고 음성으로 표현되는 간단한 명령들을 인식할 수 있는 기술이 필요하며, 이러한 기술의 통합을 바탕으로 보조장치들을 구동시키기 위한 편리한 사용자 지향의 인터페이스 기술을 개발하고자 한다.

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ZnO를 이용한 air-gap 형태의 FBAR 소자 제작에 대한 연구 (A study of air-gap type FBAR device fabrication using ZnO)

  • 박성현;이순범;신영화;이능헌;이상훈;추순남
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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    • pp.1414-1415
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    • 2006
  • Air-gap type film bulk acoustic wave resonator device using ZnO for piezoelectric layer and sacrifice layer, deposited by RF magnetron sputter with various conditions, fabricated in this study. Also, membrane$(SiO_2)$ and top and bottom electrode(both Al) of piezoelectric layer deposited by RF magnetron sputter. Using micro electro mechanical systems(MEMS) technique, sacrifice layer removed and then air-gap formed. The results of each process checked by XRD, AFM, SEM to obtain good quality device.

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펄스파워를 이용한 수중 충격파 발생 및 응용 (Shock Wave Generation and its Applications by Pulsed Power)

  • 조주현;이흥식;최영욱;조성찬;정우근
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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    • pp.190-191
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    • 2007
  • Focused shock wave generation was tested under the water by the method of wire explosion. The wire was installed a focal point of the half ellipsoid, and the shock wave was focused on the other focal point. A numerous cavitations were observed in the path of the traveling shock wave and focal point by using high speed camera.

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축 방향 자기장애 의한 아크의 거동과 전극표면의 손상 (Arc behaviors and electrode surface damage under the axial magnetic field)

  • 조주현;최영욱;한용기;한현;권오경
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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    • pp.188-189
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    • 2007
  • Axial magnetic field was applied into the hollow anode of plasma torch for the purpose of extension of electrode lifetime. The average arc voltage increased because the arc column became longer, the arc voltage ripple frequency became low. The steady state of arc voltage was removed by applied magnetic filed. The lifetime of electrode was over 1000 hours which is 100 times longer than operation without magnetic field.

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이동물체의 추적을 위한 정밀 위치추정 (Precision Position Estimation for Tracking the Moving Object)

  • 인추식;이자성;홍석교;고영길
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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    • pp.335-337
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    • 1994
  • The correlation tracker developed by John M. Fitts in 1979 is the most complex to mechanize but provides the best tracking performance in a low SNR condition. Correlation tracker would rewove the requirements for optimizing threshold and has no need to know information about the target. But if the displacement of the target is large, the tracking error of the correlation tracker tends to diverge. In this paper, we suggest a precision image tracking algorithm which improves the tracking performance via iterative application of the matched filter estimation algorithm.

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