• Title/Summary/Keyword: barrier height

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유연성 방호책을 이용한 철도변 낙석방호사례 (Flexible Barrier System for Rockfall Protection)

  • 최승일;유병옥;김경석
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 사면안정학술발표회
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    • pp.103-116
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    • 2003
  • Rockfall Protection fence is one of the most common rockfall Protection methods in Korea. If rockfall protection fences are required along the road or railway, their location, height and capacity, in terms of the maximum kinetic energy that they can absorb, should be specified. Within this paper, the best practice of rockfall barrier is introduced. Modern rockfall simulations as a means to define risks, protection requirements, dynamic loading and height of potential structures and selection of appropriate placement is presented. Technical possibilities of rockfall barriers and their actual limits are presented. Safety concepts based on probabilistic approaches are proposed. Recent studies peformed in other countries show that Flexible Barriers are also a feasible system to stop and retain debris flows. Finally an outlook onto further development is given.

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Pd-SiC 쇼트키 다이오드를 이용한 $CH_4$ 가스센서 ($CH_4$ Gas Sensor Utilizing Pd-SiC Schottky Diode)

  • 김창교;이주헌;이영환
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
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    • pp.163-166
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    • 1998
  • The mechanism of methane sensing by Pd-SiC diode was investigated over the temperature range of 400~$600^{\circ}C$. The effects or methane gas reaction on the parameters such as barrier height, initial rate of methane gas reaction are investigated. The methane gas reaction kinetics on the device are also discussed. The physical and chemical mechanism responsible for methane detection are proposed. Analysis of steady-state reaction kinetics using I-V method confirmed that methane gas reaction processes are responsible for the barrier height change in the diode.

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Pd-SiC 쇼트키 다이오드의 수소 가스 감지 특성 (A Study on a Palladium-Silicon Garbide Schottky Diode as a Hydrogen Gas Sensor)

  • 이주헌;이영환;김창교;조남인
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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    • pp.858-860
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    • 1998
  • A Pd-SiC Schottky diode for detection of hydrogen gas operating at high temperature was fabricated. Hydrogen-sensing behaviors of Pd-SiC Schottky diode have been analyzed as a function of hydrogen concentration and temperature by I-V and ${\Delta}I$-t methods under steady-state and transient conditions. The effect of hydrogen adsorption on the barrier height was investigated. Analysis of the steady-state kinetics using I-V method confirmed that the atomistic hydrogen adsorption process is responsible for the barrier height change in the diode.

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GaAs MESFET의 Source 접지상태에 따른 게이트 누설 전류 특성 (The GaAs Leakage Current Characteristics of GaAs MESFET's using Source Ground Status)

  • 원창섭;유영한;안형근;한득영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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    • pp.263-266
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    • 2003
  • The gate leakage current is first calculated using the experimental method between gate and drain by opening source electrode. Next, the gate to drain current has been obtained with a ground source. The difference of two current has been tested and provide that the existence of another source to Schotuy barrier height against the image force lowering effect.

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절연막 형성 방법에 따른 다결정실리콘 캐패시터의 특성 (Characteristics of polysilicon capacitor as insulator formation method)

  • 노태문;이대우;김광수;강진영;이덕문
    • 전자공학회논문지A
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    • 제32A권7호
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    • pp.58-68
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    • 1995
  • Polysilicon capacitors with pyrogenic oxide and TEOX oxide as insulators were fabricated to develop capacitors which can be applied to analog CMOS IC, and the characteristics of the capacitors were compared with each other. The morphology of bottom polysilicon in pyrogenic oxide capacitor is degraded due to the generaged protuberances of the polysilicon grain during oxidataion. The polysilican capacitor with pyrogenic oxide of 57 nm thickness showed that the effective potential barrier height of 0.45 eV is much less than that of MOS capacitor (3.2 eV)when the top electrode is biased with a positive volgate. The morphology of the polysilicon capacitor with TEOS oxide, however, was not degraded during oxide deposition by LPCVD. The polysilicon capacitor with TEOS oxide of 54 nm thickness showed the effective potential barrier height of 1.28 eV when the top electrode is biased with a negative voltage. Therefore, it is concluded that the polysilicon capacitor with TEOS oxide is more applicable to analog CMOS IC than the pyrogenic oxide polysilicon capacitor.

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RFID tag 집적화를 위한 $0.18{\mu}m$ 표준 CMOS 공정을 이용한 쇼트키 다이오드의 제작 (Fabrication of Schottky diodes for RFID tag integration using Standard $0.18{\mu}m$ CMOS process)

  • 심동식;민영훈
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.591-592
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    • 2006
  • Schottky diodes for Radio-frequency identification (RFID) tag integration on chip were designed and fabricated using Samsung electronics System LSI standard $0.18{\mu}m$ CMOS process. Schottky diodes were designed as interdigitated fingers array by CMOS layout design rule. 64 types of Schottky diode were designed and fabricated with the variation of finger width, length and numbers with a $0.6{\mu}m$ guard ring enclosing n-well. Titanium was used as Schottky contact metal to lower the Schottky barrier height. Barrier height of the fabricated Schottky diode was 0.57eV. DC current - voltage measurements showed that the fabricated Schottky diode had a good rectifying properties with a breakdown voltage of -9.15 V and a threshold voltage of 0.25 V.

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온도변화에 따른 백금 실리사이드-엔 실리콘 접합의 전자 터널링 특성 (Electron Tunneling Characteristics of PtSi-nSi Junctions according to Temperature Variations)

  • 장창덕;이정석;이광우;이용재
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.87-91
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    • 1998
  • In this paper, We analyzed the current-voltage characteristics with n-type silicon substrates concentration and temperature variations (Room temperature, 50$^{\circ}C$, 75$^{\circ}C$) in platinum silicide and silicon junction. The electrical parameters of measurement are turn-on voltage, saturation current, ideality factor, barrier height, dynamic resistance in forward bias and reverse breakdown voltage according to variations of junction concentration of substrates and measurement temperature variations. As a result, the forward turn-on voltage, reverse breakdown voltage, barrier height and dynamic resistance were decreased but saturation currents and ideality factor were increased by substrates increased concentration variations in platinum silicide and n-silicon junction. In increased measurement temperature (RT, 50$^{\circ}C$, 75$^{\circ}C$), the extracted electrical parameter values of characteristics were rises by increased temperature variations according to the forward and reverse bias.

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유연성 원리를 이용한 낙석방호시스템 (Flexible Barrier System for Rockfall Protection)

  • 최숭일;이창호;김덕봉
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2003년도 춘계학술대회 논문집
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    • pp.68-81
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    • 2003
  • Rockfall protection fence is one of the most common rockfall protection methods in Korea. If rockfall protection fences are required along the road or railway, their location, height and capacity, in terms of the maximum kinetic energy that they can absorb, should be specified. Within this paper, the best practice of rockfall barrier is introduced. Modern rockfall simulations as a means to define risks, protection requirements, dynamic loading and height of potential structures and selection of appropriate placement is presented. Technical possibilities of rockfall barriers and their actual limits are presented. Safety concepts based on probabilities approaches are proposed. Recent studies performed in other countries show that Flexible Barriers are also a feasible system to stop and retain debris flows. Finally an outlook onto further development is given.

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Theo Jansen Mechanism 기반 보행 기구의 최적 설계를 통한 구동의 안정성 및 속도 확보 (Optimized design of walking device based on Theo Jansen Mechanism for securing stability and speed)

  • 김경훈;김승연
    • EDISON SW 활용 경진대회 논문집
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    • 제5회(2016년)
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    • pp.513-515
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    • 2016
  • There are various walking devices based on Theo Jansen mechanism. And these systems controlled by complicate equations. So we decided to optimize the design of walking device with two points of view. The device is required to ensure stability while maintaining the high speed. To simplify the control system, we applied trigonometric ratio with ideal Jansen trajectory. As a result, we were able to draw the connection between height of barrier and Ground Length (GL). Also we could change traveling distance and Ground Angle Coefficient (GAC) by shifting the position of the joints. Through controlling these parameter, we can analyze stability and speed of the device. Ultimately, we develop the device that can walk more efficiently by the optimization process.

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Plasma Display Panel용 감광성 격벽 재료 및 Photolithography 공정 성질 (Photosensitive Barrier Rib Paste for PDP and Photolithographic Process)

  • 박이순;정승원;오현식;김순학;송상무
    • 공업화학
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    • 제10권8호
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    • pp.1114-1118
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    • 1999
  • 플라즈마 디스플레이 패널(PDP)의 격벽(barrier rib)은 일정한 선폭과 높이를 가져 균일한 방전 공간을 제공하고, 인접한 셀 간의 전기적, 광학적 혼선(crosstalk)을 방지하기 위해 PDP의 하부 유리 기판 패널에 들어가는 구조물이다. 본 연구에서는 사진식각(photolithography)법으로 격벽을 형성하는데 필요한 감광성 격벽 페이스트가 제조되었다. 페이스트는 바인더 고분자인 에틸셀룰로오즈를 BC/BCA = 30/70 wt %인 혼합 용매에 15 wt %로 용해한 다음 관능성 단량체로서TPGDA/PETA = 50/50 wt % 혼합물, 광개시제로서 Irgacur 651 및 격벽 분말을 도입한 다음 전체를 균일하게 분산시켜 제조하였다. 감광성 격벽 페이스트의 각 성분, 조성 및 공정을 최적화하여 소성 후 높이 약 $100{\mu}m$ 에 이르는 PDP용 격벽을 고해상도로 사진식각법으로 얻을 수 있었다.

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